Hey guys! This might be the wrong place for this, but I figured it got the most traffic on the forum. I'm putting this up on my Perf & PCB blog today and thought I'd share it with you guys too. Anyway, I got an EQD Bellows late last year and traced it. It's fairly simple, but it sound really good (really tho, what EQD box hasn't sounded awesome?). First the guts:
A lot of what's on the board is for the relay bypass switching. Didn't trace that as it would pretty pointless without the code for the PIC, but for the actual effect circuit, here's the schematic:
I breadboarded this and built it on perf using a J201 in place of the PF5102 and it worked well.
I had the same reaction when I traced it. Checked it like 5 times and then breadboarded it to make sure I hadn't lost my mind. I'm no EE (who I'm sure would immediately know what it's there for), but I assume it acts similarly to a diode (think Bazz Fuss), but with completely different tonal characteristics. All I know is it works. haha
I tried this out on the breadboard (first using a J201, then a few different 2N5457s), and whilst it does work it is quite gate-y and has a peculiar, "stepped" cut-off that is particularly noticeable at lower gain.
Ok, good to know, might go and try some other JFETs then. In the meantime, I stuck an LPB-1 in front of it which pretty much resolved the gateyness and turned it into a ridiculous gain beast, but a rat filter on the end helps tame the extra noise.
Just built this today with a BF245B and it sounds amazing. As others have mentioned, at low gain it sounds a little gated and flat but not too badly. It's a bit like when you roll the input off on an Acapulco Gold.
It's so nice having such great results from a quick little circuit like this after the disappointment of building a superfuzz yesterday and finding it too squishy and weak. This is the perfect antidote and it slays with DAM Red Rooster in front of it, cranked.
Thanks for the layout storyboardist, you've made my day
Definitely verified. I had to audition a lot of JFETs to get it to work properly. None of my 2457, 2458, or 201s would work properly but others have apparently got theirs to work. Once I used an MPF4393 and it sprang to life and sounds great.
Hi all, I know it might not be relevant but I don't know where else to post this : I've just done my first vero layout from storyboardist's schem (which I added here too). Tried to make it compact. Could anyone more experienced tell me if I got something wrong ?
Also, what would we need to do to get the Bellows posted to the "main" site face, since the OP's layout seems to be working ?
I personally would change the opacity of the 22n and 68n caps to show the cut underneath. It may seem obvious to us but the less opportunity for someone to ask questions the better.
storyboardist left off the power filter cap on his schematic. You can see it in the photo under the DC socket. While it's not necessary for a working effect...I would add some filtering to any of my layouts as you've no idea what kind of power supply a potential builder may use. Again...removing the opportunity for questions.