Any experience with the Source Audio Hot Hand?

[Mark Hammer]

This thing intrigues me:  http://www.sourceaudio.net/products/hothand/hothand3.php

It is not an "effect" in itself, but a controller that can be used to modify other things as one is playing.  The documentation indicates that up to 3 parameters can be controlled at once, on the X, Y, and Z axes, via the wireless finger attachment, but the unit has only two output jacks and one of them is purportedly proprietary to the Source Audio Soundblox pedals.  The documentation doesn't really indicate what the outputs are.  For instance, are they control voltages, or digital signals, or simply variable resistances electronically controlled within the unit?  Is the phone jack different than the other output jack in some manner?  I can't tell from their site or manual.

If it was something I could use (even with some modification to pedal circuits) to control three parameters at will, then it represents good value, convenience, and some exciting possibilities.  If the best I can hope to do with it, using a non-Source-Audio pedal is really no different than what an expression pedal lets me do now, then it becomes much less interesting (nothing against Source Audio pedals; I just don't HAVE any).

I'm just wondering how much this particular product could let us do things with the pedals we make or adapt for ourselves.

So, anybody know?

[jimbeaux]

I think the bass player is using one in this video (around :55)

https://www.youtube.com/watch?v=ZuunY8BTqNs

(edit - I just realized the video is linked on HotHands website -)

[slacker]

Pretty cool little gizmo. There's a couple of white papers here http://www.sourceaudio.net/technology/index.php the one for the SA601 Chip suggests that the soundblox output is two CVs of some sort, the diagram on page 3 shows them going to an analogue to digital converter in the pedal.To confuse the issue though the hot hand one talks about digital signals, but it could be missing out the interface part.

[Mark Hammer]

Yep, that's it.  Just WHAT the hell he is doing with it is anybody's guess, though.

[Mark Hammer]

Pretty cool little gizmo. There's a couple of white papers here http://www.sourceaudio.net/technology/index.php the one for the SA601 Chip suggests that the soundblox output is two CVs of some sort, the diagram on page 3 shows them going to an analogue to digital converter in the pedal.To confuse the issue though the hot hand one talks about digital signals, but it could be missing out the interface part.

Thanks for that!  Hadn't seen the link to the white papers.  I have my bus-ride home reading!

[jimbeaux]

Looks like there's a MIDI (CV?) interface available for 3rd party effects. (currently out of stock)

http://www.sourceaudio.net/products/hothand/midi_exp.php   (top & side jpg's)

[PRR]

The little jack gives "all three axes digitally through the SENSOR OUTPUT." This will be bit-wise gibberish to you, though decodable via reverse-interfacing or buying that MIDI innerface.

The 1/4" jack will output ONE axis in quasi-standard "expression pedal" interface. This is after my time but is either potentiometric or some 0-5V signal (or LineSix format, WTF is that?).

> to control three parameters

Then you have more hacking to do. Either (wait for and) hack the MIDI, or study the gibberish and use a PIC/Stamp/CPU to decode that to your knob-twiddles.

[Mark Hammer]

Thanks Paul.  I'm afraid that is a bit (or was that 16?) above me for now.

As for the "Line 6 interface", it is a simple 10k variable resistance to ground, rather than a TRS-type voltage divider control-voltage pedal.  I was able to control my M5 using a photocell with a suitable parallel fixed resistorto bring it into the right range.

I had my hopes up for the Hot Hand, as something I might be able to use to, say, control distortion amount and filter cutoff, or cutoff and resonance, but I suspect I'll have to set it aside for now.

[toneman]

hey, thanks for the info/link to the HotHands.  INteresting technology!!

[PRR]

The way it is now, it isn't "AND" unless you hack the digital output.

How bad is the price? Can you afford two or three? (I think they say you can use several on one stage without confusion.) Will they fit your hand or just be chunky?

[aron]

Mark,
This is reminding me of the EH "knob turner". I wonder if someone could wire up an arduino board to control servos that would turn pots on a pedal. It would look like a scary experiment but would be cool!

[Mustachio]

Yeah while reading this and looking at it , My first thought was arduino. I believe theirs lots of free code for using accelerometers and digital pots. I have no idea how to make em all work together. Gotta get into arduino soon! Neat little gizmo but not sure I would have much use for it myself.

