Proton 1100 preamp schematic

Artie

Super Member
Anyone have one? I just need a scan of the high-level output section.

Thanks all.

Artie
 
Wonder how much different it is, from a NAD 1020? A lot of NAD and Proton stuff shares much in common under the skin, in that era...

Regards,
Gordon.
 
Thanks Gordon. I didn't know that. One of things that I love about this preamp is that it has a small, dedicated headphone amp built in. Its not an IC, but a discrete component amp. I use it as the heart of my computer/MP3 system. If its late at night, (or early morning), I can leave the main amp off and just use headphones with some nice driving power.

The headphone amp circuit has +/-30 volt rails, so it can drive anything with nice clean sound. One of my channels has suddenly gone weak. No distortion or anything like that. I can even balance it out by putting the balance control at about the 8 o'clock position, which is, of course, almost full left. I checked for the obvious like cold solder joints. Even reflowed a few. I could hand draw out the circuit if necessary, but a schematic makes troubleshooting discrete circuits so much nicer.
 
I probably do. I have no scanner. Xerox? If you have an intermittent, spray deoxit in the headphone jack. If one channel is missing, replace the J111 fet in that channel.
 
I have the same Proton preamp - with the same problem. Will be interested to see what you find out. Sorry I don't have a schematic.
 
The balance problem was solved by replacing one of the larger caps on the output board. Its been awhile since I first posted this and then solved the problem, so I can't remember which cap exactly. However, since then, a few more cap related problems have surfaced. When I tear this thing apart again, I'll post the component numbers.

This is a good ole pre-amp. I hope to keep it humming along for quite some time. I'd still love to find a schematic, though.
 
Here's a link to a thread on the Proton 1100.

It has a link to the service manual, but I can't tell if the link still works or not (it's blocked at work).

Proton 1100

Scott
 
Thanks Scott, but I tried that already. However, CUlater is still an active member. I just PM'ed him about getting a copy.

Cross my fingers. :thmbsp:
 
Sorry to bump an old thread, but did you guys ever get the schematics? Or better yet, is there something common that needs to be replaced?

A friend just gave me an 1100 along with a d1200 amp, but one of the channels is dead and the other goes in and out. The d1200 seems solid, so I'd like to get the pre-amp working if possible. Problem is, I'm pretty new to this world.
 
I thought I'd give this a bump. Somewhere, out there in the world, there's got to be one of these. :yes:
 
Ok, I found one. But here's the rub . . . please don't ask me for a copy. I purchased this from Rick over at Stereomanuals.com, and if I made you a copy I'd feel like I was ripping Rick off, and he's way too nice of a guy to do that to. However, the manual is inexpensive, arrives fast, and is of excellent quality. I highly recommend Rick if you need one of these.

Now I can get to work restoring mine. :thmbsp:

Artie
 
I've tried twice to order from these guys... might be a nice fellow to not very competent when it comes to having an online store.
 
H
Ok, I found one. But here's the rub . . . please don't ask me for a copy. I purchased this from Rick over at Stereomanuals.com, and if I made you a copy I'd feel like I was ripping Rick off, and he's way too nice of a guy to do that to. However, the manual is inexpensive, arrives fast, and is of excellent quality. I highly recommend Rick if you need one of these.

Now I can get to work restoring mine. :thmbsp:

Artie
Hello there, I'm not gonna ask you for a copy but can you direct me to a link to buy the right fuse replacement? I'll appreciate it. Thanks
 
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