DR #37 - Carver M-400 Repair

This M-400 suffers from a "ticking" noise, audible through the speakers and withiin the unit itself. During this video, I check the triac, the diac, multiple resistors and multiple caps. Ultimately, I'll replace all caps.
- 1uF @ 50V (x2) - 493-17436-1-ND
- 1uF @ 100V (x2) - 493-11540-1-ND
- 4.7uF @ 35V (x2) - 493-16017-ND
- 10uF @ 35V (x3) - 493-1314-ND
- 22uF @ 35V (x4) - 493-1315-ND
- 22uF @ 35V (x3) - 493-1315-ND
- 330uF @ 16V (x2) - 493-1521-ND
- 2,200uF @ 25V (x6) - UVY1E222MHD-ND
- 4,700uF @ 80V (x2) - 493-8967-ND

[@allenwelsch2839]

I was a service tech at Carver in the ninety's and I worked on plenty of M-400s. Not my favorite amp to work on due to their construction and inability to troubleshoot but damn they sounded good. I'm glad someone is still showing them love. Nice work.

[@ThresholdZhor]

Excellent tutorial, I had 3 M-400 back in 1982 I start my repairing skills on those days and repair one of them, is like a class H design 30 years before, sound was good but not excellent, also had M-500 and later repair PM-1.5t that I consider the best vintage Carver in sound

[@saarike]

Excellent and interesting repair! Thank you.

[@Internutt2023]

Very to the point and informative video on toubleshooting this unit! Could you please share the PN's you used for the Triac and Diac replacement, and if you do have any info for a viable LDR replacement as well?

[@albertcalderon3421]

Saludos, geniales sus videos, muy valorados y apreciados, siga adelante, gracias por compartirlo, abrazos desde Bogotá Colombia

[@kenokeno00]

...................thought it was a canned ham on the bench.......................

[@frankgeeraerts6243]

Carver ...........canned heat............canned music.........

[@AMPLIFICADORCOMTRANSFORMADOR]

very good

[@rohitparekh1923]

Hi, I have M400 for repairs but I cant find its parts available. that is triac Q4025Z5, & diac GT40. can any one help me please?

[@DonLytle]

Good afternoon. I have two Carver M-400t amplifiers that need work. I would like to perhaps get an estimate to do a full electrolytic chassis refresh. Are you available to perform a repair?

[@doofwop]

Try Hi Tech Audio LLC in Stevenson WA, or Nelion Audio in MI. These are two authorized Carver repair centers which will have all of the experience required and in the case of Hi Tech at least, they bought all of the Carver-specific parts for these units. Rolland at Hi Tech was personally anointed by Bob Carver to service this gear. Bob's designs are different causing many competent techs to scratch their heads. For these units, though DR is quite thorough and competent, you should be sending them to Carver experts for the best results.

[@DonLytle]

@@doofwop Yo. Thanks for the info. I've used Rolland @ Hi Tech audio previously. When I sent this message, he was behind by about 9 months. I was just checking for other opportunities. But you're correct. Rolland is awesome and thorough. Thanks again for spreading the word. Peace!

[@doofwop]

I'm getting some work done now at Hi Tech actually. I was told 8 to 12 week turnover.

[@nadimpalliraviteja9517]

First comment