micro synth

[Jaicen_solo]

Well Bill, i'd have thought everybody knew you'd built one, since you did most of the layouts!
I don't recall seeing anyone else having built one besides you.

p.s. You are a legend

[swt]

thanks to bill and francisco at tonepad, and many others like munky, i'm one of those who've built it, plus i was the one who made the corrections of the original schem, by tracing a real one. there's a lot of effort envolved in this project, and it works!!!. time has passed since i've built mine, and i've never use it, mainly because i use other synths of my own, with lots of web ideas, that worked better for what i do. so i've converted it to bass synth, and now my bassist is really happy with it. only 3 or 4 caps and a resistor changed, and it's supposed to work better for guitar also. if someone is interested, go build it. it's hard, specially the troubleshooting. and you'll have to do it. there's always a mess up somewhere. ( excuse my english...). just be suer you will use it, because it's an expensive project. also you don't need to use all the ca3094 in all stages, just the one that use the buffer, the rest can have ca or lm 3080. take a look at the datasheet and you'll realise which ones use it or not. Good luck, and happy building...

[Bill Bergman]

Well Bill, i'd have thought everybody knew you'd built one, since you did most of the layouts!
I don't recall seeing anyone else having built one besides you.

p.s. You are a legend

Thanks Jaicen, but I'm only a legend in my own mind

Thanks to SWT !!!! He provided the fixes and mods that really brought my Micro to life.

[soffa]

All right....

I started to build this, and I'm in the troubleshooting phase. I've noticed a few things in the schematic that I don't understand. Maybe someone can shed some light on this for my electronics-ignorant self. Let's look at, say, IC A18 on the schematic. I am assuming that this is one of the ICs that could be replaced by a 3080. If I look at the schematic/layout, it seems like the output of the OTA (Pin 6) isn't connected to anything. Also, what seems like it should be the place where the output is connected in the schematic is connected to Pin 1 of the IC, which is an NC in the 3080 and the inhibit input in the 3094. What gives? It dosen't seem like there should be any output from the OTA in this configuration. (and there isn't in what I have completed so far, which is why I'm asking!  )

Thanks!

soffa

[Bill Bergman]

Wish I could help, it's been to long ago. I did have some trouble getting it to work. Guess I just got lucky and had help from some of my old friends here.

[soffa]

Well, Bill - if yours works and you used the layouts that you made, I probably made soem other little mistake. I haven't had time to troubleshoot it totally yet. I just want to understand how the circuit works - it seems funny to me!

soffa

[Bill Bergman]

I probably had to run jumper to pin or two or something like that. Guess you could use a signal probe to find where it stops. Besides using the signal probe I also used to use a very unscientific way of finger shorting across different parts of a circuit for a quick way to pinpoint an area that might need to be jumpered or probed futher.

[soffa]

all right, I think I figured out the answer to my own question. Because I'm cheap, I'm using 3080s in any place where they're appropriate (if only I would have stocked up on 3094s ten years ago....). Looking at the data sheet, Pin 1 of the 3094 essentially gives you access to the output of the OTA before the darlington transistor stuff at the end. In the micro synth, the schematic is drawn to use 3094s in all the positions, so to use a 3080 you would have to put a jumper from Pin 6 to Pin 1 of any 3080s you sub into this circuit.

At least, that seems to be what makes mine work...

On another note: I have had this great idea for about two years that I've been sitting on. I was planning on taking an AD633 multiplier chip and making a little ring mod with an Exar XR80308 function generator. Then I saw the schematic for the EH Frequency Analyzer. Oh well - someone already came up with this 25 years ago! Now I was thinking that I'd build it in the same case as the micro synth and incoporate some crazy mixing/routing options for lots of weird sounds. Any comments?

Matt

[ReCoC]

Hello everyone. Could someone please email me working schem and pcb of the microsynth?

san_gr@yahoo.com

Thanks a lot in advance!

[choklitlove]

hey, me too.  please.  i had one that someone mailed me, but have since lost it.

please!  thanks!



-choklitlove (at) yahoo.com

[Meanderthal]

 Yeah, I hunted and searched, maybe I missed something, but I never found the layouts... I have had the schem. forever, but it's a MONSTER! Ot, but I just scored a g-77 and gr-77b setup, so I'm diving into the bass synth world headfirst... hehe!

[ReCoC]

well...?

nobody has it???
or nobody wants to share it???

[RaceDriver205]

Ill put it up on my site this afternoon

[KaptenSpark]

Ill put it up on my site this afternoon

Really? What site is it? the web1000 one doesn't work

[RaceDriver205]

Lol, OK, ill put it here:
http://www.geocities.com/race_driver205/msynth.zip

[ReCoC]

Lol, OK, ill put it here:
http://www.geocities.com/race_driver205/msynth.zip

Thank you very much! 

[Bernardduur]

Thanks man!

I lost mine

[RaceDriver205]

Tell us how your builds go!
Ive got mine built, I just have to work out how to fit a ca3080 and transistor into a ca3094 socket.

[TELEFUNKON]

It really isn't that difficult to build on stripboard so long as you watch what you are doing, I've done it twice (I don't have layouts unfortunately). I would recommend using CA3094 where required, from memory some can be replaced by CA3080, but I am not at home today so don't have access to my circuits. Perhaps if just pins 2,3,5 & 6 are used then a 3080 will do, but let's have a second opinion.

Incidentally, this weekend we are in England's seat of learning - Oxford, my wife is at a language teachers' conference and I have come along for the ride!

second opinion? http://yfrog.com/64schematqj

[swt]

wow Bill!! thanks to you for the pcbs. that was a long time ago, hah? when everybody were making fuzzes, we manage to get this one working...it was quite a project for me back then, have to say thank you again...