Volume pedal parts question

dogload

I have a Schaller Fusschweller volume pedal which after giving sterling service for the last 30 years has suddenly stopped doing nicely sweeping swells and become an elaborate on/off switch.

I'm guessing (after taking it to pieces and cleaning and tightening everything) that it is a fault with the pot, although it doesn't crackle at all.

So, the question is, can I replace the pot with a wah pot, or does it need a different kind of taper? A quick look online has so far returned only replacement pots for Ernie Ball volume pedals.

randomhandclaps

I would say no as a general rule but it could depend.  Volume pedals (tend to) use log pots whereas wahs will be linear.  Can you post a picture of the pot you are looking to replace?

dogload

Thanks for the reply @randomhandclaps. I thought that might be the case... I'll get a picture sorted later

dogload

Here's a couple of pics. The pot value is 100k. The shaft and cog look a bit odd.

randomhandclaps

Is the cog removable?

dogload

I can't tell. I'm going to have to leave it for now- I've got a meeting to go to

I'll check it out, but it doesn't seem to be clamped on like a regular wah and it doesn't fee like it will just pull off too easily... I'm hoping it's not some kind of strange moulding. I'll have to have a proper go at it tomorrow. 

ICBM

You can replace it with a standard Dunlop wah pot, because they're also 100K Lin. The best is the Hot Potz II, although it's expensive. They come with the pinion already fitted, and I'm pretty sure they fit the Schaller rack.

Unless you're running it after some kind of buffer you may want to think about increasing the value though, 100K is quite tone-sucking as a volume pot in a passive pedal. 500K would probably be best.

But before you do anything, try squeezing the two rivets on the outer terminals *hard* onto the track-board with a pair of fairly narrow-nose pliers. On-off-switch taper could be caused by the contact between one of them and the track having come loose or got a bit of corrosion in it.

dogload

Thanks @ICBM. You think it could be that simple? I'll check it out tomorrow (left it at work as I get time to do these things there!). 

As far as buffers go, it comes after a Tonebender clone, MicroPOG and Boss CS-2 compressor so presumably that should be OK, no?

ICBM

dogload said:

Thanks @ICBM. You think it could be that simple? I'll check it out tomorrow (left it at work as I get time to do these things there!).

Not a certainty but not impossible either, although it would rely on the wiper touching the rivet at the end of the track for it to be so. If it goes full > off > off > off > off, it will be the terminal which the input wire goes to; if it goes full > very very slightly quieter > very slightly quieter > slightly quieter > off it will be the one at the ground end.

Or it could be a cracked resistance track at the same places - and if the 'switch' is somewhere in the middle it's a certainty - in which case the pot is dead.

dogload said:

As far as buffers go, it comes after a Tonebender clone, MicroPOG and Boss CS-2 compressor so presumably that should be OK, no?

Yes, the CS-2 is a good enough buffer.

I have one of these too, but I never much used it, so when my old Jen Cry Baby casing cracked at the treadle pivot I rebuilt the Schaller as a wah using the Jen circuit board. Very cool, although the jacks being the wrong way round is slightly annoying!

dogload

@ICBM thanks for the advice. Sadly the patient is not responding to treatment, so it looks like a replacement pot is in order. I suppose I shouldn't complain- replacing a moving part after 30 years of use... I wish my car was that unreliable!

So a regular wah pot should do it? Out of innterest, and considering that there is a buffer, if I up the pot value to 250k will it make any difference?

ICBM

dogload said:

So a regular wah pot should do it? Out of innterest, and considering that there is a buffer, if I up the pot value to 250k will it make any difference?

No. Just use the best 100K pot you can, which is the Hot Potz II.

dogload

Cool. Thanks for the help