I am working on this as part of my Pathfinder 10 thread, but I thought this deserved its own discussion.
I used the Tone Stack Calculator application to plot the frequency response of the tone stack, and compare it to those of Pathfinder 15r and an old school VOX stack. And then try to find values that could work and give a similar curve.
I do not know much about filters and plotting curves, so I would appreciate any feedback
This is the plot of a classic VOX. I tried different schematics like that of AC15c1, but the curve was very close to this one.
This is the stock pathfinder 10. The bass pot is a bit off to compensate for the extra resistor in the circuit. And yeah it's quite off...
This is pathfinder 15r. Still a bit off, but much better
This is what I am planning to do on my pathfinder 10. I tweaked it to come as close to the classic Vox curve with values that I have. I plan to do this point to point on top of the pots. I know that the pots won't track the same as the original, and the curves won't be identical, but the starting point should be close enough to give a good approximation
R4 will be replaced with a single resistor. That's why it's shown at 100%.
Any thoughts? Did I miss something?
I used the Tone Stack Calculator application to plot the frequency response of the tone stack, and compare it to those of Pathfinder 15r and an old school VOX stack. And then try to find values that could work and give a similar curve.
I do not know much about filters and plotting curves, so I would appreciate any feedback
This is the plot of a classic VOX. I tried different schematics like that of AC15c1, but the curve was very close to this one.
This is the stock pathfinder 10. The bass pot is a bit off to compensate for the extra resistor in the circuit. And yeah it's quite off...
This is pathfinder 15r. Still a bit off, but much better
This is what I am planning to do on my pathfinder 10. I tweaked it to come as close to the classic Vox curve with values that I have. I plan to do this point to point on top of the pots. I know that the pots won't track the same as the original, and the curves won't be identical, but the starting point should be close enough to give a good approximation
R4 will be replaced with a single resistor. That's why it's shown at 100%.
Any thoughts? Did I miss something?
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Not sure what you actually want; first and second are VOX tone controls, 3rd and 4th are Fender type.
If you want a 50k pots VOX type, use the original but with all values 20X lower impedance, so:
* 50k pots (your original requirement)
* 470 nF C1/C2 bass/mid caps
* R1=4k7
* R2=470 ohm
* C3=1000pF
* feed them from a low impedance,such as an Op Amp output
* load tone stack with >33k
If you want a 50k pots VOX type, use the original but with all values 20X lower impedance, so:
* 50k pots (your original requirement)
* 470 nF C1/C2 bass/mid caps
* R1=4k7
* R2=470 ohm
* C3=1000pF
* feed them from a low impedance,such as an Op Amp output
* load tone stack with >33k
I chose the schematic that matches the actual stack of each amp.
I tried it, and while the curve is ok, it appears ~3db higher. Granted, the input and output impedances are not the same on the pathfinder. But I think I got how this works. Thanks
Yep. I am moding the Pathfinder 10. The previous stage is an opamp, and the output is loaded with 100K
Similar to which of the several models mentioned?
If you want a classic VOX, with 50k pots, do this:
The "36r" is the tough part. Even an emitter follower may not get you there. It is possible it does not need to be that small. I suspect 1k would be fine.
Dear respected sir what is name of software you are using?
Or can u provide me the link of this software?
Thanks in advanace