CA3080 VCA 2 Harris
This is the exact same circuit as CA3080 VCA 2 RCA, except that a brand new Harris chip is used. There has been some speculation that the chip has been improved over the years, but this test shows that the difference is neglible. Actually the Harris chip was a little noisier at full gain, but that is not statistically verified.
Noise & signal attenuation
Red = signal bleedthtrough at 0V CV. Blue = 10V CV, no signal. Green = 0V CV, no signal.
Distortion (THD+N) vs. input level
|Dynamic range||10 V CV, no signal||78 dBr A|
|0 V CV, no signal||110 dBr A|
|0 V CV, 1kHz 10 V p-p in||86 dBr A|
|0 V CV, 2 kHz 10 V p-pin||78 dBr A|
|0 V CV, 10 kHz 10 V p-pin||66 dBr A|
|Headroom (over 10V p-p)||5 dB|
|CV bleedthrough||with careful trimming||2 mV|
The Harris chip was expected to be better than the vintage RCA, but wasn't.
Very low CV bleedthrough
High signal bleedthrough at higher frequencies