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 Hifigeek1's Responses in Amps Preamps  Posts
Anyone HEARD the qol 'signal completion' device?
just another fad
261
New KT150 tubes?
ARC are currently not using this tube nor have they sonically tested or life tested it as far as I know. They continue to use the KT-120 for those amps designed to use it
249
No Audiophiles in Hollywood
How about the credit for SOTA turntables at the end of House? I think I saw the turntable once or twice
168
Fremer lays an Ostrich egg...
I have talked to Mr.Fremer on more that one occasion. I have found him to be a very reasonable person. He is entitled to his opinion just as you are entitled to yours. Everyone . . .
151
Current amp vs Voltage amp
I always tell owners of ARC to try the 4 ohm tap. Some like it better some not so much. Note that there aren't many true 8 ohm impedance speakers especially just past the woofer . . .
101
Has anybody heard the new Audio Research LS 27?
In Audio Research's defense, any quality audio manufacturer has the right to improve their products as state of the art parts and technology improves. It is in their best interest . . .
93
Sadly missed manufacturers
Dayton Wright
87
Thoughts on Audio Research D70
I work on them and retube them. Use ARC tubes only. Excellent amp. After 2000 hrs it's time for an output retube. I also set the bias down to 62-63mV @ 120Vac. Doesn't hurt the . . .
79
Solid State for Rock and Tubes for Jazz, Yes or No
I agree with Mitch4t. An ideal situation. All the advantages of tube sound without all the heat from the amp output tubes, as well as the added expense
71
the best 'tubey amp - warm,smooth,liquid' ?
Most amps with EL-34 outputs sound very sweet and liquid
68
Bob Carver LLC Black Beauty Review
I saw his amp's at CES, and I'm curious as to whether there's a sonic difference between his attenuators set at half volume vs. wide open, ie. resistive element out of the circuit. . .
63
Buy tubes from Audio Research or not
The advantage to buying ARC tubes include the 90day warranty, the fact that they have been burned in at voltage for 24hrs. so bias drifting is minimized, and are matched to the amp. . .
63
Oppo BDP-95 as a pure two channel audio source?
I have a BDP-95 that serves double duty as my 2 channel audio and video system are one in the same. Currently the 95 is stock until I decide to do my own mods to it. It is not only. . .
59
ARC's new REF-75
The brightness you heard the following day could have been due to a lack of people in the room. Most of the rooms were acoustically challenged. Adding bodies to the room seemed to . . .
58
audio research REF 150
LOL I can't keep track of all the ARC Amps. I'm sure the Ref150 will use KT-120's. Check with the factory on the KT-120 Ref 110 issue just to make sure it will work. I'm sure it . . .
53
Adding Tone Controls?
I would suggest rather than use tone controls, do some research and make sure you use proper interconnects and speaker wires to tailor the sound you want. Some products are more . . .
52
XLR to RCA Adapters
A bad idea. Balanced amps require an inverting and a non-inverting signal. I know trying to do that with an ARC amp results in half the amp output and higher distortion because you. . .
49
EL34 upgrade
I agree. The Winged C's are excellent for the price. I just got done recapping 2 Marantz 8B's and put 2) quads of the Chinese EL-34's in. Seem to be very very good and strapped the. . .
48
Anyone have problems w/McIntosh warranty
This is outrageous! I've never heard of such a thing. I would contact the head of the service department and talk to him directly. I can understand a manufacturer not wanting to . . .
46
Audio Research Tube AMP Reliability
The biggest problem isn't the fault of ARC. They rate their 6550's life span to be approx 2-3000 hrs. That being said most people don't keep track of the time they put on their . . .
46
Conrad Johnson PV-10A mod experiences?
Davide, you can talk to Ed at C/J customer service. He is a super nice guy. They probably have mods for that unit. Replacing coupling caps is probably a good idea especially if you. . .
41
Amp design logic
Also remember that generally the dealer makes more on the product then the manufacturer does. Yes the dealer has overhead, but the manufacturer has much more overhead. That is why . . .
40
How many tube watts for Vandersteen 2's?
It's really more important that you have some current behind those watts. For example, you could use a pair of Dyna MKIII's but you won't like the way the bottom end sounds. Sixty . . .
40
Do amps have a sweet spot?
Let me add that some speakers sound better at higher volume as well
37
Retubing an ARC VT100 mkll
I believe there have been a few issues with the 6550EH's and ARC gear. They are currently using the Sovtek 6550WE. I would continue to use the 6922EH as that is the tube that . . .
37
What should I upgrade
Try finding a used integrated like an ARC, Prima Luna etc
36
Volume level of ARC Ref 5 seems very high
The Ref5 does not use a mechanical attenuator. It is microprocessor controlled
36
Do Mono Block amps provide better sound ??
There is a clear cut difference as to why in theory dual monoblocks have an advantage unless of course the stereo amp is a dual monophonic design. Depending on the circuit design, . . .
36
Bandwidth question?
I have never been a big fan on Mhz frequency response especially in an amplifier. Having a bandwidth that high can cause major problems including parasitic oscillation, rf . . .
35
First Tube Amp: Advice? Keep spare tubes on hand?
Hate to be the fly in the ointment but there are some amps that require a resistor replacement before attempting to swap out the bad output tube. This depends on how the tube . . .
35
Anyone talked to Dean from PSE?
I spoke with Dean a few months ago..He is alive and well
32
KT120 transformer failures
With the KT-120 it is strictly an issue with the filament supply
32
ARC Ref 3 Main Output Impedance Question
Bifwynne, Tom is a great guy. I have had quite a few nice conversations with him
32
ARC LS15: did they ever use Mundorf MCaps on it ?
To my knowledge Audio Research never used Mundorf caps in production. They used Rel,Infini and MIT in older units. Hope that helps
31
Replasment for Mullard Long Plates?
I like the JJ ECC803S. I believe they have long plates and sound wonderful. And best of all, they're quiet
31
Audio Research Reference 3 Seeking help
ARC never used .0024mfd as a coupling cap. I do not know where you are getting your info from. That value is way too small for a coupling cap as well as for a bypass cap
30
Audio Research Reference 5SE reliability
I've been fixing ARC for over 20 years as a warranty repair station. I haven't seen a single Ref5 or Ref5SE with a transformer issue. I did replace one transformer in a Ref3 years . . .
30
Power conditioning for digital gear AND tube amp?
I use a Toruspower power line isolation device. It's amazing pure and simple. Isolates all the power line garbage by at least 60dB, and does not current limit, an issue with some . . .
30
Do Tube Amps go better with QUAD 2805's Speakers??
Electrostats don't require a lot of current to drive them, unlike dynamic speakers. They prefer voltage amplifiers like most tube amps. My guess is any good sounding 50-60W tube . . .
30
? Tube Replacement Question ?
I would check with ARC but I believe it's every 5-6000 hrs. Distortion does go up as the tube ages and sometimes it happens so slowly you don't realize it until you replace them
29
Audio Research Vs115
ARC tests their tubes at hard labor for 24 hrs. prior to putting them in your amp at the factory. No other tube reseller does this. Tubes are not perfect and they do fail. They . . .
28
Audio Research Ref 250s for Magnepan 20.1s?
I would certainly contact the manufacturer and ask them. I'm sure customer service can help you with this
28
Any way to reduce pre-amp noise floor?
Use low noise resistors in that circuit. But you are always going to get some kind of thermal noise from a tube depending on the gain of the circuit
28
Pass Labs heatsinks temperature
If anyone is in the L.A. area, I would be able to help them
28
Audio Research amps - balanced & non
Martykl you are correct! When driving an ARC balanced amp with the SP-10 preamp you will find that you are unable to get symmetrical clipping out of the VT-130. At about half the . . .
28
Grey amplifier Imports from Japan?
There is a distributor for Luxman based in California as well as Accuphase. Trying to get service on the product after your purchase it may be impossible, and you would obviously . . .
