A signal inversion thing...

[strungout]

... I built the Stasis Leak from Frequency Central, but I wanted stereo output. I have used it on two amps but, while it sounds awesome, I can't tell don't know how to tell that it's stereo...
If the Echo was stereo I could listen to it ping pong between amps, but let's say it's less evident with stereo plate reverb...

Here's the schematic I drew up from Rick's design:



The original: https://frequencycentral.co.uk/wp-content/uploads/GT-Stasis-Leak-schematic.pdf

If I follow the signal, it keeps getting inverted by the op amps, but the inversion that really matters is the one that happens inside the Belton ABE-01 module and comes out output 2. Other than that one, all operations on the signal are the same: inversion.

But then I wonder... I need to feed a dry signal to the outputs to get the desired effect, so, do I need to invert that dry signal for the second output, which is out of phase with output 1, to get a proper stereo effect?

Datasheet:

https://www.amplifiedparts.com/sites/default/files/associated_files/p-r-abe.pdf

[iainpunk]

it has stereo chorus and reverb, but the delay (echo) is mono in these chips.
i have no idea how to actually check for stereo. you can compare the suspected stereo with a mono splitter, or do a null test by subtracting the signals from eachother. if the stereo is true, there should be signal comming out, if the stereo is fake, you should have no output signal at all.

cheers

[strungout]

Iain: You mean two mono in into one mono out?

I still have it on my breadboard so I can change and try stuff.

[PRR]

Any stereo will be from the delay unit. Quote:
* Stereo Chorus
- This is a standard "quadrature" chorus — two voices with 90-degree phase difference between LFOs.
* BTDR-type Stereo Reverb
- This reverb emulates the AccuBell BTDR module with some enhancements,...
http://www.belton.co.kr/inc/downfile.php?seq=90&file=pdf 

In concept: take the outputs to a stereo hi-fi with known good balance and separation across the two channels. Headphones are excellent. Mono will be smack in the CENTER of your skull. (Or exactly nowhere, far-out.) Stereo will be different each side.

[iainpunk]

if its still on a breadboard, you can just throw together a difference amplifier (google images for schematic) for testing purposes only.
if its real stereo, you'd get output signal, but if its just two times the same mono output, it will null-out to silence.

cheers

[strungout]

Thanks for the suggestions. The only hi-fi amplifier I have access to is my friend's, so I tried Iain's differential amp first. Quick enough. (I'll have to go and check out how this sounds with my friend's electronic drum kit, though.)

I get sound at the output, so I got stereo then. Thanks for helping me figure that out!


One things I'm curcious about is, on the chorus setting (through that differential amp), the sound cuts off at the top of the sweep. It sounds like a 'rounded' drop. Is that because the signals are canceling each other at that point?

[iainpunk]

Thanks for the suggestions. The only hi-fi amplifier I have access to is my friend's, so I tried Iain's differential amp first. Quick enough. (I'll have to go and check out how this sounds with my friend's electronic drum kit, though.)

I get sound at the output, so I got stereo then. Thanks for helping me figure that out!


One things I'm curcious about is, on the chorus setting (through that differential amp), the sound cuts off at the top of the sweep. It sounds like a 'rounded' drop. Is that because the signals are canceling each other at that point?

you're welcome

yes, its just two choruses with the LFO 90 deg out of phase, when the level of the LFO's match, they have a brief moment of doing the same thing, thus canceling out. should occur twice per LFO cycle

cheers