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Pedal Makers- Is there an easy fix for pedals that flip the phase when engaged?

john l

Silver Supporting Member
Messages
3,059
With one amp no one cares but with two it sucks. The pedal is a EHX Germanium OD. Is there a connection I can reverse to remedy this without it being out of phase when its off as well. I believe its true bypass so in theory it sounds like it should be possible. I dearly love this thing for a few things it does but good god man, the designers had to be on drugs when they put this thing into production as it was. It could have been so much better but thats probably why they combined it with the Germanium Muff pedal.
I have an AB box with a phase reverse slider switch that will fix this but it makes everything else out of phase when I flip it on. Big pain in the ass to do every time I want to use it. Help
 
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Skreddy

Silver Supporting Member
Messages
2,332
You can re-wire your AB box to function as a true-bypass loop for the EHX pedal and use it instead of the EHX to turn it on and off.
 

catalinbread

Member
Messages
2,456
Many many MANY pedals are out of phase... The human ear cannot hear the difference unless you are hear a simultaneous otherwise identical 180 reference. There are few situations this matters eg you are using a clean mix box, and then the ownness correcting phase is the domain of the mix box.
 

Agreed

Member
Messages
1,651
I guess it's just how out of phase we're talking that concerns me. How out of phase is the GE OD? From the original post here I get the impression that it really cancels out with other pedals in a nasty way?

I'd like a little more info, please, john l?
 

catalinbread

Member
Messages
2,456
I guess it's just how out of phase we're talking that concerns me. How out of phase is the GE OD? From the original post here I get the impression that it really cancels out with other pedals in a nasty way?

I'd like a little more info, please, john l?

Guess I am confused as to how it would do this if it is inline serially. Parallel would make more sense, but that is a problem ought to be solved by the unit that splitting to parallel.
 

Agreed

Member
Messages
1,651
I am guessing the key is the opening sentence "With one amp no one cares but with two it sucks."

So maybe it's just not a problem I'll likely ever run into anyway.
 

john l

Silver Supporting Member
Messages
3,059
I guess it's just how out of phase we're talking that concerns me. How out of phase is the GE OD? From the original post here I get the impression that it really cancels out with other pedals in a nasty way?

I'd like a little more info, please, john l?
As said earlier you wont find it a problem in most circumstances but in this situation its noticeable because it causes one of my amps in a wet dry set up to become out of phase with the other....which sucks.

If I were to just dump my board into both amps at once (lose the wet/dry concept) then this wouldnt be an issue since they would both have the phase reversed and therefore still be in phase with eachother. but since I do this to preserve the direct to amp sound as much as possible this really throws a wrench in the works.

As far as rewireing my ABY, I dont see how that would help as it would still flip the phase when turned on. This isnt a bypass issue.

Edit- Skreddy. At least I dont believe its a bypass issue, you guys are the experts. Also the ABY is a Radial JX2 so its a bit more complicated (and expensive) than your typical passive aby box and Id rather not mod it.
 
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Skreddy

Silver Supporting Member
Messages
2,332
As far as rewireing my ABY, I dont see how that would help as it would still flip the phase when turned on. This isnt a bypass issue.
1. Re-wire your AB box to turn it into a true bypass loop

2. Put the EHX (leaving it always on) in the loop to switch it "on" and "off." The only pedal in the loop, the EHX, will be the only pedal that is getting its phase flipped.

Yeah; it replaces the bypass function of the pedal even though the bypass of the pedal isn't the problem. But it fixes the phase of the pedal.

(Edit: it would appear the product you're using isn't intended for this function and may not be easy to mod).

The other obvious solution is to create a phase-flipping buffer and insert it in between the output of the EHX pedal and the lug of the footswitch it is currently wired to; but I figured it would be easier to mod the wires in an AB pedal than to add an active circuit component to an EHX pedal.
 

Agreed

Member
Messages
1,651
Right, thanks for the info :) I misunderstood the situation entirely because I didn't pay enough attention to the very first sentence of your post. D'oh.
 

virtualtoad

Member
Messages
83
This is a more common problem than people realize... and you're right, you only hear it with 2 amps... you can just wire up an inverter at the output, before it gets to the switch - or you can buy a product that is specifically designed to correct phase issues. I know of at least one manufacturer that makes such a product. But I don't want to spam :)

Seriously though, it can be as simple as a unity gain transistor at the output of the offending circuit.
 

walterw

Platinum Supporting Member
Messages
39,522
I guess it's just how out of phase we're talking that concerns me. How out of phase is the GE OD? From the original post here I get the impression that it really cancels out with other pedals in a nasty way?
it doesn't work that way, because it's not really phase we're talking about, it's polarity.

so the effect in question would either be 100% in polarity, or 100% out.

i know barber makes a buffer box with two outs, one of which is reversed polarity; put something like that in line with the offending pedal and put them both in a true-bypass looper, and the pair will keep absolute polarity when switched in and out.
 

john l

Silver Supporting Member
Messages
3,059
Skreddy,
Thanks very much for the help. Id love to see a wiring diagram for the AB box to TB loop conversion? Im sure I have a couple old morelys hiding in a closet or something.

