Ever seen this happen?

Slimbert

I bought an MXR Phase 100 a few weeks back. Lovely seller and no reason at all to suspect foul play.

Anyway, finally plugged it in today and discovered that the speed control made no difference to the sound. In fact, there was hardly any "phase" sound going on at all until the speed control knob was turned fully clockwise when the pedal did exactly as expected and made a very fast wobbly phase pedal noise. This is also the only time the intensity control would alter the sound.

Long story short...I took the pedal apart and discovered this...

https://imgur.com/gallery/O9bx3

BluesyDave

So that'll be money back or the cost of a repair then?

ICBM

"It just stopped working."




Any possibility it could be shipping damage? If a lot of force was applied to the top of the knob it might do that.

If not it was like that before it went in the box...

tampaxboo

am generally not a fan of board mounting pots and switches for this reason. pcb material is brittle stuff. ryvita is supple in comparison. very unforgiving to any bending, so the idea of having the entire board hanging off a component inside the box is stupid design.
easier to mass-build maybe, but easier to break.

they are also a major pita to replace of they go wrong. if a pot or switch is offboard you can just snip it off and put another one in. five minute job.
but if it's welded to the board like a silver barnacle, forget it. you may be able to replace the component eventuallly, but you will probably trash the tracks in the process, particularly in the era of multiple layer pcbs.

if you are not sending it back, chop that board away and reinstall a 470k into the enclosure hole and off the board. if you need to wedge the board to keep that from moving around inside you can do that another way. pcb pins or clips.

Funkfingers

ICBM said:

If a lot of force was applied to the top of the knob it might do that.

A direct hit to the control knob in the same orientation as the pot shaft would do it. 

How well was the pedal packaged for shipping? 

Slimbert

Gut feeling is Royal Mail.

The reason I haven't used till now is I've been in hospital for ages. It literally came out of the box, was added to my board, and worked as stated above.

There's an irony because it's on the very bottom left corner of my board and the reason I've been in hospital is that I've had my left leg amputated. I've only turned it on using my fingers!

Any ideas what this would cost to fix? I've never needed a pedal fixing before!

ICBM

tampaxboo said:

am generally not a fan of board mounting pots and switches for this reason. pcb material is brittle stuff. ryvita is supple in comparison. very unforgiving to any bending, so the idea of having the entire board hanging off a component inside the box is stupid design.
easier to mass-build maybe, but easier to break.

That kind of damage can happen just as easily to a chassis-mounted pot, if it has been caused by force.

tampaxboo said:

they are also a major pita to replace of they go wrong. if a pot or switch is offboard you can just snip it off and put another one in. five minute job.

but if it's welded to the board like a silver barnacle, forget it. you may be able to replace the component eventuallly, but you will probably trash the tracks in the process, particularly in the era of multiple layer pcbs.

if you are not sending it back, chop that board away and reinstall a 470k into the enclosure hole and off the board. if you need to wedge the board to keep that from moving around inside you can do that another way. pcb pins or clips.

Or alternatively you can just replace it properly.

The easiest way is to cut the component legs so the bulk of it can be removed and then the pins can be unsoldered one at a time without damaging the board. Clean up the holes and then fit the new component. No need to bodge it unless you can't get one that fits.

Slimbert

Funkfingers said:

ICBM said:

If a lot of force was applied to the top of the knob it might do that.

How well was the pedal packaged for shipping? 

Fairly well but not bomb proof.

Still think it was RM.

Ball park 200 ish pedals delivered to me over the years and this is the first bad'un...I'm not complaining too much!

ICBM

Slimbert said:

Any ideas what this would cost to fix? I've never needed a pedal fixing before!

Probably £20-£30 to have it done properly.

tampaxboo

ICBM said:

The easiest way is to cut the component legs so the bulk of it can be removed and then the pins can be unsoldered one at a time without damaging the board. Clean up the holes and then fit the new component.

definitely do this. that is like a 'rite de passage' pedal building hack.

i still remember the day i worked that out. i had stupidly soldered a 12pin rotary switch (like the one in pic above) to the wrong side of a board and was slightly panicking about how to deal with it.
eventually i worked out that if i got a fat pair of molegrips and crushed the whole thing (later learned flicking up side metal tabs is a more elegant way to do this), then plucked out the 12 pins like fleas one by one, it might cost me a £2 switch but save an otherwise decent pedal that had taken me a lot of effort to build.

but another reason i hate PCB mounted. i need idiot-proof.

ICBM

tampaxboo said:

definitely do this. that is like a 'rite de passage' pedal building hack.

i still remember the day i worked that out. i had stupidly soldered a 12pin rotary switch (like the one in pic above) to the wrong side of a board and was slightly panicking about how to deal with it.
eventually i worked out that if i got a fat pair of molegrips and crushed the whole thing, then plucked out the 12 pins like fleas one by one, it might cost me a £2 switch but save an otherwise decent pedal that had taken me a lot of effort to build.

but another reason i hate PCB mounted. i need idiot-proof.

It's no reason to hate PCB - it's a really good way of building stuff, very consistent and actually pretty damage-proof once it's all assembled. I agree that the weak point is often how semi-offboard components are mounted though.

For what it's worth, it's a pain in the bum to have to crunch a perfectly good chip up because you've soldered it in the wrong way round… guess how I know that . Better than risking damaging the board though.

tampaxboo

ICBM said:

For what it's worth, it's a pain in the bum to have to crunch a perfectly good chip up because you've soldered it in the wrong way round… guess how I know that . Better than risking damaging the board though.

would definitely put the 'sad' in a SAD1024. imagine that. you would need counselling after.

Slimbert

ICBM said:

Slimbert said:

Any ideas what this would cost to fix? I've never needed a pedal fixing before!

Probably £20-£30 to have it done properly.

Anyone on the forum known for doing repairs like this?

I know some of the pedal builders on the forum but have no idea who does repairs. I'd rather keep it "Fretboard" than go outside...it's dark and scary out there!!

ICBM

tampaxboo said:

would definitely put the 'sad' in a SAD1024. imagine that. you would need counselling after.

lol - at that point replacing the rest of the pedal might have seemed the lesser evil .

Luckily it was just an op-amp…

Slimbert said:

Anyone on the forum known for doing repairs like this?

I know some of the pedal builders on the forum but have no idea who does repairs. I'd rather keep it "Fretboard" than go outside...it's dark and scary out there!!

There are several of us who could do it by post, but since that's probably the cause of the trouble in the first place (and for a heavy pedal like a Phase 100 might not be that cheap) it's probably best to find someone local.

Slimbert

Found a local bloke who's confident he can sort it. Quoted £20-£30 all in which means it's worth saving from the bin.

Seller has asked me to keep him up to speed.