Device Flanger questions...

[Connoisseur of Distortion]

I am getting the impression that this thing will want a 15V power supply. Correct? Also, the 4047 will have to be kept away from the signal because of the whole clock timer issue, right? and why does it have so many control voltage inputs on it!? can i drop one (or all) of them from the circuit, and if so, how?

[Mark Hammer]

Yes, it wants 15v.  And yes, it is a good idea to keep HF colocks away from the audio path whenever possible.  That last part is tricky, though.  The clock lines from the 4047 to the BBD need to be kept short too to keep the pulses clean and the clock from bleeding into audio passing near by.  But of course the BBD IS part of the audio path, so you can't exactly keep the clock entirely isolated.

Why so many CV inputs?  Because "the DEVICE crowd" assumed that more sources of modulation might be useful.  For instance, with an LFO feeding one CV input and a very slow ramp wave feeding a second, you could get a gurgle whose delay range kept ascending over some lengthy period (or descending).  Envelope followers and envelope generators could be included with an LFO or multiple LFOs could be combined, and so on.  Of course, multiple inputs doesn't mean they HAVE to be used simultaneously, merely that you could leave them plugged in and adjust their feed levels for when you DID want to use them.  Feel free to drop or add as many as you like.

[Connoisseur of Distortion]

thanks for the prompt reply! i would like to drop some, as i intend to fit this project into a BB if at all possible... so where can i drop the inputs? (what resistors/caps/opamps/whatever can go with them?)

[Mark Hammer]

You can skip the voltage-controlled regen entirely, if you want and simply use the pot/trimpot combo as shown.  You can also drop either CV1 or CV2 for the modulation, shown on page 2.  If you plan to feed it an LFO which HAS a depth/sweep-width pot already, then drop CV input 1 and use CV input 2.  If you plan to feed it a modulation source which does not already have a means to adjust CV amount/width, then drop #2 and use #1.

Quite frankly, though, a 1/8' minijack and an extra 100k resistor mounted on the side of the box would not hog that much space and could make the unit much more flexible.  Remember that a single input can also be used to feed in a premixed combo of multiple sources, such as envelope followers, envelope generators, etc.

[Connoisseur of Distortion]

the flanger has no LFO? ahhh maybe an external voltage source would be useful then  :lol:  thanks for all the help, mark!

[StephenGiles]

Connoisseur of Distortion - you want to put this in a tiny stompbox?? No chance, why cram it up? Mine is in a rackmount box. I used the EH deluxe Electric Mistress LFO and the bounce circuit from the Eventide Instant Phaser. I built mine over 20 years ago - wonderful flanger, one of the best.
Stephen

[Connoisseur of Distortion]

a 1590BB is pretty roomy, and i can fit all of the parts on the board pretty easily (already checked that), and i think i should be able to fit 2 mini jacks, 2 big jacks, 2 switches, and 7 mini-pots if i plan it carefully. if this fails, i will probably resort to a DD, for the extra large face.

[StephenGiles]

How big is a DD, and what about the dual power supply?
Stephen

[Connoisseur of Distortion]

a DD is 7.38x4.7x1.3... then there's the C, which is 7.5x4.3x2.4

i didn't even think of the dual power supply. i guess i'll need to add in a little converter circuit board, to put out 15 volts + and -... probably go with the C, for the extra depth...

i just really want to keep all of my effects on the ground!

edit: the C mentioned is the taiwanese 125C

[StephenGiles]

Is that inches?
Stephen

[Connoisseur of Distortion]

yes

[Mark Hammer]

With some reasonable layout, modest size caps (they HAVE gotten a lot smaller these past few years, haven't they?  I've bought some bubble-packed 100u/25v that are half the size of the 1u/16v I used to buy 5 years ago), compact 16mm pots, and a wall-wart/on-board-regulator configuration, the DEVICE flanger should be relatively easy to build into a 1590C, which is a kind of Carl Martin sized box.  The nice thing about them is that boards can be mounted vertically in there.  It wouldn't at all be unreasonable either to use two stacked boards.  For instance one board with the input/output circuitry and companding, and a second board with the LFO, clock, and BBD.  Stack the two equal-sized boards one atop the other with spacers between, and underneath, and run some bolts from the outside of the chassis through the stacked spacers to secure the two boards to the chassis.

Another nice feature of the 1590C boxes is that the controls don't have to all be on the top surface.  There is plenty of room on the sides and rear skirt.

[DiyFreaque]

"For instance one board with the input/output circuitry and companding, and a second board with the LFO, clock, and BBD."

I took this approach with my Dim C project - almost all of the audio is on one board (companding, crossmixing, buffering, etc) and the BBD's/Clocks are on separate boards, along with the pre and post BBD LPF's.  I connect from the main audio board to the BBD boards using coaxial cable (grounded on one side of the shield).  The audio jumps to the BBD boards after compression and before expansion, so any potential mutually inducted clock noise which the coaxial cable doesn't prevent should be 'expanded out', or at least reduced considerably before continuing down the audio chain.  Ideally, the post-BBD/pre-expansion LPF filter would be on the main board, but there just wasn't room.

It works pretty well, though I still have to get one in the rack enclosure for the ultimate test (the wheels of DIY grind slowly onward).

As mentioned by others in other threads, star grounding/supply voltages is always a Very Good Idea.

Cheers,
Scott

[StephenGiles]

This is what I control my AMS 100 flanger with:
http://img.photobucket.com/albums/v317/StephenGiles/bnce_clock.gif

It might also be possible to use Mike Irwin's ADA flanger mods for almost thru zero flanging, although I won't try it with mine - being a bit of a bird's nest!!
Stephen

[DiyFreaque]

Ooh!  Thanks for that one, Stephen!



Cheers,
Scott

[mlabbee]

Where is the schem for this flanger?  (yes, I've searched - my brain is not funcitoning well today and I find nothing)

[Mark Hammer]

Chack page 9 of http://hammer.ampage.org and click on issue 9 and 10 of DEVICE.

[StephenGiles]

hey Mark, you beat me too it!!!
Stephen