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Old 24th Sep 2019, 11:19 pm   #28
MeerKat
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Join Date: Jan 2016
Location: Ramsgate, Kent, UK.
Posts: 296
Default Re: Revox A77 refurbishment advice please.

The refurb starts at last and I'm tackling the switch board first, I haven't taken it right out, too many wires to disconnect. I've taken the front metal plate off and taken the plugin boards out, first marking who came from where! I noticed the lamps though working have a green corrosion ring round their bases caused I suspect by storage in damp conditions, these were carefully teased out cleaned and lightly treated with Vaseline before replacement.

Now P305 trimmer, the existing one was 303k and it was set at 263.5k, as the new one was 263k to save having to set it right at the end I changed R305 to 100k, this should allow enough room if the crosstalk needs adjustment if the old P305 had drifted high.

A77s have a issues, the VUs banging the end stops at switchon offends my mechanical sensibilities and the VUs don't work on playback being two. I would like to correct this, now before I go attempting to reinvent the wheel has any of you modded your A77 to overcome these issues? I would be interested to know how if you have.

I'm doing the transformer assembly now and have it on the bench with the power and speed control boards removed ready to be worked on, a bit of a mission in one way but now easy to work on.
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