Virtual Toad would you please PM me the guys info?
 

walterw

Platinum Supporting Member
Messages
39,522
i'm not affiliated with toadworks at all, so i can link this without commiting a faux pas.

it looks like their "ajax" will do the job.
 

john l

Silver Supporting Member
Messages
3,059
i'm not affiliated with toadworks at all, so i can link this without commiting a faux pas.

it looks like their "ajax" will do the job.
:jo

:rotflmao:rotflmao

Wow. Sometimes I think I need a window on my stomach so when my heads up my ass I can at least see where Im going.
 

virtualtoad

Member
Messages
83
Skreddy,
Thanks very much for the help. Id love to see a wiring diagram for the AB box to TB loop conversion? Im sure I have a couple old morelys hiding in a closet or something.

Virtual Toad would you please PM me the guys info?
This is basically what you want to do:



Vin is connected to the signal coming out of the effect circuit, Vout is the 'new' (phase corrected) output. Easy as pie, should cost all of $0.50
 

john l

Silver Supporting Member
Messages
3,059
I was hoping I dodged a bullet by saying "wiring diagram" instead of schematic but there it is in all its confusing glory staring me. Im pretty good on the symbols but alas I have no idea what thats telling me. :hide2
 

stinkfoot

Member
Messages
6,138
I'm still lost at how the pedal would throw just one of the amps 180 degrees out of phase, if it's sitting in line (feeding both amps). As has already been mentioned, lots of pedals have inverted output signals, and in an in-line scenario (regardless of if that signal is then hooked up to one or two amps) you won't hear the 180 degree phase shift. If the two amps are already out of phase, the phase shift upstream may change the sound a bit. But then the problem isn't really the inverting pedal...

A pedal that inverts the output signal will become a problem when you mix it in parallel with the dry signal, and can't turn the pedal's own dry signal off - then its (inverted) dry signal will clash with the (non-inverted) dry signal in the parallel mixer. But in a series scenario, there can't be any phase issues (at that point in the chain), as there's only one signal.

So how is this (the OP:s) setup different? You mention it being a W/D rig - is the Germanium OD sitting before or after the split to the two amps? If it sits after the split (so the inversion only happens on one amp), there might be a problem. If it sits before the split, there shouldn't be a problem. Unless something else after the split (presumably on the line to the "wet" amp) is already altering the phase. The Germanium OD inverting the signal will then turn the phase problem you already have on its head.

That's about the only thing I can think of... Naturally, sticking both the Germanium OD and another inverting pedal in a TB loop (or adding an inverting buffer stage between the circuit output and the switch in the pedal) will make the combination come out in phase with the dry signal. But before you go shopping, make sure there isn't a phase issue somewhere else in the chain. Maybe there's something else in the "wet" chain that could need a parallel mixer (with the effect set to 100% wet, of course), to stay in phase?

/Andreas
 

catalinbread

Member
Messages
2,456
This is a more common problem than people realize... and you're right, you only hear it with 2 amps... you can just wire up an inverter at the output, before it gets to the switch - or you can buy a product that is specifically designed to correct phase issues. I know of at least one manufacturer that makes such a product. But I don't want to spam :)

Seriously though, it can be as simple as a unity gain transistor at the output of the offending circuit.

Indeed. I guess it is not obvious how many amps out there invert the signal... I guess if somebody is running two amps they may have a real need for a buffer/buffer-inverter. Our SCP (old news spam) used to do this, but as far as I could tell nobody used it that way so the phased outputs went away.
 

virtualtoad

Member
Messages
83
Indeed. I guess it is not obvious how many amps out there invert the signal... I guess if somebody is running two amps they may have a real need for a buffer/buffer-inverter. Our SCP (old news spam) used to do this, but as far as I could tell nobody used it that way so the phased outputs went away.
that's a good point - it could be the amp, or even the speaker wiring... and then there's every pedal in your chain... there are a lot of points where the phase can get inverted.
 




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