MN3007 ADA Flanger stereo option (anyone?)

[jmasciswannabe]

I have read of a few ideas for this and a couple people who tried it and it didn't work. Has anyone successfully implemented a stereo mod and if so, would you mind sharing a schematic?

Building the vero version!!

[jmasciswannabe]

Bump!

[moosapotamus]

I can tell you that I am not aware of anyone who has successfully done any sort of stereo mod for the ADA Flanger. As you've read, there are a number of different approaches that have been suggested. And it also depends on what kind of final result you are looking for.

For example, if you want to be able to input a stereo signal (left and right inputs) and get a stereo output, you could just build two complete circuits and run them in parallel as in the Bell Flanger (click on the schematics link at the top of this page and scroll down to Bell).

If you just want a mono input and you want to hear the effect sweep up in the left output while it sweeps down in the right output, you probably also need to build two complete circuits in parallel, and figure out a way to sync them. Or, the left and right outputs could just sweep independently.

If you just want a mono input and stereo outputs... to hear the effect swirl from left to right, you could try adding a panner circuit like the Tremulus Panneur on the output, or something similar, and maybe blend some clean signal with the output, maybe?

Another way to create a pseudo stereo effect is to output a completely wet signal to one output and a completely dry signal to the other. I did this in my Wavy Gravy pedal (modified small clone clone). There are some clips on my website. But the challenge with taking this approach on the ADA Flanger is that the wet, dry and regen signals are somewhat commingled and getting basic wet and dry signals to send to separate outputs is not so straightforward.

Maybe try searching for some stereo phaser schematics and see how they were implemented?

But anyway...

The point is, not only are there a number of different approaches that you could take, there are also a number of different end results that you could be aiming to create... all of which may be reasonable expectations, but only some that may fit what will please you and suit your needs/wants.

Since there are so many different approaches that you could take with this circuit, if you provide some more specific info about what kind of "stereo effect" you would like, I'll bet the folks here could come up with some good ideas for you to try.

~ Charlie

[artifus]

Another way to create a pseudo stereo effect is to output a completely wet signal to one output and a completely dry signal to the other. I did this in my Wavy Gravy pedal (modified small clone clone). There are some clips on my website. But the challenge with taking this approach on the ADA Flanger is that the wet, dry and regen signals are somewhat commingled and getting basic wet and dry signals to send to separate outputs is not so straightforward.

how about ye olde studio mono to 'stereo' phase trick? split output panned hard left and right inverting the phase/polarity of one of the signals. easily demo'd in your daw and super easy to implement in an external box.

[moosapotamus]

I think that would work really well for live/stage setting, using two amps and sending the left output to one amp and the right output to the other.

I might be wrong, but if used for recording, wouldn't the left and right signals cancel each other out if summed back to mono? Something typically avoided when recording, I think.

Again, depends on how the pedal is going to be used.

~ Charlie

[jmasciswannabe]

Moos - Can't remember if I pm'd you or not, but can't thank you enough for putting up those calibration videos. They were super useful! This will be my third build and wish they would have been around back when I used an early board of yours with the sad1024. I'm getting adventurous on this one and trying the vero. Anyway, I am hoping to use this in a live setup. One cab on my side of the stage for one channel and another cab on the other side of the stage for the other channel. This circuit is a little too big to do two of them (parallel), and I don't like the idea of either wet or dry on my side....

I'd like to try the inverted phase. I remember seeing this being used on the clone theory that jimi recently built.
https://sites.google.com/site/electroconducive/ehxclonetheory

I've also seen this:
http://colomar.com/Shavano/intro_opamp2.html

Any other useful suggestions for tacking on a phase inverter would be much appreicated!

[oldschoolanalog]

Anybody build that Bell flanger yet? Looks interesting. Not too complex for what it is.
Wonder how it sounds (?). Hmmm....
PS: The availability of the IC's is not an issue...

