CV, mux'es and op amps.

 I am working hard to select the appropriate mux and op amp to use for my CV multiplexer.

As stated in previous posts, the OB6 uses a combination of TL062 and 74HCT4051, very common components. When using these (or actually TL072) on my breadboard I see tiny dips of around 30mV-50mV every time the cap is recharged.

I've tried various op amps for buffering the DAC, different buffer op amps and different mux'es. None perform significantly better than what I have now (on my Saleae scope that is). 

Here is a list of what I've tried:

Muxes:

DG4051

CD4051 (worse)

DAC buffer op amps:

TLV9352 

AD711     

OPA2137

TLC071

CV Buffer op amps:

LT1014

TL062

The only thing I have yet to try is the 8ch DAC used by the OB6. It supposedly does not require a buffer.

This is the config I'm going for:

DAC feeding into a 2x gain TL072 op amp using two 10k resistors that feeds a CD74HCT4051 through a 470R resistor. 

The CV buffer is a TL072 with a 1nF C0G cap.