Proper splitting and mixing for parallel distortions on the same pedal?

[Esppse]

Hey, I'd like to a put 3 different distortions in the same box, and have them mix together at the end.

As for the input, do I need a buffered splitter before they go to each their effect circuits or can I just simply tap all 3 to the input jack?

Same question for the output, do I need a mixer circuit or can I just solder all the outs of the distortions to the output jack?

Thanks

[PRR]

Try it.

Feeding all three inputs together often works.

Shorting all three outputs together will not work. You need a mixer. At minimum three resistors. This adds loss, and depending how the three paths sum, you may want gain after. It is hard to believe a 33:33:33 mix is exactly what you want; I would plan for a full 3-knob mixer.

[blackieNYC]

You will want a buffered splitter up front and a simple mixer combining the outputs. Since the distortions will have an output volume you won't need mixer level controls.

[Esppse]

Ah, I understand now. I just however got ambitious with its design, my plans have radicalized into a 7 distortion, all parallel to each other. So I will need to split my signal 7 times (no I'm not making horcruxes ), and a 7 channel mixer.

I've located the following layouts.

Splitter
http://tagboardeffects.blogspot.com/2014/08/amz-2-channel-splitter.html?m=1

Mixer
http://4.bp.blogspot.com/-TMi6BBdPyDs/UObo-ooAw0I/AAAAAAAAAbw/1y-_teZK2-M/s1600/4chan-mixer.png

Can these circuits be modified to bump up the channels to 7? This is where my DIY electronics experience falls short.

[marcelomd]

VFE's Triumvirate does just this.

Schematic: http://vfepedals.com/schematics/triumvirate.pdf

[marcelomd]

Also. Quadrafuzz:

[Esppse]

This was the circuit that made me want to do parallel drives, but I don't want to use it's clipping circuit. I'm using 7 other distortions of all different tones to get a massive sound. Im wondering if there could be a circuit I can make that can handle a 7 way split. I'm concerned with signal loss with this much going on. Which made me curious if there is any layout that handles such a massive replication.

[Esppse]

Ay, I actually don't know how to pull out just the splitter part of the circuit. I'm embarrassed to admit I don't read schematics, I've only just read Vero layouts and hope it works after soldering.

[Mark Hammer]

Just make sure that all circuits you want to be able to blend have the same phase relationship at output.  Used one at a time, you have the latitude to shrug and say "Inverted, shminverted.  Who cares?".  And the circuit developers have the latitude to not have to care if the output is opposite phase to the input.  But used in combination, you'll get unwanted cancellations. 

Now, it may well end up sounding interesting, but it will be at a noticeably lower output level, such that blending will be more involved than a mere tonal-flavour change, and always require adjusting overall output level.

So, assuming that all circuits involved are phase-coherent, you should be okay in using a mixing strategy as shown in the Quadrafuzz.

[Esppse]

Ah phase,

Would a simple 180 degree phase reversal switch per channel, like a standard one found on a guitar mod do the trick? Or would phase issues be somewhat less than or greater than 180 degrees, in which inverting the phase would be useless?

[marcelomd]

This was the circuit that made me want to do parallel drives, but I don't want to use it's clipping circuit. I'm using 7 other distortions of all different tones to get a massive sound. Im wondering if there could be a circuit I can make that can handle a 7 way split. I'm concerned with signal loss with this much going on. Which made me curious if there is any layout that handles such a massive replication.

I can't do a proper drawing now, but it is easy to understand. Using the Triumvirate as an example, the signal is split three ways at pin 1 of IC1. The distortion circuits would begin at C12, C2, LOW potentiometer and end at the volume potentiometers (TREBLE, MID, BASS).

[Danich_ivanov]

Ah phase,

Would a simple 180 degree phase reversal switch per channel, like a standard one found on a guitar mod do the trick? Or would phase issues be somewhat less than or greater than 180 degrees, in which inverting the phase would be useless?

Actually, I don't think that phase switch per channel will be necessary, since out of 3 effects, 2 will be in phase with each other either way, so you will need only 1. Theoretically a simple, unity gain inverting amplifier should work just fine.

[Mark Hammer]

True (and good catch!).

So, assuming you DO have one naysayer circuit, but you don't know which one...or maybe you DO want to fool around with cancellation...the most sensible strategy is to have a phase-inverting op-amp stage (unity-gain) that you can "assign" to any of the distortion outputs (pre-mixing) via a rotary switch of some sort.

One of the things that usually makes a multi-amp/multi-pedal signal sound "huger" is the very small delay between the components signals, nominally produced by two or more amps being mic'd at different distances.  Kinda makes you wonder who no one has ever made a double-drive pedal that would let you stagger the drive-tones by a couple of milliseconds.

[Esppse]

I'm about to do a layout incorporating the AMZ buffer to split the signal 7 times and ask you guys if I did it right.

