Metal Muff top boost issue

fabien

Good evening people,

I bought a used metal muff that only works when a pedal is pluged in the FX loop return, it also works when send and return are pluged... So, no FX loop = no metal muff!

It sounds like black magic to me, what do you think?

The amp is a wonderful sounding Orange #4

Schuss

Fabien

AntonHunter

The pedal only works when something else is plugged into the FX loop of the amp? Like it doesn't turn on otherwise? That's baffling.

fabien

Exactly Monsieur! I read post on this forum saying that this pedal could be a pain, so...baffling, black magic? Maybe I will try to find someone to fix it.

ICBM

Is it powered from the same power supply as the pedal in the loop?

fabien

Yes, a cheap one.

thermionic

Failing/dirty contacts on the switching part of the fx loop sockets?

ICBM

fabien said:

Yes, a cheap one.

I think you've got some sort of problem with the power supply, or possibly the EH pedal - it sounds like it needs the ground path completed via the amp in order for the pedal to work. It could be as simple as a broken solder connection on the socket in the pedal.

Can you reconnect it the other way round, with the supply cable that goes to the pedal in the loop (we know the ground connection is OK on that one) connected to the EH? If so and it still doesn't work, I think the fault is in the EH pedal.

fabien

Good evening ICBM,

Thank you for helping, as usual!

Still doesn't work.

The metal muff also works when another pedal is plugged to it. It's not so bad... Is that a ground issue?

ICBM

Can you give the full signal chain?

I’m assuming guitar > Metal Muff > amp input, and (other pedal with nothing connected to its input) > amp FX return, with both pedals on the same power supply, but if that’s not correct I might be starting from the wrong place…

Does the Metal Muff also take a battery?

fabien

The signal chain is guitar > Metal Muff > any other pedal >amp, doesn't matter if the FX loop is used, I was wrong in the first post...

It works with another pedal, so it's fine for me. I use the Metal Muff only to play with a friend sometimes when I quickly need a clean tone, like in Seasons In The Abyss for instance.

Otherwise I only need the boosted gain from the Orange amp, much more pleasant to my ears!

So, thank you everybody!

Fabien

ICBM

Yes, I'm now fairly sure that it's the negative (ground) connection from the power supply to the Metal Muff which is the problem - quite likely the power socket in the pedal itself, either a broken solder connection on the PCB, or the centre pin is not making a good contact with the tab that goes to the PCB.

So when used on its own, it won't power up - but when there's another pedal on the same power supply which is connected to the Metal Muff via the signal cables, the negative connection is made via the grounds of those cables. If you simply unplug the output cable from the Metal Muff and the LED goes out, that more or less confirms it. It should be fairly straightforward to fix if you need it done.

fabien

Thanks ICBM, I will give it a try!