27
Audio Research VS 115 bias Adjustments
First off, KT-120's are not available yet through ARC for re-tubing. They are only available for new production. Hopefully this will change in the next few months. If you are . . .
27
audio Research REF 110 and KT 120 tubes
The KT-120 actually can run at a maximum plate voltage of 700-800Vdc! This is a very very robust tube. I have fitted a set in one ARC amp in warranty. It is taller, heavier, and . . .
27
Power cord for CJ MF2500A
If you live close to the west coast I can accommodate you. I have replaced power cords on C/J's in the past with custom power cords. The problem with putting an IEC socket on any . . .
27
Audio Research Corporation ARC Reference 600
Although I am an ARC warranty repair station and would be happy to service them for you, the fact is with a total of 32 6550 output tubes and 8 regulator 6550's you have multiplied. . .
26
recommendations for tube dampers???
I'm partial to ARC's O ring dampers for small signal tubes. The do the job and are re-useable
26
Removing power conditioner...
The biggest issue with power conditioners is one of high source impedance, something you don't want. You want to find one that provides a low source impedance while isolating all . . .
26
ARC VT100 with KT-120 tubes ?
Well the bias setting is the same as with the 6550. I can tell you it's at the very least an improvement in power output. They sound very good. No down side. I've only heard them . . .
26
KT120 Tube compatibility w/ Jadis Defy 7 Amp MK 1
As I have stated in a few other threads....the KT-120 is NOT a drop in replacement for the 6550. The KT-120 draws more heater current per tube. Using it could pose a potential risk. . .
25
Fuse burned out in shipping? ?
It's possible the fuse got damaged in shipping from mechanical vibration. It's easy to tell if the fuse was damaged mechanically vs. was blown. Mechanically, the fuse element would. . .
25
Any HiFi equipment sound similar to YBA sonics ?
I own a YBA 2HCDT. I will never part with that amp
25
Upscale Audio -- Tubes and Reliability
Caveat emptor
25
Amp blowing fuses
It could also be a problem with the filament supply i.e. bridge rectifier, and not the high voltage supply. Hard to say without a circuit diagram
24
Tube issues, 12at7 affect KT88?
Well whatever the problem with that tube is it's causing that KT-88 to run away. Usually, if the DC voltage operating points are upset, that will upset the balance of the amp and . . .
24
Did I blow my tube amp?
Normally, when I bias a tube amp, unless the manufacturer says to have a load on the output, I don't. I do however, have shorting plugs for the single ended inputs. That way I know. . .
24
Audio Research D-90
There is also an adjustment around the cross coupler 6FQ7's that needs to happen to set their operating points. That being said it is also possible that one or more capacitors on . . .
24
Need recommendations to replace ARC VT100 MkII
If you like the way your ARC sounds, I would just get an ARC integrated amp. That being said, you will not get the same bass impact that you currently get on the VT100mkII. The SP-. . .
23
Tube amp down, need guidance from the experienced
The tube arced a resistor may be open. I suggest you contact the McIntosh service dept. for further assistance
23
Audio Research, next upgrade?
I don't think upgrading to the MKIII version is going to buy you anything. You may want to consider a VS115. It uses the KT-120 as well as 6H30's. You would get greater dynamic . . .
23
new tung sol kt 120
The following is a list of ARC amps that are authorized to use the KT-120: VS55, VSi55, VS60, VSi60, VS110, VS115, REF110, VM220. I hope people find this useful as there seems to . . .
23
Audio Research Contact.
It's not easy and I'm sure with the Xmas rush and the CES show early next year it's crazy there. Chris doesn't take customer calls and recommends you contact Kalvin. If you are . . .
22
How to restart tube amp and pre in boxes for 2yrs
Swampwalker, great idea! A variac is the way I do it with equipment that's been off for a few years or more. I will usually pull the output tubes, and monitor the voltages from the. . .
22
Audio Research Classic 60 & 120 owners
I have worked on quite a few CL-30 and CL-60. Yes the transformer does get quite warm. I also remember the power transformer being close to the output tubes. They are designed to . . .
21
Phase Linear 700 & 400 series II
They tend to like to blow up
21
Why did this fix my problem?
I guess there was an impedance mismatch between your amps and your preamp. It sounds like either the amps were oscillating, i.e. motor boating, or the mismatch was forcing the . . .
21
Replacing 6550s with KT 88s
Just so everyone knows, the Winged C factory burned down. At least that's what I was told. ARC now uses 6550WE
21
ARC preamp line up
ARC SP-11
21
Anyone replaced Fuse with Circuit Breaker?
I agree, bad idea. Breakers take too long to trip
21
When to get your amp up graded caps ???
Filter caps last between 10-15 years. Life span is a function of the quality of the cap,(some are better then others), the ambient temperature surrounding the cap,( high temps. . . .
21
AUDIO RESEARCH D-76A
What is the V number of that 12AX7 tube and I will investigate it for you
21
Audio Research D70 mark1 + schematic
I believe that unit shares a similar power supply with the D115 in which case there are indeed solid state devices in the voltage buffer circuit unless somebody removed them. It's . . .
20
Preamp with tone controls?
If you don't need a preamp with a remote, consider a used ARC SP-3C. This all tube preamp is a classic and made better in the C version by the use of a FET regulated power supply. . . .
20
ARC VS-115 Amp with new KT-120 Tubes
Bias is set to 65mV. There would be no overheating issues as ARC said that it's ok to use those tubes in that amp. Issues may be with much older product and/or the tube not fitting. . .
20
Vandersteen Amp?
The is an advantage to designing an amp to go with a particular pair of speakers
20
Conrad Johnson Premier 140 6922 tube swapping
Although a bit off topic, I would suggest you make sure that amp has the upgraded film caps in the regulated power supplies. The old polystyrene caps have issues. If one shorts, . . .
20
NOS KT 88s or GE 6550s
Contact Ed at C/J and find out if you can put KT-120's in that amp
20
Tube Preamps?
I am not a big fan of the SP-9. It is a hybrid using old FET technology. BTW there are 3 versions of the preamp with the MKIII version being the best of the three. They have . . .
20
Hum from both speakers...This is New Please read.
Sometimes it's a ground loop involving the subwoofer. Have you tried unpluging the subwoofer from the wall?? Sometimes the audio isolator works at the rca inputs to the sub if you'. . .
19
harman kardon citation 16 amp?????
Very good amp. BTW the Citation 12 was the first amp to use a differential input stage. I believe both the 12 and the 16 were designed by Matty Otala. A very gifted designer in the. . .
19
Amplifier for Quads
The fact is electrostats prefer voltage amps (tube) not current amps (transistor). That speaker needs only 40-50Wrms maximum. Anything higher than that, and you're looking for . . .
19
ARC SP16 vs SP8
The SP-8 was just below the SP-10 in the product line. It is an expensive proposition to keep the SP-10's phono stage in low noise tubes. The SP-8 had a tube regulator and was more. . .
19
6550 Tube Blew - A Few Questions
Invest in a DVM (digital volt meter) That way you can measure resistors when you need to. Be advised, sometimes there are no bleeder resistors in the power supply. In this case the. . .
19
ARC SP-6 Warmup time
The mute time should not be more then 3.25 minutes. After that the LED should glow bright and the signal should be un-muted. If this is a B, or C version its usually caused by a . . .
19
Tube question for the electrical engineers
Contact McIntosh and find out of your tube wear/noise is typical. The head of the service dept. is a very nice
19
Does a tube preamp warm up sound of SS amp?
Ldworet, I think it would totally depend on the preamp. Some tube preamps don't sound particularly tube like. That being said, I would look for a tube preamp that sounds warm and . . .
19
What tubes for ST-70
I would heed the advice of Stonedeaf....The 7199 is a medium mu triode / sharp cutoff pentode that is very prone to capacitance problems when it ages causing hum and premature . . .
19
Primaluna-TungSol KT120s in triode mode
The KT-120 sounds different in each manufacturers amp. If the amp was voiced with the KT-77 then it would sound better with the KT-77. ARC amps that are designed to use KT-120's . . .
