Matchbox Goodrich 7A Total bypass?

[Bob Snelgrove]

Can any of you gurus figure out how to have the 7A in bypass mode when off rather than disconnected?

thx

bob

[Dave Grafe]

Not clear what you mean here, bypass is by definition disconnected

[Mike Auman]

The 7A's I have worked on had a battery on/off switch so you could disconnect the battery when you're not playing, for longer battery life. None had a bypass switch for the signal. If you wanted to switch a 7A in and out of your signal chain (bypass) without unplugging the cables, it would be possible. That would just require adding another toggle switch (DPDT) and rewiring the input/output jacks to it. If you can post several good pics of the inside of your 7A, I can mark them up to show you the changes needed.

[Jack Stanton]

My 6A has a factory tone bypass

[Bob Snelgrove]

The 7A's I have worked on had a battery on/off switch so you could disconnect the battery when you're not playing, for longer battery life. None had a bypass switch for the signal. If you wanted to switch a 7A in and out of your signal chain (bypass) without unplugging the cables, it would be possible. That would just require adding another toggle switch (DPDT) and rewiring the input/output jacks to it. If you can post several good pics of the inside of your 7A, I can mark them up to show you the changes needed.

I'll take some pics. Thanks, Mike!

bob

[Bob Snelgrove]

My 6A has a factory tone bypass

Heck, I shoulda got a 6A then!

[Bob Snelgrove]

Pics

[Mike Auman]

Bob, look for a double pole double throw toggle (DPDT on/on) that's small enough to fit on the top of the enclosure, on the other side of the Input jack from the battery toggle. The green wire should just about reach, and you can shorten the orange wire. The new wires can be any color, of course. Be aware that you might hear a pop thru the amp when you switch the bypass on/off unless your volume pedal is heel-down. Unlike guitar effect pedals, the 7A wasn't designed to be switched in and out of bypass, so they didn't need to include some of the features that prevent popping.

Wiring Goodrich 7A Jacks Original.png

Wiring Goodrich 7A Bypass DPDT.png

[Bob Snelgrove]

Wow, That's awesome, Mike!

After the mod, will the battery continue to drain even in the bypass position?

Is this a good candidate:

https://www.amazon.com/mxuteuk-Terminal ... BW6XZ&th=1

Thanks

[Mike Auman]

Yep, that Amazon switch is fine.

The Battery toggle can be used to disconnect the batteries. When it's on, the circuit continues to draw current from the batteries, regardless of the position of your new Bypass toggle.

[Bob Snelgrove]

Thanks again Mike. So to be clear I'm adding the new toggle switch not replacing the existing one correct?

[Mike Auman]

Right, leave the battery switch as-is and add the bypass switch, across from it, on the top of the enclosure.

[Bob Snelgrove]

Right, leave the battery switch as-is and add the bypass switch, across from it, on the top of the enclosure.

Ok, no way to have one switch to rule them all?

[Mike Auman]

Ok, no way to have one switch to rule them all?

Sure you can, not all those who wander are lost. Measure the diameter of the enclosure hole for your existing battery switch, and find a 3DPT on/on toggle that fits the same hole size. Remove the battery toggle switch and replace it with the new 3PDT, with this wiring scheme, which is just adding the 3 battery-switch wires to the third row of 3PDT contacts. One switch now controls both bypass and power on/off. Definitely expect to hear a pop if you flip the switch with your amp on.

Wiring Goodrich 7A Bypass and Power 3PDT.png

[Bob Snelgrove]

You da Man, Mike!

I found this one but can't figure what the mounting hole (shaft size) is?

[Mike Auman]

6mm diameter hole. The 2.4 mm diameter hole to the left of it is for the anti-rotation lug on the washer, if you choose to use it.

Switch hole diameter.jpg

[Bob Snelgrove]

Thanks again, Mike

I'll measure my existing this weekend

bob