Bob the Tech Audio recently performed partial restoration and repair of this vintage McIntosh MC2300 power amplifier. This iconic 1970s vintage power amplifier is famed for its use by Jerry Garcia. It’s shown here with a brand new C70 preamplifier commemorating McIntosh Laboratory’s 70th Anniversary.
As part of the repair and restoration we replaced old and faulty electrolytic capacitors on the input and driver boards. Additionally, we replaced the input differential input amplifier on one driver to remedy a DC offset in the bias. The offset was causing the associated heatsinks to get warm even when idle, as well as placing a small DC voltage on the speaker output.
A tired and dirty mono/stereo switch was causing noisy performance, so we rebuilt the switch. We gave the contacts a good cleaning and tightened them up. As a result the switch is making solid contact which eliminated the noise on power up.
This was a relatively minor repair and restoration of the iconic McIntosh MC2300 power amplifier. Nevertheless, it was great to have it in the shop. It was fun to set it up with the brand new C70 for a listening test. For restoration of your fine vintage audio components, or service for your modern equipment, contact us at our service-request page.