18
Tube rolling 12AX7As
I like the JJ 803S
18
Firing up old tube amps. Should I worry?
The amp should NOT be powered up unless you monitor voltage while running the amp up on a variac. Either buy a variac, or bring it to a tech who can do that for you. If you value . . .
18
I think my speakers are killing my amps.
It possible a capacitor may have arced. I have seen situations where the speaker was damaged by high frequency oscillation before the amp failed. Given its age, it sounds like the . . .
18
B&W N802: Which amp??
I would use a high powered Bryston. Would work great
18
Audio Research M100 Thumping
This is called motor-boating and it means the amp is oscillating. M100's run very hot. Make sure the driver tubes are okay. I believe (from memory) they are either 7119's or 7044's. . .
17
Are Rodgers ls3/5a as good as advertise? & Why
The LS 3/5A was a product of BBC research and development. This was a very important speaker for it's time. The final design was licensed to various British speaker manufacturers . . .
17
help with audio resesrch d76
I like the D-76 a lot. I'm working on a D-90B right now. Both are great but the D-76 with new caps actually sounds better then when it was new as all the poor twist lock lytic caps. . .
17
Driver/Input tubes
Wolf, who knew your amp was such a 'swinger
17
Does this amp have a problem or is it OK to buy?
Remember hum through the speakers can be caused by cable tv issues, interconnects etc. or other external issues that have nothing to do with the amp itself. Also, if there is a bit. . .
17
Should I buy a new amplifier; and if so, what?
The problem is..older amps use large single caps for plus and minus rail voltages. They take up a lot of space as well. Newer amps use many small caps in parallel to make up the . . .
17
Onix A-120MKII Gets hot fast.
Did it just start doing this? How old is the integrated amp? How old are your speakers
17
Scott 222 B tube amp
The face is as stated by Atmasphere, bad filter cans can damage a power transformer. Unless someone has run the thing and determined the caps are ok, which is doubtful given the . . .
17
Ultrasonic Oscillation
Also many SS amp manufacturers use something called a Zobel Network. It amounts to a series inductor (coil) and a capacitor or just the inductor. This is used as a filter and is . . .
16
about the kt 120 tube
It's a tube made in Russia just like Sovtek and Electro Harmonics. In this case, it's branded Tung Sol. I believe the Chinese might be trying to make a copy of this tube. I don't . . .
16
Audio research vsi-60 power concerns
You might find using KT-120's instead of 6550's, if it's possible with that integrated, may give you a bit more headroom and a bit more slam in the bass
16
Audio Research VT100 tube replacement
In another thread I commented that when I service an ARC product I get my tubes from ARC. It saves a lot of grief. It's also a good insurance policy because if an ARC tube goes out. . .
16
System very bright after adding Mcintosh amp
..I was going to add maybe you're having a problem with your speakers/crossovers
15
Audio Research VSi60 integrated reliability?
ARC amps do not explode. Occasionally, if an output tube arcs, a resistor might blow which is what it is supposed to do
15
powering two pairs of Dahlquist DQ10s
Find a pair of Audio Research D-76A's. I have a customer who had modified DQ-10's. I refurbished his amp and it sings!!!!It sounds better than when it was new because the new caps . . .
15
DC issues using a Krell KSA 150 w/ tubed preamp?
Atmasphere explain that to C/J. I just got done working on a Prem140 that had Polystyrene film caps at the input and output of a 440Vdc regulated power supply. Every single . . .
15
Audio Research SP3A-1 or Conrad Johnson PV11
ARC SP-3C (power supply upgrade) hands down
15
What a better pre-amp Arc Ls-27 or Ref-3
The Ref3 is very up-datable. I have a customer who may be bringing one in for update
15
Conrad Johnson MV60SE vs. Audio Research VS55
As someone who has done these upgrades the C/J sounds excellent. Coupling cap upgrades are always nice provided the caps used are complimentary. It does take some time for those . . .
15
Bedini still in business?
John.. As someone who had serviced your amps in the past, I'm happy to hear you are alive and well and planning to make a comeback. I want people to know that you are a great guy . . .
15
McCormack DNA 0.5 Deluxe thumps turning on/off
I believe there is a mute relay on turn on/off which might not be working. The relay could be locked in the on position. I know there is a protection circuit in that amp. I have an. . .
15
McCormack DNA-1 runs hot
Bias needs to be re-adjusted
15
Anybody tried KT120 tubes on Conrad Johnson amps?
Well I service C/J as well as ARC and it's funny you mention it because I asked them about KT-120's last week. Their answer was..."We do not plan on using that tube". So . . .
15
My 1st tube amp: transformer buzz audible 15 feet?
It sounds like a defective transformer. Is this unit new? Who makes this unit? A mild buzz is not uncommon in a unit that's a few years old
15
Precision Fidelity C7/A: To modify or leave as is?
I remember there was a guy by the name of Joe Bermudez involved in that company. The power supply design reminded me a bit of an Audible Illusions as well as some early C/J product. . .
14
Who Can I send my dynakit ST-70 to for a rebuild?
I rebuild them as well
14
Counterpoint 5.1- Beyond My Comprehension
If that tube is used as a voltage reference or as a voltage regulator and the voltage was low, that could potentially cause a loss in gain. I'm just guessing at this point. The . . .
14
ARC VM 220 WITH VANDERSTEEN WOOD QUATRO
How many hours are on your output tubes
14
Anyone compared 6922 Sovtek & Electro-Harmonix
I stopped using the Sovtek 6922 at the same time ARC did. They are just too inconsistent. I would measure one and it would measure great, measure the next Sovtek and it measured . . .
14
ARC Ref 3 bad tube?
I agree on finding an ARC warranty repair station. I have seen residue in 6550's and the tube was fine. If it's only happening on one channel it's not the power supply. First just . . .
14
Is it safe
No, not a good idea at all. Use one or the other, not both
14
Does the ARC Ref5 sound better than Ref2/3 ?
Ulf, Some manufacturers tend to overbuild the first model and then continue to try and improve, fine tune the next product. Sometimes that means using fewer parts. Sometimes it . . .
14
12AX7 tubes for Music Reference RM-10
I have an AVO tube tester in my shop if you need to check some tubes. I've also had very good luck with JJ E83CC/12AX7 tubes if you were looking for a particular brand of tube
14
audio research
I would not go with the SP-9 unless it was a MKIII version. The SP-9 had issues with crosstalk and manifests itself as a lack of space between instruments, as well as a somewhat . . .
14
Harman Kardon Citation 22 No Love?
H/K was the first company to realize the importance of square waves and wide frequency response. H/K i.e. Matti Otala designed their amps, including the Citation 12, to output . . .
13
Has anyone tried KT150s in their ARC Ref 110?
Nothing yet from ARC. I also noted in the other thread not to use the new (if you can still find them)Winged C tubes as their problematic. Use the 6550we instead
13
KT120 in Audio Research Pre-amp?
Do NOT use a KT-120 in the power supply of an ARC preamp. Use the 6550 only
13
Contact info of Steve Huntley
Maybe I can help. I'm on his list of ARC service providers
13
Problem with AR Ref 300 Mk II - any experience?
Output tube can go at any time. Tubes last approx. 2000 hours in ARC equipment. After that it's like Russian Roulette
13
Tube replacement for Dynaco ST 70
Make sure your highly modified Stereo 70 does not include a solid state rectifier with a lot of filter capacitance. Unless there is some kind of ramp up circuit, that's a sure way . . .
13
ARC Hybrid FET/Tube audio circuit
The above info is incorrect. The SP9 uses one tube in the phono stage and one tube in the high level stage. The SP14 utilizes one tube in the phono stage. The high level stage is . . .
13
Opinions on ARC VS110/Ref110/VT100mkll/VTmklll
I would tend to stay away from the VT100mkII. The mkIII is fine but I agree, the Ref110, which I'm working on at the moment would be my choice. Well behaved and reliable for the . . .
