Any DIY pedal builders on TB? Strut your stuff!

[NNNN]

@Passinwind @jw23mind @Luke the Fluke Thanks for the responses. I've been playing around with parallel pedals and I was curious about the differences. One pedal uses a LPF loop and a HPF loop, and another uses tilt EQ knobs to do it. Both sets of controls give similar results, but I also noticed that I leave the LPF and Tilt knobs untouched for my "low end" pedal, since it has its own tone knob that gets rid of the high frequencies.

Regardless, sounds like they all function differently! Here's a followup question: where tone knobs are concerned, they all seem to roll off the high frequencies (on a pedal, passive bass, etc). Is there a simple "reverse" tone circuit that rolls of the lows? A different cap value or a reverse pot?

 

[davelowell2]

Yes, one example is G&L L-1000. I think some guitars also, maybe?

 

[agedhorse]

This seems like as good a place as any to ask:
Is there a big difference behind the scenes between a tone knob, a LPF, and the left half of a tilt/EQ knob?

Good question.

Yes, there are generally very significant technical differences BUT the marketing folks and those who are not educated in filter topologies tend to mis-describe them to the point that it's absolutely confusing.

A HPF and LPF are types of shelving filters (not to be confused with shelving EQ's), they will have a -3dB cutoff defined frequency (except for constant power summing HPF's and LPF's which are generally Linkowitz Riley type and specified at -6dB because the voltage is squared in the power equation), a Q at the corner and a slope. These can be 6, 12, 18, 24 (or even higher) dB/octave rolloff slopes. The frequency can be variable but often not.

A low-high tone control is typically based on a Baxandall filter topology, always 6dB/octave and has a flat section in the middle, a corner, a 6dB slope but will generally plateau 12-18dB away from the corner. The amplitude is variable but how the corner frequency is specified is totally not standard so comparing between brands is almost worthless. As the amplitude of boost or cut is changed the effective corner frequency shifts as a byproduct. These filters can be active or passive surrounded by active circuitry.

A tilt EQ is generally 6dB/octave and the easiest way to visualize it is like rotating the bass control clockwise while simultaneously rotating the treble control counter-clockwise on a conventional Baxandall EQ for tilt in one direction and vis-versa for tilt in the other direction. It's kind of a quick and dirty tone control except that the effect can be a useful creative tool.

A mid eq is any type of peak-dip bandpass filter that will always have a variable amplitude but may also have a variable frequency and Q. There are many ways to execute a mid eq circuit, there are state variable topologies, there are multiple feedback topologies, there are gyrator topologies, there are even LC topologies (a gyrator is a simulated inductor)

All of these filters have phase shift characteristics associated with them. Those marketing dudes that claim their eq's have no phase shift are making things up (obvious once you solve the equations)

There are also simpler filters and combinations of simple filter elements (which can become quite complex), the best example of this is the Fender tone stack.

 

[NNNN]

Thanks @agedhorse that's super helpful

 

[Passinwind]

Nothing some of us haven't seen before, but a contributor to my open source preamp project is using JLCPCB to provide very inexpensive fiberglass fascia plates:

View attachment 5014932

Since his version already uses a PCB from JLC it makes for a pretty convenient printed graphics solution, although since everything else is sourced from Tayda he also could've just had them do a direct UV print.

And here's my first take on this project that came from @Tassieviking's awesome work, using a pre-drilled Tayda case that they UV printed for me as well:

All on one inexpensive circuit board from JLCPCB, through-hole parts mostly or all sourced from Tayda, and a very quick and easy DIY build. Details will be posted on Github soon: GitHub - Passinwind/PW3B-LPF: Open Source Filter Preamps for Bass, Guitar, Mandolin, and other musical instruments

And the more uptown WTHPF version, also open source but not so beginner friendly since there are quite a few surface mount parts and three separate modules to wire up:

 

[disssa]

Peavey Centurion Preamplifier:

 

[mdalamond]

I’m not sure if I’ve posted this build before.
I had some PCBs made from a schematic drawn by someone known to me as M. Chittum on another forum.
It sounded very close to the demos I’ve heard but something just wasn’t quite right. It always sounded too fizzy to me and the blend had the dry overpowering the effect.
I am a little OCD and probably have spent more time and effort trying to get it to sound exact more than anyone would probably care to know.
I have spent countless hours and literally years on it.
I know it’s mostly just a modified Superfuzz and some think it’s nothing special and it has a horrible blend circuit. I don’t care, remember the OCD thing, lol. I had to find that sound.
Well I recently and FINALLY acquired an original, that also took years. Now I could hear them against each other , one on one.
As suspected, the clone didn’t quite match up. Definitely way to fizzy and the blend sucked. I spent some time to confirm the schematic and it was good.
In the end after some more poking and prodding I finally cured my OCD and have made an EXACT sounding copy. There are a few tweaks here and there , I did not use the suggested germanium diodes. I guess some had them and some didn’t, my original doesn’t.
I did use the original 2N3707 transistors and styrene caps, though I’m not really sure the styrene caps have anything to do with the results they look cool.
For those who have built this before , I used a 220k for the blend resistor. At the end of the day I’m very happy with the results. My OCD has been put to rest on this one. It’s kinda bitter sweet. Like the coyote catching the road runner, now what are ya gonna do.
Have a great weekend,
Matt

