Matriarch - chorus patch with delay

[sdwillingham]

Hi All,

I recently bought a Matriarch, and I love the overall sound and feel (except the sliders )

I anticipated having a lot of fun with the voltage-controllable stereo delay. But so far, I have found it to be very frustrating and I wonder if I misunderstand the operation, or maybe my unit has a bug.

Basically, the delay seems to work as documented for static delays. Sounds good and clean, though darker than I generally prefer. But I cannot get any satisfactory results using the 'Time 1/2 In' controls. They have an gross effect on the delay and I can get general seasick wobbling and warbling. But when I try to do any subtle, smooth modulation, I just get lumpy, lurchy sounds. I have patched either LFO into attenuators (even two attenuators in series) and cannot get a nice smooth subtle modulation of the delay.

Some large modulations seem relatively smooth. But these are too large, even for vibrato. Only seasick sounds. There seems to be no level of modulation small enough for good results at short delay values. Weirdly, the modulation seems to get more "lumpy" when its amplitude is reduced. I am hoping to be able to dial-in a chorus sound, but nothing is even close. It seems that online videos show MF-104 demos with nice modulation, but I have not found anything that shows the Matriarch with smooth, subtle modulated delays.

Any suggestions? Could my Matriarch (Dark version, bought two weeks ago) be defective?

Thanks!

p.s. I am an analog integrated circuit designer by profession, so I have a lot of experience with laboratory circuits and debugging. I should be able to try most suggestions, even without needing too much detail.

[nezzyidy]

I haven't tried that, what are the settings for the delay knobs that you think should work?

[nezzyidy]

This article plus comments has some relevance:

https://electricdruid.net/investigation ... ally-does/

The rate modulation unfortunately changes the pitch so people use non-triangle modulation waveshapes to try to minimize the wackiness.

One person said, "Nice work. Though the optimum frequency modulation for chorus is not exponential. It is hyperbolic, as that gives zero pitch warble. For small modulations, an exponential modulation looks approximately hyperbolic which is why it works OK."

Another said:

"If it’s of any value, I used to mess around with BBD devices (before digital became a realistic alternative for home constructors) and this ‘non-linear’ pitch shifting was annoyingly evident when modulating a linear VCO clock source with triangular or sinusoidal waveforms.

I never tried to mathematically unravel it but my thinking was that there were two effects going on. One, as you state, the amount of pitch shift is related to the rate of change of the delay time and the second is that the longer the delay time the greater the pitch shifting effect, but this is also a function of the relationship between the delay time and the wavelength of the signal passing through. If the delay time is much shorter than the wavelength, the amount of pitch shift with a given modulation rate will be smaller than with a longer delay or shorter wavelength.

As a result the modulation waveform’s effect on pitch shift varies over its cycle and the change of polarity at the longest delay is most pronounced. I read somewhere (possibly an E&MM magazine) that this effect can be compensated for by changing the shape of the mod waveform. A triangle waveform was suitably biased and put through a diode to perform a logarithmic conversion of sorts, to produce a very nonlinear asymmetrical waveform with a sharpish peak and shallow bottom. I seem to remember that this worked quite well but took a bit of fiddling with levels and bias to get an optimum waveform. But every time you changed the delay time, the depth of modulation had to be adjusted to get the effect right. Room for improvement…"

[sdwillingham]

This article plus comments has some relevance:

https://electricdruid.net/investigation ... ally-does/

The rate modulation unfortunately changes the pitch so people use non-triangle modulation waveshapes to try to minimize the wackiness.

Thanks! That's a really good article that I haven't seen before. I was aware of the nonlinear pitch modulation -- I built a PAIA Hyperflange/Chorus back in the day However, I have been thinking it wouldn't be so much of an issue with short delay and subtle modulation like a chorus effect. I'll definitely give it some thought and experimentation.

