In a Revox G36 pickle...

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Urskov

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Jan 6, 2020
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22
Location
Fredensborg, Denmark
Hi DIY'ers

I recently acquired two Revox G36's very cheap, one being a four track the other a two track. The seller said, they are somewhat functional, though need an overhaul. I have no idea if it's mechanical or just a cap job or something.

Now this might've been an impulse buy, because really, I'm a digital native convenience fiend and primarily want to use analog gear for tracking into a DAW. But I remembered reading about tube R2Rs like the Akai M7/Roberts 770 and the Revox being excellent material for preamps here and elsewhere.

But then I got to thinking if it would be to underappreciate - potential sacrilege! - a potentially usable R2R as a mic pre. If I wouldn''t be better off selling them and instead DIY'ing G9's or Redd 47's or 1073's or...

So my pickle is:
- Give it an overhaul and install transformers (which I believe is what it lacks to be usable in a modern studio?), otherwise as is. (Heard it can double as a decent guitar amp??)
- Salvage it for the pres and rack these
- Sell it and DIY something else

I should note that I've only dabbled in guitar pedal electronics (made about 30 pedals the last year or so), but already read up a good deal of tube amplifier theory (mostly guitar amps). This is why I'm seeking you guys with electronics and DIY knowhow out.
 
Last edited:

PermO

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Joined
Mar 16, 2011
Messages
318
Location
Hilversum, Netherlands
I've got one running and I love it.

To adapt it to my setup I made a cathode follower stage to bring down the output impedance.
I don't think you can get a great mic pre from it, especially if the mechanics are still ok it will be a waste of a really nice tapemachine.

If you want a tapemachine, restore it, they are worth it.

If you want a mic pre, just build a mic pre.
 

Bo Deadly

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Dec 22, 2015
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New Jersey, USA
Because of the build and frame everything is mounted on, it's a little difficult to adapt something like that to other purposes.

All that matters is the heads. Lay it down outside in bright sunlight, wipe the lens off on your phone and take many close-up pics of the heads at different angles and distances. Then look at the pics on your computer and select one or two that show the heads clearly. Specifically, look for a change in shading in this rounded surface. Post them here are we'll judge.

If the heads are in great shape you should restore the machine. You can get a restoration kit with all of the caps, motor run caps, trimmers etc from a company like Nagravox. It's not super expensive but it is a lot of work, requires above average skill, patience and planning. If that's not you, sell it to someone who likes to do that sort of thing.

If the heads are worn but still have a little life left in them, then I would just do the bare minimum to get the machine to run and then use it as a sort of tube limiter. It's filled with 12AT7s and tape compression could be used as an effect of sorts for tracking for example. You could take some shrill synth or fuzz guitar and tame it down by passing it through the G36 and then run the monitor out directly into your converter. Mix with dry and you have a tape delay.

If it's just a disaster and everything looks corroded inside, then maybe just put it on Ebay and see if someone needs it for parts.
 

Urskov

Member
Joined
Jan 6, 2020
Messages
22
Location
Fredensborg, Denmark
Thanks! The answer(s) I was expecting + more! So glad I didn't go ahead and do anything.
Because of the build and frame everything is mounted on, it's a little difficult to adapt something like that to other purposes.

All that matters is the heads. Lay it down outside in bright sunlight, wipe the lens off on your phone and take many close-up pics of the heads at different angles and distances. Then look at the pics on your computer and select one or two that show the heads clearly. Specifically, look for a change in shading in this rounded surface. Post them here are we'll judge.

If the heads are in great shape you should restore the machine. You can get a restoration kit with all of the caps, motor run caps, trimmers etc from a company like Nagravox. It's not super expensive but it is a lot of work, requires above average skill, patience and planning. If that's not you, sell it to someone who likes to do that sort of thing.

If the heads are worn but still have a little life left in them, then I would just do the bare minimum to get the machine to run and then use it as a sort of tube limiter. It's filled with 12AT7s and tape compression could be used as an effect of sorts for tracking for example. You could take some shrill synth or fuzz guitar and tame it down by passing it through the G36 and then run the monitor out directly into your converter. Mix with dry and you have a tape delay.

If it's just a disaster and everything looks corroded inside, then maybe just put it on Ebay and see if someone needs it for parts.

Thanks for the tips! I've had the patience to restore drums and build guitar pedals, so why not also a tape machine. I live right next to an audio engineer who repaired his Studer A80 on his own, so he might be able to help me.

I like this idea to use it as an effects machine enough to keep one, at least! I'll start another topic for that when/if I undertake that project. Will sell the other right away.
 

PermO

Well-known member
Joined
Mar 16, 2011
Messages
318
Location
Hilversum, Netherlands
I don't know the condition of your machines, but I would suggest you restore the 2 track as it will have a better fidelity over the 4 track using the same 1/4" tapes.

Getting new tape is also a bit of a thing, you can still find it, but it does not come cheap.
I bought three 26.5cm spools of LPR35 from Thomann, don't know if they still have this.

I build my cathode follower output from this site info; Teflon coupling capacitors & More No-Gain—No-Pain Tube Buffer Circuits
Or just run it into a pair of High Z DI/Preamps
 
Last edited:

Urskov

Member
Joined
Jan 6, 2020
Messages
22
Location
Fredensborg, Denmark
I don't know the condition of your machines, but I would suggest you restore the 2 track as it will have a better fidelity over the 4 track using the same 1/4" tapes.

Getting new tape is also a bit of a thing, you can still find it, but it does not come cheap.
I bought three 26.5cm spools of LPR35 from Thomann, don't know if they still have this.

I build my cathode follower output from this site info; Teflon coupling capacitors & More No-Gain—No-Pain Tube Buffer Circuits
Or just run it into a pair of High Z DI/Preamps
Yeah, I thought as much about the 2 track being higher fidelity. Will take some pics of that one and begin a new thread here - and list the other.
 

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