Mainline Balanced switch + Tube matching

[PT]

Hello,
Just finished my Mainline kit, got a few questions:

1) There is an audible difference when flicking the balanced switch when using TRS jack. There is zero audible difference when I am using 4 pin XLR, this has been verified by voltage measurement too. Should there be any? I have double checked the wiring everything, seems to be O.K.
2) What is the normal mV difference between L/R channels? I have quickly measured the voltages using 1000Hz Tone, R is 225 and L s 250mV, this was @ 300 Ohm load. This switches 180 when I swap L/R tubes, so must be tube related, right?

 

[Paul Birkeland]

1) There is an audible difference when flicking the balanced switch when using TRS jack. There is zero audible difference when I am using 4 pin XLR, this has been verified by voltage measurement too. Should there be any? I have double checked the wiring everything, seems to be O.K.

This is normal. 

2) What is the normal mV difference between L/R channels? I have quickly measured the voltages using 1000Hz Tone, R is 225 and L s 250mV, this was @ 300 Ohm load. This switches 180 when I swap L/R tubes, so must be tube related, right?

That's a difference of a bit less than 1dB.  It's quite likely that after 100 hours of use, that difference will decrease a bit.

 

[PT]

Thank you PB,

The difference was not noticed during innitial testing. The amplifier sounds fantastic. I don’t want to get into cheesy descriptions or comparisons, but it exceeds all my expectations and is the best sounding amp I have tried. And ohh I have tried a few.. ;-)