Effects that use 2x sad1024's?

[captntasty]

I find myself in possession of two functioning sad1024's... I'm aware of the Deluxe Electric Mistress, ADA Flanger, etc...  are their any effects where both 1024's could be used?  Short analog delays?  Any other kind of funky effects?

[Hides-His-Eyes]

Keep them for repairs, build modern effects with modern components. It's not right to make a new build with such rare chips when one day there might be hundreds of useless Electric Mistresses knocking around.

(OPINION)

[12Bass]

If you must use them for a new build, I'd suggest a flanger (or two), as that's where the SAD1024A shines.  For longer delays, there are other, better, ways....

[Mark Hammer]

+1

If you look back at circuits from the 1979-1983 period, you'll generally see that the moment companies had an opportunity to replace multiple 1024-stage devices for a single higher-capacity chip, they lunged at it.  The reasons were many: cost, footprint, the nuisance of biasing and balancing individual BBD chips, etc.  So use 'em for what they are good at: flangers.

If you want an uber-project to commit those two chips to, make yourself a pair of flangers, but build in the option to set one of them for a short fixed delay, so that you can produce through-zero flanging by employing both circuits.

Just a quick refresher: "through-zero flanging" is produced when the swept delay approaches, and moves ahead, of the "clean" signal, in time.  So, if the clean signal is set to, say 1.5msec fixed delay, then a swept delay that goes from 1msec-15msec gets to be "ahead" of the clean signal by a half millisecond for a portion of its sweep, when those two are combined.

Through-zero is not the sort of thing one uses frequently, but it is very dramatic when one does use it on long slow sweeps, preferably with a distorted or wide bandwidth signal, and is the benchmark sound people associate with the well-known examples of tape flanging.

It is not enough to simply have two flangers to accomplish this. You need a 1-in-2-out splitter and 2-in-1-out mixer to send the signal to the two processing paths and recombine them again.

[oldschoolanalog]

+10¹⁰ on save 'em for repairs.

[Derringer]

+1

If you look back at circuits from the 1979-1983 period, you'll generally see that the moment companies had an opportunity to replace multiple 1024-stage devices for a single higher-capacity chip, they lunged at it.  The reasons were many: cost, footprint, the nuisance of biasing and balancing individual BBD chips, etc.  So use 'em for what they are good at: flangers.

If you want an uber-project to commit those two chips to, make yourself a pair of flangers, but build in the option to set one of them for a short fixed delay, so that you can produce through-zero flanging by employing both circuits.

Just a quick refresher: "through-zero flanging" is produced when the swept delay approaches, and moves ahead, of the "clean" signal, in time.  So, if the clean signal is set to, say 1.5msec fixed delay, then a swept delay that goes from 1msec-15msec gets to be "ahead" of the clean signal by a half millisecond for a portion of its sweep, when those two are combined.

Through-zero is not the sort of thing one uses frequently, but it is very dramatic when one does use it on long slow sweeps, preferably with a distorted or wide bandwidth signal, and is the benchmark sound people associate with the well-known examples of tape flanging.

It is not enough to simply have two flangers to accomplish this. You need a 1-in-2-out splitter and 2-in-1-out mixer to send the signal to the two processing paths and recombine them again.

sorry to hijack ...

I have two Bf-2 flangers and a splitter-blender
how would I set the two up to make zero-through-flanging ?

[Mark Hammer]

I applaud your spirit of adventure!

The first thing you have to do is make each of those units "single-signal" devices, since they each presently deal with both clean and delayed signals.  This involves lifting one side of R28, a 47k mixing resistor that carries the clean signal.  This is found midway near the wire side of the board just adjacent to the 4558 chip that's closest to the wires.  Just unsolder either end and lift it, so the mod is reversible.  I did the equivalent to my pair of BF-1 units.

Now, perf or breadboard yourself a simple splitter that can be as basic as an op-amp buffer stage with two outputs.  The mixer stage can be a variant of this basic circuit - http://www.generalguitargadgets.com/diagrams/mixer_sc.gif - with two inputs.  Set one of the BF-2 units for minimum depth and just a bit of fixed delay via the Manual control, and set the other one for the "highest" (i.e., up into the treble range) sweep you can get.  Mix them in equal proportions and you should get thru-zero at the mixer output.  The extent to which the swept one passes zero will be a function of what the minimum delay is on each unit.  If you want to get really nuts, don't set either of them for fixed delay and have them both sweeping.  Since the LFOs are not synced to each other, doing that will make the thru-zero point occur at unexpected occasions.

YOu should probably pop a Gravol before firing it up.

[Derringer]

Nice!

thanks Mark

[StephenGiles]

Oh for heavens sake use them for flangers, they are useless in a box.

[Derringer]

I applaud your spirit of adventure!

The first thing you have to do is make each of those units "single-signal" devices, since they each presently deal with both clean and delayed signals.  This involves lifting one side of R28, a 47k mixing resistor that carries the clean signal.  This is found midway near the wire side of the board just adjacent to the 4558 chip that's closest to the wires.  Just unsolder either end and lift it, so the mod is reversible.  I did the equivalent to my pair of BF-1 units.

Now, perf or breadboard yourself a simple splitter that can be as basic as an op-amp buffer stage with two outputs.  The mixer stage can be a variant of this basic circuit - http://www.generalguitargadgets.com/diagrams/mixer_sc.gif - with two inputs.  Set one of the BF-2 units for minimum depth and just a bit of fixed delay via the Manual control, and set the other one for the "highest" (i.e., up into the treble range) sweep you can get.  Mix them in equal proportions and you should get thru-zero at the mixer output.  The extent to which the swept one passes zero will be a function of what the minimum delay is on each unit.  If you want to get really nuts, don't set either of them for fixed delay and have them both sweeping.  Since the LFOs are not synced to each other, doing that will make the thru-zero point occur at unexpected occasions.

YOu should probably pop a Gravol before firing it up.

in a nutshell ... I would basically be running the two flangers in parallel right?

by removing R28 I would be removing the clean signal mix from the output of each flanger?

would it be possible to just run the two flangers in the dual loops of my splitter-blender and flip the phase switch so that one side is out of phase with the other ... thus canceling the clean signal?


update: just tried it, I'm not really sure what it is that I should be listening for here anyway ... got any examples of how TZF  ?

[Mark Hammer]

Here's one for the Foxrox Paradoz Thru-Zero Flanger: http://www.foxroxelectronics.com/Resources/tzf4.mp3

The thru-zero point is the one where the sound just seems to get sucked away and then returns.

[Derringer]

yeah, i was pretty much there then ... but that dude had extra delay coming after the flanging in that clip right?
I wasn't able to get any dramatic delay effect like that

where the sound "sucks out" is where 180 deg. inverted waves combine right ?

[Mark Hammer]

Well, they're never really completely out of phase since there is no phase shift applied, only time shift.  Some frequencies are 180 degrees out, others less so.  However, at some delay times, there is more cancellation than others.