Superphon Revelation II schematic

[Dean Jagels]

I have a Superphon Revelation II that lost its left channel many years ago. Two years ago, I did some work to revive it - replaced electrolytic caps and a couple of suspicious resistors. This helped; I thought that I'd succeeded, but after about 2 hours of power-on, the left channel still disappears.

I'm going to give it another try. I have a schematic that came with the manual, but it's rather hard to read. It looks like it was run off on a mimeograph machine, and the lettering is small, so the labels are rather blobby.

While I can use what I have, I'm wondering if anyone has a decent schematic. I can post what I have, if that's helpful.

 

[bimasta]

I found some schematics for the Rev II in an old file. They may not be much clearer than yours, and if that's the case there's no point copying and sending them to you.

Please post a sample of what you have — if mine is clearer, I'll send what I have.

 

[Dean Jagels]

I absolutely will post what I have - but my scanner just rolled over .

Without further delay, though, I will say that I found my issue. It's the mute relay. The design is sly - it uses a powered relay to hold a ground shunt open. No power, and the output signal goes to ground. Under power, the shunt is held open and the signal goes cleanly to output with no switch in the path.

So, the relay went sour. When first powered, it does its job, but after time it lets the shunt close on the left channel.

I routed around the relay on both channels. The darling is singing reliably now. And the mute switch is useless. C'est la vie.

Now, a gratuitous plug - I do love that pre-amp. It is weak when it gets hit with a lot of chaos, but it is wonderfully definitive when given even half a chance. Works engineered in the 70s and early 80s walk around the room if they so choose.

Cheers,
Dean

 

[Dean Jagels]

I found some schematics for the Rev II in an old file. They may not be much clearer than yours, and if that's the case there's no point copying and sending them to you.

Please post a sample of what you have — if mine is clearer, I'll send what I have.

I finally got my schematic scanned. Hopefully, I've uploaded it properly so you can see what I have.

 

[bimasta]

I found some schematics for the Rev II in an old file. They may not be much clearer than yours, and if that's the case there's no point copying and sending them to you.

Yours is clearer. Good tip on the relay; I have the same issue on mine (one channel drop-out) I've been unable solve. Now I'll look for that relay — but mine is not the Rev II, there may not be a relay.

I do love that pre-amp. It is weak when it gets hit with a lot of chaos, but it is wonderfully definitive when given even half a chance.

Agreed. But I never noticed the 'chaos' weakness. Are you sure it's the preamp?

 

[hlaos123]

I finally got my schematic scanned. Hopefully, I've uploaded it properly so you can see what I have.
View attachment 1194617

Hi
I am searching for superphon revelation 2 schematic or service manual but I can't.
Because my superphon has hiss noise.
So I need it.
If you have it, can you share it with me. I know this post old but I am desperate that I love this preamp. Thank you.

 

[mgrisoli]

Hey folks,

Any chance I can get a hi res scan of this schematics?
I think the resolution of the one attached to this thread is really bad, unless there is another way to visualize it.

Having similar left channel issues on this one, a couple LEDs wont light up.