+4 -10 with Feedback Circuit

[pittsburgh]

  Anyone have a circuit design for a +4/-10 and -10/+4 w/ feedback circuit? Trying to integrate a Revoxx B77 1/4" reel machine into my DAW.

  Thanks.

  -P

 

[pstamler]

Is your +4 coming from a transformer or transformerless circuit?

Meanwhile, here's a -10dBV unbalanced > +4dBu balanced circuit:

http://www.stlecd.org/hold/dublinv3.bmp

The opamps can be the two halves of an OPA2132 or an LT1469. If you want to drive a 5k or greater balanced load, either will work; if you want to drive a 600 ohm load, probably you'd be better off with the LT1469.

This works as long as you can promise that Pin 3 will never be shorted to ground -- for example, by an improper XLR-1/4" adapter cable. With that one proviso, this will be an excellent converter circuit.

Peace,
Paul