The DoubleDeka Ultrasonic VCO

[frijitz]

Good news ... The DoubleDeka is now for sale at bridechamber.com!



Ian

[drapdap]

http://www.bridechamber.com/bridechamber.com/F%20DoubleDeka.html

Not cheap, but f+++! A dream came true, a hardware wavedraw osc.
Congratulations on that Ian, you are massive!

I wanted to ask about the sliders, - it might have been mentioned earlier-
but how many kiloOhm sliders are we talking about?

róbert

[frijitz]

[pristak]

Well, my full kit is finally in the mail. I've been intending to order this for a while.

Is anyone else working on this one? I think this will jump ahead on my list since most of my other projects are waiting on backordered parts.

[pristak]

I made a serious dent in this project last night. There wasn't much interest on here, so my pics and progress so far is here http://www.muffwiggler.com/forum/topic-5095.html

[pristak]

I had some more progress on this. The pic's are up on the muffwiggler site.

[pristak]

Finished. It worked fine first try. I still need to calibrate it and reverse the wiring on the Sync switch, but everything worked first try.

[dave_3283]

Does anyone know the size on the linear pot PCB? I've been doing 4u Serge-ish panels and would like to figure out if I can make this project fit...

[frijitz]

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[Coriolis]

Pristak, that is downright nice! Sigh..I'll never get that to fit in my panel format...

C

[pristak]

I won't likely have a chance to get serious mp3's together for a while. I am reorganizing my studio and don't have all the power cabling and placement worked out. I get married very soon as well so time is limited right now.

I may be able to put up a quick demo sometime soon, but I've done that before and been real disappointed when I listened back later. We'll see.

[frijitz]

There is some discussion on the sdiy list about what a Saw run through a Sin shaper would sound like. I set up the DD to produce both a Saw and a rounded Saw so folks can hear the difference. The rounded Saw is closer to a Square wave than a straight Saw is, so it has relatively fewer even harmonics. Of course, these are ten-step approximations, but that doesn't matter too much in making the comparison. On the mp3, the rounded Saw is first and the regular Saw is second.



Ian

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[pristak]

It's calibrated to the best of my abilities with what I have available. Ie, it stays in tune according to my guitar tuner across the octaves.

Samples are up on the muffwiggler site.

http://www.muffwiggler.com/forum/post-71331.html#71331

[lexvortex]

Hi Ian,

I just finished building two of these They sound awesome!! I am however having a slight problem with the second one I built, it tracks well in the lower frequencies up to the mid-high frequencies but after it hits C7 or 8 (I'm not sure if it's that high) it will start to go down in pitch for about four notes then goes silent past that, my other one goes to this pitch easily. I don't know if it makes a difference but I accidentally put one 1N914 rather than an 1N4148 for one of the diodes on the slider board but I figured it didn't matter too much. Any help would be appreciated.

Also how do I wire up the HF out?

Thanks,
Dave

[frijitz]

[pristak]

Ian:

Its in the same thread I started earlier. It is in the DIY subforum. They changed the layout and the DIY section is near the bottom now. I liked it better when it was near the top.

lexvortex: The HF out is wired directly from the pole of one of the 6 position switches.

[pristak]

Ok, lets try this




Doubledeka w/cgs tube vca. Sequenced by Doepfer maq 16/3. Recorded straight into Cubase using a Presonus Firestudio. A little compression (UA Fairchild) and eq (UA Neve 1073) as put on in the mix.

[pristak]

I like this one better. Where did my fade out go in the last one? heh...



Doubledeka VCO, Into LPG Sequenced by Doepfer MAQ 16/3. About 1 minute in, exponential FM is provided by a Jerkster chaos. Recorded straigt into Cubase using a Presonus Firestudio, no fancy effects.

[frijitz]

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[lexvortex]

Hi Ian,

Thanks for the responses I figured out what was wrong... just 4am retardation I had the octave switch up too high in comparison to my tuning source and got them all confused. Got it all sorted out today and both are working great!!

Cheers,
Dave

[sduck]

I'm just about done with the wiring on this, and wanted to ask about something that's been vexing me. On the pcb there is a hole marked v/o on the side next to R7. There's also a hole marked v/o over in J2, which is connected to R6. These both feed into the same place through identical resistors, so I'm wondering - why? Am I missing something?

[frijitz]