13
Congestion, clarity problems gone: M.R. RM-9
Your Marantz definitely needs work. I have worked on quite a few 8B's and when they are running properly they are simply amazing
13
Locating capacitors
Make sure the amp has been off and you know the high voltage power supplies have been bled. Otherwise you might be in for the shock of your life. I also suggest you get caps rated . . .
13
Audio Research SP-11 MK2 ...
I've worked on both the SP-11 and the SP-10 extensively. The SP-11 is probably a bit quieter in the phono stage then the SP-10. Both are marvelous preamps. Both bench test very . . .
13
CJ PV-14L replacement tubes
What is the tube compliment for that unit
13
Quatre dg-250 amplifier
Wow that name is truly a blast from the past. I had one in for service a long time ago. It was pretty well built. A lot of room under the cover. Unfortunately, I don't have a . . .
13
Audio Research SP-8 or Quicksilver Full Function ?
The SP-8 is actually an improved SP-6. In fact the final revision of the SP-6E1 is almost identical to the SP-8. I think the SP-8 sounds a little less lumpy in the bass. Also the . . .
13
ARC Ref-300 or 600 or 210: Which sounds best ?
Ref-210. Awesome dynamic slam due to the 6550 drivers. Relatively simple circuit too. Great amp. G
13
Is it worth refurbishing my tube Marantz?
They are beautiful pieces and yes if they do nice work I recommend you get them fixed. The filter caps in the preamp and the amp will need to be replaced. The selenium rectifier on. . .
12
McIntosh to be on How It's Made this Thursday
Thanks for the heads up on that. Would have been nice to have the whole show dedicated to the Mac tour. I still don't understand the l.e.d.'s under the small signal tubes. I guess . . .
12
What might cause LOUD hum in a Conrad Johnson pv6
Given it's age it does sound like a power supply issue
12
Audio Research Reference 3 voltage conversion
You can not convert the primary transformer windings to 220Vac on newer ARC products. This was done to protect their European Distributors. I also doubt they would sell you a . . .
12
bias Classic 60, Audio Research
I will throw my 2 cents in. You need long hook clip probes to safely measure the bias. There is an issue biasing this amp because it uses an opto-coupler and an IC to servo its . . .
12
Tube recommendation for Audio Research LS-2b?
The Chinese 6DJ8 drew a bit more heater current then the standard Russian 6922 if my memory serves me. So a different value resistor was used for the Chinese tube. The Chinese tube. . .
12
Capacitor Size
Are you asking about power supply aluminum electrolytic caps or film capacitors
12
Help with Modified Audible Illusions Modulus 3
If the caps that were replaced are shorted or the wrong value it could cause the preamp to be unstable. I am always careful to use the same value parts in any preamp I update. That. . .
12
Aesthetix stellar customer service
So did Oppo.....that's not that unusual
12
What 6922 tube will improve bass definition?
Amperex 7308. Great tube
12
Sonic improvement with Threshold FET 9 refurb?
I update a lot of fine audio gear. I don't see the controversy. The fact is, most electrolytic capacitors last 15-20 yrs, less if they're in a hot environment or the equipment had . . .
12
Audio Research SP8 MK II Sounds
I am an authorized repair station for ARC and a past owner of an SP-6B. I have also owned a McIntosh C-20. They are very different sounding preamps. The C-20 uses a tube rectifier . . .
12
ARC SP8 as Phono Stage
Newbee couldn't agree more. The SP-8 and SP-10 are decades old products and in it's day the SP-10 was considered SOTA. The SP-10 had an awesome phono stage in it, much better then . . .
12
Heads-Up: ARC introducing new G Series
I believe the G series would come under the heading of audio jewelry, a segment opened by Dan D'agostino. The visual/mechanical design of the G series was designed by Italian . . .
11
Repair-Restoration Tech for Vintage Sansui Amps??
Just be advised to the fact that some series of vintage Sansui amps have issues with the glue that was used to hold the capacitors to the circuit board. That glue, over time, . . .
11
amp repair in san francisco bay area ML 335
TruSound..Nick Gowan
11
Leave tubes in phono section if not using it?
Some preamps not only want phono tubes left in, but if the tubes are not quiet they can cause issues with the power supply and can actually cause problems for your high level/line . . .
11
Passing of James Bongiorno
It's a nice amp that's easy to carry
11
Replacement meters for Mcintosh MC2125
Are you sure it's the meter and not the drive circuitry to the meters? It seems a bit odd that both meters would have failed
11
Which is Your Favorite Marantz Amplifier?
Model 9 or 8B
11
ARC Ref150 or Aesthetix Atlas with Vandersteen 5A
ARC hands down! They are made for each other
11
Recommendations for good Class A SS Amp 100-200W
Krell's are known for their bass slam as they regulate the high voltage to the output transistors. This is mostly unheard of and very expensive to do. This makes the amp have a . . .
11
Dielectric grease and tubes
Also, over many years a tube socket my lose it's insulation properties and have to be replaced because the tube socket itself is arcing
11
low bass on Audio Research LS27
No, there are things that can be done to the LS-26 to improve the bass. You can email me if you like by looking up my screen name info
11
McCormack REV B upgrades. Better than a new amp?
I have updated a number of DNA-1's and it's a much improved amp afterwards. The whole mother board gets replaced and it's a good idea to do it. The new board is simplified. The . . .
11
cooling mono amps
Larger diameter fans spinning slower are much more quiet then a smaller diameter fan spinning fast both moving the same amount of air
11
ARC REF 110 owners
You may want to run your speakers off the 4 ohm tap of the ARC. Also, don't be so quick to blame the amp, interconnects and speaker wire play a huge role in the sonic signature of . . .
11
Does anyone know someone who can modify Mesa Baron
Farmersre. Truly sorry for your loss. Astrosytomas are mean SOB's! I will give you my 2 cents. Just listen to it for a while in triode mode. Don't just rush right out and have . . .
11
Help/Advice Choosing SS integrated
YBA 201..awesome and pretty to look at as well
11
Audio Research Classic 150
I'm not a big fan of these amps. Check to see if the units have the old grey Mepco Filter caps in the center of the amps. If so, they must be replaced. The Classic 150 followed the. . .
10
When to recap?
A ploy for income purposes??? That is baloney. It is true that many Mac solid state amps have G.E. computer grade electrolytics in the main power supply that can last quite a long . . .
10
Alternative to 12AX7-EH tube needed...new to tubes
I've always found U.S. 5751's to be a bit noisy and microphonic. How are the JJ's 5751's vs. the JJ ECC803s? Anyone
10
kt-120 or kt-88?
You would need a 'scope, a signal generator, and an 8 ohm 'dummy' load to see the difference in RMS power output in ARC products...I have. A bit more power but doubtful it would be. . .
10
McCormack DNA .5 - No Sound - Help
Hyounessi It's possible your amp is not coming out of protection mode. You might have failed output devices or a defective protection circuit. Some of these units had circuit board. . .
10
Vintage Crown D 150A II Amp -- How good was it?
Well...the Crown was a very reliable amp that had the dubious distinction of being the first solid state amp to use an i.c for the input. It was considered a workhorse. Compared to. . .
10
Audio Research SP-3A-1 part
Hi there....Send an email to service@audioresearch.com. The parts guy is Kal. They do have the bulbs. I would order a few at a time. You may also wish to consider their tube . . .
10
ARC D-115: What tubes and cables?
Agree with Rrog SED's, Winged C's, 6550WE or Philips 6550. The amp was voiced with the Philips. Prefer the GE 6FQ7's for stock. RCA Black Plate 6FQ7/ clear top for nos. If this is. . .
10
Tube amps and loads.
