BrendanK wrote: Sat Nov 22, 2025 9:59 pm I feel like it's time for me to ask my every five years question of "any luck with the EHX Freedom Preamp"?

Yes? Maybe? Its re-entered the mental queue for sure.

Dr Tony Balls wrote: Sun Nov 23, 2025 10:15 am

BrendanK wrote: Sat Nov 22, 2025 9:59 pm I feel like it's time for me to ask my every five years question of "any luck with the EHX Freedom Preamp"?

Yes? Maybe? Its re-entered the mental queue for sure.

haha alright
well please put me down for one if it comes to fruition

There is a version here I might give a go this week and see if I have all the parts....doesn't seem too complicated.

https://dirtboxlayouts.blogspot.com/202 ... pedal.html

Frankie99 wrote: Sun Nov 23, 2025 8:43 pm There is a version here I might give a go this week and see if I have all the parts....doesn't seem too complicated.

https://dirtboxlayouts.blogspot.com/202 ... pedal.html

So the distinction is that is the circuit used for the "Freedom Preamp" pedal and I think some of the later Freedom amps. The circuit that has some legend swirling around behind it is the earlier version used in the Freedom amps which is all discrete components, no ICs. I have a hand-drawn schematic for one around here somewhere...just never quite got around to getting a pedal-ized one up and running.

BrendanK wrote: Sat Nov 22, 2025 9:59 pm EHX Freedom Preamp

So here's the thing...

I forget WHY we were chasing this dragon in the first place. I *think* there was rumor that a Freedom Amp was used for some Hot Snakes recordings, but I'm not sure. I also forget WHY I have it my head that the discreet component version is the one to chase. To my knowledge, the versions are:

1. The discreet version. I have a hand drawn but official looking schematic for this, but it must be incorrect. I built it up and it works as a preamp but the controls do nothing, so its just a weird dirty boost. If I had one of these amps in my presence (or even good photos of the PCB) I could trace it and generate a correct schematic but I dont.*

2. The "dirt road special" amp. This has an op-amp driven preamp with a Small Stone phaser built in.

3. The reissue "freedom amp". This has an op-amp driven preamp that is essentially the same as #2.

4. The "freedom pre-amp" pedal. This has an op-amp driven preamp that is essentially the same as #2 and #3.

I have schematics for all of them but only tried building #1 and its a dud. So unless i'm wrong (very possible) about which is the desirable version, i'm kind stumped right now. If you or anyone recall anything, lemme know.


*I have offered to take a Freedom amp in for repair, but unsure which version it is. If its the right one I can check/redraw schematics.

I gave up looking after I found the version I posted, but during my brief search I did see posts from you on other boards chasing this going back to at least 2012 lol. So I think it goes back that long.

I've got two schematics. The official hand-drawn EHX one that Dr. Balls mentioned, and another one that somebody drew up in KiCAD. No idea where I got it.

There's some differences, mostly in component values, but the connections around the "Bite" control are different also (C21 and R111 are tied to the 9V rail instead of GND?). There's a connection between R11 and C12 across the top that was washed out of the hand-drawn schematic. I always assumed it was there and was the result of a bad photocopy.

Oh interesting! That KiCad one is plenty different to the hand drawn one. I'll give it a whirl tomorrow morning and see what comes out. C21 and R111 def seem suspect to me, though.

i have one of those amps, is there something I can check on mine to see if its a good one? Mine worked but I don’t remember it ever screaming Hot Snakes or anything.

You are right - there was a Tym Guitars article (or someone associated with them), but I don’t think it was ever verified one way or another.

Yeah, I remember there being a hubub about it based on John Reis talking about it I think. I don't really know which one is the "preferred" one. I do have an old dirt road special that I'd be happy to bring down and leave with you next time I'm in the city. It can nail that hot snakes sound pretty well, but there's also some weirdness in it that if you every change anything in the signal path before it (e.g. kicking on or off another effect) the signal totally drops for a few seconds which makes it kind of unusable as is (right now at least.) I don't know.