A few side notes that I hadn't found the time to share...
*Still happy with the tone circuit that I've published above in March 2024. With the pot at 6/10, it gives an EQing extremely close to the response of a real BK Tube Driver, all controls at noon. Comparative frequency analysis below...
*Different tubes definitively make a difference... Beside the stock 12AX7, I've tried half a dozen of valves including a Pentalab, a vintage long plates Ei, a GT 12AY7 and so on... The most pleasing harmonically was the Ei... but it was incredibly gainy and the bias pot hadn't enough range to provide 6.3v to its heater... The worst was the Pentalab, albeit this tube was easier to bias and sounds good in another Tube Driver clone that I've built... 12AY7 remains my choice for the TC Tube Pilot: it's not the nicest sounding but it avoids the gain to get too high (and can be biased properly with the inner trim pot).
*I've tried a variable resistance instead of R37: a 10k in parallel with a 100k trim pot, itself in series with a 2k resistor. The whole was therefore going from 1.67k to 9.1k.
In MY case, it didn't work well at all: increasing the value of R37 made far worse the farty splatty sputtering sound typical of starved plate designs. Low resistance closest to the stock value gave the smoothest gain, whatever was the tube used.
Mileages may vary (not saying increasing R37 is a bad idea: just testifying about the fact that in one of MY Tube Pilots, it didn't work).
FWIW: sum up of a mod diary on a cheap pedal...
"Cheap trick" to smooth the tone of a TC electronic Tube Pilot...
Hi,
I saw this post and thought “ I have this pedal and hate the tone !!! “ lol
Did my first real pedal mod using an on/off/on toggle switch and two caps, .022 uf and .047 uf. The beauty of this in the off position it’s in the stock tone, if you still want that sound.
But I love the change in the sound with this pedal, to me. It’s way more usable now and the bass from my guitar is back !! Going to be using this pedal a lot more frequently now.
I saw this post and thought “ I have this pedal and hate the tone !!! “ lol
Did my first real pedal mod using an on/off/on toggle switch and two caps, .022 uf and .047 uf. The beauty of this in the off position it’s in the stock tone, if you still want that sound.
But I love the change in the sound with this pedal, to me. It’s way more usable now and the bass from my guitar is back !! Going to be using this pedal a lot more frequently now.
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Last edited by andrewj on 29 Apr 2025, 13:40, edited 1 time in total.