I am sick of failing amplifiers

[wil]

Rex

I actually went back to my tech and said I have to have the ground issue fixed. I had been disconnecting the safty ground in the power line to get rid of thr hum. I asked he really dig hard. Sure enough, he confirmed there is 4 to 16 ohms.of leak inside my amps. Seems no one wanted to see it until I really pressed the issue. He says the only reasonable way to find the ground issue is to remove the entire amp from the box they are set in and start picking it apart piece by piece. He said its going to be thousands to find it and fix it. At least I have confirmation I am not crazy. I finally found a technician who knows what he is doing.

So now I am stalled out. Do I sell the amps for $2500 for parts. Loose $10k. I can't sell something I know is defective. Its just me. I would have to tell the buyer the amps have ground issues. If I was told that when I bought them, I would have passed. Its difficult to find anyone who knows how to fix stuff. The manufacturer could not find the issue. Hovland could not find it. But its there. And now I have readings to validate its their. You just have to look.

I have been mulling, do I dump them, or bread board them, and while I am at it, have a 300B or 6SN7 become the front end. I don't know. Its an additional $6k to do that. And then I have to spend probably another $2k to dial in the sound.

Or do I dump them and get a new amp. I do like the 845 sound. I think it has enough power for my speakers. I thought of a Whammerdyne 2A3. I just worry that 3 watts is not enough.

Rex, you have the Dartzeel 108. I would highly recommend demoing the Atmasphere MP3 pre with the Dart.

IMO, this is a great combination with the Atmasphere delivering some serious life energy. I don’t think you would miss your 845’s.

 

[microstrip]

(...) Every time i have gear from the USA, something always goes wrong, whilst stuff from EU has never given me problems.

I must be lucky - except for the dCS Vivaldi's that never had any problem, all my gear comes from the USA. Except for one blown cathode resistor in an amplifier having 20 power tubes that was easily replaced, I did not have any issues for the last ten years.

 

[microstrip]

I actually went back to my tech and said I have to have the ground issue fixed. I had been disconnecting the safty ground in the power line to get rid of thr hum. I asked he really dig hard. Sure enough, he confirmed there is 4 to 16 ohms.of leak inside my amps. Seems no one wanted to see it until I really pressed the issue. He says the only reasonable way to find the ground issue is to remove the entire amp from the box they are set in and start picking it apart piece by piece. He said its going to be thousands to find it and fix it. At least I have confirmation I am not crazy. I finally found a technician who knows what he is doing.

So now I am stalled out. Do I sell the amps for $2500 for parts. Loose $10k. I can't sell something I know is defective. Its just me. I would have to tell the buyer the amps have ground issues. If I was told that when I bought them, I would have passed. Its difficult to find anyone who knows how to fix stuff. The manufacturer could not find the issue. Hovland could not find it. But its there. And now I have readings to validate its their. You just have to look.

I have been mulling, do I dump them, or bread board them, and while I am at it, have a 300B or 6SN7 become the front end. I don't know. Its an additional $6k to do that. And then I have to spend probably another $2k to dial in the sound.

Or do I dump them and get a new amp. I do like the 845 sound. I think it has enough power for my speakers. I thought of a Whammerdyne 2A3. I just worry that 3 watts is not enough.

I can't understand what is meant by "he confirmed there is 4 to 16 ohms.of leak inside my amps" . Leak from where to where?

My humble suggestion - try another technician. Ground loops are not properly rocket science. With proper tools and methods they are usually simple to diagnose - no need disassembling the ampliifer part by part.

For more information on desperate cases please also look for "hum-loop block network" in the excellent article referred in this link http://www.valvewizard.co.uk/Grounding.html . It has helped more than one friend!

 

[adrianywu]

I actually went back to my tech and said I have to have the ground issue fixed. I had been disconnecting the safty ground in the power line to get rid of thr hum. I asked he really dig hard. Sure enough, he confirmed there is 4 to 16 ohms.of leak inside my amps. Seems no one wanted to see it until I really pressed the issue. He says the only reasonable way to find the ground issue is to remove the entire amp from the box they are set in and start picking it apart piece by piece. He said its going to be thousands to find it and fix it. At least I have confirmation I am not crazy. I finally found a technician who knows what he is doing.

So now I am stalled out. Do I sell the amps for $2500 for parts. Loose $10k. I can't sell something I know is defective. Its just me. I would have to tell the buyer the amps have ground issues. If I was told that when I bought them, I would have passed. Its difficult to find anyone who knows how to fix stuff. The manufacturer could not find the issue. Hovland could not find it. But its there. And now I have readings to validate its their. You just have to look.

I have been mulling, do I dump them, or bread board them, and while I am at it, have a 300B or 6SN7 become the front end. I don't know. Its an additional $6k to do that. And then I have to spend probably another $2k to dial in the sound.