I usually do not load the output of the amp unless there's an issue with the amp i.e. coupling caps leaking etc.. What I do however is to place shorting plugs at the input
10
Audio Research dsi200 questions
Contact Kalvin at Audio Research and ask him
10
B&K amp parts source
You might wish to contact Byston as they used a similar on/ off switch. The only question, is the hole size for the button
10
Audio Research REF II failed
Sounds like DC is coming out of your preamp
10
Why do I like Class AB better than Class A?
Does this amplifier have enough hours on it to be considered broken in
10
conrad johnson mv60 retube
Try the JJ 12AX7's or the 603's are even better
10
Where to get regular fuses for an amp?
Digikey does have a minimum order of $25.00 I believe. Try Mouser. They have no minimum
10
Are Mcintosh Tube Amps really all that?
In the early days of tube stereo products, McIntosh was 'it' in terms of reliability, low distortion specs., the Mac clinics, as well as visually with their characteristic glass . . .
10
Maintenance for Tube Preamps
I would stay away from Cramolin. It does tend to keep cleaning even when you don't want it to and can leave crud behind. I use pro gold but again if it isn't broke don't fix it. . . .
10
4 or 8 ohm with Harbeth
On some ARC amps, the feedback is taken from the 4ohm tap. I find it sounds the best. When a speaker manufacturer says their speakers' impedance is 8 ohms understand that this is . . .
10
Audio Research VSi55 Tube Rolling
If you can still find winged C 6550's don't use them. The last of the production was not reliable. Apparently the plant burned down and are no longer available
9
Audio Research CL-30 Bias Drift
That's because the bias on 2 of the 4 tubes use a servo. The best way to check that is to wait a half hour while monitoring the tubes that are part of the servo. It has a slow time. . .
9
VTL Verses ARC, which is better?
From a service perspective I would opt for the ARC
9
Audio Research d79 blows plate fuse
Output tubes. When were they replaced last
9
ARC Vsi60 with KT120 valves - issues
Like tone controls, the KT-120 will sound different depending on the amp and system, so there is no right or wrong answer. Bias specs will vary depending on the amp it's put in. . . .
9
Who has info on R&R caps in ARC D90B amp?
I have on many occasions R&R'd those caps. If you are unfamiliar with twist-lock-lytic removal find an ARC repair facility near you to do it for you. You don't want to damage the . . .
9
McIntosh Vintage C22 Telefunken 12AX7 or ECC803's?
Consider tubes like a tone control. Whatever sounds best in your system. I do like the 803s tubes from JJ
9
Converting tube preamp from 110v to 230v
If the preamp has multiple primary windings on the power transformer, it's simply a matter of moving or using jumpers to wire the primary to 220Vac. Using an external transformer . . .
9
Which amps cannot be repaired locally?
Schubert is correct. I found Spectral to be downright rude when I tried to service one of their preamps. It had a shorted transistor in it. I was basically told if I worked on it, . . .
9
Good 61NP replacement tube for NovaPre?
I believe you mean 6N1P. As far as I know, no one else is making that tube unless you can find a cross for a 6N1P
9
Now that my amp's blown...
Naim for sure
9
Kenwood L-09M Service Manual?
Just out of curiosity, what is wrong with it
9
Help to complete a system
I would go with the Naim. Excellent sounding
9
Low level noise from spkr when nothing is playing
Is it possible you have the gain cranked up on the center channel and needs to be adjusted? A line conditioner will not solve that problem if the issue is only the center channel. . . .
9
PSE Studio V
PSE products were designed by Dean Kleinfelter. Great stuff. I do not know what happened to him. Unplug the unit, open the top and make sure the fuses are ok
9
VTL ST-80 EL 34 Feedback and experience
I service high-end electronics as well, and tend to stay away from VTL products in general
9
12AX7 preamp tube failure last night
Well if the tube has been in that amp for seven years then, yes, it's possible for the tube to fail. Even small signal tubes wear out and need to be replaced, usually after 8-10,. . .
9
Why shutting down?
It really depends on what the protection circuit is sensing. If it's D.C. at the output, it could be a leaky output transistor. It could be as simple as the protection circuit is . . .
9
Audible Illusions hiss
Minimal use is actually a bad thing for capacitors. Those units also have a regulated filament supply and its possible one of the transistors or the IC has gotten noisy. That would. . .
9
Good tube amp kit for sale these days
Bob Latino's stuff looks very interesting. The only question I have is regarding the twist lock lytic power supply cap. Since there's no heat shield around that part, they usually . . .
9
Noice from fan in Audio Research VT 100 MK III
It's is very easy to replace the fan. If you can use a Philips screwdriver you can do this. There is no soldering required. Place the amp on its side and the rest is easy. Just . . .
9
Bridge Robertson 4010 Question?
BTW Robertson products were designed by John Iverson. I used to work for the company responsible for assembling Electro Research Speakers. He was a very interesting man to say the. . .
9
Hovland HP100 service?
They may be Holco resistors. I know Holco's had issues with high voltages. They would become very noisy
8
ayre mx-r versus audio research ref150
Ref150 is an ideal match for 5a's
8
Lazarus Audio any Schematics Anyone?
Are you having an issue with the preamp
8
McCormack DNA 1 Rev A Mono blocks WOW
It's a good idea to have the mother board replaced as well as the old emitter resistors. The early boards had issues with the through hole plating over time and the protection . . .
8
Inexpensive Amp for KEF 107s?
Find a used Bryston amp
8
Aragon 4004 vs. McCormack DNA-1?
I've worked on, and listened to both including a DNA-1 that I updated, and I much prefer the DNA-1 sonically. Less of a compromise. Higher current design. Sonically superior
8
Pass xa 100.5 vs Musical Fidelity AMS100
Pass
8
Screech when turning tube pre on
Youra6 what is the sensitivity of your speakers? It's possible the speakers you own are far more sensitive than the reviewers speakers, hence the hiss. Note that with preamps that . . .
8
CounterPoint SA3000 Repair Technician
I may be able to help...Contact me
8
How do I free up a stuck volume control?
Is this a motorized volume control
8
Thoughts on Amperex PQ tubes
The 7308 is an amazing tube and very hard to get. It is the top of the 6922/6DJ8. Usually the glass is etched
8
Audio Research LS9
The volume control can be replaced with a non stepped type
8
Audio Research Ref 110 break in period
I've never heard of an ARC amp that does not have the teflons take 600hrs. to break in. I would say a maximum of 1-200 hrs. should be sufficient. That being said, if it does change. . .
8
Moving Up the ARC Chain: Some Observations
Enjoyed your remarks. It amazes me that there are people out there that buy expensive audio equipment without first getting information about the company they just purchased it . . .
8
When I turn it up, it turns down
Try unplugging your Nad for a few minutes. Plug it back in and see if that solves the problem
7
ARC VS-115 vs ARC Ref-110
I don't know if you really gain all that much. Sonically I'm sure there will be some improvements. The bigger step would be to go to the Ref-150
7
is there anyone that modifies audible illusions?
I mod them
7
My power amp ARC VT 100 keeps blowing tube
First off, I never use KT88's in ARC products. That being said, I'm guessing you have a problem underneath V16 tube socket, or the tube socket itself is bad. The problem is not . . .
7
What tubes fro my el84 amp?
The EL84 is also a 6BQ5 in the U.S.A. The 6CG7 is also a 6FQ7
7
Question About Tube Dampers
It depends on the material the damper is made from, and the location you put them on the tube. Dampening rings should never be placed over the plate assembly of a small signal tube. . .
7
Tube Amp replacement
Not a fan of VTL. Suggest tube preamp with solid state amp i.e. Bryston or similar. Better current delivery
7
Audio Research VM220 tube monoblock amplifiers
Set the bias for 65mV that's it. Going higher buys you nothing except decreased tube life. I tend to set em a bit lower actually like 63mV
7
OPT question: AirTight w/ Tamura vs Marant 8B
Interesting question. I know Mr. Mura, the designer of Air Tight products. His amps are excellent and the output transformers are very good as well. They are beautifully built and . . .
