volume swell pedal

[markeprice]

Are there any plans out there for making a volume/swell pedal?  I am thinking like guitarist Steve Howe and how he swells violin style...

[markeprice]

As a follow-up, I have a Morley Wah that has a volume pedal mode, but it is too sensitive.  With barely any movement, the volume goes too low too quick.  It seems a volume swell needs a "longer throw" so to speak.  Thx

[jkokura]

A slow gear clone is coming from JMK, and that's a volume swell pedal.

Jacob

[markeprice]

I was kind of wanting one where you have to move your foot as opposed to an automated swell, but, it might be interesting....

[jkokura]

Then I think you'll need to just get a volume pedal. That's what you're asking for right? There isn't really any good DIY versions because the design is very simple, and the DIY enclosures available aren't really well suited.

If you really wanted to, you could get a Wah shell and pot and wire it up as a volume pedal instead of a wah. That's about as good as you'll get I think.

Jacob

[davent]

There's lots of guitarists adept at doing volume swells by rolling the guitar volume knob with a spare finger while they're picking. Saves the cost of a pedal and pedal board real estate.

With Cry Baby's and such, the treadle travel only covers part of the full rotation of a pot so that's going to create issues in getting a well functioning volume pedal from that enclosure. There are circuits out there such as the Jen wah/volume that do offer up a wah/volume pedal from a single unit.

Ernie Ball Volume pedals used to be had on ebay, haven't needed to look in years,  for what a beat up Cry Baby was going for.

dave

[RobA]

As a follow-up, I have a Morley Wah that has a volume pedal mode, but it is too sensitive.  With barely any movement, the volume goes too low too quick.  It seems a volume swell needs a "longer throw" so to speak.  Thx

This used to be one of my favorite things to do. I used one of the old giant Morley optical volume pedals to do it. I don't know how it compares to whichever Morley you are using, but the one I had used a piece of film between an LED and an LDR to do the volume. The film had a taper to change the amount of light that went through to the LDR. You could change the profile of the volume curve by changing the shape of the film.

There is a way you do this using a CV pedal and a little ATTiny MCU to control a vactrol based circuit that would let you setup whatever control curve you wanted. It would be a pretty simple circuit, but require a bit of programming to get it just the way you wanted.

[micromegas]

There is a way you do this using a CV pedal and a little ATTiny MCU to control a vactrol based circuit that would let you setup whatever control curve you wanted. It would be a pretty simple circuit, but require a bit of programming to get it just the way you wanted.

I use a big morley volume pedal too, but the mcu way sounds very interesting. Any more info about that?

[RobA]

I'll have to play with it a bit to see how well it works. If I an get something to work well, I'll put up some information about it and maybe a layout if I can get some time.

Of course, if you could make it be a CV controlled wah too ... hmm.

[electrosonic]

One approach would be to use a lm13700 circuit as RG outlined in his paper

"Applications of an OTA Current Controlled Amplifier" -

http://www.geofex.com/Article_Folders/VCA%20Applications.pdf



Another approach is to have a micro controller control and LDR  Its would be a little tricky to get a smooth fade in and out because the resistance of the vactrol is not linearly related to the current through it.

That Corp. has a paper on digital control of VCA's. Not the cheapest way to go - and you  need to program a micro controller.
http://www.thatcorp.com/datashts/dn02.pdf

Andrew.