Arp Avatar- anyone ever get one function as intended?

Meanderthal · September 06, 2006, 11:46:28 AM

Ok, so I'm looking for... something in the chaos that is my basement, and I had to move my abandoned Avatar out of the way. This reminded me that this is one of the many things that remain undone- I have gotten it to respond very well by CVing it to my(also abandoned) SCI pro-one, resulting in some of the coolest and wierdest sounds I've ever heard. When I scored this thing(many moons ago), I had intended to actually use it as a guitar synth. Well, I didn't get the pickup with it, and have repeatedly tried to get the DIN jack to respond directly to... anything. Never a peep. Well, I got one of those g-vox pickup/interface thingies, came with a hex pickup. Pretty cool in its own way, so I never really tried to butcher it into the avatar, especially since I've never gotten the pitch-to-voltage converter in the avatar to actually do anything.

I've scoured the web, and found sites with many mods and all, but nothing really about getting it to work as intended. Mark Hammer's site actually had the best/most info about it in those scans of that old publication(Thank you for that!) I'm aware that it has/had a bad reputation as a guitar synth, but the info on mark's site implied this is because it needs calibrated/tuned to your setup and such. I'm also aware that this is a rare beast, and it's possible that no one ever really used it as intended, so I don't hold much hope that I'm going to be able to figure this thing out... not many users and all.

Anyway, this may be too much to hope for- my real goal with this thing would be to convert/use it as a bass synth. Is there anyone who has any experience/knowledge/ideas they'd like to share about how to go about achieving this? Or is it maybe a bad idea to waste my time trying to get something to work that... just never really did?

Rodgre · September 06, 2006, 09:16:01 PM

I inherited one years ago because a friend at a music store had it in the basement forever.... and knew I was the only person who would adore it like it should be adored. I have never gotten it to make a peep in the ten years I've had it. I've run CV into it, and I've tried injecting signal into it at the mixer stage and I get nothing. I would love it if you lived somewhere near me that we could start an Avatar support group and see what we can do with these beasts. I get to messing with it about once a year. I have the software version of the Arp Oddyssey, so I know what it's capable of. I want to hear this thing roar!

Roger

Meanderthal · September 06, 2006, 09:43:24 PM

Kind of a dumb question, but have you ever gotten it to self-oscillate? Mine does that- you know- filter resonance. All by itself without hooking anything up to it you can talk to humpback whales and scare the Krell off the forbidden planet.
It sounds like yours might have a problem in the VCA section...
This is really a leftover from the days when I thought I was going to become a keyboard player. The Avatar was going to be my version of a keytar... At the time you could probably find analog synths laying by the side of the road- no one wanted them. Everyone wanted a DX7. Midi was new. And I was snatching up those monophonic analogs that nobody wanted. Got the avatar for $50.00! And that's just one example.
But then I eventually found out that I couldn't really play keyboard, just don't have those piano skills. Not compared with... oh... a REAL keyboard player. I'm just a bass player who monkeys with stuff all the time.
But if I could get this thing going, It would be in my opinion the coolest guitar/bass synth ever! Maybe also the world's largest stompbox(well, I wouldn't go stomping on it just yet)

trevize · September 07, 2006, 05:28:26 AM

try on the electro music forums

http://electro-music.com/forum/

forum index>>intruments and equipment>>diy synths
forum index>>intruments and equipment>>circuit bending

Meanderthal · September 07, 2006, 01:33:16 PM

At least someone cares... thank you for that!

The advice in the past from the synth guys was something like- "you've got a great analog synth module, what's the problem, can't you play bass lines on a keyboard?" or- "Is it for sale?" (see the gear lament thread in the ot lounge for my feelings on that) Well, I CAN do that, (play simple bass lines on keys)but it comes across a bit cheezy. None of the gosh wow stuff as far as a performance goes, more of a yawn. Oh yeah, here's another one "get a pitch to voltage thingy". Gee, I had thought this had SIX(6) of those. Sorry if I sound bitter, but I am. hehe.

I had a little hope that maybe the stompbox crowd might have solved this puzzle at some point, but, given the reputation of this thing I guess that's a bit unrealistic. Still, it don't hurt to ask, right?

Maybe I should just get a boss pedal... yeah, right.

Sorry 'bout that...

slacker · September 07, 2006, 02:43:03 PM

I don't think it's practical to make your own pitch to CV convertors, so I think your DIY options are going to be limited. You could make or buy a MIDI to CV convertor and get hold of an old Roland or Yamaha MIDI pickup to drive it.

Mark Hammer · September 07, 2006, 03:13:21 PM

You guys have schematics for it, right?

Meanderthal · September 07, 2006, 03:47:19 PM

Ummm... midi lag.... a little like getting a fork stuck between your teeth. I DO have a g-vox system. Not exactly a true synth guitar setup(a guitar to pc interface with hex pickup), but will let me do that stuff with the help of a computer, however, just like every midi guitar setup I ever tried the term "real time" is at best a little misleading. Also, that still leaves me using a guitar, been a long time since I've seen a true bass synth pickup/setup. Let's just say disco was still acceptable then, but not to me.

I've seen the PAIA stuff, hmmmm maybe....

I've pretty much accepted that I'd most likely have to wind a quad-coil pickup myself for bass since no one seems to sell them for some reason... I mean, really, wouldn't you think the bass is a better suited instrument for controlling a monophonic synth?

