I am sick of failing amplifiers
- Thread starter Kingrex
- Start date
Or bad design, most Krell amps get killed by excessive heat, under dimensioned cooling, later Krells have incorporated cooling fans. My other SS amps have worked flawlessly, MBL run cool my Primare 928 amps have a run 35 years without problems, they are on 5-6 hours every day, they have tiny fans that only engage when they are run hard.
Sounds like you have microphonic Voltage amplifier tubes in both channels. If I were you I'd buy 10 or 20 of them and swap them into the amp one at a time, tap on them to see how bad they are and use the ones that have the least microphonics. The system will thank you.
If tubes are microphonic you can damp them but that will only affect them by maybe 5%. You're far better off having low microphonic tubes in the first place.
Microphonics contribute to distortion and tonal nastiness- the higher the volume where the amp is sitting, the worse it is. I tell people frequently 'Its not enough to just buy some nice NOS or boutique tubes. Any tube that goes into high performance audio equipment must be vetted regardless of the source of the tube. To be vetted properly they have to test good on a good quality tube tester and then be placed in the circuit and auditioned for noise and microphonics, as well as sensitivity to shock (crackling is no good).'
I'd never have used a 6DJ8 or any of its variants as a Voltage amplifier FWIW; they are all microphonic. If in an SET the 6SN7 is a better choice IMO. That tube can be microphonic too but not nearly so bad; in a power amp I've never heard one be a problem in that regard.
I don't get why you say this. One amp I can tap on the input and driver tube and I don't hear anything through the speaker. Move those tubes to the other amp, and tap on them, and it's extremely loud.
I believe it's something in the power supply of that one amp that's making these tubes very reactive.
The E88CC are all beautiful in my preamp. Dead quiet.
Its easy to see the power supply circuit is different between the 2 amps. This microphonic noise was one of my complaints before I sent the amps to be rebuilt. A third time. One amp has a modified power supply per Audion. And that amp has no microphonic tube issues. The other did not have the power supply modified and it continues to have this persistent microphonic issue.
I'm pointing my finger at the amp. Not the tube.
I misinterpreted what you wrote earlier.
And I agree with you- its something in the amp. I'm glad the tubes are actually quiet.
we are getting closer to the problem
sits on the board where tubes are, also coupling capacitors usually small values mkp cap. I would suggest a cold solder joint, or defective coupling capacitor can also be microphonic
sits on the board where tubes are, also coupling capacitors usually small values mkp cap. I would suggest a cold solder joint, or defective coupling capacitor can also be microphonic
So am I. Telefunken E88CC are expensive. I have 4 sets. I bought them because I Ioved them in my preamp. After my last preamp upgrade, I actually prefer the stock tube that is about $40. I was sort of bummed to have the stock and no use. But they work wey well in the Audion. So now I have a place to use them.
What??? With the quality work in the picture.we are getting closer to the problem
sits on the board where tubes are, also coupling capacitors usually small values mkp cap. I would suggest a cold solder joint, or defective coupling capacitor can also be microphonic
I will look at the caps. I'm sort of pissed the tech took 2 VCaps that cost me $1000 and put a pair of something else in. I need to find a picture to prove it.
The wiring under the pre/driver looks pretty clean and identical. He rebuilt all that. He also changed out the input transformer. He was also into the power supplies to some degree. That gold resistor is new as well as the wire routing on the quiet amp.
Turn off the power to the amp, wait an hour( 1000 volt dc one hand rule please), then check the soldering points on the tube socket or re-solder them. There must be two coupling caps between the ecc88 and the driver tube ecc182 and the capacitor between the ecc182 and 845. Unfortunately, you always give us a little bit of information about what is installed. Input transformer or interstage transformer between the tubes?What??? With the quality work in the picture.
I will look at the caps. I'm sort of pissed the tech took 2 VCaps that cost me $1000 and put a pair of something else in. I need to find a picture to prove it.
The wiring under the pre/driver looks pretty clean and identical. He rebuilt all that. He also changed out the input transformer. He was also into the power supplies to some degree. That gold resistor is new as well as the wire routing on the quiet amp.
Both amps play equally loudly or?
the same tubes only american number or european nummer. And more gurantied
life time 10000hours
Agreed. This thread drudges up a lot of issues inherent to "high end" audio. For better and for worse, I have always been drawn to artisanal and theoretically cutting edge manufacturers. I have experienced a lot of joy and gotten to know a lot of kool people. That being said, I have also experienced the dark side of that paradigm as well on more than one occasion. While the DIY garage mystics can spit out some gear, they can also morph into incorrigible trolls when their messianic egos are injured. Some of my more unpleasant interactions have involved the world of tubes. Resurrecting a tube circuit from the 50s with parts alchemy is not in and of itself innovation and is often bereft of true R+D development that assures future soundness. And Rex, you are not alone. I have been the recipient of blame shifting for faulty engineering more than once. It's a real treat. When shopping for artisanal gear, you need to look for three things: sound, true engineering chops, and integrity, with the last variable being paramount. While I no longer own my ASR Emitter I, Friedrich represents a gold standard in costumer care. I bought a used unit at one point on Audiogon and had an issue one year in. I contacted him. He knew the details of the unit based on the serial number and had me sorted out in no time. No attitude. No ghosting. He owns and loves his business and his creations like children. We need to give oxygen to companies run like that.