Or do I dump them and get a new amp. I do like the 845 sound. I think it has enough power for my speakers. I thought of a Whammerdyne 2A3. I just worry that 3 watts is not enough.

I had similar experiences to yours at the beginning, but that was a time when I was just starting out in my career and could only afford to buy second hand. Over time, I became a DIYer and started to build tube amps. Having experimented with classic circuits such as the Mullard 5-20 and the Williamson, I went on to more complicated circuits such as the Telefunken V69. I then went deep into DHTs, but with differential circuits. I always managed to sell what I had built and recouped my cost or even earned some extra. I went on to built my preamp and my speakers also. Having the experience, one no longer needs to rely on others. I am pretty obsessive and have a hard time accepting some of the work done by some techs. An interesting story: Almost 20 years ago, I bought a pair of the classic Brook 12A amplifiers. These are push-pull 2A3 monoblocks that Paul Klipsch favored to drive his horns. The seller was very honest and told me that the amps were problematic. He had his tech work on them but could not get the problem fixed. He therefore listed them as defective at a cheap price. I thought what the hell, I will take the gamble. They were indeed problematic with very unstable bias. What was curious was why the same problem was happening to both monoblocks. I downloaded the schematic off the net and checked all the wiring, voltages etc. I then found the problem. There was a filter capacitor that went from the 2A3 grid supply to ground. However, the schematic marked the capacitor with the -ve terminal to ground, even though the supply was at a negative potential. As the capacitor used was a polar electrolytic, the grid bias became very unstable. (see attached schematic) I changed the capacitor around and violà, the amps became perfect ! I wrote to the seller and told him the problem, really to let him know that his tech made the error. The guy must have downloaded the same schematic. The seller was pretty pissed.......

 

[Kingrex]

I can't understand what is meant by "he confirmed there is 4 to 16 ohms.of leak inside my amps" . Leak from where to where?

My humble suggestion - try another technician. Ground loops are not properly rocket science. With proper tools and methods they are usually simple to diagnose - no need disassembling the ampliifer part by part.

For more information on desperate cases please also look for "hum-loop block network" in the excellent article referred in this link http://www.valvewizard.co.uk/Grounding.html . It has helped more than one friend!

These amps are an absolute nightmare to work on. They are basically inside a metal box that has no access. You have to strip it apart and lift the guts out of the box to access any part. Its extremely time consuming.

When the intentional grounds are lifted, there is still between 4 and 16 ohms of ground resistance to earth. Its grounding in some unknown place. Both amps. And it bounces around.

If I get time, I may pull them out and board them myself. But I have so much else going on.

Wil, my preamp and Dartzeel are amazing together. Fantastic symmetry from what I hear. I might buy a Dartzeel preamp if I wanted to make the Dart the best if could be. I just miss tube tone. It sounds different. Maybe its all wrong and full of distortion and how could anyone like the bloated nature of a SET 845 tube. I don't care. I like it. It works with my speakers. I had considered altering the front end if I stripped them as my amps are a little to forward on the midrange. More than I want. That becomes a can of worms too.

Or I just get something else. But I really don't have $15k to drop on more amps. And that seems to be about what it cost to get qualty parts and quality craftsmanship.

 

[dan31]

The Dart will pull you through. Keep saving or making plans for down the road. Tubes do have a quality that cannot really be replaced. I hope you get some peace of mind and a path forward. Not sure I would put another penny into the troublesome amps you have.

 

[Kingrex]

The Dart will pull you through. Keep saving or making plans for down the road. Tubes do have a quality that cannot really be replaced. I hope you get some peace of mind and a path forward. Not sure I would put another penny into the troublesome amps you have.

Thanks. The Dartzeel is very nice. Nothing wrong with it. Its a stable and tells me what is going on. It plays very pretty. Notes are natural. As good as can be in my room.

I like the big bottle tubes. I have had a lot of PP amps. Good PP today sounds close to good SS. They have a similar characteristic. Much closer than a SET is to either of them.

There is a Whammerdyme mono that is 7 watts for about $8500. I am considering a listen. I have no idea what a 2A3 sounds like. And especially monos using 2 tubes per block making about 7 watts. I'm pretty sure it is not PP. I wish I had more time. I was in Portland this week working on a job. I had to get to another project in Tacoma and did not have time to get by Pats place to listen.

I have also swirled around Line Magnetic.

 

[Kingrex]

I had a good talk with my friend Scott Sheaffer of Found Music. He makes the Blade amp Jazdoc uses. He's an amazing designer. He might take my amps and use the iron and sockets to make a new amp. Saves me a little money. He can make me a completely custom one. He likes the Hashimoto iron. But he will take a shot using my electaudio iron.
He might be able to use the case too. But he wants to use a different driver tube. I'm not sure how big it is. New boxes are not inexpensive.
Scott was really encouraging me to assemble it myself. I'm not confident in doing as such. I'm sure what would take him 40 hours would take me 200. And I have a lot on my plate. I'm about to present 2 new products for sale and scaling up for some audio shows.

