HELP! Diptrace - First try at PCB layout
- Thread starter Blooze
- Start date
Blooze
Well-known member
@Chuck D. Bones
I breadboarded this using a TL072 (didn’t have an LM4558) and it works no problems other than it was pretty gated and barely made unity volume . Changed the 470k resistor to a 330k and that solved it the gating but smoothed it out a bit more than I like. I put an LPB1 before it (liked it better than after) and that took care of any volume issues but it’s noisy. Needs some tweaks for noise as I didn’t do any real supply filtering.
I breadboarded this using a TL072 (didn’t have an LM4558) and it works no problems other than it was pretty gated and barely made unity volume . Changed the 470k resistor to a 330k and that solved it the gating but smoothed it out a bit more than I like. I put an LPB1 before it (liked it better than after) and that took care of any volume issues but it’s noisy. Needs some tweaks for noise as I didn’t do any real supply filtering.
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Blooze
Well-known member
Finally put in a 4558 and that fixed everything. All the low slew rate chips I put in work fine. A pretty nice distortion and no need for the LPB1 at that point. I've added some asymmetrical clipping between pins 6-7 (two red LED and a Bat41) and that helped rough it up a bit more. Looking for more buzzsaw sound though yet so I'll try adding diodes in parallel with the 470k feedback loop too. I tried hard clipping right before the output but didn't care for it as much. I've noticed this is the predecessor to the Black Cat OD-1.
Noticed that once I start adding diodes, all I need is a tone control and I'm most the way to a Cream Puff Fuzz.
Edit. Tried all different combos of diodes on the feedback loops and although I could get a slight fuzz the pick attack was atrociously clanky. Ended up with two red LEDs to ground on the output, changed the input resistor from 22k to 100k, and the feedback resistor fro pin 2-1 to 390k. I’m done. It pushes my Vibrochamp into compression with the volume knob on the amp at 3 or more. Doesn’t sound half bad for a distortion.
Noticed that once I start adding diodes, all I need is a tone control and I'm most the way to a Cream Puff Fuzz.
Edit. Tried all different combos of diodes on the feedback loops and although I could get a slight fuzz the pick attack was atrociously clanky. Ended up with two red LEDs to ground on the output, changed the input resistor from 22k to 100k, and the feedback resistor fro pin 2-1 to 390k. I’m done. It pushes my Vibrochamp into compression with the volume knob on the amp at 3 or more. Doesn’t sound half bad for a distortion.
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Bricksnbeatles
Member known well
Speaking of DipTrace— does anyone know of a good parts library for the mini rotary switches?
jimilee
Well-known member
Seems like thee is one on this forum somewhere.
@JamieJ pointed me to this thread and it has been really helpful so far! Thanks to all!
Question for @Grubb: You mentioned pads alignment to match the pedalpcb breakout boards.
Any reason why you don't PCB mount the 3PDT OR for that matter I've seen other layouts where they don't PCB mount the IO jacks? Is there some concern to PCB mount these?
Question for @Grubb: You mentioned pads alignment to match the pedalpcb breakout boards.
Any reason why you don't PCB mount the 3PDT OR for that matter I've seen other layouts where they don't PCB mount the IO jacks? Is there some concern to PCB mount these?
Grubb
Well-known member
Firstly welcome! You will no doubt learn a lot here, as I have.
There's no real concern for mounting I/O hardware or other things on the board, it's just that the more items on the PCB, the harder it is to get a good layout with simple routing and short traces. 3PDT switches are taller than standard potentiometers, so if you board mount the 3PDT on the same PCB as the pots, you need to get pots with longer legs or wire them offboard, which defeats the purpose. It's easier to have the 3PDT on its own board, or wire it old school.
Having a somewhat modular, offboard approach allows you to substitute other parts when you can't get your preferred items. Recently, that has been handy. It's more flexible, rather than designing for a specific part, which may drop off the market.
Also the modular approach allows me to go between my own parts and boards and anything I want to get from PedalPCB. Like my recent Stinger pedal in the build reports section, which has a PPCB main circuit but my own LED footswitch board.
But don't let us stop you if that's the way you want to go, it can be done if you put the time into getting the internal design of the pedal right.
Grubb
Well-known member
Did you find this? I imported the part recently into my own library and am happy to send it to you if you still need it. It took a lot more internet ability than normal to find a working pattern on this part for some reason.
Bricksnbeatles
Member known well
No, I didn’t! It would be great if you could send it to me. Thanks!
bilisnegra13
Member
Hey.. im searching also for a mini rotary switch library... Would you mind to share with me your file? Thanks in advance
Blooze
Well-known member
To expand on adding a BMP tone control and diode protection. Here is what I have so far. I know it could be infinitely smaller I'm sure. I have the tone pot mounted down and the Bite/Level up to form a triangle.