7
Cary SLP-05 Output Capacitor Question
The only thing you are potentially doing is raising the frequency of the -3dB down point in the low end
7
Mystery 30 Minute Sound Degradation
Teflon caps are notorious for taking forever to break in. I would suggest you wait till you have at least 100hrs. break in on the caps before you start changing anything in your . . .
7
Jan GE 6cG7 what other tube recommendations
The 6CG7 is also a 6FQ7 and you might find more options with that number. I've always liked the GE's or the Philips/Sylvania
7
Power switch substitution for Marantz 2270
I think you mean a 2235? I believe that is a single pole switch. You could use a single pole switch and wire the A.C. outlets in the back unswitched all the time, i.e. hot. The . . .
7
Audio Research LS2B mk2 cap ugrade
I disagree with that. You should retain the same coupling cap values. Changing the value of the coupling caps to smaller values may cause the low frequency bandwidth to shift and . . .
7
Help diagnose problem with my amp
It's possible there's an issue with the power supply voltages. Voltage regulators can fail and/or no longer regulate properly. Voltage may have dropped causing a decrease in gain. . . .
7
Svetlana KT-88
I suggest you try the Tung Sol KT-120's. It looks to be a very reliable tube provided your amp is capable of handling a slight increase in heater current draw per tube. I believe . . .
7
McIntosh MC40 / Eico HF60
Ketchup, Regarding the MC-40 they are nice little amps. If you find a pair try and have them looked at by a qualified technician before you buy them. Those amps are very old and . . .
7
ARC vt100mkiii Questions?
Leonard is no longer at Audio Research. If the bass is a bit lacking, I would suggest your output tubes need to be replaced. I always tell customers if your buying a used tube amp . . .
7
SS Power Amp upgrade
Bryston all the way. You gotta love a company that has a 20yr transferable warranty on their products. It's made well. I had one for 8 years and sold it because I got bored with it. . .
7
upgraded fuse holder
I'm assuming the .5A fuse is for the screen supply of the tube amp in which case I might use a ceramic fuse vs. a glass fuse as glass fuses can shatter. Any properly rated fuse . . .
6
Audio Research VT100 upgrade to VT100 MKII
The best update was to the VT100 mkIII as it did away with the innerstage DC balance adjustments which can be a real pain. Most people with the MKI and MKII just replace the front . . .
6
Tung sol 6550 tube smell??
The ink on the tubes smells a bit when first powered up. It goes away in a few hours
6
Audio Research LS9 volume control is not working..
Well that is pretty odd. Not a common failure at all. The volume control in that unit is a 100 k ohm blue alps control. They can get noisy but I have not heard of the wiper in the . . .
6
ARC LS7 vs LS16/I
For the record, the advantages of using a jfet input are many but the single most important advantage is the decrease in noise. Comparing the SP-16 an all tube preamp and the SP-17. . .
6
Audio Research D-52B: any suggestions for caps?
Large value, high voltage computer grade 'lytics are almost next to impossible to get and very, very expensive. The cost would exceed the value of the amp. There are some very good. . .
6
Mcintosh MC240 + Audio Research SP-8?
If the SP-8 has not been recapped in 15 yrs. or more, it would be a good idea to do that. It will improve the sound of the preamp
6
advice? Value of Gold Aero 7308s??
Real 7308's were made by Amperex and have numbers etched into the glass. Amazing tube
6
Opinions on ICL, Inrush Current Limiter
Not necessary at all. The D90/D115 do not need an inrush limiter. They have line fuses....The D90 originally had a relay and in some instances proved to be a problem. I have . . .
6
McIntosh Marantz Tube Equip Repair Recomendation
I may be able to help you with that. Email me. I'm in L.A
6
Rogue Zuess tubes won't bias in Ultralinear mode
It could be motor boating. When switched to ultralinear, are the bias fluctuations cyclical? Is it possible that you have low line voltage? Bad solder connection on the ultralinear. . .
6
MX 110 Troubleshooting
It's caustic so remove it before it eats into the chassis
6
Amp with a mind of it's own...
I suggest you contact the manufacturer
6
Manufacturers' warning not to change tubes
I totally agree with Jmcgrogan2. Let me also add that manufacturers like ARC 'voice' their products with a particular type or types of tubes that are not NOS. They do this so that . . .
6
Tube Audio Design TA-60 schematic
A 50W 100 ohm resistor in the power supply
6
6550 replacements for upgraded CD7
I think he's going to tell you not to use a 6550 because it's supposed to be a 5881/6L6. That tube is used as a pass element in a voltage regulator circuit and should not be . . .
6
All Audio Refinement ints have channel bleed?
A selector switch problem could cause the cross talk issue you're describing
6
One source delivering higher volume.
Check your owners manual. Some equipment allow you to vary the input sensitivity so you can match the levels of all your inputs. You can also email Arcam
6
Scott amp update/speaker question
NS-10's were used a lot in recording studios as near-field monitors. Your 30T's may be similar in design. The NS-10's tended to be a bit bright on the top and rather revealing . . .
6
does anyone have experience with h/k citation 16a?
Good amp. A bit better sounding than the Citation 12. Fast but not too articulate unless updated. Fast. A bit on the ugly looking side..imo..lol
6
Mcintosh C 220 pre amp tube life....
It's usually 10K hrs. however, sonically they might go down hill sooner than that. Since it happens so slowly, the only way to know for sure is to replace them and see if you hear . . .
6
Aragon 4004 MK II
I've had to service a few over the past years. Great amp. Very well behaved. Good sounding. Nice current delivery. Good bandwidth i.e., frequency response
6
Levinson 331 humming followup...
It's odd that Philips caps would be leaking. I have used many of them in the past for service replacement and found them to be very good,with very low series resistance which is . . .
6
VTL ST-85 Repair
Regarding VTL..My mom always would say if you don't have anything nice to say about someone don't say it...That being said, I would check your bridge rectifiers and make sure they . . .
6
Mcintosh MC275 vs Marantz 8/8b
Marantz8b all the way. Less tubes in the audio path. Superb output coupling transformer. The Marantz can drive electrostatics like Quads and any speaker with a sensitivity of 88dB/. . .
5
5Z4 half-wave rectifiers replacement suggestion
I believe the 5Z4 is a full wave rectifier and you can use a 5Z4GT if you wish. Usually the letters at the end indicate updated version, rugged version, glass envelope size and/or. . .
5
ACCUPHASE E-202 restauration advises?
That amp is built like a tank! Good luck with the rebuild
5
Cj Premier 11A fuse
Those fuses are not cheap. Most C/J products use the large KTK fuse. I suggest you call them back and ask for Ed. Tell them you never received a return phone call. They should be . . .
5
Audio Research SP-10 owner manual
Circuit diagrams are only supplied to warranty repair stations. You might find a copy on the interweb
5
German "plug and play" turntable
Find a turntable that has a tonearm that allows you to raise and lower its height. That way you are not stuck with one particular cartridge
5
Can't bias tubes on amplifier
I agree with Newbee. It's possible that the window of bias adjust,i.e. negative voltage, is insufficient to properly bias the KT-88's you received. Therefore the tubes are running . . .
5
Audio Research VM 220 versus the VT200
I just got done repairing a VT200. It's a brute. You were wise to go to the mono blocks although I don't know if the VM220's are on the ARC list of amps that can use the KT120's. . . .
5
Robin or Rodin Mod of an ARC SP3-A1???
Interesting. The SP-3A1 had a tone defeat switch for the tone controls. It does not however have a tube rectifier in it. I have an SP-3C preamp. The preamp uses a newly designed . . .
5
By-pass fuse and add a circuit breaker
The other problem with circuit breakers is they can be slow to trip. Generally, when overloaded, fuses will open sooner
5
Help: Replacement Caps Advise
Make sure the caps are rated for 105 degrees C. Don't scrimp on the quality of the caps you use as the power supply is the heart of the amplifier. Nichicon caps work well
5
Re Biasing a SS Amp?
You don't say what amp this is so it's difficult to know. We also don't know if the outputs of this amp are bipolar or FET. That makes a difference. In a bipolar amp you can adjust. . .
