Building and standalone Clean blend splitter with phase inverter and clean boost

Started by yebar16037, July 16, 2023, 04:56:57 AM

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yebar16037

Hey guys, I wanted to add a clean blend to the Green Lemon by PCB Mania, but I got quite confused about my options here. 🔍 I checked most of the Clean blend-splitter circuits available as PCB but seems that most of them have issues related to Phase inverting, clean signal volume, or noise.

So I took a look at some circuits I really like which feature a clean blend, such as JHS Moonshine and Darkglass b3k series and I noticed that all these circuits start with a Buffer before splitting the signal. Is this really necessary? 🤔 would you recommend adding it?

Then I was thinking of adding a toggle for inverting the phase of the clean signal so I can mix it with some other pedals I want to as a standalone clean blend pedal. Somehow I thought this would be better than adding it on the dirt signal... but that's just my guess, I'd love if someone with deeper knowledge could give me his 2 cents on the topic.

Some other thought I had in my head regarding this project is the signal output levels, I'm a bit afraid the clean signal would be too weak compared to the output of the Drirve section. thought about adding some Opamp section to boost the volume, maybe with an internal trimmer as a volume control. maybe also a switch to bypass this section if needed.

I'm attaching here the schematic I have so far and the stuff I used as inspiration. 👀📄👇

https://ibb.co/VYtHk25

Hope you guys can bring some clarity to this
Crafting sonic wonders at DIY Stompboxes, where passion and creativity fuse into musical art!

bluebunny

Welcome!

I've moved your thread into the main "building" area.  Seems more appropriate.  Expect more replies shortly...   :)
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Ohm's Law - much like Coles Law, but with less cabbage...

garcho

QuoteI checked most of the Clean blend-splitter circuits available as PCB but seems that most of them have issues related to Phase inverting, clean signal volume, or noise.

There is practically nothing simpler to design/build. If people are selling PCBs that have those problems, the people reporting said problems have either miffed up their build or the person selling them is a crook. I'm going for number 1.

QuoteI noticed that all these circuits start with a Buffer before splitting the signal. Is this really necessary?

Yes.

QuoteThen I was thinking of adding a toggle for inverting the phase of the clean signal so I can mix it with some other pedals I want to as a standalone clean blend pedal. Somehow I thought this would be better than adding it on the dirt signal...

The chances of your signal passing through other guitar pedals' circuitry without changing phase are small. That being said, if you want this option, you can just build a non-inverting buffer. Buffers don't need to be inverting, in fact, in this case, being the initial circuitry after your pickups, it would be better to have non-inverting anyway, for the ease of high input impedance with less noise.

Quote...the signal output levels, I'm a bit afraid the clean signal would be too weak compared to the output of the Drirve section. thought about adding some Opamp section to boost the volume, maybe with an internal trimmer as a volume control. maybe also a switch to bypass this section if needed

I would just build a whole separate pedal that's a non-inverting buffer with two outputs, each with an outboard volume control. The volume control could be an inverting op amp, followed by another inverting buffer. Then you could have a switch for phase that taps either output (before or after the inverting buffer). You could also include returns if you need to combine the signals for an amplifier with a single input. I bet you'll find having something like that handy for more than one reason, as opposed to build in to a dirt pedal.
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"...and weird on top!"

idy

I also do not see a split/blend PCB out there that has:
A phase switch
a built in boost. And I think boost is a good idea when mixing with distortion.

Yes you need a buffer.

I don't think it matters whether you invert phase of clean or distortion side. (I think you have the + and - inputs reversed on your phase inverter opamp on the schematic you linked to.)

I think the best approach is a separate pedal, a splitter/blender, with your distortion and a clean boost in the effect loops. Then you can use any distortion pedal, or all of them.

https://www.sabrotone.com/request-rog-splitter-blend/

is a strip board layout that has splitter/blender with phase switch, from the ROG schematic.
http://www.runoffgroove.com/splitter-blend.html


m_charles

If you hit my profile, then past posts, I asked a similar question and with everyone's help came up with a neat simple circuit based off an old design. Check it out.

John Lyons

Basic Audio Pedals
www.basicaudio.net/