Tube Amp Archive

Tobyk wrote: ↑Thu Sep 04, 2025 1:21 pm Will this second stage CF create as much compression and H2 as one with two stages before it?

I think not.. an earlier stage would render less compression

Will this second stage CF create as much compression and H2 as one with two stages before it?

Is this an amp project or a pedal project? It's rather easy to acquire cheap speakers and most of the old valco/supro amps weren't too complicated. If it's a pedal thing, you could also put a tiny speaker in a box with a microphone and get the real deal. Something like a spring reverb circuit would...

Yes, but I’m trying to use D3 to stop the direct signal from going backwards. Is there a way? Or is a mixing resistor the only way to do it? A speaker might have something like 10% distortion at full power. But only low order harmonics, so way different from hard clipping, which produces a lot of h...

With this wiring the diodes will act as a symmetrical (bidirectional) clipper (as used with many distortion units) to both the direct and the low-passed signal. BTW, speaker bass distortion is insignificant within its rated power. Yes, but I’m trying to use D3 to stop the direct signal from going b...

You need a significant resistance between the D3 and C3. I suspect it won't be the tone you're looking for. But then it will be an ordinary mixing resistors circuit :). I was hoping i could use D3 instead to stop the current going backwards. Guess it’s not possible then. About the tone, it’s possib...

Thanks all. I had something like this in mind, a low pass filter so that only bass frequencies gets clipped (to emulate speaker distortion). Will it work? Yes, I'm a noob..

maxkracht wrote: ↑Tue Jul 09, 2024 3:34 pm Only if you want to clip the signals you are mixing.

Yes I want to split the signal for a frequency dependant clipping, and then mix that signal back again. But I’d rather not use mixing resistor that would lower gain. So basically no signal will flow through the diode the wrong way?

Since diodes only transfer current one way, will they work well as mixing resistors?

Quick question – is it possible to use a JFET as a cold clipper? That is, the equivalent of a 100K Rp/10K Rc 12ax7? And if so, will it produce similar result on the signal? Yes, you can bias a JFET "cold" and get asymmetrical clipping. Will it sound the same as a 12AX7? Not exactly, but similar. Se...

You have a problem putting in a JFET around valve circuits with high rail and signal voltages. Max Voltage drain to source is typically is 40V at best. Could be done but protection circuitry would be a must. If you want to try a solid state cold clipper I would suggest you try LND150 which is a del...

Quick question – is it possible to use a JFET as a cold clipper? That is, the equivalent of a 100K Rp/10K Rc 12ax7? And if so, will it produce similar result to the signal?

Here’s someone who thought of it back in 2016.
A lot of broken links, but one embedded schematic survived in the post.

https://www.diystompboxes.com/smfforum/ ... c=115071.0

I think that’s the correct answer, thank you! JFETs seems to be quite similar to triodes.

Does anybody know if this ’Direct DC coupled cathode follower’ setup for compression can be done with transistors instead, with the same compression result? That is, ’direct DC coupled emitter follower’.
Was thinking of trying this for a pedal..