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Does anybody here know who in the USA can repair/troubleshoot a Yamamoto Soundcraft A-08S amplifier? I went to Venus Hifi's site, but see they are no longer in business. I'd hate to have to ship this amplifier to Japan. Any info would be greatly appreciated. Thanks much.
Kevin T"religion is the opiate of the masses"
Follow Ups:
In case it helps, Samuel Furon (Atelier Audio, link below) is the distributor for Canada. He might be able to be of assistance.
Thanks for the info. I got the issue handled. It seems that a dirty speaker connection was causing the problem. I've never in my life experienced a dirty connection cause that kinda of loud, popping noise.
The thing that concerns me the most though is that I sent an email to Yamamoto telling them about the problem and I have received no replay back from them in over a week.
Kevin T
"religion is the opiate of the masses"
Mr Turner: I want to thank you for your casual remark in an old post to the effect that a dirty speaker connection had caused a loud, popping noise in your Yamamoto A-08. I came upon your post after days of cleaning and retensioning sockets and testing tubes. I had experienced not only popping but humming, crackling and hissing sounds. I was looking for a repairman in the US when I came on your old post. Sure enough: those massive speaker connectors were heavily tarnished internally, and cleaning them cured all the problems. I'm very grateful.
Glad my documented frustrations from almost 8 years ago could be of use. Hope you're enjoying the Yamamoto. It is an amazing amplifier. I've moved on to Kharma speakers now so unfortunately a 2 watt amplifier won't cut it any longer. I still miss my Supratek/Yamamoto/Von Schweikert dB99 combo.......
Kevin T
"religion is the opiate of the masses"
Good to know you got the problem taken care of.
Yamamoto-san's english is very minimal and he relies exclusively on his distributors to handle those situations. He does not reply to my emails either :-)
So I decided to do some in depth checking today. I inserted a pair of shorting RCA's so that only the amplifier is connected to the speakers. My preamp and other sources are all off and out of the loop entirely.
With the A-08S on and a new pair of Shuguang 2A3C's inserted, I hear popping out of the left channel. I turned the A-08S off and inserted a pair of EML 45's and I still hear popping out of the left channel.
I turned the A-08S off and reversed the speaker cables and now the popping is coming out of the right channel speaker (which is connected to the A-08S left channel).
I turned the A-08S off and returned the speaker cables to their correct position and the popping is coming out of the left channel again.
I turned the A-08S off and replaced the 80 rectifier tube and the popping is still coming out of the left channel.
I turned the A-08S off and replaced the 717A driver tubes and the popping in the left channel stopped, but I hear it ever so faintly in the right channel. I have several pairs of 717A that I purchased several years ago. I'm starting to wonder if they weren't as "NOS" testing as they were proclaimed to be. I turned my preamp on and noticed that when I'd insert a pair of the 717A's, some times the left channel would cut out, but if I reversed the tubes, both channels played fine. ???!!!
As a last ditch effort, I put a new speaker cable on just the left channel and the popping is still present though significantly more silent. When the preamp was on using the old cable, I could hear the popping across the room. Now I have to put my ear against the tweeter to hear the popping even with the preamp on.
I put the old left channel cable on the right channel and there was no popping. I then put the old left channel cable back in place and the popping sound remains more silent than before. I guess I'm gonna run some contact cleaner across all the connections and see what happens. This is confusing me to say the least.
Kevin T
"religion is the opiate of the masses"
I've got a whistle and static in one side. Yeah, I know it's a tube and I messed around with it time and time again. I got it to change from one side to another. But it quits after 5 minutes or so.
Then I can't test it any more.
I really should sort out the noisy tube. It's surely one of 16 or so.
Or I can just turn it on 5 minutes early.
-Rod
Noisy tubes are a major pain to chase down. Having to reverse pairs, power on, wait for noise, power off, repeat....
I have to break down my system twice a year to polish and wax my audio racks twice a year to keep the hardwood from drying out. I guess I'll add cleaning all the contacts on my system to the mix since everything is apart anyways.
Kevin T
"religion is the opiate of the masses"
But, you may want to use contact cleaner on the sockets and tube pins. Just a little bit. May help.
Good luck!
I used DeOxit and then DeOxit Gold on all the binding posts, rca's, and tube pins. I inserted the tubes into the sockets and worked them in and out gently . I think the only thing I missed was the power connections. I'll get them later.
Kevin T
"religion is the opiate of the masses"
Its a very simply designed amp. What's wrong with it?
First suspect without mentioning any symptoms would be a tube.
Stu
It's kind of a long story as to how I arrived at the Yamamoto as the culprit to my problem, but the gist of it is that the amp makes a spitty, popping sound out of the left channel tweeter. I've swapped the tubes to the other channel, replaced all the tubes with new tubes, changed the cabling, and even tried on another set of speakers. No matter what I do, the popping doesn't stop and seems isolated to the left channel. It's exacerbated by the fact that I use a high gain preamplifier (Supratek Dual Cabernet). Unfortunately, I'm not very technically inclined so I can't troubleshoot it myself beyond replacing tubes. Music seems to play fine and the amp powers up so I'm thinking/hoping the problem is in a resistor somewhere as I once had another tube amplifier display some spitting noises which turned out to be a bias resistor.
I've contacted Deja Vu Audio as well as Jeffrey Jackson at Experience Music about the repair, but before I send it off I'm gonna double check everything to make sure I can isolate it as the Yamamoto. All my testing has been done over several days so I may have missed something.
Kevin T
"religion is the opiate of the masses"
I'd try Nick Gowan at True Sound in Campbell, CA. True Sound is an authorized USA service center for Audio Note and some other brands. Nick has an excellent reputation for repairs and modifications of tube gear. Sourcing exact replacement parts for your amp, if needed, could be an issue as it appears there is no longer a US distributor. Good luck to you.
Contact info at the link below.
plus 1 on Nick.
He's the best.
The ONLY person I trust with my
Garber/FI amp and pre.
Thanks for the suggestion. I'm waiting to hear back to Yamamoto and the European distributor to see if there is a new US distributor. Ideally, if there is no US distributor, I'd like to find a repair center somewhere in the Southeast to minimizze the shipping times, but I'll keep Nick's info handy just in case.
Kevin T
"religion is the opiate of the masses"
Another possibility is Deja Vu Audio in McClean, VA. Not so far from Atlanta. They make their own line of tube amplifiers (including SET) and do a full-service repair business of other brands.
Thanks for the suggestion, Gary. You still enjoying the EML 2A3's I sold you almost 4 years ago? ;)
Kevin T
"religion is the opiate of the masses"
Actually, I evolved to a 300b SET, but before than used the EML 2a3s in a DejaVu SET for a year or more and enjoyed every minute.
Ah, amp evolution. I know about it all too well. I tried out an Allnic 300B integrated to see if it would dethrone my Supratek/Yamamoto combo. It did not. I'm just gonna stick with what I have (if I can get it repaired) because I've grown tired of trying to chase "better" sound.
Kevin T
"religion is the opiate of the masses"
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