Stereo crosstalk question

[3MaJ]

Hi,
I've ordered Crack a couple of days ago. By looking at how the assembly looks like, it appears to me that intertwining the input signal wires on the right side would only introduce additional stereo crosstalk. Moreover, they are not shielded and passing just next to the input transformer, whih would (at least in theory) add a subtle 50/60 Hz component (depending on the region). It's not that I'm playing smart, but do my concerns make any sense, and wouldn't it be better to separate left and right channel and use shielded wires for both? Or, even better, drill two holes just next to the potentiometer, and place the input connectors there?

[Doc B.]

I guess you would have to try it both ways and compare to be sure.

[Paul Joppa]

Both concerns are technically plausible. Another plausible concern is using AC on the heaters. In practice however, no such problems have been observed out of the hundreds of Crack amps in the field.

The wire has fairly thick insulation, so the capacitive coupling between channels will be quite small. And the weaving produces an effective twisting, which reduces magnetic coupling substantially; also the magnetic field of the power transformer is parallel to the wires rather than perpendicular, which also reduces the possible coupling.

We have in the past used input connectors near the front, and we still do this on the phono preamps where the low frequency gain is 1000 times greater than the headphone and power amps. But most customers dislike the inconvenience and appearance so we made the change many years ago to the other products.

[3MaJ]

Thanks, this makes sense. Anyway, I'll try to measure stereo crosstalk in the default configuration and post if I find anything interesting.