That said, I wonder why Moog doesn't have some modulation shape compensation built-in? How have they sold so many MoogerFooger delays with built-in LFOs with this kind of behavior? Seriously -- I haven't yet found a single sweet spot in modulating the Matriarch delays. In contrast, the rest of this machine is full of sweet spots and easy to dial-in.

Thanks again!

[nezzyidy]

Forgive me for not be able to test until Tuesday. But did you already try fastest Delay time, zero feedback and 50% wet? That’s in addition to what you are already doing with the attenuator to send very little modulation and trying fast and slow LFO times.

[sdwillingham]

Forgive me for not be able to test until Tuesday. But did you already try fastest Delay time, zero feedback and 50% wet? That’s in addition to what you are already doing with the attenuator to send very little modulation and trying fast and slow LFO times.

Yes, I have tried every combination of knobs I can think of, especially at the shorter end of the scale. I’ve even tried using the “Delay Sync CV Bend” feature of the firmware, which as described, should also work for smooth modulation. However, the results are very odd. Sometimes wide/fast modulations work. But slower, smaller modulations always become jerky and burbly.

I appreciate if you can try it out when you get a chance. Thanks for your help.

[nezzyidy]

Yeah I can get subtle effects (although hard with one attenuator ) but I don't get phaser/chorus much because the delayed signal is darker.

[Desperate4sleep]

@sdwillingham
I've just been trying to get a chorus effect on mine. Funnily, I tried everything you tried and I experience exactly the same (Well described btw ).
I have been trying this only with a guitar going into the instrument in however.

An idea just came to me that might work, or get closer results (might only work with an external instrument in but anyway).
Try to record a sequence within a small range (maybe an octave) on the Arp/Seq, take the CV out from there to put in the Delay time In, dial the glide/portamento up and hopefully, a smoother and more subtle modulation can come out of that for a chorus-y type thing where the delay time modulation wont sound jittery.
It might not get results as smooth as a pure sine wave, but it might tame things.
If you give it a shot, let us know. I will do the same when I get a chance

[sdwillingham]

Well, I finally got around to installing the 1.3.0 firmware patch. AND, the delay time1/time2 inputs are still entirely worthless. I’m very disappointed. IMO — the Matriarch delay remains intensely dark, bland, and featureless.

But maybe I’m missing the point. I really don’t give a damn for synchronizing an analog delay precisely to the sequencer/arpeggiator/external clock. Smooth patchable modulation of the delay is far more interesting to me.

[Synth.builder]

Well, I finally got around to installing the 1.3.0 firmware patch. AND, the delay time1/time2 inputs are still entirely worthless. I’m very disappointed. IMO — the Matriarch delay remains intensely dark, bland, and featureless.

The Matriarch delay circuit has two features that stop it being a good chorus or flanger effect.

1. The available bandwidth for the audio signal is by default severely restricted and it doesn't change with delay time. Some analogue delays (I would say my favourite ones) automatically increase audio bandwidth as the delay time is decreased. The Matriarch's delay will always sound muffled and dark by default. However, there is an option in the global menu system that allows the delay's internal filters to be partly turned off. This should brighten up the sound but will increase the clock noise at longer delays.

2. The main problem however is the inability for the Matriarch's central processor to handle dynamically changing control voltages in a timely manner. The processor creates the high frequency clock signals that determine the delay time. It is not a fully analogue delay in this respect in that it has no high frequency VCO that can be modulated like a traditional BBD chorus or delay. It would great it the processor responded more quickly to the delay CV input. But it doesn't and it glitches in an unmusical way. This could be fixed in a future update if the processor has enough spare capacity.

[sdwillingham]

As a circuit designer, I fully agree with your assessment. The question to me is: why did Moog design it this way? Much of the charm (if any, with modern tech) of analog delays is in the smooth and continuous modulation of the timebase.

If one wants a murky delay with glitchy clocking and tempo-sync features, why not just save money and go digital? There is no value to the analog implementation at all.

All my opinion, of course.