Lead length

[hesamadman]

I'm doing a build that I've done before, however this is going to be a combo amp so the tubes are placed on the bottom lip of the chassis onstage of the top of the chassis. The chassis I have been using is 10" in depth. When this was a head style build, my tube sockets were mounted on the chassis only about an inch or 2 away from the circuit board. On the combo style of the same build, my tube sockets are about 5" away from the circuit board. I was wondering if this distance would give me any fits. If I should take any precautions for this. Also my signal exits the first half of the triode and hits the preamp volume knob. That one lead alone is probably going to be every bit of 12" by the time it bends down from the socket to go under the board and comes back up to hit the pot. Would a shielded cable be necessary for this? Is any precaution necessary?

[PRR]

I would worry more about the weaker signal coming *back* from that Volume pot.

I'd rather see less than 5 inches, but I've seen much longer work.

[hesamadman]

I would worry more about the weaker signal coming *back* from that Volume pot.

I'd rather see less than 5 inches, but I've seen much longer work.

Once the signal leaves the volume pot it only has to go an inch or so to contact it's place on the board.

[vibrolax]

I always use shielded cable between front panel controls and tube grids, because the grids are high impedance nodes.  I connect the shield to a ground terminal at the source end, e.g. the volume control ground.  The shield is not connected at the other end.   I don't use shielded cable from a plate coupling cap connection.

Jon

[hesamadman]

I got it all together. I used shielded for that long run. It's as quite as any amp can be in my house with bad grounding. Ha