5
conrad johnson mf-2300a heat
You can also contact C/J and ask Ed. I believe that amp uses FET output devices which tend to be biased higher and therefore run hotter. If you can't keep your hand on the heat . . .
5
Protection Kicking On At Low Volumes?
The SP-4 uses 'transistor modules' and one of them may be putting out D.C. This would force your amp to shift operating points especially if its D.C. coupled at the input. Not a . . .
5
Amplifier distortion help please
Have you checked to make sure your wall outlets are wired properly? You can buy inexpensive testers at Home Depot etc
5
Who can fix Supratek preamp???
Please email me. gary.mf1@gmail.com
5
KT120 tubes in AudioResearch ref 300 MK2
The best thing you can do for those amps is turn them into CL-150's. Triode connect the outputs. It will sound better and make it more reliable
5
Audible illusions Mod 3a right channel popping
Yes you may have D.C. voltage sitting on the volume control in which case a coupling cap may have failed. Did this problem exist before you had the tube sockets replaced
5
Problem with loud buzzing noise on amplifier
Is this a mechanical transformer issue, or do you hear the buzzing through the speakers? What must be determined is whether or not the problem is coming from the preamp/amp itself. . .
5
why is a step up transformer used
The step-up transformer in the phono stage is used to optimize the impedance mismatch between a low output moving coil cartridge and the phone stage itself. It is a passive device. . .
5
KRELL Mono Class A amp problem
Usually with old Krell amps the caps go bad and in this case it sounds like the relay/protection circuit. Sooner or later the other amp will do the same thing. I would suggest . . .
5
Upgrading coupling capacitors on EAR 834p
Changing the value of the coupling caps can be critical and dependent on the locations of the coupling cap in the circuit. For example, doubling the value of the cap, in some . . .
5
ARC CA-50 tube changing
Seeing as that is an integrated amp it might be a bit tricky as the board might be mounted vertically. This may make access the test points tricky. Do you see any bias pots? There . . .
5
Replace pre-amp
It might be your speakers. Nestorovics are quite old. Do the woofers have foam surrounds on them? If so there toast unless you have had them repaired. Try switching speakers
5
schematically speaking
Definitely brush up on your soldering skills. You could potentially damage a circuit board trace by over heating your work. Remember, just because a tweak works well on one product. . .
5
Audio Research VT200 Biasing Schematic ETC.
Re VT-100 mkl and mkll. I prefer to use 2 volt meters. Still kind of a pain. I suggest people get some grabber test leads as it's safer rather then just using probes
5
Krell KSA-200 Problems, Caps Etc.
Some Krell amps generate a lot of heat. Given it's age, heat generated, and the fact that it has not been used in 2 years, (bad for filter caps), it's a sure sign it's time. It is. . .
5
Audio Research VT 100 MK III vs. VS55
It sounds like the amp may be due for a re-tube. I try and tell people that no one ever sells a used amp with new tubes in it. If the amp sounds a bit diffuse,smeared, it might be . . .
5
Audio Research VT100 MKII retubing blew resistors
VT100 MKII's are a bit tricky to set up. They sometimes require 2 volt meters as trimming one trim pot will effect the others trim pot setting. I don't believe this should be done . . .
5
EAR 834 Integrated tube help needed
You might want to try calling the US distributor. It's EAR USA and the gentleman's name is Dan Meinwald. Hope that helps
5
Power Tubes for ARC VT100 MkI. Genalex or SED?
Your amp was voiced with Winged C 6550's. Not a big fan of any KT-88's in an Audio Research Amp. As I said in another thread, I don't believe your going to get 2000 hrs. out of . . .
5
Audio Research VSi60 int amp OR LS17+VS60
Suggest the VS60/ LS17 combination. I think you will find it's will sound better. I assume the Proac D38's are 87-89 dB/1w@1m
5
capacitors to Thrshold S/160 amp
Try and find the cap that has the highest ripple current spec. These caps usually also have low ESR (equivalent series resistance), that means they charge up quickly and discharge. . .
4
Luxman SQ-30u noise
You may have a dirty or intermittent tube socket on the noisy channel
4
regulator in AR D70
I thought I gave you all the voltages you needed to check to make sure the regulator was working properly and why post this here
4
upgrade from Audio Research SP6C
The SP-6C is good, the SP-3C is better if you like a warm tube sound. The 3C has a recently updated FET regulated power supply. The SP-8 is a better sounding preamp than the SP-6C.. . .
4
ARC Preamp going to full volume
Sounds like one of the volume control IC is failing, or the voltage regulator that supplies voltage to the chip is faulty
4
anyone use KT120's or KT110's tubes in MAC 275 ?
Check with McIntosh regarding the use of KT-120's in your Mc275. The KT-120 will sound different depending on the amp, speakers, etc
4
I need help with a Jadis amp
You did not say which speakers you were using
4
Quad II/forty problem solved
There may also be a solid state rectifier for another supply in that amp that may be shorted. It's also possible that a power supply cap is partially shorted or one of your output . . .
4
System down. Need your help and recommendations.
If neither channel is operating I suspect either a tube, a power supply issue, a broken mute switch, a selector switch issue, or a volume control issue
4
ARC LS5 Mk II - tube rolling
Amperex 7308 provided they are legit. Best tube of the series ever made. From top to bottom....7308, 6922/ ECC88, 6DJ8
4
Need to know Power supply caps for Aragon 4004 II
Since you have plenty of room in that chassis, why not just get a perf board and buy multiple leaded radial capacitors and just string them all together in parallel. Put standoffs . . .
4
AudioResearch VTM-200
I think you mean tubes. ARC uses the 6550WE's made by Sovtek. The 6N1P are Russian as well. The 6AS7's are Sovtek, but many good American Military versions are also available
4
??slight hum from the speakers ?
It's possible your interconnect cables are running too close to the power transformer on your tube preamp
4
Looking For Someone To Make A Vandersteen X-2
I would definitely talk to Richard Vandersteen. He's a nice guy. I believe the X-2 crossover is a first order 6dB per octave slope. Basically it's one capacitor but the value will . . .
4
Best Speaker Impedence for Tube Amplifiers
It's really trial and error. What sounds better to you. For example, in some older Audio Research Amps, the 4 ohm tap can actually sound better with a 6 ohm dynamic speaker. With . . .
4
Help with a Kora Galaxy tube amp
That really doesn't make any sense at all. It either has an adjustment pot for each tube or one for each channel. It's a matter of adjusting the voltage across the cathode resistor. . .
4
Harmon Kardon citaion 1 kit telefuken
You would certainly have to reform all the electrolytic filter caps and hopefully they are still good. Given the age I would doubt it, as they dry out with age. All I remember . . .
4
Blown Classe CAP-80
I totally agree. Both JFet diff amps should be replaced in both channels
4
Music Reference RM 9 Question
So....if all the tubes were installed at the same time, and you have exceeded the tube life based on what Roger says is the maximum hourly tube life of the output tubes in his amp. . .
4
voltage converter and phono stage
If you can avoid the step down transformer I would. Who is the manufacturer of the Phono Stage and how old is it
4
Biasing Question: ARC VS 115 Hifigeek
Hello. Well first off I normally set bias at 120Vac input. The bias always shits around a bit and it depends on your DVM and how often it samples the voltage it's measuring. How . . .
4
Differences in the revisions of HK Citation 16?
First off, given the age of the amp you may wish to replace the filter caps in the amp. Allowing an amp to sit for years is not good for the electrolytic caps. Regarding the IC . . .
4
Marantz 2240 B Maintainance
The knobs must be removed and I believe you will find a nut holding the face plate on that's on one of the control shafts. Be very careful. If the slider isn't noisy, do not clean . . .
