Moog guitar, controllable sustainers on each string

[David King]

Some guy wants me to build him a 9 string bass with a Moog Guitar ( http://gizmodo.com/5015099/moogs-fir...nd-have-a-bite ) type sustainer with separate circuit for each string that can be set or programmed to sustain or mute each string via a foot controller.

I'm wondering how much juice I'd need to apply to move or stop each string. I'm thinking low impedance coils with an iron core. I don't see the need for an actual magnet here on the sustain/mute circuit but obviously the sensor that tells the system what the string is doing wants to be a normal pickup. On most sustainer systems I take it the sensing and activating coils are adjacent inside the same humbucker soap bar. What keeps them from interfering with each other? Maybe cross talk isn't a problem?

Does anyone here know more about this stuff?

[David Schwab]

Wow... I hadn't seen this before. Nice looking guitar!

Way back when, Roland had their first synth guitar, the one that looked like a Les Paul. In place of the neck pickup was a black box. That black box was a magnet. The bridge had nylon saddles as to insulate the strings from each other. A signal from each string (via the hex pickup) was fed to a small power amp that used the string as a speaker coil. Supposedly each string was about 8 Ohms. The audio connection to the strings was at the tailpiece and nut.

When the signal was fed to the string, a magnetic field was produced, and reacted to the black box magnet, and this caused the string to sustain.

You wouldn't need much power, and I'd think one of those IC amps (I think it's the LM380?) would work fine. Bass strings might need more.

Maybe Moog is doing something similar? I wonder if they have applied for a patent.

[Possum]

Moog guitar at NAMM

I got spammed by some music merchandiser and here's a link to the Moog Guitar. Despite my thinking stuff like this end's up collecting dust in the back of the closet under the 80's porno magazines, I can see a use for this in new age or electronic music etc. Its more than just a sustainer, they are controlling harmonic content of each string to a point, watch the video:
http://www.gearwire.com/media/moog-guitar-overview.mov
Definitely NOT approved by the "Blues Police."

[ake]

One of my friends Per Boysen (http://www.looproom.com/) is using Sustainiac Model C http://www.sustainiac.com/ He playes new age kind of music on a fretless guitar.

[David King]

Possum, thanks for the link, I guess that guy is Paul Vo?
I looked up some sustainer patents on line but couldn't find anything more recent than the Fernandes patent of 1996 or so.

What I'm wanting to know about these systems is how do they control the phase shift of the amped signal to control the string? Don't the strings follow the rules of gyroscopic progression so that you need to lead the string by 90º?

Engineering types always tell me that changing phase of a signal is easy -until I tell them what I want to do. Then somehow they can't give me a definitive answer.

ake, I'll check out your friend, thanks. I'm curious what the sustainiac has over the fernandes sustainer...

[David Schwab]

The simple way to change the phase of the string is reverse the output from the amp.

For variable phase you need something like an all-pass filter. That's how phase shifters work. They have multiple stages of all-pass filters. Phase is really akin to a small time delay. Flangers work with a delay line.

The sustainiac patent is 5932827. The original sustainor, as used by U2 on that one song, was invented by someone else (cant remember his name). The owner of Sustainiac said he wouldn't patent that design, since they didn't invent it, but they do use it. That's the one with the neck pickup coil.

Strings vibrate in a circular motion, so they aren't moving 90° from the surface all the time.

Another cool invention is the E-Bow... same idea.

[David King]

David ,
Thanks for the sustainiac patent number, I hadn't realized it was newer than than the Fernandes sustainer.

I screwed up my physics terminology. I was thinking gyroscopic precession not progression. I'm not even sure if that's the correct term regarding exciting a string as it moves in a circle as it vibrates up and down the length.

[David Schwab]

I hadn't realized it was newer than than the Fernandes sustainer.

It's a convoluted story... I was reading all about it once when I was on a sustainer kick (after seeing Robert Fripp). I think Sustainic was around first, and they had some kind of dealing with Fernandes (which is what Fripp uses).

I'll have to try and find the story. It was very interesting.

[David Schwab]

OK.. the guy who invented the sustainer is Michael Brook. That's the device heard on U2's With or Without You from The Joshua Tree. He called it the "Infinite Guitar".

Here's the article I read:

Breakdown - Michael Brook

Alan Hoover, the owner of Maniac Music, who makes the Sustainiac, says this in the article:

[they credit him as "Alan Hoover, of Maniac Music, on the Stealth Plus (Fernandes Sustainer & pickup)"]

We first made our acoustic type sustainer in 1986 (the Sustainiac Model T, soon followed by the Model B). Then, we heard about the Brook Infinite Guitar when U2 played in Indianapolis in late 1986, as I remember. Edge's guitar tech called us, and allowed us to play a few notes on the instrument after the afternoon sound check. I thought that seemed like a neat way to make sustain, so we designed our own version of such a sustainer after looking at the I.G.

We never attempted to patent any of the basic principles, such as a pickup being used in reverse to drive the strings, because we always felt that that credit belonged to Michael Brook.

Curiously, Michael (whom I met and talked to at length in 1990) never followed up with his British patent that he filed sometime around the 1985 timeframe. Typically, patent offices reject first applications over technicalities. It is up to the inventor to persist and argue his/her case. Michael gave up and didn't argue his case, so he never got a patent.

Then, Floyd Rose et al got a U.S. patent on a magnetic sustainer driver in 1990. Curiously, they claim never to have heard of the Brook device prior to making their sustainer. I know of no facts to contradict this. We have a patent cross-licensing agreement with them.

We sold several thousand of our Sustainiac GA-2 sustainers to Fernandes around 1990. I personally trained several Fernandes personnel in the operation and installation of the GA-2. Soon after that, the company that was manufacturing and distributing the Sustainiac GA-2 for us (Audio Sound International, of Indianapolis, IN) went out of business.

So.. which came first? Confusing, eh?

[David King]

The sustainiac preamble doesn't read very well but it brings up lots of the problems inherent in these devices and claims to address them.
First off is the way it cancels out the effect of the "driver" on the "sensing" pickup by using a stacked coil arraignment.
I'll have to think about that as I would think that the driver signal would be quite directional and therefore difficult to mask.

[David Schwab]

Some of the newer models of Sustainiacs use a split coil design, which is what their patent is about. Also, you can only use the bridge pickup when the sustainer is working (at the neck position) since they will feed back if too close to a pickup.

[David King]

Aha!
So they aren't using separate drivers for each string...

[David Schwab]

Aha!
So they aren't using separate drivers for each string...

No, but the Moog does. I see the Moog has piezo pickups in the bridge... I'm sure that's where the signal comes from. That would prevent the feedback problem as well.

[greenfingers]

No, but the Moog does. I see the Moog has piezo pickups in the bridge... I'm sure that's where the signal comes from. That would prevent the feedback problem as well.

You beat me to it!, I think ths signal comes fron there, it would make sence since you can isolate each string.

[David King]

Velly interestink Piezo bridge sensor also lends a nice 90 degree phase shift too. I hope it works..

Anybody want to hazard a guess as to how many watts I need to supply to each string driver? I suppose sensitivity will also be frequency dependent.