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Messages - ampetrosillo

#1
I have found the following design on the 'net:

http://xipix.de/elektro/gimos50.html

It looks interesting, although very unfamiliar to me: it's a soft clipping power amp with, by what I read, low global feedback, current feedback and (therefore) high output impedance. It looks very well suited to guitar duties, although I'm not an expert (I can find my way around preamps and I can also design them, but I'm not familiar with power amps).

I've tried deciphering the schematic, but as I said, a lot is unfamiliar to me: the input stage isn't the common differential pair and kinda looks like an output stage? Also, it employs MOSFETs while most of the things I've read up on employ BJT transistors (there shouldn't be much difference though, MOSFETs are biased similarly to bipolar transistors, with the difference that the gate is basically electrically isolated).

Could you please walk me through it and explain to me if and where it can be improved upon?
#2
Amplifier Discussion / Re: Remote channel/FX switch
October 22, 2021, 05:12:29 AM
A digital pot would also require digital circuitry (a microcontroller, even a simple PIC chip, etc.), if I could do without digital circuitry it would probably be better (easier to shield, no interference, etc. mine is just a hobby project), but with some help on best practices I suppose it could be done.
#3
Amplifier Discussion / Remote channel/FX switch
October 20, 2021, 10:51:02 AM
I'd like to implement a clean/dirty channel switch for my design, and also a vibrato/reverb on-off switch. I'm using DG419 parts (nice and reliable, clean if a bit fast, etc.) for switching, although I could use simple relays as well (but the cost and complexity is basically the same, with the added bonus that the DG part is solid state, therefore potentially more reliable) and I'd like to be able to both operate the switch from the panel and via a footswitch. Are there any schematics you could point me to? Secondly, I'd actually like to have a remote reverb mixer (as well as the panel-mounted one), this screams VCA of course, but what would you suggest?