Vintage Asylum

Classic gear from yesteryear; vintage audio standing the test of time.

Return to Vintage Asylum


Message Sort: Post Order or Asylum Reverse Threaded

Revox A50

87.167.83.184

Posted on March 15, 2011 at 04:06:44
alexpop
Audiophile

Posts: 61
Joined: October 3, 2003
Revox A50
1 channel working.
The faulty channel is distorted and low in volume.

Anybody know what it could be ?

Thanks !

 

Hide full thread outline!
    ...
RE: Revox A50 , posted on March 15, 2011 at 11:27:43
Marantzguy
Industry Professional

Posts: 2845
Location: Berkeley, CA
Joined: June 21, 2002
Hello, Alex:

It helps to describe what the A-50 actually is.

I assume that it is an integrated solid-state amplifier.

Your problem could be ANYTHING, but I encourage you to open it up, if you have not already done so, and assuming that construction may be based upon individual circuit cards for the various parts of the electronics, to swap them, channel-to-channel to see if the problem also moves accordingly and then try to isolate the issue from there.

And, if the construction is based upon carded circuits on removable boards, to clean the contacts in the sockets and also clean the edge contact points with DeOxiT or Caig Gold and reinsert to see if things change.

Any piece of electronics which is as old as I assume this product may be, probably also needs to have the majority of its original capacitors changed, along with general cleaning here or there.

Again, have you searched online to see if there is a print on the circuitry?

That also is essential in any sort of attempt to repair such an item.

I once owned an A-50 amplifier, but that was over twenty years ago and got it cheaply from a local police auction here in Berkeley. I was not particularly impressed with it, either. I would get in there and test voltages against a published schematic and then replace handfuls of old failing and unreliable capacitors. They do not last forever.

The ReVox A-77 and B-77's are comparatively easy to work on, though.

Same era, obviously.

Best of luck!

Richard Links
Berkeley, CA

 

Here's the ReVox A50 Service Manual . . ., posted on March 15, 2011 at 17:08:34
RoscoeManx
Audiophile

Posts: 131
Location: Central Virginia
Joined: February 12, 2007
You can get most Studer/ReVox manuals from the Studer ftp site. For the ReVox A50 it's:

 

Edit out the "http://" at the beginning of the ftp address., posted on March 15, 2011 at 17:11:00
RoscoeManx
Audiophile

Posts: 131
Location: Central Virginia
Joined: February 12, 2007
Studer/ReVox ftp site for the Revox A50 is:

ftp://ftp.studer.ch/Public/Products/Revox/Revox_A50_A76_A78/

 

RE: Here's the ReVox A50 Service Manual . . ., posted on March 16, 2011 at 00:06:44
alexpop
Audiophile

Posts: 61
Joined: October 3, 2003
Thanks for the link Roscoe !

 

RE: Revox A50 , posted on March 16, 2011 at 00:16:22
alexpop
Audiophile

Posts: 61
Joined: October 3, 2003
Hi Richard,

The Revox being 40 years old ..no doubt it's the capacitors.
But not being a hands on guy I'll have one more peak inside to see if there's a wire loose, apply contact cleaner.
If no luck, decide either to stick to glorious mono, or get it serviced.

Thanks for your help !

Alex

 

RE: Revox A50 , posted on March 16, 2011 at 11:06:57
Marantzguy
Industry Professional

Posts: 2845
Location: Berkeley, CA
Joined: June 21, 2002
Hi, Alex:

If the assembly consists of carded circuits, and you have a schematic or can identify the capacitors in question, as long as you match or exceed the voltage rating, but keep the capacitance pretty much according to spec, and OBSERVE PROPER POLARITY, using a low-wattage soldering iron and solder wick, you might enjoy the experience of replacing lots of small caps!

I have done this on some of my old ReVox A-77 open reelers over the years and have a lot of fun doing so.

Sure cuts the overall cost of repairs and preserves the units for the future.

Good luck!

Richard Links
Berkeley, CA

 

RE: Revox A50 , posted on March 18, 2011 at 03:22:33
alexpop
Audiophile

Posts: 61
Joined: October 3, 2003
Hi Richard,

Re: 1 channel working.

I can listen to stereo only with headphones.
I think the 2 pin din socket is loose..perhaps requiring re-soldering.

regards,
Alex

 

RE: Here's the ReVox A50 Service Manual . . ., posted on May 4, 2011 at 06:11:20
Here is the link to get you to the Studer-Revox documentation easily.

ftp://ftp.studer.ch/../../Public/

You may need to right-click some of the pdf files to get them to download.

Best regards,

Terry Nelson

 

Page processed in 0.017 seconds.