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Those McCurdy cards were used in at least a couple of different McCurdy mixers in the mid-60s. They are the preamp units. There was a summing/output card as well which had the output transformer on it. According to the old post linked below, they appear to have been included with both the PE-2400 and PE-2600 (likely a 4 channel and 6 channel version of the same mixer) and from the pictures in the post appear to be for remote broadcast or PA use. The documentation for the PE-2600 at least appears to be floating around out there somewhere. The link to the old upload service it was posted to is dead though. Maybe someone around here stashed it away.

https://groupdiy.com/index.php?topic=41737.0

You probably won’t have much luck finding the summing/output card, but if you can get hold of the docs, you could build your own (with different iron. A Hammond 850G would probably be a good bet to get you close to the original). Assuming you can figure out the power requirements, even if you can’t find the docs it would be pretty easy to make one for each channel using an output stage design from another mixer from that era using an 850G on the tail end. Given the era, I’d bet dollars to donuts that it’s unipolar 24 or 28V.
 
A google search for PE-2600 yielded this as the first hit:

http://www.bottlegardenstudio.com/mccurdy-pe2600-console/

Pretty cool. The 2600 is a 6 channel board. The 2400 is a smaller, portable unit without sliding faders. Your PC63 preamp card is pictured below the mixer pic.

There are a couple of owners between these two links who seem to love them. You might have the building blocks for a little gem, who knows. From the post it looks like they modified theirs for direct outs, which would bypass the summing amp and go straight out, unbalanced, from these cards. As expected, the output is lower than you’d probably want.

Now that I think of it, as for the power supply, I did work on a pair of AT264 FET preamps from that same era, and they run on 48V power. This one might just use that as well.
 
I also have one summing amp and one oscillator card, but only three edge connectors.
I have a copy of the mixer manual that the cards came from.

Manual says that the cards want to see +33 DC.
From the schematic, I was able to determine the power connections and the balanced in, the rest is Greek to me.
So.....powered up a preamp and sent signal to the input using an unbalanced source and a DI.
Determined that there are two output options.
Pin 4 and the wiper of the Davin 5k pot (pin8) both have clean signal.
I am guessing that the pictures of the API meters I posted are from the original chassis.
Why I have two is a mystery, as there is only one per mixer.

Nathan
Don't know why, but I don't see the expected option to reply to your PM.

Last bit has nothing to do with selling Bruce's' gear.
A bunch of us have got together to demo and rebuild Bruce's' garage.
At almost 68, I am having a bit of a tough time keeping up with the young bucks. :-\
cheers
Roly
 
Roly said:
Nathan
Don't know why, but I don't see the expected option to reply to your PM.

Last bit has nothing to do with selling Bruce's' gear.
A bunch of us have got together to demo and rebuild Bruce's' garage.
At almost 68, I am having a bit of a tough time keeping up with the young bucks. :-\
cheers
Roly

Ill PM you my email address if thats easier. :)
 
Hi
iampoor1
Please PM me your email address.

I am poor too... :)
 
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