Aion Blueshift Biasing

[Timko]

Ok, that sounds like it has much motion as mine does now! 

By chance could you just pass some sort of sine wave into it if you have a function generator?  I notice the movement a lot more when I'm not using an instrument.

BTW, your effect sounds really good.  It's got move more movement than the new Waza Dimension C which I think is a good thing.

[gordo]

Here's a mono version of the old original.\:
https://youtu.be/gK8rZHKwizQ

[gordo]

I agree though, at least in the Mike Hermans video the Waza version is more flanger sounding with a lot less movement.  Maybe a shorter delay time?

[Timko]

I agree though, at least in the Mike Hermans video the Waza version is more flanger sounding with a lot less movement.  Maybe a shorter delay time?

Maybe this is actually a disadvantage for me, but I have a friend who's got an original DM-2 who works at a store that sells Waza stuff.  So I was always comparing the motion of my build against those two pedals.  That said, that demo you shared of the original has motion more similar to mine (more pulsing sounds as you select higher modes) while my friend's old DM-2 sounds more like the Waza version. 

NOD (new oscilloscope day) is tomorrow for me though so I plan to take a LOT of screenshots on both of the delay sections.  I hope to use it to determine if there is something awry with mine or if it works correctly.

Thanks for all the help!!

[EBK]

I think the pulsing and "motion" are separate phenomena.  In the Blueshift, the delays are modulated by opposite LFO signals, but there is a point in the modulation cycle where they line up. The result is a chorus that pulses. This is different from motion where you perceive a distinct pitch shifting up and down from a single modulation direction (a woozy, uneasy, seasick chorus effect).  That is my understanding anyway.

[Timko]

I am starting to feel the same way about pulsing and "motion."  This weekend I plan to put this thing through the paces with an oscilloscope, measuring the LFO, clock and delay signals, and comparing the two delay paths to see how much they are perfectly out of phase so I'll be able to back it up with some hard data.

A quick aside because I spent quite a long time staring at this schematic.  Are the opposite LFO signals created when IC5 and IC6 ?  It appears for the 'top' delay IC6A goes into IC6B.  In the bottom delay IC5B goes into IC5A (so reversed).  That was the only difference I could find in the between the two.  Is there a connection difference I'm missing or is that what causes the phase difference?

[Scruffie]

IC6A is inverting, so the LFO gets flipped 180 for that channel, that's where it happens.

[gordo]

Here's shots of my scope:

This is the input signal.  8K at 2v p-p


This is TP1 biased


This is TP2 biased


And this is the output with all 3 switches up, variable waveform so just a snap of what I could get.

[Timko]

Thanks to everyone who's commented so far.  I bought a proper oscilloscope (A Rigol1054Z that I unlocked with all the options + 100 mHz bandwidth).  On a side note, if you are becoming serious about building (and at this point, I would define myself as a serious hobbyist), make the investment in a Scope.  It answers so many questions you may have.
Now onto my particular investigation.  Using the scope (which generates a function signal itself), I was able to shape the waveforms coming out of TP1 and TP2 per the instructions.  So good so far.  I wanted to then put both TPs on the scope at the same time.  However, I was unable to do this using standard edge triggering.  One of the signals would remain stable while the other would never trigger.  I spoke with an electrical engineering friend who thought the frequency of the signal was changing.  And what do you know, I think he was right.

* The frequency on TP1 and TP2 both oscillate (from 7.95mHz to 8.06mHz)
* The voltage on TP1 and TP2 both oscillate (from 2.65V to 2.85V)

So looking through the scope triggering options, I found a method called delay triggering, which triggers if the 1st and 2nd signal are within some proximity of one and other in terms of shape.  I chose to trigger for anything less than 1us.  I then alternated between triggering the directions in opposite directions (out of phase) and the same direction (in phase).  Both would trigger, then jump around, then trigger, then jump around.  To me, this picture describes what I was seeing:



There's something Gordo posted in his initial build where he mentioned that the pedal has a "vague modulation that doesn't really seem to start or stop."  This sort of describes that.  I still think my effect has a little more movement than the sound samples Gordo posted, but at this point I think the overall way my effect is working seems correct and I'm going to box it and call it good.  However, if that voltage/frequency oscillation seems wrong, let me know because I'll have to rethink my hypothesis.