4
Good Speaker For Vintage McIntosh C22/MC275
I totally agree with Pdreher. Even LS-3/5A's would work, Silverlines etc
4
Audio Research LS2B: hissing noise from a channel
Sounds to me like it could of been a constant current source/ Fet in that channel
4
Audio Research Analog Modules
I would also check the main filter caps on that unit to make sure they aren't leaking. Some amps of that era were prone to it. Also check the emitter resistors on the board that . . .
3
Marantz Community
Will be joining
3
Bias setting help needed
Did they supply you with a circuit diagram
3
Can KT120s be used in ARC D70 Mk2?
The D-70 was never designed to use KT-120's. Winged C's are going away because the factory burned down so when they're gone, they're gone. That being said the 6550WE's are just as . . .
3
Moscode super it or audio research ph3 ???
ARC PH-3 with the SE update
3
Power supply caps for CJ PV-5
Unfortunately.... sadly, Ed has retired and there is no one there to answer those types of questions. I don't know what's going on with C/J. I have used auracaps in my updates and . . .
3
Popping noise when muting pream
DC offset at the output of the preamp and then muting it could cause a pop. Also if you had a faulty ground connection inside one of your interconnects or RCA jacks that could also. . .
3
do it yourself fans..........
You may wish to consider learning how to solder. Practice on things other than your audio gear, or you will destroy it
3
Plinius SA50 1990 - Worth replacing Caps?
Agree. it's time to replace the electrolytic caps. Seems like that's all I ever do
3
Transition Audio Design modded Altec 1570B
That he is
3
Getting Rid of a Ground Loop
Disconnect the mains from the Sky set top cable box and see if the hum/buzz goes away....This should stop the buzz in your system. If it does, your cable box needs to be grounded . . .
3
MC275 KT88 tubes blowing left and right
First off, power strips can really mess up the sound, especially if they have cheap surge suppressors in them, i.e. MOV's. I would avoid them. That, however, has nothing to do . . .
3
ARC owners do you have schematics
As far as I know, ARC is no longer supplying proprietary circuit diagrams to customers
3
Need to replace meter lights with leds Carver amp
I'm assuming the bulb you are try to replace is of the incandescent variety. First thing to determine is if the bulb is running on A.C. or D.C. If it's running on A.C. voltage, it . . .
3
VTL Compact 80 Issue
Don't try sticking another tube in there as you could damage any tube you try putting in that spot until you determine what the problem is and fix it. I no longer repair VTL's
3
exposure 21 PREAMP/ circ 2000
Where are you located
3
fuse for audio research D-400 mk2
The fuse rating should be on the silver end caps of the fuse
3
Audio research vs audio valve
I like the VS-115 and find it easy to service and well built
3
Naim Nait 5i Intermittent Channel
Loose or defective speaker fuse in the integrated
3
Has any one tried the Van Alstine st-70 input mod
Although I am not familiar with the Van Alstine mod I am familiar with the ST-70. The front end tube of the stereo 70 is the 7199, 6AN8 on the MK lll. That tube really needs to go. . .
3
Can't get proper tube bias per manual
Newbee is correct. I would also check the actual bias supply voltage. It's possible that it's low to begin with in which case either resistors or a resistor have changed value. It'. . .
3
Audio Research SP-6C vs. SP-6C-1?
I will have to look but I believe the difference was the removal of a regulated stage for reliability issues. If I get a chance I will compare both and let you know
2
kt120 tubes for audio research vt 100 mkIII
Because the transformer is in the way and the fact that the tubes mount horizontally, it is not possible or recommended
2
Hafler DH-220 problems
Depending on where the DC offset adjust is, it could either be an output transistor or transistors in that amp. I believe they're FETs. Or it could also be an input device, . . .
2
McIntosh 2105 - no power from left outputs
Given it's age, they typically need electrolytic caps unless you have blown fuses on that channel. They should all be replaced on the driver boards
2
Harman Kardon Pre amps
Agree with Atmasphere. But they also tended to become rust buckets....Not easy to find a clean one and most if all of the stock electrolytic caps need to be replaced
2
Bryston 3B repair in Philly
Sounds like your amp needs some new filter caps as well. Good luck trying to find the right size caps for that amp. I really would suggest sending it back to Bryston. Regarding . . .
2
Aragon or Acurus from Indy Audio Labs?
Saw them and had a nice chat with Rick at The Show in Newport Beach last week. Very impressed with both the Acurus and the Aragon product. I can tell you I had a 17 y.o Acurus amp . . .
2
Troubleshooting Linn integrated
Sounds like a cap or transistor is failing
2
MC240 vs 8B
I've had experiences fixing both the MC240 and the 8B. I love them both however my heart belongs to the 8B. A more simple circuit then the MC240. BTW Bob is a great guy. The 240 . . .
2
Wright 2a3 SE monoblocks..
I would think you would be able to see if there are other taps on the primary of the power transformer not being used
2
An affordable step up from AR SP14 is?
As far as I know there really aren't any preamps in that price range with MC phono stages, especially if it's a low output moving coil you're wanting to use. I would suggest a high. . .
2
help please
Not a fan of the 20 year old plus Eagle amps and I have had the displeasure of working on them, even though they were designed by John Iverson whose past design work I admire . . .
2
RM 200 with KT 120 Tubes
Sbfx the KT-120 is not an exact replacement as it pulls a bit more heater current per tube. Roger is probably trying to do some long term reliability tests just to make sure it's . . .
2
Audio Research SP16 vs SP3A1 and SP3C
The advantage of the SP-3A1 and SP3C are of course the tone controls if you require them. Hands down the SP-3C sounds superior to the SP-3A1 in tonality as well as quietness, . . .
2
How to clean vol pot of ARC LS15
...and those ARC units that do have actual mechanical volume controls use the Alps Blue pot and they are sealed. If the pot gets noisy, it would have to be replaced. Daniel, is the. . .
2
any good 110v-220v voltage converters??
Albert you pronounce it cayble??? It's Gary from L.A., and I agree with Mr. Porter. Using any kind of step up/down transformer can create a sonic nightmare. Any chance that . . .
2
el 34 tubes for McIntosh mc 60
Those amps don't usually sound harsh. If anything they sounds soft. How old are the tubes currently in there? When was the last time you had them serviced? G
2
ARC SP-8 replacement B+ filters
If ARC has them, get the caps from them. They now use better non twist lock-lytic caps on a special little circuit board so they fit in the board properly
1
LS25 MK2 Manual?
There is a toggle switch on the front panel that says Bal/SE. Up for balanced down for single ended. Enjoy
1
Test Values On 5AR4/ GZ34 Tubes
Generally speaking when I test a twin diode (rectifier) it's either good or it isn't. Generally the failure mode is as follows: they are usually weak and measure poorly, or they . . .
1
Music Reference:Design Your Own Preamp youtube vid
Very informative
1
Servicing Mcintosh MC2105 amp
There are screws under the amp..You must take the bottom cover off to access them
1
Audio Research D240 Service Manual
Well you should know there are no service manual's for ARC products. Circuit diagrams are only supplied to authorized warranty repair stations
1
ARC SP-11 MK1 and ARC SP-11 MK2...
I will try and find out for you on Tuesday as the factory is closed today
1
KT88 on mc275 commemorative
I would contact McIntosh and see if you can use the KT-120 on that amp
1
Kenwood Basic M2 Repair?
You haven't said what the fault in the amp is?? What is it doing or not doing
1
Enough amplfier?
I don't see any reason why not. However, it will depend on the size of your room. Also, the furnishings,(does the room have a lot of overstuffed furniture, curtains, carpeting etc. . .
1
Audio Research LS-9
I believe what you are seeing, are the chips for the logic circuitry/ volume control. From the pics it looks discrete
1
Amp Replacement Recommendation
Bryston
1
Klyne SK-2
I believe the Klyne has little switches under it's top cover for adjusting input impedance to match the cartridge. I always ran MC cartridges wide open i.e. 47K unless there was a . . .
1
Amp blowing right channel fuse?
The first question would be: is this a line fuse, or a B+/B- rail fuse, or a speaker fuse
1