Doctor Quacky times two; DRQx2 (with photos and schemo)

[sean k]

Ages ago Mr Hammer helped me design up a Dr Q with two drives and amps and I've finally got it together and going.

Now it really is kinda quacky isn't it! I, so far haven't got the two quacking 'cause as soon as both volumes are up it's just normal. But when I turn one volume right down I can get that farty blatty fuzzy sound going but it's ultra finnicky.

For starters I'd like to amp the output 'cause even at full bore it's a little below unity so that'd just be a matter of changing the 12k on the output amp to maybe 24k?

Then I'd like to get the range wider somehow as those LED's seem to be very, how can I describe this, A wider glow range maybe. At the moment they aren't very dim at no input and not completely bright at a hard picked note. I'm thinking that a wider range will make the difference in opening and closing the transistor. Maybe a smaller cap after the attack pot?

Also I'm wondering if the caps off the collector are too close in value between the two "shifter" amps. The 6.8 nanos, in the upper amp could be made bigger, like 15 nanos and the 1 nano riased to 6.8. Any ideas?

The other thing is that I've got some nice little inductors that I used in a drum thing, for cymbal sounds, which were set up like the little schemo in the bottom left corner, and the white noise from the avalanched transistor kinda built up and faded accross the output transistors collector resistor because of the inductor..., well thats my reasoning... and I liked it alot. I'm wondering where I could drop in these inductors in the quacky to get the same kinda of rise and fall. The smallest I got are 150 mH and then values up to about 680mH. I thought accross the 470k in feedback network as they'll suck up the treble and let the bass through and follow it later with the treble. Is that right? I don't suppose they'll have m ch effect in the driver circuits though... or will they?

I've got more questions but I'll shut up now and post this then shut down so hopefully the PC starts up right with USB so I can upload some phots of the thing as built.

[sean k]

So this is what it looks like.

The little short knob shaft at the top and to the right is the sensitivity and the two LED's either side are the drives.

The Doc with his guts hanging out undergoing minor surgery!

as a refrain this is what I'm using to generate noise through it. Two cello strings on a fretless neck over a tamborine shell without jangly cymbals. The bridge sits on an aluminium milkshake shaker lid and is curved on the bottom with an arm so it can be trembled. Does nice things to the feedback.

It's got a piezo and an electret in it and it feedbacks like a sick horse.

[John Lyons]

Once again I dig what you have going here aesthetically and creatively.
Nice way out of normal enclosure!
No advice on the circuit but I wanted to give a thumbs up on the build.

I miss my studio space and experimental music partners...different state, different times....

john

[sean k]

I've started going to a thing called Vitamin S every monday night so I have to make something new each week... until I get bored with it. It'll be my second time with instruments this week, last week I played the synth stick and they made me do it twice!
http://www.vitamin-s.co.nz/