Revox A77 Capstan Motor Upgrade Service

Description

Revox A77 Capstan Motor Upgrade Service. NOTE: this is a service, not a motor.
The Revox A77 is legendary for its sound quality, much of which stems from its superb direct drive capstan motor. Unfortunately, after more than forty-years, the motor has aged and no longer runs at spec.
I will take your A77’s capstan motor, and upgrade it to better-than- new performance by:
1. Replacing the stock bearing with a custom-made bearing that runs with greater precision and lower friction than the factory original.
2. Cleaning the motor inside and out.
3. Lubricating the sleeve bearing (if your motor is a sleeve bearing type) with a proprietary oil I developed that exceeds the original factory specs.
4. Checking the rotor balance and re-balancing the rotor if needed.
5. Check the speed control pickup; if it’s defective I will attempt to repair it. Most often, it’s the plastic Mount that has cracked. If it can’t be repaired I have a few spares, and I will have to add for the spare pickup. Don’t worry, in the past 40-plus years, I have seen only two dead pickups.
6. Restoring the matte finish of the capstan. When new, the capstan has a slight texture to give it some “grip” eliminate tape slippage between the capstan and pinch roller. Over time, the texture wears smooth, allowing some slippage to occur, which increases flutter-and-wow, degrading sound quality. My machinist has developed a treatment for restoring the matte finish to factory specifications.
7. Modifying the rotor using my proprietary process to reduce the high pitch whine that the A77 makes when it is running. True, you hear it only when the room is quiet and you’re next to the A77, but let’s face it — the whine can be annoying and it’s the only blemish on an otherwise superb tape recorder. The modification doesn’t hurt the motor’s performance, it merely reduces the whine/whistle sound.
8. Testing the finished motor by putting it into an A77 and running it for 24 Hours to be sure it will give you years of reliable service.
NOTE: Flutter-and-wow are deviations in the speed of your A77. The effect is like adding vibrato to everything that you record or play on the machine. That sounds terrible, harsh and strained, especially for piano and violin. The lower the flutter-and-wow, the better your A77 sounds.
The Process: First, remove the motor from the A77. LEAVE IT ON the mounting plate that also has the speed control pickup.
Next, pack very carefully. Don’t mummify it with packing tape, wrap it in cardboard first then in bubble wrap. Be sure that you have 4” of packing material on all sides! Don’t use those airbags because they don’t work with heavy items like this motor assembly. Absolutely never put any packing tape on the motor itself, because I will have to charge extra to remove the tape residue.
Enclose a note with your name and address so I can be sure that your motor doesn’t get mixed up with someone else’s motor.
Finally, send me the motor insured for 0 to the address that I will send to you.
Please allow me 3 weeks to do the work. As soon as I finish the work, I’ll send you the motor back.
Your upgraded motor will run smoother, with less rumble, giving your A77 lower flutter-and-wow… which is a significant sonic upgrade for an already outstanding tape recorder!
If your motor should be in such bad condition that it cannot be upgraded, I’ll send it back and refund your payment. This is extremely rare, and frankly I have never seen a completely dead capstan motor.
I am a former Revox service tech, along with several other brands, and have worked on the A77 when it was made new. Also, I own three A77s, each one of which I have tweaked and upgraded.