"Dalek's Handbag" (The synth in the 'Pictures!' thread) Soundclip

[salocin]

Wanna post some pics of the boards and maybe we can reverse some of it for you?

[Ben N]

I really can't believe all these guitarist want to build a synth - what are they on drugs or something???

Well, DUH! 

The final touch for guitarists would be to turn some of those knobs into proximity controllers.

[moritz]

   It's..... it's.... it's...    beautiful! 



EXTERMINATE!! EX-TER-MIN-ATE!!!

[Ben N]

The final touch for guitarists would be to turn some of those knobs into proximity controllers.

Looks like I may have been on to something: http://www.youtube.com/watch?v=Gic4BCBfR5c&feature=related

[oldschoolanalog]

The final touch for guitarists would be to turn some of those knobs into proximity controllers.

Looks like I may have been on to something: http://www.youtube.com/watch?v=Gic4BCBfR5c&feature=related

Kitty on Acid. Hmm... Interesting  .
Dave

[dellamorte]

any forecast on the rest of the schematics?

[Ronsonic]

y'know, when I first saw the name of this project I considered it borderline blasphemy. Then you convinced me, it is indeed worthy.

[dellamorte]

i breadboarded the lfo , power supply and noise generator successfully last night and have been fiending for more
im quite happy to do up pcb's when i have all the schematics!

[frequencycentral]

i breadboarded the lfo , power supply and noise generator successfully last night and have been fiending for more
im quite happy to do up pcb's when i have all the schematics!

OK - someone happy to breadboard this thing! That's great - makes getting the project together easier, as you can test what my memory/my reverse engineering says I did.

Chapter 5 - VCO

This is how I did the VCO - the LM13700 bit is from the data sheet basically. I think the transistor exponential convertor is the one I used. You can experiment with the value of the 0.47uf cap. The four 100K resistors are for the CV inputs. You can apply a control voltage through one of those resistors from a 100K Lin pot, hook up pin 1 to +12v, pin 3 to ground, and the wiper to the 100K resistor.



EDIT: Pin 11 appears three times on this schematic for some bizarre reason! Oops......

[dellamorte]

is it possible to use the vco section of a 4046 to replace this?
i cant find the lm13700 locally and while i wait for my futurlec order id like to have something to play with

[Cliff Schecht]

is it possible to use the vco section of a 4046 to replace this?
i cant find the lm13700 locally and while i wait for my futurlec order id like to have something to play with

You can make a functionally similar device using just two transistors .

[dellamorte]

could you shed bit of light on that?

[Cliff Schecht]

I meant that an OTA is a a current programmable amplifier. A similar device can be made from a differential amplifier where the connected emitters can act as a programmable gain pin. Doing this method works, but it can't compete very well with an IC such the 13700's (IC-based transistors can be easily matched, discrete parts aren't).

[frequencycentral]

is it possible to use the vco section of a 4046 to replace this?
i cant find the lm13700 locally and while i wait for my futurlec order id like to have something to play with

You could try it! Post your results. I found this VCO while looking at the LM324 datasheet, you could try this too:



I can't vouch for it though. It should work with any dual opamp. I think the V+/2 node is just a vref.

[orangetones]

Looking good there Rick.  Can't wait for the rest of your schematics! 

Maybe I will breadboard up that Funky MMF later today and see if I can get that to work too!

[frequencycentral]

Chapter 7 - VCA (I know we've skipped a chapter I know)

The CA3080 can be subbed with one half of a LM13600/LM13700 if you can't get one.

The 'Initial Gain' control can set the VCA to be 'always on' by whatever amount you dial in.

The CV input is fed by the inverted output of the Envelope Generator.

The 100K trimpot needs to be tweaked so that you hear no sound when the envelope is resting and the 'Initial Gain' is at minimum.

[orangetones]

Coming along Rick!  Can't wait for the rest of thes eschemo's.  I am looking forward to trying this one out myself.

[frequencycentral]

Coming along Rick!  Can't wait for the rest of thes eschemo's.  I am looking forward to trying this one out myself.

Oh yeah - well I did do some work on it last week! Just the VCLFO and 4024 to go I think.......I'll get onto it!

[AudioMime]

NOOOOO!

Has there been any progress Rick!

[sean k]

I was quite pleased to see this one pop up again as I've got on the cards to do this as well.
http://casperelectronics.com/drone-lab-schematic/

I'm thinking there'd be quite a cross fertilization between the two. Take your time Rick. It'll be worth waitinng for all of us who are interested in this kind of stuff.