Until the Revox B77 MK1 found its way into my collection, I've had no experience with the brand.
I received the electrolytic capacitors, about 30 of them, from Mouser Electronics. Posts about this machine, on the Tapeheads forums, recommended replacement of all the electrolytic, and motor drive capacitors. The motor drive capacitors were supplied by Erhard Audio.
The most annoying part of the project involved the parts on the tape drive, and power supply cards. These circuit cards are attached to the power transformer, and due to several soldered connections, required a little patience. The other circuit cards were easily removed.
The majority of parts replacement required extensive disassembly of the machine. The motor drive caps were much easier.
Step one - remove the case.
Next, remove the front panel.
Then, expose the motor caps, which hide behind the voltage selector.
Unsolder the leads to the old caps.
I was unfamiliar with this brand and type of capacitor. When I saw the black 'goo,' I wasn't sure if it was from internal pressure, or if this was the normal appearance for a sealant applied during manufacturing. Since the sealant looked different between the capacitors, I decided to replace them.
Responses from the Tapeheads forum indicated that these caps are filled with a clear oil. These did not have any drips or other signs of clear oil leakage; however, I replaced all three.
If these would have popped, perhaps some extensive damage could have occurred.
The caps are attached to the front panel, via a 1/4 20 threaded stub. Install the new ones, and resolder the connections. These motor drive caps are not polarized, as they are designed to work with AC voltages, so there is no need to worry about which terminals the wire pairs connect to.
After everything was reconnected, I gave it the smoke test - it powered up just fine. I then put it back in the case, reattached the front panel, and set it up for a test recording - for a full 10" reel - at 7.5 IPS - about 1 hour 8 minutes of audio.
Depending on one's taste in music, it might not sound right - this is some glorious, live, Sonic Youth from a show in Germany, 1996. It sounds exactly the way it should.
The right audio meter has a bad lamp. I tried to replace it some time ago. Due to the plastic in the meter housing, I gave up on it, as it was stuck so hard that I didn't want to break anything. There are certain parts that you really don't want to have to track down.
The machine is now to the point where it I think it should be reliable for a long time.
