Pitch Bending amped harmonica with a handheld expression pedal

[dominico]

Coincidental Timing with Brendan's Midi Pitch Bender,

I've been working on some handheld experiments for changing the pitch of amped harmonica:
Here's a quick demo video:
https://youtu.be/oQarDqO116U

The most straightforward way to do this is to use something like a digitech whammy or other pitch shifting pedal, but I wanted something I could hold in my hand for more fine grained control than my foot.
While in the middle of that I came across a "digital whammy bar" meant for guitar, but as you can see in the video it works just fine for harmonica as well. In the video I have it set to be able to bend a whole tone down and a perfect fourth up. This thing, while working well for both the guitar and the harmonica gives me confidence to continue building my handheld expression controllers for pedals that take expression input.

What I need now is to design and print some good way to mount the things to my mic.

In a similar vein...
I've also started building my own handheld momentary switches to add pedals like pitch shifters or octave pedals or harmonizers into the chain only when the button is pushed. These will make for some cool effect opportunities when I get them working as I expect. Once I get something worth showing I'll post it here. I already made a working "poor man's" version of the Digitech "Hammer On" Pedal using a cheap Donner Octaver pedal and a momentary switch, so I know I'm on the right track.

[dominico]

Screenshot_20251221_131730_Gallery.jpg

I redesigned my mount to make it work for multiple controls.

I also created a circuit to emulate what "pinch harmonics" would sound like if you could do them on a harmonica.

Here's a video of them in action (music style is hard rock / metal) https://youtu.be/oaFg7HUKr_k?si=SYL49f-WD97FGBUH

[Brendan]

Sorry, just saw this. Ingenious Domenick! And very effective too, especially the digital whammy. The bent notes (certainly in that amped setting) sound similar to the normal notes and bends.

I guess it only works where the amplified signal is all that's heard via the speaker and headphones, as the acoustic note will still be sounding and will be a different pitch to the bend? Without headphones that could be quite disconcerting I guess!

From your description and demo, I gather there are two types of bend available: one down and one up. Each can be set to a certain pitch. You have chosen a tone down and a fourth up, but they could be other degrees?

Regarding the whammy bar, if you only move it a small way, do you get a small degree of bend? I assume so. That could open up a possible approach to get more bends.

What would be nice is to be able to get stable bends of different degrees. Depending on what note you are in the scale, a 2 semitone bend won't always be appropriate. Would it be possible to make some kind of selective device for that whammy bar so it only bends 1, 2, or 3 semitones?

I'm doing something like that with my PS2 joystick on the DM48X Midi harmonica. I have two buttons attached to probes that push the joystick by different amounts, giving different degrees of stable bend.

I did it also with three probes on a Chinese Midi harmonica with the PS2 joystick incorporated in it, the HM12. (I have some photos on my PC, will post shortly).

It could be tricky to adapt for your whammy bar, but might stimulate some other idea.

Or maybe you could do it electronically, with some kind of current selector that limits the digital bend itself to different degrees. Set it to three semitones down but then have a couple of other buttons that, when pressed, stop the bend at 1 or 2 semitones instead, even though the whammy bar still moves as normal. Just speculating, because I'm not an expert in this stuff.