kahles
New member
Hi there,
this is my first build ever, I'm proud that I've got it working and want to share my experiences!
I wanted to build a case for my 19" Palmer Macht power amp, that I kept when I sold my Kemper, to be at least able to play through plugins on my 1x12" cabinet. Building an 1U box around it seemed boring and I wanted to be able plug my guitar into the front and play without having to start my computer ... then I discovered PedalPCB, decided to integrate some vintage sound and ordered a M800
The case was a bit more work than expected since my miter saw was a bit too small for the dimensions and I had a lot of ideas making it look nice
The wiring was a funny experiment, since I read that too long wires would act as antennas ...
At this point it got tricky, because I made a n00b-mistake:
I had soldered the transistors the wrong way, because I had the MMBFJ201 from PedalPCB, got some wrong schematic and thought that all TO-92 FETs are wired identically and gate has to be soldered left ...
But I found Mcknib's great document about how to build an audio probe, built one and found my mistake.
It also helped a lot for biasing the transistors which I did only by probing different points and listen. The great benefit here was, that I learned much about how this circuit works. It's funny how much distortion you can get when cranking up Q1
- but then the sound at lower gain levels gets too fuzzy ...
After at least one evening of biasing I decided that it's done:
My conclusions:
... but I will use the time waiting for my next component order by reading this pedal design guide to understand more of what I did
this is my first build ever, I'm proud that I've got it working and want to share my experiences!
I wanted to build a case for my 19" Palmer Macht power amp, that I kept when I sold my Kemper, to be at least able to play through plugins on my 1x12" cabinet. Building an 1U box around it seemed boring and I wanted to be able plug my guitar into the front and play without having to start my computer ... then I discovered PedalPCB, decided to integrate some vintage sound and ordered a M800
The case was a bit more work than expected since my miter saw was a bit too small for the dimensions and I had a lot of ideas making it look nice
The wiring was a funny experiment, since I read that too long wires would act as antennas ...
At this point it got tricky, because I made a n00b-mistake:
I had soldered the transistors the wrong way, because I had the MMBFJ201 from PedalPCB, got some wrong schematic and thought that all TO-92 FETs are wired identically and gate has to be soldered left ...
But I found Mcknib's great document about how to build an audio probe, built one and found my mistake.
It also helped a lot for biasing the transistors which I did only by probing different points and listen. The great benefit here was, that I learned much about how this circuit works. It's funny how much distortion you can get when cranking up Q1
- but then the sound at lower gain levels gets too fuzzy ...After at least one evening of biasing I decided that it's done:
My conclusions:
- I like the sound: It's vintage sounding, although it has some fuzzyness at low gain levels and when the strings ring out. When my next component order arrives, I'm going to try out J112s and MMBF5457s and see what happens.
- Despite of the long cables I'm suprised, that is produces nearly no noise - you can hardly hear, when it's turned on
- The EQ could do a bit more, but at least now it's definitively working, after I discovered that this depends on the transistor settings (I think it was Q5?)
- The effect of the presence control does nearly nothing at higher gain levels - this seems to depend on the Q6 setting ... I will investigate this further when I disassemble it for testing the new transistors
... but I will use the time waiting for my next component order by reading this pedal design guide to understand more of what I did
