5f1: Noise danger with adding 5f2a tone control near input?

[lwgramith]

Hey all, this is my first post, but I've been around the forum as a viewer for a while.

I recently built a Mojotone 5f1 Champ kit, with some of the standard modifications -- switchable cathode bypass capacitors, variable NFB, etc. It worked well on start up, and I'm really liking the tones I'm getting with my Strat, but I've noticed that it's a bit darker than I'd like with my 339, especially when I have to turn it down a bit at night. It looks like the easiest way to brighten it up would be to add either a bright cap or a 5f2a-type tone control. I tried out the tone control today with alligator clips and found that it worked very well, with much greater flexibility than the fixed bright cap. But my problem is this: given the small chassis and the other modifications I made, the only location I can fit a tone pot is between the volume knob and the second input. It's not ideal aesthetically, but I'm more worried about potential noise problems. The pot will fit, but just barely. It would essentially be located within a millimeter or two of my preferred input. Currently the amp has no noise/hum problems at all, and I'm hoping to keep it that way. Is placing a tone pot/control so close to the input likely to cause noise problems? My first thought is that it should be fine given that there will be no DC on the pot and the AC signal will be relatively weak at that point, having only passed through one gain stage, but I may be mistaken. Just wanted to check with some more experienced builders before I drill an irreversible hole.

Thanks. Looking forward to hearing your thoughts.

[sluckey]

I would remove one input jack and put the tone pot in the vacant hole.

[lwgramith]

Thanks, sluckey. That's a much better solution -- and reversible. If I'm not mistaken, I should be able to replicate the sound of 5f1's input 1 (in the two-input system) by using a single input with a 34k grid stopper. Can anyone confirm?

[sluckey]

yes