What is KVR Audio? | Submit News | Advertise | Developer Account

Options (Affects News & Product results only):

OS:
Format:
Include:
Quick Search KVR

"Quick Search" KVR Audio's Product Database, News Items, Developer Listings, Forum Topics and videos here. For advanced Product Database searching please use the full product search. For the forum you can use the phpBB forum search.

To utilize the power of Google you can use the integrated Google Site Search.

Products 0

Developers 0

News 0

Forum 0

Videos 0

Search  

Foot switch signal re-creation

Anything about hardware musical instruments.

Moderator: Moderators (Main)

CinningBao
KVRian
 
1308 posts since 15 Apr, 2004, from Capital City, UK

Postby CinningBao; Tue Apr 23, 2013 2:42 pm Foot switch signal re-creation

My old school pal just sold me this beauty

FRONTLINE X-2 DUAL DRUM SYNTHESISER

http://www.youtube.com/watch?v=Gha5bvv_AjY

for a fair price, and amongst other inputs it has this 'preset switching' input, suitable for foot switches.

I think it would be rather too much fun if I could sequence this foot switch from the old compinguter, from an output on my Motu828mk2 which, although unsupported, is often used to send up to 5v to modular devices, although, in this forum, you probably already knew that..

Anyway, I just tried a simple sync signal I sampled from the (birthday) Monotribe; that didn't do anything.

Any idea how I emulate a foot switch to perform sequenced switching on an old drum device?

cheers! :)
CinningBao
KVRian
 
1308 posts since 15 Apr, 2004, from Capital City, UK

Postby CinningBao; Wed Apr 24, 2013 3:37 am

I don't believe this is an unknown.. push up for visibility!
BertKoor
KVRAF
 
8291 posts since 8 Mar, 2005, from Utrecht, Holland

Postby BertKoor; Wed Apr 24, 2013 4:11 am

I was a bit hesistant to reply at first, but you drew me over the line.

First you'll have to figure out how this particular footswitch jack operates before you can fool it. First step is to plug in an ordinary foot switch (contact between tip & sleeve only closed when pressed) and test weather it works at all. If it does, then continue. Otherwise: :shrug:

For a fool-proof approach you can use a simple relay: the voltage supplied by the audio interface will physically close a switch which you connect to the pedal input jack.

Making it work by feeding it a current, I have my doubts weather it really is that simple. Usually there's a stable current between tip & sleeve contacts of the jack, and electronics detect weather the voltage drops. In theory, if you supply the same but negative voltage then the same should happen. But I think this is risking both devices and maybe more electronic parts are needed to get it working in a safe way for both.

So I'd put my money on the relay solution. That should definitely work!
We are the KVR collective. Resistance is futile. You will be assimilated. Image
My MusicCalc is back online!!
CinningBao
KVRian
 
1308 posts since 15 Apr, 2004, from Capital City, UK

Postby CinningBao; Wed Apr 24, 2013 6:54 am

I'm glad you decided to respond BertKoor - I like a good puzzle!

I sampled the footswitch, it looks like this

Image

and looking, and thinking, I see, and note, that it is a sustain pedal, not a standard footswitch.

Loading the sample in to Sampler (Live) and increasing the volume to 36dB it seems to behave in the same way; the device switches to the preset sound when it should.

My problem is that the footswitch 'in' is very sensitive to the pattern of voltages. Simply looping the sound with a steep release doesn't behave as expected.

Next I am going to build a sampler in Bidule which plays the correct signal on release - there seems to be quick double-tap in the final release which isn't being created by simply loading the sample and playing it back.

Image

I'll update progress here becasue I can't be the only person on the planet who wants to do this! ;)

If all this turns to a sad face, I may have to resort to relays! Thanks for the pointers :)
CinningBao
KVRian
 
1308 posts since 15 Apr, 2004, from Capital City, UK

Postby CinningBao; Wed Apr 24, 2013 10:37 am

Solved, by using the same signal sampled from Monotribe 'sync out', turned up to +36dB and routed out of he 828..

That was a lot simpler than it looked! ;)
BertKoor
KVRAF
 
8291 posts since 8 Mar, 2005, from Utrecht, Holland

Postby BertKoor; Wed Apr 24, 2013 11:29 pm

I'm glad you solved it!

CinningBao wrote:it is a sustain pedal, not a standard footswitch.
There are two types of switches indeed. What I described was a momentary switch, as used in sustain pedals. This is the most common type generic foot switch, can be used for anything. The other type is a latching switch, as found on old guitar pedals. Press for contact on and press again for contact off.
With a simple flip-flop circuit a momentary switch can be turned into a latching switch. But turning a latching switch into a momentary one is less trivial.
We are the KVR collective. Resistance is futile. You will be assimilated. Image
My MusicCalc is back online!!

Moderator: Moderators (Main)

Return to Hardware (Instruments and Effects)