Levinson 331 humming followup...

Hi again. I wrote a month and a half ago about the used Levinson 331 i bought off audiogon. It was humming from the RT channel (when looking from rear) when i rec'd it. My last post was that i took it into a local dealer to repair it. I got the amp back after about 3 weeks and the hum was fixed. They replaced a bad filter capacitor on the rt side and did a "complete test". Well, the amp does sound pretty nice but what the tech did NOT do was replace any of the big power capacitors. One of which was leaking and had crusty white stuff like on the top of a car battery terminal. I didn't want to cause trouble as they did take care of my chief complaint, the hum. Believe it or not, A very kind fellow audiogon member here actually lives within 4 miles of me and insisted that we can save $$$ by not sending the unit to Levinson. He figured out the best replacement cap we could buy and replaced all 4 of the large caps. It took us 6 whole hours working as a team but we did it! This amp clearly is clearly built like a tank but it definietely has some design flaws. these design flaws made it hard to work on but not worth the $1200 to $2000 plus shipping the Levinson sites wanted. Now i hope the amp will provide me with listening pleasure for another 10 years. I think the unit is at least 14 to 16 years though but i'll be happy with 10. For those of you that responded to my previous post, the original Levinson large caps were made by Phillips NOT Mallory. The 4 small ones are made by Nippon and had no signs of leakage. We installed Cornell Dublier caps which were recommended by a friend of a friend from Japan. The internet is truly a great place. W/o this site, I would have never been able to learn such things and meet such wonderful people. Thank you.

It was a pleasure to work with another Audiogon member. This was my first time repairing a Levinson. The reason it is a daunting task is because of several design flaws. First off, the four large power electrolytic capacitors valued at 44000UF and 2 inches in diameter is made by Phillips - not a high end manufacturer. Secondly, in order to change the caps, you have to open the heat sinks. Inside you will find five output transistors on both sides that are completely covered by a plate which inhibits air flow. Removing the top five screws on the transistor is the initial step in a complex process. Interestingly enough, Levinson had the country of origin blackened out...hmm? We replaced 44000UF capacitors with 46000UF/75V Cornell Dublier high end U.S. made caps. These are the only 2 inch diameter caps. This job can be done if you have time, patience and know where to buy the parts. Even better yet, you can replace the 44000UF caps with the very expensive 47000UF/100V Cornell Dublier caps, but you'll have to modify the holder due to space. This whole job can be done for 1/3 of the cost of what Levinson charges,including replacing filter caps and electrolytic caps. In conclusion, the Levinson is a very good amp and similar to Luxman, Krell, Pass, etc. Feel free to email me if you have any questions about the Levinson complete cap replacement. Thank you very much.
So Levinson obviously was putting inferior caps on most of the 300 series amps? Wonder what the cost savings was and did they know the Phillips caps were inferior?
Sounds a lot like legacy Classé amps, especially the larger models. Half of the output transistors mounted upside down under the upper half, as many as thirty-six 4,700uf 100V main PS caps in the largest model, mounted under the main board, etc., etc. Too much disassembly involved in servicing.
Just for the record,Levinson 332/333/335/336 amps uses 50000uf/100V and 125V Capacitors.I recommend using 50000uf/125V Capacitor made by BC Components.You need 4 caps price 400 dollars.The Cornell Dublier 51000uf/200V Capacitor is very expensive price 800 dollars for 4 of them.These Capacitors are very hard to find.I can get these caps.

In conclusion,For Levinson 331 and 334 parts will cost you 250 dollars.For levinson 332/333/335/336 parts will cost you 400 dollars using BC Components.When this job is done amp is good as new.
It's odd that Philips caps would be leaking. I have used many of them in the past for service replacement and found them to be very good,with very low series resistance which is important in a good filter capacitor. It is possible that those caps were operating at a higher voltage than they were rated for and that can cause premature failure. Also, if the caps are being operated in a hot environment that can also cause premature failure as cap manufacturers will de-rate the cap based on surrounding temperature. Note that caps take 10's of hours to break in, so the sound of the amp will change for the better once the cap has broken in.
I'm not surprised to see that cheap caps were used in the 331. I once had a Levinson 23 amp which developed a problem. A skilled local tech found the problem related to a cheap part and commented on some of the other cheap parts used. I quickly sold the amp and would not own any other Levinson equipment.