Transformer balanced output for modular synth

Hello,

I have two transformer balanced output modules ripped out of an old mixer that I want to use in my oakley modular, but I would like some final and hopefully simple help.

Here is the schematic:
http://www.robomatique.com/robert/diy/eelalineamp.jpg

I though of building a simple mixer in front of it, would this section work
in front of the above module (I might leave out the DC filtering electrolytics):
http://www.robomatique.com/robert/diy/mixer.gif

Important question:
Would it handle the modular signal levels (10 volt peak to peak)?

Non important but would be nice questions:
Could I easily add a "distortion" led to it in a simple way?

Anything else that seems really stupid of me :roll:

Thanks for any help on this!!!

Robert

Would it handle the modular signal levels (10 volt peak to peak)?

Click to expand...

Both the passive summing network and the output amp can easely handle 10 Vpp. Note however that the summing network has several dB loss, which means that your output well be pretty weak.

To lower the loss, you could change R1 to 1 meg. For full compensation you'd need to change the gain of IC1/2 or IC1/1.

However, there is a simpler solution: remove R1, R2 and IC1/2--this will get you a nice active summer. R3 may need adjustment for suitable gain (higher values give more gain).

Samuel

[quote author="robomatique"]Hello,

I have two transformer balanced output modules ripped out of an old mixer that I want to use in my oakley modular, but I would like some final and hopefully simple help.

Here is the schematic:
http://www.robomatique.com/robert/diy/eelalineamp.jpg
[/quote]

Hmm, hadn't seen this before, why all the bother of both neg & pos feedback in this circuit ?
Just thinking out loud, looks like circuit gain is increased as loading increases (because of the different output- attachments of the neg & pos feedback networks), so probably they went for some counteracting a dropping output-signal.

The non-ground connection of the node C3-C4-TX-prim is also interesting, OK, why not.


Regards,

Peter