Panning for Fun.......but whats the loss???

[AllyP]

Ive been reading RGs Panning for Fun and also the What are all those parts for? articles to get some knowledge before I start modding the Shin Ei ciruit.....

The question is....

How do I work out the loss of the first pan circuit that contains the opamp with the inverting ip?

It says

"The value of the  resistor to do this is 1/loss or 3.41 * R"

Where did 3.41 come from? Surely this means that:

1/loss = 3.41 * R SOOOO loss = 1/(3.41*R)

but if R = 15k this makes the loss 0.0000195?!?!  





ALso....I cant seem to find a specific 'articles'  page on GEO.....am I just blind/stupid :wink:


Cheers,


Ally

[Nasse]

First time I saw this kind of circuit was in an old National Semiconductor Audio Handbook. If you can find that book there is whole article about such panner circuit and some maths explained. Calculating gain response is somewhat tricky, I remember. The man who invented the circuit was R.Orban or something, probaply he patented it. Maybe you can find some info about it by doing internet search.

I may be wrong, but for mixer channel pan applications you can accept some tolerances, as those are used as "tune by ear" or "what sounds good" principle anyway, and this is not "real" stereo that sounds like stereo recordings made in real room with stereo microphone pair.

But because it is very popular with mono electronic signals mixed for two-speaker stereo it is good circuit.