Never ending passive mix

[Joechris]

This is based on NewYorkDaves general purpose mix design, but I wanted to have some stereo channels and a aux send. Could someone (ehmm...Dave :wink: ) please see if this is the right way to sum a stereo channel to one aux send without getting to much crosstalk..and what about values for those resistors?????
http://studio.pogostick.net/st.mix.jpg

jo

 

[NewYorkDave]

The formula for the mix resistors is right in the chart. Plug in the number of channels and you're done.

I would suggest adding series resistors to the aux send pots so that the minimum loss is the same as that of the panpot (6dB). This will also help to isolate the volume control from additional loading. For instance, you could use a 10K resistor in series with a 10K-audio pot for the aux send.

For the stereo channel, a better way to implement the aux send is to wire it up the same as the mono channels and use a dual pot.

The way you split up the panpot in the stereo channel will result in a pretty weird taper. There are better ways to do it. Put your ORCAD project file online somewhere and I'll redraw it to show what I'm talking about.

Lastly, why not just use 10K audio pots for the faders? The way you have it wired, the faders can only attenuate by 6dB or so.

 

[NewYorkDave]

By the way, JoeChris is referring to this:
http://electronicdave.myhosting.net/pdf/genpurposemxr.PDF

 

[NewYorkDave]

Never mind about the ORCAD file. I drew this sketch tonight while listening to the debate.

http://electronicdave.myhosting.net/miscimages/joechrismixer.gif

 

[Joechris]

Wow, thanx a lot. Kerry won the debate, and i got myself a schematic :grin: . I want to use the mixer after my Motu interface, so the 6db fader arrangement is for fine adjustments of the computer mix. I migth even make it as a 6 way rotary to get 1 db steps, to make it possible to "recall". That was the idea anyway. This is yours :guinness: if i pop by the big apple :grin:

jo