Swapping Tone Stacks

[jhawk]

I'm trying to piece together some Fender amp schematics to make an amp I want. Can I put a blackface twin reverb tone stack (treble, middle, bass) in place of the single tone knob on a brownface princeton or deluxe? I imagine I may have to experiment with cap values and such to make it work, but will a new tone stack dramatically change the tone/character of the amp? i.e. will it still sound like a brownface?

[xtian]

I replaced a single knob tone control in an Ampeg Reverberocket with a Treble/Bass stack from AA164 Princeton. Sounded great. But was a much lossier stack than the original, so I had to steal a gain stage from the reverb driver to make it up.

[jhawk]

I replaced a single knob tone control in an Ampeg Reverberocket with a Treble/Bass stack from AA164 Princeton. Sounded great. But was a much lossier stack than the original, so I had to steal a gain stage from the reverb driver to make it up.

Ahhh makes sense. Still sounded like an Ampeg though?

[xtian]

I have no idea, having never heard one before. Owner and I both hated the stock sound which was really, really mid forward. Fender tone stack made it sound much, much better. And yes, I tried the amp thru different speaker cabs.

[rock_mumbles]

If you take a 6G2 Princeton and keep the tremolo you'll end up with a really, really clean amp if you add a TMB tone control ... basically you are building a (AA964) blackface Princeton with a mid control ...

If you want the amp to have some dirt, the TMB tone control needs a gain recovery stage after it to recover the signal loss through the tone control ... the cathodyne PI needs a gain stage before it for PI gain ... so you really need four triodes for the preamp and PI ...

In the cathode biased non-Reverb Princeton I built put an interstage attenuator between the second and third triodes (reverb send/return location) to control the dirt in the amp ...

[printer2]

I built a cathodyne cathode biased amp that used parallel triodes up front going into a tweed tone control. I also added a switch to bring in a BF tone stack but knew with only three triodes it is shy on gain. I ran the signal after the stack into one of the input triodes and came up with a sort of Princeton Reverb but without the reverb. More than enough gain for my tastes.

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