 

[Solypsa]

If a brilliant designer is offering to make something special I would be inclined to let him use the iron he likes. Can't imagine the budget vector is so large between recycling the old amps for chassis and iron versus selling them as-is and going with new.

Besides then you have a no excuses product...not a designer saying 'still sounds good but I'm not so sure about that iron'.

 

[sbo6]

Buying new or newer SS is the best bet IMO. If you can get a demo unit from a dealer with a warranty at a discount that's also a good way to go.

 

[Zeotrope]

The Dart will pull you through. Keep saving or making plans for down the road. Tubes do have a quality that cannot really be replaced. I hope you get some peace of mind and a path forward. Not sure I would put another penny into the troublesome amps you have.

I have a full tube setup (Kondo Japan M77 and Souga) and the DarTZeel combo (108 and 18NS). The DarTZeels are still breaking in, but it’s already apparent the sound is spectacularly better than the Kondo gear… and I love the Kondo sound, and I have high efficiency (103dB) horns.
The Zeels sound like tubes, with the benefits of solid state. They really are that good. But the price is not a joke…
they do come up pre-owned in the low $30s though…

 

[Kingrex]

That begs an interesting question Surge. For the same money I could turn my model 1 into a model 2.

My Dartzeel model 1 is very natural. A pretty amazing amp. Maybe I'm barking up the wrong tree. Maybe I should calm the amp itch and look at my sources instead. A friend/rep (Solypsa) is taking on a new cartridge line (Adias). I have a Hana ML and Denon 103R upgraded with Midas/Soundsmith. Both good. But both probably a limitation to higher performance.

 

[Zeotrope]

That begs an interesting question Surge. For the same money I could turn my model 1 into a model 2.

My Dartzeel model 1 is very natural. A pretty amazing amp. Maybe I'm barking up the wrong tree. Maybe I should calm the amp itch and look at my sources instead. A friend/rep (Solypsa) is taking on a new cartridge line (Adias). I have a Hana ML and Denon 103R upgraded with Midas/Soundsmith. Both good. But both probably a limitation to higher performance.

Interesting options! I don’t know enough about your sources, nor do I know enough about the differences between the 108 Mk 1 vs Mk 2 to have an opinion. The cost of upgrading a Mk 1 to Mk 2 is $30k? I thought it was about half that?

 

[Kingrex]

Interesting options! I don’t know enough about your sources, nor do I know enough about the differences between the 108 Mk 1 vs Mk 2 to have an opinion. The cost of upgrading a Mk 1 to Mk 2 is $30k? I thought it was about half that?

I thought Mark 1 toMark 2 upgrade was about $12k plus shipping. Not fully sure.

 

[Chorus]

I love my Pass 25INT. Not that I'll lilkely ever need it but the service is 2nd to none. Pricey -yes.
Worth it- Oh yeah!!

 

[Kingrex]

A little update on the Audion 845. I have had this amp at a new tech who works with the importer of Audion to the US. The tech has been working closely with Audion. I have received a lot of disturbing news about the heritage of this amp. I don't think it was ever meant to be a listeners amp. I think it was for Bob Hovland to experiment on and see what he could do with the circuit. Hence it looked like many hands had been in it.

So the tech says he has the circuit correct. Yet the power transformers are total junk. Nothing like Audion uses now. Its spraying emf all into the amp. Audion send the tech new power transformers for a fair price.

Then the tech says there is still noise. The one circuit board holding all the power supply capacitors is flawed in design. There is a ground trace too close to a power trace that is injecting noise into the circuit. Same problem I had with my Ampsandsound. So now hes trying to sort that out.

Overall I'm pretty happy on a few levels. First off I feel validated in my assertions this amp was not a functional amp when sold to me. It played, but it was flawed on multiple deep levels. Second, this new tech seems to really get it. He seems to know what to look for. He is using tools and measuring for real issues, finding them and adressing them. In the end I should have a high performing SET845 amp to enjoy.

 

[Kingrex]

My Audion SET845 are finally done. I can pick them up. Its been a long wait. I'm very curious how they will voice. It will take me a couple weeks to get to Portland to get them.
It will be interesting to compare to the Blade. Since Scott was last here and helped tune my system, I am stunned at how musical and engaging the Blade is. I generally have something I'm reading while listening. Lately I find I am sucked into the music. I put down what I am reading and sort of sit in awe at how much detail comes to me, yet I don't find myself focusing on it. Its layer upon layer of distinct and clean sound. But its not a grab you event. Its more an awe and wonderment. I am second guessing the Audion not hearing it. But I juat don't see how any other amp will do what the Blade does. I really hope I can Biamp my speaker. The Audion does have a built in volume. Of course I will try.