 

[crguti]

To all DIY pedal builders.... I need (mainly) to read smd capacitance values of the order of 1pF.
Can someone recommend me a very good LCR Meter for reading small capacitance values?
Cheers.

 

[G.Bisson]

Here's my latest set from PedalPCB.
From left to right:
Kid painted Gadget fuzz, similar to ZVex Machine.
Gerkin fuzz, similar to Swollen Pickle.
Sherwood overdrive, similar to EQD Westwood.
Caesar chorus, similar to Walrus Julia.
Gravitation reverb, similar to EQD Levitation.
Fat Piggy "bacon fat" overdrive, similar to Pigtronix bass fat drive. Thanks to @karter2000 for posting bass specs.

Fat Piggy and Caesar are my top picks of this group.

 

[disssa]

Pearce BC1 clone:

 

[Passinwind]

Here's my latest set from PedalPCB.
From left to right:
Kid painted Gadget fuzz, similar to ZVex Machine.
Gerkin fuzz, similar to Swollen Pickle.
Sherwood overdrive, similar to EQD Westwood.
Caesar chorus, similar to Walrus Julia.
Gravitation reverb, similar to EQD Levitation.
Fat Piggy "bacon fat" overdrive, similar to Pigtronix bass fat drive. Thanks to @karter2000 for posting bass specs.

Fat Piggy and Caesar are my top picks of this group.
View attachment 5072718

Cool, I won a gift certificate over there in one of their frequent contests and just ordered my first couple of their boards. I went with guitar oriented designs for this first go round, figuring it would be a lot easier to flip them if they don’t make the cut for my own guitar usage. Went for a Klone and a Dumble amp in a box, both rather basic builds that could probably be modded for bass pretty easily.

 

[AudioTaper]

Here's my latest set from PedalPCB.
From left to right:
Kid painted Gadget fuzz, similar to ZVex Machine.
Gerkin fuzz, similar to Swollen Pickle.
Sherwood overdrive, similar to EQD Westwood.
Caesar chorus, similar to Walrus Julia.
Gravitation reverb, similar to EQD Levitation.
Fat Piggy "bacon fat" overdrive, similar to Pigtronix bass fat drive. Thanks to @karter2000 for posting bass specs.

Fat Piggy and Caesar are my top picks of this group.
View attachment 5072718

One of these days I'll remember to order the rest of the parts for my Caesar

 

[MoireBass]

Pearce BC1 clone:

A Pearce clone? That's very extremely interesting, more info please. Is this a kit, a project you designed yourself, etc.? What about a B2p preamp?

 

[MoireBass]

Inspired by this thread and @johnk_10 version I recreated the preamp of the Peavey Century Version A:

I already built version B:
View attachment 5042483

Cool. I thought the Century with the quasi-parametric was the best-sounding Peavey amp for bass, still have one in the closet as an emergency backup.

 

[disssa]

A Pearce clone? That's very extremely interesting, more info please. Is this a kit, a project you designed yourself, etc.? What about a B2p preamp?

It is not a kit. I used the schematics to create a pcb-layout.
I can't find any schematics from the B2P.

 

[disssa]

1:1 comparison with the original:

 

[disssa]

Can someone provide me with the schematics of the Pearce B2P?

 

[J Posega]

Considering how nearly-unobtainable they are, it would be cool to see someone to create a pedal inspired by the 3Leaf Audio Doom 2.

 

[MoireBass]

It is not a kit. I used the schematics to create a pcb-layout.
I can't find any schematics from the B2P.

Beautiful work, very impressive. And none of that uber-annoying surface mount!!

Does the BC1 use the same long-out-of-production and very-expensive-on-gray-market transconductance op amps that the B2p did? That's a CA3280 for crunch and a CA3080 for limiting, by Intersil and Harris.

If you did have the B2p schematics and board layouts, hypothetically, could you create a new version of the B2p preamp, maybe with a couple of minor improvements?

 

[johnk_10]

Pearce BC1 clone:
View attachment 5090951

View attachment 5090952

beautiful very, very nice work!