Electro Wagnerian Emancipator

[Gregory Kollins]

After an extensive and relatively fruitless search for any information regarding the circuit behind this one-of-a-kind effect (including a couple of posts in various Frank Zappa-centric forums, which were not all well received. You tell me why, because I have no clue), I have decided to post here and see if anyone would have tips on building my own, or know of a good, simple synth circuit, because I need TWELVE.

Alright, according to two interviews with Zappa, both for Guitar Player mag, what it does is plays every note in the chromatic scale, following your guitar notes, and you can select which of these notes to leave in or take out. So, I'm thinking you could build 12 guitar-synth square-waveish circuits, and tune each of them to occupy one note of the chromatic scale or, more accurately, to occupy a note a certain number of steps above or below the guitar note. Do this with 12 and you have the chromatic scale. Make each switchable on-off. Easy?

But problems!! -
Forgive my ignorance if I'm wrong, but wouldn't splitting the guitar's current into TWELVE circuits severely deplete tone? Wouldn't it divert all the voltage away from you clean guitar signal? Even with ample power supplied, the concept just seems tone-sucking.

I would want nice, smooth synth tone. Should I try to do something digital instead of analogue? The vast majority of guitar "synthesizers" sound like poop-stick distortion. I do NOT want this. Could I feasibly build TWELVE circuits that would "listen" to the note I play and play back a note a determined distance away? Digitally?

And NEW IDEAS!!!

TONE CONTROL!

For EVERY NOTE(or synth channel...whatever)!

YEAH!

The idea of this project makes me excited, the Zappaness, the bizzaro tones, and having a 1-of-a-kind, 2-of-a-genus effect.... mmmm.

[Ben N]

It's a harmonizer, made with 1977 technology. Not a real good candidate for a DIY project, and certainly not for a first DIY project. Plus, I would expect that that is something that can be done a lot better today than then (although you may lose whatever chaotic Zappa mojo you are after). Here is a demo for a Boss 2-voice harmonizer in pedal format--not as wide harmonic capabilities as the Zappa thing, though, particularly in terms of doing small intervals. If you want the full capability, you shell out the bucks for an Eventide--which is what ole Frank eventually did.

[Br4d13y]

Could you use a zvex ringtone modulator? You could tune each pitch in the sequence if i am not to be mistaken

[snufkin]

try this post out for size

http://www.diystompboxes.com/smfforum/index.php?topic=69221.0

basically you only need one tracking circuit and an organ divider to get all the intervals

the e&mm harmony generator project thread is knocking about here (its been tested and works) and could be modified for multiple outputs at one  but thats a bit out of my league

[Gregory Kollins]

Wow, thanks man! The organ divider idea is a good lead, as is the pitch shifter chips. I'll start looking into that.
And as for you Ben.... This isn't my first project... 
I know a POG or, even better, a HOG, would do something along these lines great, but those work in octaves and fifths, I want the whole chromatic scale. Why? Because Zappa had it. No other reason whatsoever.
And those are really expensive pedals anyways....

Anyways, I was completely ignorant of such divider chips as were mentioned in the other thread. While this wouldn't be my first build, at 3 failed and 6 successful, plus a handful of mods, i am still a novice... So I don't know about all these cool parts. These chips answer one of my questions in my first post.

To address the idea of using a pitch shifter, do you think i could basically slap 12 pitch shifters together? Are any of you familiar with the DH pitch shifter (on GGG)? I've never heard one, and can't find a clip, but it looks like if I striped it down to just the pitch-shifting part, it would be fairly easy to build twelve. But again, without knowing what it sounds like...

Edit:
I think in might be cooler to leave most of this DH pitch shifter intact. While I don't need a wet-dry mix (for obvious reasons...), it would be amazing to have at least volume for every note. That way you could mix the synth with your dry signal to sound more musical with each synth-chord you assemble. I don't really know what "robot-control" is... but it suggests that this circuit might be a monster in and of itself.
Also... Vibrato control...?

Edit num. 2:
Just read the HT8950 data sheet. Apparently this is a chip from voice-modulators in.... toys. Hmm. But the robot control which, and I quote, "converts an input voice into a robot voice"... That gives me hope for the goodness of man. It's digital and 8-bit.... So it probably sounds like the simultaneous death of an entire flock of blackbirds. Anyways...
Anyone heard it in a circuit?

[Ben N]

No offense--I'm not sure where I got that impression now that I look over the original post.

[snufkin]

i have heard the HT8950  and its messy there aint no way you could get it to do what your seeking cool effect all the same

if you were to build something with 12 vices there are only a few practical ways to do it simply duplicating circuits driven directly from the guitar probably will just end in complicated mess what you need is to keep the control simple

pitch shifters dont really exist in the diy world

maybe try a pitch to voltage converter like the one on ampage (search here or at electro music for more info) and then build a whole synth based of that you can control as may oscillators as you want from one CV source (of course tracking isnt perfect) and then tune each oscillator to a different interval. They would then all track the original signal moving up and down with playing

I own a korgx911 with can get pretty convincing harmony sounds with the original signal (it uses pitch to voltage but only has one oscillator

also of interest will be loss1234's project the audio ark it does not use frequency to voltage conversion but uses a similar method to the octave divider circuits to track pitch http://www.diystompboxes.com/smfforum/index.php?topic=72532.0

[DougH]

I know a POG or, even better, a HOG, would do something along these lines great, but those work in octaves and fifths, I want the whole chromatic scale.

Get yourself a Boss PS-5 Super Shifter then. It does intelligent harmonies based on the mode/scale/interval you dial up. Or check out the old Boss Harmonist, which will do two different harmonies IIRC.

Or if you have a lot of money to burn, check out the Eventide stuff. (edit- Oops, just noticed that Ben already mentioned the HR-2 and Eventide stuff.)

