SAD1024 in hand - What flanger to build?

[cdw2000]

Hi Folks,

I have an original Reticon SAD1024 bucket-brigade device (BBD) IC which was used in several of the classic pedals such as the original A/DA Flanger, the MXR M117 Flanger, the EH Electric Mistress and Electric Mistress Deluxe.

I have the know-how, schematics and the means to build any one of these, but am have trouble deciding which one. ( I do intend to use a socket for the SAD1024, so can always build a different one later)

So ... if you could only have one, which one of these would you have in your arsenal?

Are there any others that I overlooked?

[Kap'n]

I'm kind of partial to the Ross stuff.

[cdw2000]

Thanks, Kap'n.

I did a quick search on the Ross Flanger and did not find a schematic, though several sites indicate that it is essentially the same as the MXR Flanger. I will do some further research to see if that is true. It maybe the same topology with some value changes.

BTW, whichever one I build, I will be altering the design to eliminate the need for an AC power cord. I will be using a special charge pump voltage doubling IC so it can run off a 9V battery or standard 9V pedal supply.

[Kap'n]

Yep, I'd pass on the AC requirement too. That's thing about my Ross D/P Combination. It's essentially a Distortion Plus and a Phase 90 with a feedback control in the same box. Who thought that needed a plug?

Where did you find a SAD1024?

[cdw2000]

I had a box of parts given to me by a co-worker back in the mid-90's. I nearly forgot I had it and ran across the box a few days ago.

I saw the SAD1024 and thought "I should really do something with that."

I also have a metal can CA3080 (ala Ross Compressor), some top-octave divider chips and an old console game sound synthesizer chip.

I recently acquired the ability to make photo-etched circuit boards, so building more complex effects got a whole lot easier :-)

In the 80's you used to be able to buy the SAD1024 at Radio Shack, they also had a circuit board to allow you to build an echo/flanger box, which I experimented with (the circuit was very noisy, but I got some interesting sounds out of it). I wish I still had that one as well. If only I could see into the future...

[chuckocaster]

I don't know what chip it uses, but I'm partial to the big box MXR that has an AC plug you have to plug into the wall. Like a fool I traded the one I had for some Seymour Duncan strat pups...

[cdw2000]

I'm moving forward with the MXR "big box" flanger build, though my version will not require AC power.

I have not found a PCB pattern on the web that also incorporates the voltage doubler circuit, so I am creating my own.

[chuckocaster]

Very cool!

[cdw2000]

While doing research on Flangers, I found some articles on TZF (Through Zero Flanging).

Apparently none but a few commercially available analog flangers replicate the original dual tape-deck flanging effect. Most flangers can only add in a positive delayed signal to the dry signal. Whereas the original flanging effect would have negative delay (i.e., the wet signal would at times come before the dry signal in time).

This can electronically be accomplished by running the "dry" signal through a fixed delay so the "wet" signal can sweep through a positive and negative delay with respect to the dry signal. This adds a little latency to the signal, but no more than many digital effects processors.

I have two DOD FX75C flangers from which I can harvest a matched pair of MN3207 BBD chips. So I'm thinking of designing my own TZF capable flanger after I finish the MXR clone.

(need a mad-scientist smily)

[chuckocaster]

Anything ever come of this?

[cdw2000]

Sorry, just noticed this thread resurfaced. I built the MXR clone using a circuit board from MadBeanPedals (thanks Chuck for introducing me to that website). As far as I can tell, not actually having owned one, but looking at YouTube videos of the real thing, this sounds just like it.

Low noise, no clock bleed-thru except at highest Manual setting (longest delay). Runs off a single 9V battery or source thanks to the LT1054 voltage doubling circuit.

Its got very nice sweeping sounds and one can get that full jet engine filter sound if you want it.

I never did pursue the TZF option. Maybe will revisit at some point.

I still have the original SAD1024 chip waiting for a home, so am planning at some point to build the Deluxe Electric Mistress so I can pretend I'm Andy Summers. I have not found a suitable PC layout that I like, so will have to create my own, I think.

Right now though, I'm looking at building a JangleBox clone... My research indicates that it is pretty much the same as the compressor that was built into the Rickenbacker 12 strings at one time. Except for component value changes, the Ric compressor is the same circuit topology as the Ross or Dynacomp compressors except for the elimination of a capacitor (do a Google search on Dynacomp and Jangle mod).

Cheers

[chuckocaster]

I'm excited that you did build the MXR clone!!! To this day I kick myself for trading mine...

I'll check out that mod, I think I still have my RI DynaComp, somewhere.