New York Dave Summing Mixer

[Robby]

Hi,
I try to build a NYD summing mixer.
I am a newbie in this area. I built passive eqs and SSL clone comps but never summing circuits.

In the circuit from NYD he uses 5kA dual input pots. But these pots are hard to find.

Is it possible to use 10kA dual pots?
Would these pots change the input impedance?

I hope you can help! ;-)

Best
Robby

 

[ruffrecords]

NYD's designs are neatly optimised. The two x 5K pots set the inout impedance at about 10K which is ideal for line bridging. You could change them to 10K and that would increase the input impedance to around 20K - not a problem.

However, the rest of the circuit would need to be altered to take account of this. Basically you need to double the values of the bus feed resistors so they do not excessively load the input pots. The bottom line is this will result in 6dB of extra attenuation of the signal so yu will need 6dB more make up gain and the noise will be 6dB higher.

Cheers

ian