[Gregory Kollins]

Well, don't you have to tune harmonizers to a scale? The only situations on which I would use this devise would probably be live venues, when my and fellow band-mates just breakdown into a constantly changing test of our dynamics, and rumble along making up riffs and beats as we go (alot of fun). That... and other noise-rock stuff, and some ambient playing. In any case, I need to be able to switch scales and/or keys. Without adjusting anything.

I like the boss for what it does, but it doesn't do this..

Alright, moving back to the EWE...
I've been looking into some of the things snufkin suggested, and I need somebody to sort of... walk me through the logic of this. (correct me if I use any terminology in the wrong way)
Ok, so I build a synth. It is controlled by one CV via input jack. It contains 12 oscillators, each of which plays a note that is manually tuned and, because it responds to the voltage level, will remain in tune with what I play (i.e., the same distance from my note). Each of these are mixed into the output. This I know. But... Questions.

1. What steps, circuit wise, are involved in this? I really have know clue what goes into a synthesizer (for example, I don't know what an oscillator is, as far as circuitry goes). Could anyone refer me to a basic schematic just so i can map it out logically?

2. Would I mix each of the oscillator outputs into a single synth outputs, which would be, in turn, mixed with a dry guitar output? This makes sense to me, but, again, I know nothing about how synths work.

3. Oscillator... what is it? What I would deduce from how it is used is that it is a circuit that "creates" - but not really -  a voltage at a level determined by you, and this voltage translated into a note... at the speaker. So it is the heart of the synth, right? Is this true and, if so, how would this be different from building 12 pitch shifter circuits, besides sounding better (not that that isn't reason enough)? Is the only difference that it "creates" it's own voltage vs. modifying the guitar's?

Oh and Ben N., I was just being... mean, or nitpicky, or anal, or whatever. I'd rather you assume my ignorance than assume I know all kinds of stuff I don't, and just end up confusing me.

[caress]

i think you've got a lot of reading ahead of you...

you're thinking of an extremely complex project without knowing the basics

Oscillator... what is it?

this is a start for reading about oscillators:  http://electronics.howstuffworks.com/oscillator.htm

1. What steps, circuit wise, are involved in this? I really have know clue what goes into a synthesizer (for example, I don't know what an oscillator is, as far as circuitry goes). Could anyone refer me to a basic schematic just so i can map it out logically?

synthesizers are such a vast subject... but basic analog synth architecture consists of oscillators, envelopes, amplifiers and filters.
oscillators produce the basic sound and all the rest of the stuff modifies it - i guess you could liken it to a guitar with pedals...  sort of.
you should probably just check out various synths and see what they're all about.  minimoog, arp odyssey, modular synths...

www.musicfromouterspace.com is another GREAT resource, btw.  check out the links...

[snufkin]

a normal mono synth uses resistance or  capacitance based keyboard (they work slightly differently but basically its a row of switches with different values) to derive a control voltages
these are then used to control the pitch of oscillators and trigger amplifiers and filters that shape the sounds

for a guitar synth you need an extra step, a pitch to voltage converter that 'listens' to the frequency of the guitar signal and produces the correct control voltage (amplitude can also be derived as can trigger signals) this CV is then fed to the oscillator

if you have one or more oscillators an audio mixer is used to combine the signals


basically as said before you have a LOT of reading to do 

i still think an organ divider like Mark said in that older post is your best bet

pitch-shifting circuits are impractical here for many reasons it almost impossible to DIY them and they might not give you the tonal control needed to balance the 12 notes
an oscillator circuit in comparison to a pitch shifter circuit is very simple. To make 12 pitch shifters you would have to make an active splitter mixer to boost the guitar signal in to there inputs and mix there outputs where as the synth rout is complex but not a total disaster waiting to happen

[Gregory Kollins]

I just read, between wiki and how stuff works, how transistors, capacitors, inductors, oscillators, leds, radios, and tube TVs work. I feel good. Like... when you have a speck of dirt in your eye for a long time but can't get it out, so you just start to ignore it, then about a half hour later, it just blinks out randomly and all the sudden everything feels so good.

So, this is now the plan.

Guitar input -> CV circuit (reading up on this as well) -> 12 individual oscillators -> envelopeyewihg-ampli-dkgjhs stuff I'm looking up and reading on as I write -> Mixer -> Universal tone control, any other signal effectors i choose to add -> wet-dry mixer -> output

A universal frequency filter? more realistic and simpler than individual ones (I have a feeling I know the answer)? But I have another question. What is entailed in altering waveform? Like, sine wave, square wave, etc? Could this be done at the "universal" level instead of immediately after each oscillator?

By the way, I'm a big fan of the MFOS site. The people who run it seem like they must really love thier job.

Edit:
I just searched experimentalists anonymous for "control voltage circuit", but all three words were omitted from my search because they were too common...

[snufkin]

By the way, I'm a big fan of the MFOS site. The people who run it seem like they must really love thier job.

thats Ray Wilson for you !

in answer to the waveform question yes and no while you can tack on some circuitry after an oscillator to alter its wave form this cannot be done to the output of 12 oscillators at once

most VCO (voltage controlled oscillators) are multi waveform deals anyway but the more wavforms the more complex circuitry


this is gonna be an expensive project! 

[Gregory Kollins]

I know! it might have to wait for more than just my skill level to catch up to it... But I'm making some serious cash over spring break, so after that i may be able to buy what I need. But I'm envisioning this awesome enclosure... hand painted, large and boxlike.... with slider pots... countless nobs and switches....ahhh. That keeps me going.

update, more for me than anything else:
Guitar input -> CV circuit -> 12 individual oscillators -> Filters -> Amplifiers -> Synth Channel Mixer -> Synth-Guitar Mixer -> Output