On the other side, is this a suitable phase inverter?
https://www.parasitstudio.se/uploads/2/4/4/9/2449159/bufferphaseinvero.png

Since there will be 7 circuits, and if like 2 or more are out of phase, wouldn't I need more than just 1?

[Danich_ivanov]

I'm about to do a layout incorporating the AMZ buffer to split the signal 7 times and ask you guys if I did it right.

On the other side, is this a suitable phase inverter?
https://www.parasitstudio.se/uploads/2/4/4/9/2449159/bufferphaseinvero.png

Since there will be 7 circuits, and if like 2 or more are out of phase, wouldn't I need more than just 1?

7? Thought it was 3 

Sure, then you'll likely need more than that. You know what you can do, you can take this amz multi buffer, and turn each buffer into a phase splitter, then you wouldn't have to add any amplifier, nothing, just a switch for every splitter. Are you going to use jfets, opamps or bjt's?

[Esppse]

I'm about to do a layout incorporating the AMZ buffer to split the signal 7 times and ask you guys if I did it right.

On the other side, is this a suitable phase inverter?
https://www.parasitstudio.se/uploads/2/4/4/9/2449159/bufferphaseinvero.png

Since there will be 7 circuits, and if like 2 or more are out of phase, wouldn't I need more than just 1?

7? Thought it was 3 

Sure, then you'll likely need more than that. You know what you can do, you can take this amz multi buffer, and turn each buffer into a phase splitter, then you wouldn't have to add any amplifier, nothing, just a switch for every splitter. Are you going to use jfets, opamps or bjt's?

I was going to use this buffer,
http://1.bp.blogspot.com/-6nCYx7qrgXQ/USDHAdqgsTI/AAAAAAAABzE/G22l6v30leE/s1600/AMZ-Super-Buffer.png

And then shoot them into isolated transformers, and then into their 7 circuits.

As for the phase inverter, I thought that goes after the distortion? Ahhh so confused. I was going to do like a phase inverter for all of them, now I'm not so confident.

[Esppse]

Hey guys,

I just finished this layout of the Buffer and the 7 way splitter on one board, as well as I modded the 4 channel mixer to take 7 inputs, by simply adding 3 caps and 3 resistors. I'm not sure if anything component wise has to be changed on the mixer? Do you guys see any errors?

Buffer
http://1.bp.blogspot.com/-6nCYx7qrgXQ/USDHAdqgsTI/AAAAAAAABzE/G22l6v30leE/s1600/AMZ-Super-Buffer.png

Splitter (only the transformer half of schematic)
http://geofex.com/FX_images/spltr2.gif

Mixer
http://2.bp.blogspot.com/-mu5xmdE1r5g/UsVJhfhgLoI/AAAAAAAAET8/xdCd5HSDwsU/s1600/4chan-mixer-rev1.png



Is the buffer enough to drive 7 signals? I haven't taken the Phase Inverter into consideration yet.

[ElectricDruid]

What's the need for transformer isolation, given that all the circuits are in the same box on the same supply? That seems like you're making things needlessly complicated. I'd drop the transformers and go straight from the buffer op-amp's output to the inputs of the drive circuits. As to whether there's enough signal...it depends on the drive circuits. If they all provide a decent impedance, there shouldn't be a problem, but if some of them are low impedance inputs, it'll start to drag everything down.

HTH,
Tom

[Mark Hammer]

1) SEVEN distortions mixed together?  If you can even hear differences in the various combinations, I'd be very surprised.  That said, I have two units sitting awaiting final wiring-up.  One a rackmount with two banks of 6 different clipping "engines" of various kinds, selectable via a rotary switch.  The other is a stompbox with 5 different fuzzes and a clean boost, selectable via a rotary switch.  But these all provide ONE thing at a time (the rackmount provides a separate output for each bank, so they could be mixed).

Mixing a couple of voices is one thing.  But mixing 7 will be regrettable.  You'll have bragging rights, but nothing more usable than that.  So I say consider grouping all the distortions you wish to have into two "clusters", based on some common characteristic, use rotary switches to pick one from each cluster (with true bypass), and use a two-input mixer to blend them.

2) The transformers are unnecessary.  If the Quadrafuzz can simply feed 4 parallel clipping circuits, then so can you.

[Esppse]

OK I'll drop the transformers from it. Having 7 distortion doesn't mean they all will be on at the same time. Sometimes its 1, 3, 4. Or 2, 5. Or 4, 6, 7. I wanted any combination choice.

So it's just the buffer for the front end then. I still am confused where the phase inverter would go, whether in front or after distortion.

https://www.parasitstudio.se/stripboard-layouts/simple-buffer-and-phase-inverter

On the info page:
"I didn't include polarity protection, DC filtering and an output capacitor since this is meant to be used together with another effect (not stand alone)."

Is the DC filtering important if I'm throwing the inverters in?