A bad power supply filter cap would not cause one tube to flash or overload. A shorted coupling cap, or one that's leaking DC voltages, will. (http://www.geofex.com/ampdbug/coupling.htm)
Cary SLI-80 capacitor problem questions
Apologies in advance for the length of this request.
I have a Cary Sli-80 F1 integrated that I've enjoyed for several years. Recently there was a sudden intermittent popping noise in the left channel and the EL34 tube in position 2 was flashing in time to the popping. Foolishly, I assumed it was a tube failure and put in another set of output tubes. On power-up the KT-77 tube in #2 began to heat up and glow dramatically so I shut off the power immediately.
Trying to avoid the cost and damage risk of shipping the amp back to Cary I took it to a local shop which is an authorized Mcintosh repair facility. The diagnosis is, "A shorted capacitor is causing the amplifier to blow the 2nd output tube." I'm assuming their diagnosis is accurate but they seem not to be familiar with Cary amps and I'm not thrilled with the two repair options they offer. One is to replace all the coupling capacitors with generic polypropylene caps or order the Jensen oil-in -copper caps from Cary at a cost of $600 for the caps, plus labor. They're also insisting that I supply a complete set of new tubes if they're going to warranty the repair.
So the questions are, can I source the four caps myself and what would be your recommendation for caps? I had a recommendation a couple of years ago from my dealer in Seattle to replace the Jensens with Cardas but they're no longer in production. I've found opinions online that either Mundorf or V-Caps would be a good option.
And, is it reasonable to consider replacing the caps myself? I've done a fair amount of DIY soldering and think I could probably figure that part out, but what do I need to do to ensure I don't zap myself if I decide to go ahead with doing the work myself?
-thanks in advance for your advice and help. Apologies for cross posting to audioasylum hoping I can find someone who has advice about this obscure issue.
I have a Cary Sli-80 F1 integrated that I've enjoyed for several years. Recently there was a sudden intermittent popping noise in the left channel and the EL34 tube in position 2 was flashing in time to the popping. Foolishly, I assumed it was a tube failure and put in another set of output tubes. On power-up the KT-77 tube in #2 began to heat up and glow dramatically so I shut off the power immediately.
Trying to avoid the cost and damage risk of shipping the amp back to Cary I took it to a local shop which is an authorized Mcintosh repair facility. The diagnosis is, "A shorted capacitor is causing the amplifier to blow the 2nd output tube." I'm assuming their diagnosis is accurate but they seem not to be familiar with Cary amps and I'm not thrilled with the two repair options they offer. One is to replace all the coupling capacitors with generic polypropylene caps or order the Jensen oil-in -copper caps from Cary at a cost of $600 for the caps, plus labor. They're also insisting that I supply a complete set of new tubes if they're going to warranty the repair.
So the questions are, can I source the four caps myself and what would be your recommendation for caps? I had a recommendation a couple of years ago from my dealer in Seattle to replace the Jensens with Cardas but they're no longer in production. I've found opinions online that either Mundorf or V-Caps would be a good option.
And, is it reasonable to consider replacing the caps myself? I've done a fair amount of DIY soldering and think I could probably figure that part out, but what do I need to do to ensure I don't zap myself if I decide to go ahead with doing the work myself?
-thanks in advance for your advice and help. Apologies for cross posting to audioasylum hoping I can find someone who has advice about this obscure issue.
- ...
- 22 posts total
After 10 years of very good service , On my AES Superamp AE-25 signature ( by Cary ) I had problem of brighter tube glow and getting very hot output tubes on left ch only , also sound distortion and very low volume on left ch only . I tried to solve it through help of Cary through emails , buying circuit diagram , etc. Finally sent the amp to Cary for through repair , service and upgrades . They replaced 4 coupling capacitors ( Jensen 0.22, 1000v copper foil in oil , actually only two had gone bad , but assuming life on other two was limited also , I allowed them to replace all 4 ) , one Solen cap , 6 Hexfrade diodes ( as upgrade) , one Kimber RCA jack that had gone was showing slightly bad , and Nobel volume pot . I got all tubes replaced new . They had ran it for 24 hours . I asked them to check everything that could possibly be replaced including Kibmer silver internal wiring , all other caps , power supply etc. But they said no need as they are fine. Then sent it to me. For last 3 years I have been thoroughly enjoying this amp and it sounds much better than what original amp what I bought which itself was heavily upgraded . It did cost me a bit more , but I am very happy with Cary service and I have good faith it will continue to give me problem free service for next 5 years or so. Sfar , I would recommend to send your amp to Cary and ask for upgrades. If you want to save cost , I would say , you buy 4 numbers of Jensen oil caps ( or Mundorf silver oil or Teflon V cap ) from PartsConnexion or elsewhere and have them replaced yourself as DIY . This will save large cost in your repair. Then send the amp to Cary for service , repair and upgrade . |
I recently had a positive experience with Cary's Service Dept. (they added a mod to one of their older AES pre-amps for me, bench-tested it and then 'listen-tested' it for a few more days :) and they have a pretty well-thought-out and -executed RMA system on their website where you can check on repair status, etc.. There's a former Cary tech, Kirk Owens, now works on his own (kirkowens@soundsgood2me.net) who replaced some blown output transformers and did some upgrades to my Cary SLA-70 amp a year or two ago - real nice guy who knows his Cary stuff inside-and-out, though perhaps not as quick a turnaround as Cary (he does his mods/upgrades/repairs as a side-business, I believe). At least that would be another option that would give you a higher level of confidence on your Cary meter :) |
Here is a link to Soundsgood2me, the company run by Kirk Owens that Steveaustin is talking about. |
Many thanks to all of you for taking the time to give me the benefit of your technical expertise and sometimes hard-won experience. I learned a lot that has helped me get to a tentative decision about how to deal with the amp problem. I had a great conversation yesterday with John at Audio Connection, the Cary dealer in Seattle. Id had good dealings with them when I lived there and knew he is very knowledgeable about Cary amps since they not only sell them but repair them, as well. Unless there is some problem beyond a shorted capacitor they can replace all the caps in the amp, not just the coupling capacitors, for about the same price as the local place was going to charge for just the four generic caps. They have a stock of the discontinued Cardas caps and recommend them very highly based on other replacements theyve done. Shipping charges will be a factor, of course, but the costs would seem to be very reasonable compared to the alternatives and I do have some confidence in their work based on past experience. Ill update with results within a few weeks, I hope. Thanks again |
- 22 posts total