I think some pictures from others are being misconstrued as my amps. They are not. And lets back up.
My amps came from Cobra216 and were a hodge podge of fiddle funking over the years. Bob Hovland was experimenting with this pair and Fd them all up. They showed up broken and unusable. I was too young and naive at the time to know I should have mailed them back to Cobra and to file a paypal complaint. So I ended up going down this c***** road, I never wanted to be on. I got screwed by a fellow whatsbester.
From there the amps were serviced a few times by a tech from the importer and a local engineer who is supposed to be good. Non of these people knew what they were doing. $$$thousands went out of my pockets and the amps were still broken.
This last time I was told Audion got more involved and assisted in getting the circuit updated to the current BS II. Problem is, the tech probably felt under pressure to meet a budget and decided to cut corners. He updated the power supply in one amp, and in his words, thought it too much a hassle to bother with the other. If he had done both, I assume I would only be posting in the SET thread how much I liked them.
And god I wish the first tech knew what he was doing. And the second. The 3rd for the most part did, but he is sloppy, lazy and had poor tool skills. Beware who works on your gear in Portland OR. I don't know who he is. Just where he lives.
Anyhow, I assume a new pair of these amps from Audion may be a nice amp. I don't know for sure. But they are enjoyable. The only real structural issue with them is a god awful stupid case design where you have to disassemble the amp, remove it from the case to access anything to work on it. What an idiot to keep the enclosure for 6 update iterations over 20 years. Thats just foolish and shows a lack of ????? . That is my only real gripe with Audion. The case. I have never seen a stock amp to know how clean the wiring is from the factory. To say mine represent a factory product is wildly untrue.
My amps came from Cobra216 and were a hodge podge of fiddle funking over the years. Bob Hovland was experimenting with this pair and Fd them all up. They showed up broken and unusable. I was too young and naive at the time to know I should have mailed them back to Cobra and to file a paypal complaint. So I ended up going down this c***** road, I never wanted to be on. I got screwed by a fellow whatsbester.
From there the amps were serviced a few times by a tech from the importer and a local engineer who is supposed to be good. Non of these people knew what they were doing. $$$thousands went out of my pockets and the amps were still broken.
This last time I was told Audion got more involved and assisted in getting the circuit updated to the current BS II. Problem is, the tech probably felt under pressure to meet a budget and decided to cut corners. He updated the power supply in one amp, and in his words, thought it too much a hassle to bother with the other. If he had done both, I assume I would only be posting in the SET thread how much I liked them.
And god I wish the first tech knew what he was doing. And the second. The 3rd for the most part did, but he is sloppy, lazy and had poor tool skills. Beware who works on your gear in Portland OR. I don't know who he is. Just where he lives.
Anyhow, I assume a new pair of these amps from Audion may be a nice amp. I don't know for sure. But they are enjoyable. The only real structural issue with them is a god awful stupid case design where you have to disassemble the amp, remove it from the case to access anything to work on it. What an idiot to keep the enclosure for 6 update iterations over 20 years. Thats just foolish and shows a lack of ????? . That is my only real gripe with Audion. The case. I have never seen a stock amp to know how clean the wiring is from the factory. To say mine represent a factory product is wildly untrue.
Bruce B
WBF Founding Member, Pro Audio Production Member
I've had my Pass XA100.5 amps for about that long. I saw someone post on FB, asking Kent if their amps needed a "refresh". It got me to thinking. I contacted Kent and he told me to send mine in. Since I didn't have any boxes, they sent me boxes and I shipped them in. Pass had them for about 2 weeks and I just got them back last week. I believe they sound better than they did when they were new! He gave me a list of parts they replaced and I can't say enough good things about Pass. I've had their amps, pre-amps forever and they just work......
I thought you were going to say you got your amps back from pass, and there is a note saying nothing to do.
what a schizophrenic tale. At the end of the day, it still involves ethics something in short supply these days….
We're also going to see a lot of failures with class D amp years to come. The reason is that many companies build them with very poor cooling, thus components will get over heated
We've already seen it with some only after a few years where they literally cooked, but this will increase after more years have passed. Many of these are simply not build to last.
We've already seen it with some only after a few years where they literally cooked, but this will increase after more years have passed. Many of these are simply not build to last.
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