Angry Charles - or "Perturbed Charles"

[BurntFingers]

I installed a copy of EAGLE, which is what Robert uses to design the boards here. Having trouble getting started. For now, I want to use it to draw schematics, but will do board layouts eventually.

R12, is the one you want to reduce to permit more Bass boost. You can easily go down to 4.7K or even further. It should have very little effect on the mids. Fattening up C11 and C12 won't hurt either.

Pedalpcb use diptrace. We had an email discussion last week where this came up.

I use eagle though. First thing you have to do is download the madbean library for parts. No other library (gauss Markov) is correct for our kind of stuff.

 

[HamishR]

Hey EB - just tried this pedal out with gain and mids on full and yes, there is a whistling sound. Doesn't bother me because I don't use it anywhere near like that but if you do you will have a problem!

 

[Elijah-Baley]

It's the second veroboard layout that got in this issue. In case I will build this or the other layout the oscillation could be a problem, I mean I don't like this kind of limitations. I always want a pedal that works in any setting.
I think this is the usual problem caused by the input and output track too much close. I'm not so expert, but in your layout I see that the output pass next to the the input stripe for a bit: the jumper coming from the pin 1 of the OPA2134 goes to the stripe under the input strip.
I see how hard could be move the parts, but maybe a little bit we could do, if somebody want to try before me. Probably I'm not going to build this pedal too soon.

1. I'd say that we could cut the track of the input wire just after the 1M, and not near the 2.2uF cap. This is the most fast and simple thing I can think. And maybe HamishR can try it, if he want. It's enough to add a cut track.
2. Or, if this is not enough and we want to move some parts, we could try to turn away a bit more the input signal from the output signal moving the input wire and the bottom side of the 22nF and the 1M one stripe above, and cut the track on the left side of the 100uF cap.
In this moment I can't think something better than this, and we can't know if this will work fine or just a bit better until somebody will try it.

 

[Chuck D. Bones]

What schematic editor does pedalpcb use?

Hi I was wondering what editor you use to create your schematics. Looks great and clear. Cheers

forum.pedalpcb.com

In this thread pedalpcb said he uses diptrace.

Thanks for clearing that up, my bad. I'll check out diptrace.

 

[HamishR]

Hey EB - just cut the input trace right next to the 1M. Actually I drilled a hole from the top because it's too much hassle to pull everything apart again! So I drilled a hole just for you and guess what? The whistle is still there.

I'm not really fussed about this. I've had amps which howled if I turned everything on 10 but that's not how I use them usually so I don't worry about it. I understand your point but it's only an issue to me if it affects my enjoyment of the pedal - and in this case it really doesn't at all. I kinda work with the limitations of vero. I don't know if this is a result of the vero layout or whether it's a design issue - does the original pedal have this quirk?

 

[Elijah-Baley]

Indeed, I'm wondering if even the origianl pedal has this issue, but I don't know, it will be strange.
Now we know that an hole next that 1M doesn't work.
I don't know, maybe even a hole to the left of the 2.2k resistor, upper side. This will not make so in contact that two stripes.
For a more massime mod we could try to move even this 2.2k resistor on the column 6, of course moving the cut track on the downer side of that 2.2k resistor, too. I know it's a bit difficult explain this with words.

Anyway, all these moving is an attempt to keep a bit off the input track signal from other "gainy" or louder track signal.

 

[Elijah-Baley]

Thank you HamisR for sent me the project file.

I tried to make the movement I told early. The target was to take away the input track from the close Middle pot track, assuming that could give some annoying about the oscillation/squeal this effect gets with mid and gain at max, or at extreme setting.

- Looking at the original layout in the previous page I moved the input wire one stripe above, and of course I moved the 22nF input cap and the 1M pulldown resistor, too. And added a cut track to disconnect them from the 100uF negative side.
- I moved the 2.2k resistor coming from the Mid 1 to the column 6, and placed the cut track on the right just close the 6.8k. (Maybe we can place it just next to the 2.2k itself for better result?)
I added a cut track in J4, it's not necessary because it separates nothing, but this just make the stripe shorter and keep the signal further far away from the input signal.

This new layout is still UNVERIFIED, this means it probably will work like the original one by HamishR, but we don't know if has solved the oscillation/squeal problem.
Maybe we could move even other parts, but the thing will be a bit difficult, especially without to build it another one.

I still never built none layout version of this effect. But I hope our effort will worth.