[artifus]

Any other useful suggestions for tacking on a phase inverter would be much appreicated!

http://en.wikipedia.org/wiki/Phase_splitter

check out the revised mofet booster over at amz - disregard c5, r6 and switch:

http://www.muzique.com/schem/mosfet.htm

*also* http://www.diystompboxes.com/smfforum/index.php?topic=73802.0

[jmasciswannabe]

....I was just reading about the super chili picoso.....

That is definitely do-able. I'll get this built up and report back with the results.

[moosapotamus]

Anybody build that Bell flanger yet? Looks interesting. Not too complex for what it is.
Wonder how it sounds (?). Hmmm....
PS: The availability of the IC's is not an issue...

Hi Dave! I've been curious about the Bell Flanger for a long time too, but never found the time to roll up my sleeves and dig in to it. It has some cool features, like envelope control. Maybe a mono version for starters.

Any other useful suggestions for tacking on a phase inverter would be much appreicated!

The way you are thinking of doing it looks pretty straightforward, Ian - Just like artifus suggested, above. You could use something like a transistor/mosfet phase splitter, but you still need an opamp to duplicate the output section around IC2b for the second output. So I guess I would try going with a dual opamp, one side for an inverting buffer, and the other for the second output section. Either way, I'll be interested to hear how it works out for you.

~ Charlie

[Mark Hammer]

Static stereo - i.e., it sounds different on this side than on that one - is only moderately interesting.  MORE interesting is movement across the stereo field.  The Tonecore Liqui Flange does its through zero thing as it moves across the stereo field....VERY impressive.  I'm wondering if  one might productively add a few stages of swept allpass on one side, and modulate them with a 2nd LFO....or is that what the Flanger Hoax does?

[moosapotamus]

Cool idea, Mark.

I could be wrong, but my guess is the Hoax is a little different. It only has the one rate control for the modulator,so it doesn't appear to have a second LFO to sweep the filter. It just lets you switch in more/fewer stages to get more/fewer degrees of phase shift. It also does not really have stereo outputs, either.

But, I wonder if you could use just the one LFO to sort of sync the modulation of the phaser stages with the flanger sweep? If I'm wrong about the Hoax, maybe that is what it does.

~ Charlie

[artifus]

i have to admit to being ignorant of the circuits being discussed but with regard to the signal split phase idea, as you now have two outputs you can apply further effects to either (or each) output, a delay for example, for variation/animation, no?

[moosapotamus]

Cool idea. A 100% wet delay on one output might sound pretty cool, even as an alternative to inverting the phase on one output.

~ Charlie

[Mark Hammer]

What about a few fixed lead allpass stages in series with the wet signal on one output, and the same number of lag stages on the other?

That is, let's say 4 stages in series like the one below, where R1=R2=R4=10k, and C3=.047uf, added to the delay signal, providing an additional 360 (or is it 720?) degrees of phase shift for content around 340hz and above, on top of the time shift provided by the BBD.  When the wet signal gets fed to the mixer for the other channel, it goes through 4 stages where C3 and R4 are flipped around, so that there is 360/720 degrees of phase shift for content below 340hz.  If I'm correct, then the spatial location would appear to shift from left to right as the pedal sweeps up and down.  As it sweeps down, one output is a little more time delayed than the other, and as it sweeps up, the opposite channel is a little more time delayed than the other.

Is that accurate/valid, and does it make sense?

[newperson]

the ibanez flying pan has the two stereo fields.  you might check out what is going on with it.  sounds neat with 2 amps.

[Jdansti]

I've got an old Fender UltraChorus amp that has an MN3007 stereo chorus.  The chorus is really nice and can be adjusted to give a bit of flange.  It's a combo amp that uses the 2x12's for the stereo chorus effect. Here's a schematic of the amp including the chorus. Maybe you can zoom in and cull out the chorus from the rest of the scheme.

http://db.tt/QYo31IWm