Substituting Mini Adjustable Bias Pot with a full size CTS Bias pot

[Clear Guy]

I am rebuilding a Princeton Reverb reissue from the ground up using the Hoffman AA1164 turret board. I would to use the full size 10kl CTS bias pot that is already in the my PRRI instead of the mini bias pot that mounts up on the board. I am wounding if it would be better to solder and run all the wiring from underneath the board to the pot instead of on top? Anybody done this already? Best way to do this?

[mresistor]

You could run underneath the board, but if you do, strip the wires a little longer than usual and bring the wire all the way up to the top of the turrets and bend a little down over the top. so that the wire won't fall out later on after the board is in the amp.
I've thought about doing the exact same thing, but haven't done it yet. The plus side is you can mount the pot so that you can access it without taking out the chassis. It would also be wise to put 1 ohm reisistors on the cathodes of your power tubes and run wires to some test terminals to also monitor cathode current externally. Still need to know HV too for bias. Or just use a bias tool.

[Paul1453]

+1 for mresistor's suggestion.

I personally like the bias adjustment and test points easily accessible without having to disassemble the amp. 

I have done this, not on this exact same build, but I will continue to modify my fixed bias builds in this fashion.   

[Clear Guy]

"You could run underneath the board, but if you do, strip the wires a little longer than usual and bring the wire all the way up to the top of the turrets and bend a little down over the top."
Thank you for the replies. I will do that extra step to bring the stripped wire all the way through the turret and over.

"It would also be wise to put 1 ohm reisistors on the cathodes of your power tubes and run wires to some test terminals to also monitor cathode current externally."
I usually just use the my old Weber Biasrite I have used for years with good results. I would like to add the bias test point jacks to this build just for the convenience. 

Any need to twist the 3 wires together or run them in a certain way as to not add any hum/noise/interference???

[Paul1453]

Twisting wires should not be necessary. IMO

This part of the circuit isn't AC, and is relatively low voltage/low current.   

[hesamadman]

I dont believe it would hurt to do this but it isnt a high current or even ac voltage so I doubt you would get any interference.

[Clear Guy]

Sounds good I will just zip tie them to keep them neat. Thx for all the replies from everyone. This forum is priceless!!!