Two interesting effects :
Aion's Beta Preamp with toggles to swap between Bass and Guitar modes.
https://aionfx.com/app/files/docs/beta_preamp_documentation.pdfI'm glad I could manage to fit these two extra switches, both settings are great with a very noticeable change in the tone and the EQ controls.


There was something wrong with the Treble control. A 10k resistor between the Treble pot lug3 and the pcb pad solved it.
Guyatone PS-024 Distortion H
https://dirtboxlayouts.blogspot.com/2021/10/guyatone-ps-024-distortion-h.htmlA simplified clone of DEFX Hive. I was curious about the 5-bands EQ chip.
First time using a pre-painted enclosure. I think i like it...but it's a bit too simple. I added a piece of veroboard to make it a bit more suited to my tastes.


Here is a demo, I hope you'll be able to hear the EQ's action :
https://soundcloud.com/ehlabas-ma-chaussure/ps-024At 2:15' I tried the circuit with different transistors and ICs, but I am not sure there's a real difference. I've still added the sound clip in the demo, just to hear how little is the variation (RC4558P & BC550C vs. MC1458 & 2N3904).
Never tried an HM-2 before, but I don't think the PS-24 is very close to the HM-2's sounds. I'd say there is a more traditional "DOD 250" character in the PS-24. It's not as metal-oriented as the HM-2.
The EQ sounds like it is only boosting some frequencies. At first I thought the flat position was 12', but when all EQ controls are fully CCW, it sounds good, like flat distortion. Only downside is that we can't cut some frequencies from the flat distorted sound, EQ controls has to be set somewhere CW, to be able to dial down one of them, and cut some frequencies from the signal.
That's why I don't think it's as effective as a GE-7, which can increase or decrease the volume of the frequencies, even when starting from flat settings.
As comparison, I'd say it feels like a GE-7 with sliders that can only go up...
Edit : If I understand correctly the datasheet, it looks like M5226P is able to cut frequencies, +10db or -10db. I guess it means the flat EQ setting is 12'.
https://html.alldatasheet.com/html-pdf/140262/MITSUBISHI/M5226P/1809/3/M5226P.html