API 312 input and output transformers

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Consul

Well-known member
Joined
Jun 3, 2004
Messages
1,653
Location
Port Huron, Michigan, USA
I am building a pair of API 312s which will utilize the Melcor 1731 op amp. My dilemma right now, though, is that I was unable to get in on the necessary group buys at the time to obtain the input and output trafos I need to complete this project. In fact, I don't even know what brand or kind of transformers are needed. Is there anyone who can fill me in on this and where to get them?

Thank you all for your help!
 
Hi Darren,

Check with Tommytones about the output transformers - he coordinated the group buy. Maybe he has some extras. I have no idea how long it could be before there are 2622 replacements. Hopefully not too long, but I guess we'll have to see.
 
Jensen makes the output.
They even might have an input also.

I got the api link back up, had a little glitch at my site.
Click on UTC and then api:
http://www.vacuumbrain.com
cj
 
You could use the Jensen 110K or the 115K on the input and pick one of the many 1:2 ratio output transformers from their list. I have a 123-ALCF (1:3) for low impedance load testing.
 
everyone's taste is different, but I'd try to find a 1:7 input, Ive used a jensen 1:10 and didnt like it at all, but api uses a jensen 1:10 in the 3124, so go figure...

dave
 
Yes they make a lot of bi-filar wound line outputs that will work, anywhere from 66.7 to 600:600 ohms, in 50 or 80 nickel.

Look in the line output section.

http://www.comtran.com/

cj
 
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