REVOX G36

Google is your friend:
http://www.freeinfosociety.com/electronics/schemview.php?id=2400

analogguru

GL1, GL2 and GL3 are Selenium Gleichrichter ... these are prone to failure , EVEN NOS  put 1N4007 instead and bridges for the low voltages types !
Pierre

ftp.studer.ch/Public/Products/Revox/Revox_G36/

Everything you need is there, operating manual, service manual, factory mods, you name it!

Axel

(edited link)

Hi all
I just totally refurbished a Revox G36 MK3/4 with a full overhaul kit from Nagravox. The guide is pretty intense but overall it covers everything and great support from them.
I am not about to finish and I have a hum on channel 1, repro... It is driving me mad, I have tried all sorts of stuffs, been scouting everywhere I can't find the source of the problem. When I disconnect the head I still have hum.
I know this is a very long shot but I figured maybe someone here has encountered a similar issue... or has an old trick or tip they can share.
Back at it ...
Cheers !
Thomas

What if you short circuit the input of the preamp to ground ? I sometimes use a large foil cap and short circuit signal to ground with it to check what stage of the amplifier is the cause if an issue. Beware of discharges of the cap once it has been charged.

It also can originate in the heater supply.

Did you change the original circuit ?

I will try that, but the preamp does not hum. Only the tape repro without any tape rolling so its between the headblock and the output, or maybe the ground is messed with somewhere. I'll try your method !
It is not modified, except for updated power supply (modern diodes instead of the old selenium rectifier) and also I have wired one of the input straight to the volume pot ( "A77 mod" style, to avoid the first preamp stage), it doesn't seem to be the source of my problem but I'll desolder this just to double check.

is that the Ritchie Blackmore model?

dang, 2010 links are busted

there's a mirror site !
https://www.reeltoreel.nl/studer/