Please help! - Theremini MIDI problem

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Gordon Charlton
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Please help! - Theremini MIDI problem

Post by Gordon Charlton » Thu Aug 13, 2015 7:11 am

I am giving a talk about the theremini at Lydia Kavina's Hands Off 2015 on the 26th of September, and I would like to demonstrate the use of an Eowave USB MIDI Expression Pedal with aTheremini.

( http://www.eowave.com/instruments.php?prod=52 )

I am not a MIDI expert, but after much head-scratching and documentation scrutinising I have configured the pedal to send CC 74 to Channel 1 with values between 0 and 127, which I believe from the theremini manual should vary the filter cut off frequency. I have connected the USB MIDI expression pedal to the Theremini via a powered USB hub. Operating the pedal appears to have no effect on presets that use a filter. :-(

Please can anyone suggest what I may be doing wrong, and how I can make it work. I would very much like to resolve this problem in good time for my presentation.
Check out my theremin videos on my youtube channel.

synthguy
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Re: Please help! - Theremini MIDI problem

Post by synthguy » Thu Aug 13, 2015 11:42 am

Hi Gordon:
Nice to see you again!
The Theremini and your Midi pedal are both "slave" type devices, and need a Midi host to get them to talk directly to each other. 74 is the correct CC for the filter cutoff.
Since you have an IPad, that's a good way to start. Output of the powered hub into the IPad through the CCK adapter, and Theremini and Eowave Into the hub inputs. Thay may get things rolling right there,

But....

Midi on IOS can be difficult at times, and you'll find that an app like Midibridge can be REALLY useful in seeing what's on line and hooking them together in any way you want. Otherwise it's a bit of a crapshoot as to what happens between devices. It's a bit more expensive than some apps, but it has an incredible amount of functionality if you're going to really work with Midi, and a very easy to use graphical interface to allow you to see ( and control) connections on the IPad.

Miditoolbox is another very useful app, as it has an event monitor to show Midi data as it happens (very useful for troubleshooting) and a sysex librarian (I use this to backup preset data for my effects devices and Midi pedals).

I hope this gets you rolling! Best of luck at the conference!

Cheers,

Synthguy
Visit my synthblog...Moogs and more!
Www.synthguy.com

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Gordon Charlton
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Re: Please help! - Theremini MIDI problem

Post by Gordon Charlton » Thu Aug 13, 2015 2:41 pm

I have done as you suggested and it all checked out ok, so I checked the configuration of the eowave, and it had reverted to cc code 1. I found some other forums where people had the same problem, and no solution was forthcoming.

I have MidiBridge and Miditoolbox (possibly on your advice, I remember that someone suggested them.) and have stared at them several times with a look of incomprehension and bewilderment. Miditoolbox has a Japanese manual, which doesn't help.

I think MidiBridge might provide a solution. Is it possible for it to receive a CC1 from the eowave and transmit a CC74 to the theremini? If so, how? (Yes, I know there is an English manual, but I have a pesky neurological disorder and this is exactly the sort of stuff that makes my brain collapse in a soggy heap.)
Check out my theremin videos on my youtube channel.

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Gordon Charlton
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Re: Please help! - Theremini MIDI problem

Post by Gordon Charlton » Thu Aug 13, 2015 5:51 pm

Update. Turns out it is within my intellectual capacity, and I'm a glutton for punishment. :-/

So after some brain melt, idle poking around found the "Holy Mapper" in MidiBridge. Does exactly what it says on the tin - maps control codes onto other control codes. (Also channels and other stuff.)

Happy!

:-)
Check out my theremin videos on my youtube channel.

synthguy
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Joined: Wed Sep 17, 2014 7:37 pm

Re: Please help! - Theremini MIDI problem

Post by synthguy » Sat Aug 15, 2015 11:41 am

Hi Gordon:
Glad you got it sorted out! That's a very interesting problem...I'm surprised that the Eowave company hasn't been forthcoming about fixing such an obvious problem. This is one of those things that the monitor on Midi Tool Box can be really helpful with.

Here's an english manual..
http://mtb.artteknika.com/help/en/index.html
The developer for Midi Tool Box has been very helpful. I was having trouble using the Sysex Librarian to save preset data with my Midi Pedals, and he upgraded the program to allow me to slow down the data transfer rate so these older devices could deal with it without freaking out. I love it when a plan comes together!

If you set the I/O settings so that the input is looking at your Eowave pedal, and then select the event monitor page, it will show the Midi stream as you move the pedal up and down...the CC number, the Midi value, and the Midi channel. The CC# would show up as 1, and there would be the culprit. Does it revert once it's powered down, or just at random? An annoying problem, and congrats to you for isolating it!



I remember there being talk from one of the members at another forum (Rick?) about getting the Behringer pedal and the second party upgrade chip to do extended Midi control. This might be a good avenue if you're thinking about really getting under the hood of the Theremini for some of those excellent and unusual compositions of yours.

We moved last year, and I've finally gotten around to getting my music room going. I'm basing a lot of the operation around the IPad, and getting Midi sorted so I can integrate my various toys is always a nagging problem. I just bought a decent USB hub, and am currently trying to figure the best way to get everything to play nice together. It can be a challenge :mrgreen:

Cheers!
Visit my synthblog...Moogs and more!
Www.synthguy.com

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Gordon Charlton
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Re: Please help! - Theremini MIDI problem

Post by Gordon Charlton » Sat Aug 15, 2015 4:37 pm

I get the impression that customer support is not one of eowave's strengths.

Thank you for the manual link. I've put it right next to the app for instant access.

The pedal reverts consistently. One day I'll discover the raw MIDI to reconfigure it from my iPad. Until then I'm am happy for MidiBridge to intervene - it's a way to change the functionality fairly easily while playing, if not ideal. I've got a slider app (TouchOSC) sat in a folder waiting until I am 1 confident enough with MIDI and 2 familiar enough with the theremini to know what functionality I want, and then I'll build me Some UIs that fit my needs (i.e. just the controls I need for a piece of music, to minimise the time I spend tapping a screen rather than playing the instrument.

I like simplicity. Which is largely why I have avoided MIDI and mostly stuck with straight forward guitar pedals on my etherwave. Sometimes though, simplicity can be a complicated thing to achieve.

One of my long term projects is an Envelope Pedal, an ultra-low profile push-switch plate (it needs to be ridiculously thin so it feels no different to tapping the floor) that triggers note-off and note-on portions of an envelope generator modulating the volume of an incoming audio signal on contact and release (i.e. the reverse of a keyboard key), and also outputs MIDI note events and a CV gate to control other devices so I can get proper staccato notes out of my theremins.
Check out my theremin videos on my youtube channel.

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