EHX POG2 modded with Mammoth Electronics Clickless True Bypass relay kit
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Posted: 05 April 2016 07:45 PM

Hello, I want to change the stock bypass footswitch on my lovely EHX POG2 for a soft-touch one.


I already have a Clickless True Bypass kit from Mammoth.  What I need to know are the correct leads to connect from the POG2 to the True Bypass relay. 


I opened up my POG2 and studied its footswitch.  It’s a 3PDT, and after a lot of Googling I think I have the correct labels on the 6 leads.  Here’s what the switch looks like:

My best guess is, from left to right in the first image: Input Jack, Send, 9v(?), LED(?), Output Jack, Return.  Not sure about LED and 9v.


If I’m right then I have almost everything I need to know to connect to my kit.  What I don’t know is:


1. Am I right (amirite) ? and
2. where can I find a “ground source”? My kit requires me to connect it to a ground source.


I’m throwing in some more pics of the EHX PCB in case this ground source is found elsewhere.


Edited: 05 April 2016 07:57 PM by karljam
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Posted: 03 May 2017 04:02 AM | Link to this reply (#1)

Hi I’ve been looking at the same thing
I plugged in two balanced leads. The results were different with the input pulled out!

With the the unit off I checked which of 1 to 6 were connected to ground (ie the input lead ground) and which to the input tip, with the switch in both positions. The ring on both sockets is connected to ground.

So using the 9 solder points on the pog2 switch pcb, looking at the way they were connected and using a multimeter:-

with switch in bypass
C2 is connected to C3 & ground
input tip goes to C1 is connected to C5 and output tip

with the effect on
input tip connects to C1 is connected to C2
C4 is connected to C3 and ground
C6 is connected to C5 and output tip

so from this
C1 is input
C2 effect send (gets pulled to ground during bypass)
C3 is ground
C4 is pulled to ground when the effect is on - assume this is to connect the LED to ground
C5 is output
C6 is effect return

The only thing that bothers me about this is the LED (C4) connection is just a ground connection and the LED is on the main board.

Really hope this helps

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Posted: 03 May 2017 04:35 PM | Link to this reply (#2)

Sir, you are a modern day hero.

I kept meaning to learn how to use a multimeter and I’ve had the project on my shelf for a year now. Bless you.

VanityProjekt - 03 May 2017 04:02 AM

so from this
C1 is input
C2 effect send (gets pulled to ground during bypass)
C3 is ground
C4 is pulled to ground when the effect is on - assume this is to connect the LED to ground
C5 is output
C6 is effect return

I’m looking at the Mammoth instructions, and I still can’t figure out where to connect these two things (from the Mammoth PCB):
- the positive tip of the LED
- 9v source

Any thoughts?

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Posted: 03 May 2017 04:47 PM | Link to this reply (#3)

Here’s a pic of the manual from Mammoth…

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Posted: 05 May 2017 11:30 AM | Link to this reply (#4)

I think the LED would need to have the anode(+) lead disconnected from the pog2 original board and connected to the LED point (+) on the new board. this looks pretty awkward to be honest, but possible.

The 9v positive needs to connect +9v centre pin on the incoming power. Anywhere on the board connected to this centre pin would be good.

A relay which replicated the 3pdt would be better. Most of the kits are 2pdt with led direct from the kit board.

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Posted: 06 May 2017 08:19 PM | Link to this reply (#5)

Guess I need a multimeter after all.  I will try to solve these final two puzzle pieces and report on progress (may be awhile).  Thanks loads!

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Posted: 09 June 2017 09:31 PM | Link to this reply (#6)

I’m going to try using a J175 P Channel JFET as a switch for the LED ground. They are very cheap. I’m going to put it on the led terminals on a stompville board (very similar to the mammoth one) and use it to switch the led ground connection (C4). I’ll post more when I’ve tried it.

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Posted: 10 July 2017 12:12 AM | Link to this reply (#7)

ok so I replaced the resistor before the A anode connection for the LED on the bypass board with a J175 p-channel JFET:-

a(L)——> Resistor>—circuit
C—-circuit

changes to

a(L)—->J175 SOURCE   J175 GATE—-> Circuit (the J175 replaces the resistor, the gate reacts to voltage to switch off)

J175 DRAIN——> C——> circuit (this is the ground connection of the JFET)

This made A switched ground - I connected C4 The LED ground connection to A

I took the main effect board out and ran two leads for +9v Red and 0V (-) Gnd across the other side of the board - (see pic)
C1, C2 , C5 and C6 connected as appropriate.
C3 isn’t required.

It works faultlessly and the LED comes on correctly.

Edited: 10 July 2017 12:24 AM by VanityProjekt
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