Best RtoR tape for a Revox A77

Just make sure that the azimuth is OK.

Essentially, what you are saying is a flat FR is the ultimate goal when adjusting bias and EQ. If FR is flat, don't mess with anything? 

If in playback, Yes.

If in record, also yes, but there are two approaches to setting record head bias that might be used on that machine. The first is the 'consumer method' which is to record at 100Hz and 10KHz, setting the bias so that during playback both tones playback at the same level. Then you adjust the record current (assuming the VU meters are properly calibrated) so that 0VU in record plays back at 0VU.

The 'pro audio' method is to record at 1KHz and increase the bias so that the playback peaks and then continue until the playback has fallen off by 1dB. This (or a similar technique, depending on the machine) should get you the lowest distortion rather than the flatest playback.

Thanks for the info!  I'll pass it along to my tech guy who is working with one of the A77s. 

I think we're fighting the battle of which 0.47uF is going to fail next. When the left most cap on the drive board fails, the capstan motor does not run. That's happened to both my A77s within a few days. Once we get all the caps replaced, we'll get on with the fine tuning. 

I've had these A77s for over 50yrs and am getting very emotionally attached to them. 

Thanks so much, all of you on this forum, for all the good advice!

CWZ