Analog volume controlled via midi?

[progmr]

Wondering if it is possible to build a simple solution to controll the volume of a normal analog signal via midi?  

What I'd imagine is a potometer that is controlled via midi 0 - 127 messages.

I have no clue if such a product exists or if it can be built.  If it can be done can you please provide how?

Thanks!

LJ in VA

[The Tone God]

I belive such products do exsist but I can't think of any off the top of my head. A good web search will turn somthing up.

You can build one but considering your asking these questions I doubt you have the neccessary skills to do it. Its not a matter of a couple of wires to a pot. We're talking microcontroller stuff here. Not too much DIY MIDI is disscussed here since it is generally above the average pedal DIYer. There are forums that have people that play with DIY MIDI. Once again a nice search could help out.

Andrew

[loscha]

it could be doen with  a PIC microcontroller, use 7 pins of the output to an R2R ladder, hook up that voltage a VCA (use a 3080 or something, they're in vogue this week :wink: )

I'm not good with PIC programming, but, it wouldn't be too hard to get happening.

[puretube]

though I got to admit, that I`m not in love with this company,
http://www.doepfer.de/home_e.htm
I got to admit, they (used to) have everything a midi heart desires...

[Carlos]

Have a look at this inexpensive product:

http://www.nobels.com/cgi-bin/products/show.pl?e_mv-c
Regards

Carlos

[Carlos]

[barret77]

hey, can anyone suggest schematics for building this?

the ones being sold are about $ 130, toooo pricey for me....

[barret77]

http://www.maxmidi.com/diy/foot/index.html

found it...

[zachary vex]

that looks like a pedal that generates midi information, not what you were originally asking for.

[barret77]

I was caffeine-free by the time I wrote the post.
I meant exactly what that schematics show... I'll build it soon - a "midi wah wah"

[Paul Perry (Frostwave)]

The schematics for building a midi controlled volume controller is pretty simple, but the programming of the chip isn't, at least for me :cry:
If anyone is doing it, the cheap (and pretty stupid in my opinion) way to do it, is ultrasonic PWM from a PIC micro.
Better would be PWM from the PIC controlling the diode in a vactrol.
Maybe even better would be a digital pot controled by the micro! (? do these have an unlimited number of rewrites?)
If anyone is going to do this, let me know!! because, someone asked me yesterday to make a midi controlled crossfader :wink:

[downweverything]

ive done some midi stuff for some other projects and i was thinking of making some kind of midi controlled remote switching if there was enough interest (recievers and transmitters), implementing a sort of volume control too wouldnt be that difficult.  a digital pot connected to the microcontroller would prob be the easiest solution.  i could prob make some pre-proggrammed microcontrollers available for around $10-15.  then you can use them in your own schematics, would this be of interest to people or is the cost too high?

[The Tone God]

If anyone is doing it, the cheap (and pretty stupid in my opinion) way to do it, is ultrasonic PWM from a PIC micro.
Better would be PWM from the PIC controlling the diode in a vactrol.
Maybe even better would be a digital pot controled by the micro! (? do these have an unlimited number of rewrites?)
If anyone is going to do this, let me know!! because, someone asked me yesterday to make a midi controlled crossfader :wink:

Been there. Done that. Got the t-shirt and coffee mug. The digital pot is not the way to go for a number of reasons which right now I'm too lazy to list. There are pros and cons to some of your other suggestions. Each method has its merits depending on what your doing. There are a few other ways to skin that cat but I won't get into it due to afformentioned lazyness.

Andrew