[Mark Hammer]

Well, there are things like this: https://www.sparkfun.com/products/9267

[Kipper4]

Is this the same gizmo Matt Bellamy (Muse) uses on his guitar?

[Mustachio]

Looks nice, I think I've seen 3 axis accelerometers for 5-7 bucks on ebay .

I've done a little android dev in the past and was always interested in idea's for hardware. I seen some neat stuff people have done using the accelerometer in an android phone to control things in the real world like a giant tilt ball game. It sent the xyz wirelessly to an arduino board that adjusted motors to tilt the large game.

This wasn't the original video I seen but only one I could find at the moment.

Just spit balln here since I don't have good enough background to technically express my thoughts on this. I'm geussing some way to convert the accelerometer data to a digital potentiometer that would output that info to a TRS jack. Possibly something like a variable resistor setup ala' lm13700 to output to the TRS jack. I do think most of the code to do it with arduino is out there for free it would just be some foot work and experimenting. Just spit balln like I said , you guys in this thread are leagues ahead of me in knowledge and understanding. I usually just sit back and read every post you guys make looking at the screen like this  

[Mark Hammer]

I sent off a note to Source Audio yesterday, and they very kindly replied today.  Here is the reply, in its entirety.


Hi Mark,

I forwarded on your question to our VP of Engineering, Jesse Remignanti.
He wrote:

The Expression output is a digital potentiometer wired like any expression
pedal would be.  It just looks like a variable resistance to outboard equipment.
The sensor output is a voltage out.  The default signal range is small
only about +/- 200mV but if he use the Sensor OUT Processed Mode in the
output mode selection, he can get a 0V to 3.3V range roughly.

The Sensor jack looks like this:
Tip-3.3V IN (not necessary if the external power supply is used)
Ring 1 - X axis out
Ring 2 - Y axis out
Sleeve - Ground

All the best,

Will Cady
Source Audi

This bodes well; particularly since a voltage output can be harnessed to a commercial or home-brew optoisolator, or indeed used to control anything that is voltage controllable (within limits).

My interest in getting one is resurrected.

[Mustachio]

Very cool Mark! Excited to see what you make of it all.

So I'm thinking bluetooth along with the accelerometer to send the signal wirelessly to the digital pot.

Or could do it all in one unit maybe like that Electroharmonix wah that has no pot it just rocks back and forth on the floor.

I'm sure tons of implementations are possible. The more I think about it this would be great to give use of a wah to some one that has no use of their legs , and many other instances where a person is in need of a new way to control something in an unconventional way.

I hope no one gets the bright idea of attaching these to a drummer and invent some new type of dub step 

[zombiwoof]

Mark,
This is reminding me of the EH "knob turner". I wonder if someone could wire up an arduino board to control servos that would turn pots on a pedal. It would look like a scary experiment but would be cool!

A couple of years ago some company resurrected that old EH device that had a rocker pedal attached to a cable, that then attached to a pot on your amp or pedal to turn the pot (what was the EH one called?).  I believe the new version was called the "Third Hand" or something like that.  It may still be around.

As for a servo-controlled device to turn pots on pedals, Neil Young has had a custom made box (he calls it the "Whizzer") that does exactly that for the controls on his old tweed Deluxe amp for years, it uses servos to turn the pots to preset positions, as the controls on those old tweeds are very interactive, and he get several different sounds by turning the controls to different positions.  I'm sure it could be adapted to control the pots on pedals instead of an amp.

Al

[Mark Hammer]

That was the "Tone in Progress" Third Hand, which was a definite improvement on the EHX Hotfoot.  I owned and used a Hotfoot, back in the day, and it had a number of limitations, one of which was that it applied so much torque, it would flip a small light pedal over, unless it was secured down, and another of which was that the part that clipped onto the pot shaft needed so much clearance around the pot to function, that only things like the big box EHX pedals were suitable.

Although Neil Young's Whizzer is a great idea that lets him squeeze every ounce of magic out of his 5E3 amp, it's not the sort of arrangement you want to use for moment-to-moment changes on the fly, since sooner or later the pots will get crackly.  A more sustainable arrangement is that of control voltages and non-moving parts, which the Hot Hand provides quite nicely.