I've had the 500 since I bought it new in the 80's. Some point in the 90's it developed a problem with one of the channels cutting in and out so I wrapped it up in a towel and put it away until about a year ago when I sent it to https://www.carveraudiorepair.com. Rolland is the person who worked on it and did what they call a chassis refresh to it.
"Chassis Refresh" This is our signature service and includes replacing 100% of the electrolytic capacitors throughout the amplifier including all power supply capacitors, updating resistors in all critical areas for guaranteed performance and reliability, calibrated to factory specifications. Baring misuse or abuse this service will give you on average 30 years of service
M-500t Chassis Refresh
Repair all issues
Touchup all poor solder
Install all factory updates
Replace 100% of the electrolytic capacitors throughout the entire chassis
Upgrade High Rail capacitors to 8K4UF 100V per rail
Calibrate to factory specifications
One year parts and labor on the entire chassis
Modification for sonic improvements to the midrange and high frequency performance
Polypropylene bypass capacitors in the signal path
Low noise High Slew rate opamps
They did a great job. I can't tell you what the difference in sound might be because it's been years since it was in use until now. All I can say is it sounds and works great and I'm very happy with the work.
I also replaced the faceplate. The unit was mint but for a small nick in the faceplate (Have I mentioned I'm "OCD" with equipment?) A seller on eBay sells brand new faceplates and other parts for Carver amps. The stuff he sells is amazing in terms of quality.
I'm glad I kept it. It's those damn meters. I love meters. LOL!
