Hi, i don't know if this was done before but i made a improved version of the classic TMB tone stack making it a bit more versatile, this version has few tweaks to make the treble pot more useful and independent from the middle potentiometer, for example, the frecuency response isn't flat anymore when the mid is up and the rest at 0, now the treble can boost and roll off high frequencies. The middle control now attenuates ~25 dB compared to the 15 dB from the original circuit, also the bass control is more noticeable now thanks to the better frecuency separation from the rc filter.
How does it work?, is pretty simple, C1(the 470pF one) and R1(33k) are now two T high pass and low pass filters, this separates the highs and lows so the controls affect only the proper frequencies. R3 Bleeds the low frequencies
from the treble pot when its necessary, if the bass knob is up R3 is off so more lows and mids stay in.
It maybe good for mods because you keep the pots the same values, you just need to replace and add some resistors and caps.
I hope this can be useful to someone that doesn't like the original TMB stack 🙂, personally i think its more practical and sounds better but that's subjetive, if you try it any suggestions will be very appreciated.
Green : New
Blue : Old
How does it work?, is pretty simple, C1(the 470pF one) and R1(33k) are now two T high pass and low pass filters, this separates the highs and lows so the controls affect only the proper frequencies. R3 Bleeds the low frequencies
from the treble pot when its necessary, if the bass knob is up R3 is off so more lows and mids stay in.
It maybe good for mods because you keep the pots the same values, you just need to replace and add some resistors and caps.
I hope this can be useful to someone that doesn't like the original TMB stack 🙂, personally i think its more practical and sounds better but that's subjetive, if you try it any suggestions will be very appreciated.
Green : New
Blue : Old
Attachments
Last edited:
You have an amazing number of views for a thread with no comments, figure you deserve at least one. Looks interesting. I will give it a try once I get back to building this winter. How lossy is the stack? What impedance is it diven at. 4ok as a regular gain stage or 1k as a cathode follower?
hey! thanks man, is not lossy at all it works pretty much like the original stack, i tested it at 1k but at higher z to 5k works as well, anyway i'd rather use a cathode follower than a gain stage to drive it
Last edited:
> i'd rather use a cathode follower
Yes. The input impedance goes quite low (toward 15k) at the top of the audio band, so feeding it from a plate will be "dark".
Yes. The input impedance goes quite low (toward 15k) at the top of the audio band, so feeding it from a plate will be "dark".
Building this into an amp yesterday. Pretty darned cool. Would love to discuss a few options if you have the time.