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.
128x128sfar
I'd send it back to Cary. I needed a cold solder joint fixed and they repaired it out of warranty, so I had them put in Cardas caps so I would not have to ship it again in a few more years. It also made the amp sound better. Cary will also run your amp for 24 hours to make sure everything is working before sending it back. Best of luck.
Since yours is an F1, as is my SLP98P, I have another suggestion for you; make sure you have all of the upgrades that you are supposed to have. I would check with the local shop first, but don't have them remove anything.

I bought an maxxed out SLP from Upscale in 2008. It didn't work out of the box and went immeadiatly back to Cary, where they fixed it, and sent it back. I have always loved the way it sounds. I had to send it back to have a tube socket replaced in about 2010, no problem, they did great work.

This year I switched all the other gear out in my system, and I was having some issues. A friend told me to check that I hadn't burned out a capacitor, so I talked to Cary on the phone, and then sent them a picture of the inside of the preamp, and he sent me back a picture with labels on what to look for.

My unit was supposed to be loaded:

AudioOne Caps
Jensen Copper Oil Filled Caps
Home Theater Bypass
Direct Coupled
Hexfreds

That's what the my box said, that's what I bought for a very large premium, but it was not Direct Coupled, and did not have the very expensive Jensen Caps.

I was pretty ticked off. Although it's been almost 6 years, Kevin at Upscale was helpful and told me that the Jensen Caps and Direct Coupled were mutually exclusive. It was one or the other, and all of the units with HT Bypass should have been Direct Coupled.

Cary at first tried to say, I was out of warranty, then that I hadn't returned my warranty card (even though they had repaired the unit twice), then that I had the unit modified somewhere else. Finally they offered to modify it to direct coupled for me, if I paid the bench fee and all shipping!! Really, so you want to charge me again for what I already bought from you??

Finally they agreed to make my unit what I originally bought, but I still paid over $100 in shipping. It was pretty bush league.

I love the equipment they make, but Cary seems unsure about what is in each of these units, and they were not customer focused on fixing what might have been an oversight, but now has made me wonder about their commitment to customers. This stuff is expensive, they should have had no problem making this right.

So, check and make sure your unit is what you think it is.
I don't think it's the coupling cap. It's the cap in the power supply or the connection to the "problem tube location" caused the tube to flash. I had similar problem with rogue amp. Not sure the cary uses wire or printed circuit for connection. Any way, just take all tubes out. Get a meter to probe between ground (any ground trace you can find) and the all the pins of the working tube socket. Write down voltages at each pin. Do the same to the problem socket. One of the pin that controls the current, if not having correct voltage, would cause the tube to light up. Do this first. If you find a different voltage, flip the board or trace the connection to that node and make sure it has the good connection. While having the board flipped, inspect the cap in power supply for leak or any abnormal sign. Worst case is to change a few cap in power supply. BEFORE flipping the board to inspect, make sure you discharge the voltage by having a large resistor 10K (small value may damage resistor if too much current going thru) or so and connect between the ground and the output of power transformer (few hundred volts, use meter to check). Let it discharged. Measure again to make sure it drop to zero volt before working on the board. Good luck.
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)
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 .