CA3080 VCA 2 Harris

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

Frequency response

Test results

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

Summary

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