Yeah, so I make myself a pickup... and then what? Adapt it to the EADG strings on a system designed for guitar... might not be that easy though?

But I DO appreciate the suggestion!

DOH! I guess I should have posted the schematics if I wanted any real help, I can't just go assuming everybody has'em. Sorry 'bout that Mark. It's a maze, though. Actually, I think I got these from you...

http://s86.photobucket.com/albums/k99/jprak1/?action=view&current=ArpAv1.gif&refPage=&imgAnch=imgAnch3

http://s86.photobucket.com/albums/k99/jprak1/?action=view&current=ArpAv2.gif&refPage=&imgAnch=imgAnch2

http://s86.photobucket.com/albums/k99/jprak1/?action=view&current=ArpAv3.gif&refPage=&imgAnch=imgAnch1

StephenGiles · September 07, 2006, 04:08:02 PM

But that is only part of the story, you won't get far with just those circuits!

Meanderthal · September 07, 2006, 04:20:45 PM

Yup, the secret module thing. And there lies my problem. I did see a patent with very blurry vague schematics once...

Meanderthal · September 07, 2006, 04:42:10 PM

Found it! :

http://www.pat2pdf.org/patents/pat4300431.pdf

Meanderthal · September 07, 2006, 04:51:31 PM

OMG it'd take me a year to fill in all those values- I'd have to manually trace the whole damn thing. That's the brick wall I ran into when I last investigated this- this thing's just plain way over my head. Sigh. I might try repairing it using the shotgun method, but I don't even know if it's broke, or if it never worked in the first place. What a mess.

Meanderthal · September 07, 2006, 04:53:01 PM

Oh yeah, I was wrong- one pitch-cv converter, 6 distortions. OOps!

Rodgre · September 07, 2006, 05:09:57 PM

Quote from: Meanderthal on September 06, 2006, 09:43:24 PM
Kind of a dumb question, but have you ever gotten it to self-oscillate?

Not a stupid question, but that was the first thing I tried to get it to do. I don't remember if I tried to feed an output directly from the VCF or not though. I did download schematics and service notes at one time, so I have tried to trace the circuits. There's just SO much going on in this thing....

I am interested in getting it to work solely as a CV module, not necessarily for guitar. I have my GR-300 for that

In High School, I was also trying to build a Paia Gnome into a guitar synth. I'm still trying to finish that.

Roger

Meanderthal · September 07, 2006, 05:33:58 PM

So how's that Roland for midi lag? Or is that n/a because it's ... not midi? I'm unfamiliar with the newer Roland stuff. I tried one out years ago(don't remember the model#), and the lag was horrible, plus the sounds were... not so interesting. Didn't have a bunch of knobs or sliders either, just a led display/presets. Don't know if it was programmable- I handed the guitar back to the salesman almost immediately and said "no thank you" becsause he had wasted my time claiming the lag was so minimal you'd never notice it. It was no better than a Casio midi strat copy I tried out once. Plink......(waiting).......BROOONG. Ugh.

Rodgre · September 07, 2006, 05:50:14 PM

Quote from: Meanderthal on September 07, 2006, 05:33:58 PM
So how's that Roland for midi lag? Or is that n/a because it's ... not midi? I'm unfamiliar with the newer Roland stuff. I tried one out years ago(don't remember the model#), and the lag was horrible, plus the sounds were... not so interesting. Didn't have a bunch of knobs or sliders either, just a led display/presets. Don't know if it was programmable- I handed the guitar back to the salesman almost immediately and said "no thank you" becsause he had wasted my time claiming the lag was so minimal you'd never notice it. It was no better than a Casio midi strat copy I tried out once. Plink......(waiting).......BROOONG. Ugh.

This is pre-MIDI. The GR-300 has pretty much NO lag. It's like playing a guitar. Totally analog with two VCOs per string. It sounded like it sounded. I love it, but never find uses for it's sound in my music. I just like playing it

Roger

Meanderthal · September 07, 2006, 07:33:41 PM

Hey, THAT looks awesome! I'm seething with envy...

Meanderthal · September 07, 2006, 09:23:07 PM

Here's something of interest. Found this while looking into your guitar synth. Not for an avatar, but a DIY interface for the gr-300 allowing you to interface with a 'normal' guitar using a hex pickup!

http://www.marksmart.net/gearhack/gr300/analogmods/gk2gr300interface/Gk2Gr300Interface.html

Rodgre · September 08, 2006, 03:19:28 PM

That's a cool link. Lots of interesting stuff. I actually like my G-505 as a regular guitar. Mine's sunburst, unlike the photo I posted. Plays like an early 80's Ibanez strat because, well, it sort of is one!

The GR-300 was a really great system, as long as you weren't interested in making other sounds than the ones it made. The filter sounds great. The oscillators are fat. The tracking is superb. I wish it had CV interfaces, but for a polysynth, that's asking a lot. Does anyone know if the oscillators and filter were used in any other Roland synth at the time?

Roger

Mark Hammer · September 08, 2006, 03:48:17 PM

Probably a pretty good chance it was using those IR3109 quad OTA chips for filters. These were used in the PH-2 and RPH-10, as well as a number of early MIDI synths in the early 80s. My Juno 106 uses a bizarre little gooped-up module that contains an IR3109 and a pair of BA662 OTAs for each of the 6 voices. Not quite an SSM2040, from what I hear, they nevertheless aimed for that territory.

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Arp Avatar- anyone ever get one function as intended?