Visual Sound H2O, want to shorten min delay time

[vseriesamps]

Hi you all

I have a Visual Sound H2O delay/chorus pedal which is a cool thing, but I'd like to shorten the minimum delay time for the delay side. Their website says the pedal uses two chips, an MN3102 and an MN 3207, I can't say myself if they are shared by the chorus and delay or what. Their tech help says these chips set the delay time and the pedal as is cannot be modified to make it shorter. I'm wondering if there is another chip I can use as a ddrop-in replacement that would have a shorter min time? or is there another trick to be employed? I wish I could offer up a schematic . . .

Thanks everyone in advance,
-k

[puretube]

Hi:
when you repeat your post in the main forum:
http://www.diystompboxes.com/smfforum/index.php?board=2.0,
chances are that more people will read it,
and quite sure M.H. and/or others will soon respond...

(it is not a digital pedal)

[vseriesamps]

cool. just did it. I guess bucket brigade chips don't actually make something digital? I missed the distinction.  Would be curious to know more if you have a sec.

Thanks!
-k

[SeanCostello]

"Digital" usually refers to circuits that are both discrete time and discrete signal levels.

Discrete time - time quantized into samples. BBD lines are discrete time.
Discrete signal levels - the input signal is stored as quantized levels (8 bits, 16 bits, etc.). BBD lines have an analog signal representation.

Sean Costello

[puretube]

err, I usually don`t want to argue against you, Sean,
but a real choppy tremolo (like the current original) E-H PULSAR
"quantizes" time too, but is fully analogue...


to me, "digital" means: audio A/D-converted- processed - D/A-converted
(like in the PT2395)
see the other thread:
http://www.diystompboxes.com/smfforum/index.php?topic=49584.0

[GFR]

I don´t know the Pulsar, but a chopper doesn´t "quantize" time. When the chopper is letting the signal pass, the signal is fully continuous. To be discrete in time it would need a Sample & Hold.

A BBD is discrete in time, but not in amplitude, as Sean pointed out.

That Craig Anderton fuzz that uses a Schimitt Trigger is discrete in amplitude (1 bit ), but continuous in time.

[puretube]

when it chops the signal completely off, there is no outputsignal left;

imho, the same like what happens in a one-bucket "BBD", just slower,
and without being passed on (= no delay).

[GFR]

when it chops the signal completely off, there is no outputsignal left;

imho, the same like what happens in a one-bucket "BBD", just slower,
and without being passed on (= no delay).

But when it´s not chopping the signal that is passing is continuously changing. The signal that a BBD passes on is a single value, that depends on how much the first cap in the line got charged. The signal in a BBD is stepped, only the steps can be of any size, not a discrete size like a completely digital signal.

[puretube]

when I speed up the chopper to a frequency twice as high as the highest signal,
it comes down to the same what`s happening in one stage of the BBD,
except that it is not being stored at the 1st clockpulse, and passed on at the 2nd pulse,
but let through (in realtime at the 1st pulse, and muted at the second pulse.

but every second portion is left out, like in a BBD.

[Mark Hammer]

I guess this is more of a conceptual debate than anything else, BUT.....

For me, chopping is not the issue.  Rather, something moves from the analog to digital realm when there is any coding or "representation' involved.  Now, does what the Nyquist Aliaser does to the signal qualify as a "representation"?  In the sense that it "represents" instantaneous signal amplitude in a periodic way that corrupts or misrepresents harmonic balance, I guess I'd have to say that it fals more on the digital than analog side, though not by much. 

In the case of tremolo choppers like the Pulsar Ton describes, I'm less sure.  Unless the chop rate goes high enough that sidebands are added, then what is "misrepresented" is overall envelope amplitude, not instantaneous amplitude.  That, I would put more in the analog camp.

[GFR]

when I speed up the chopper to a frequency twice as high as the highest signal,
it comes down to the same what`s happening in one stage of the BBD,
except that it is not being stored at the 1st clockpulse, and passed on at the 2nd pulse,
but let through (in realtime at the 1st pulse, and muted at the second pulse.

but every second portion is left out, like in a BBD.

You're right, the very first section of a BBD is fed a continuous  signal (unless it is preceded by a S&H) and it's very similar to a ultra fast chopper. And I don't consider it discrete in time.

Each and every one of the other stages in a BBD, however, are fed with a signal that was previously sampled by the previous stage, so they are discrete in time.

[GFR]

I guess this is more of a conceptual debate than anything else, BUT.....

For me, chopping is not the issue.  Rather, something moves from the analog to digital realm when there is any coding or "representation' involved.  Now, does what the Nyquist Aliaser does to the signal qualify as a "representation"?  In the sense that it "represents" instantaneous signal amplitude in a periodic way that corrupts or misrepresents harmonic balance, I guess I'd have to say that it fals more on the digital than analog side, though not by much. 

In the case of tremolo choppers like the Pulsar Ton describes, I'm less sure.  Unless the chop rate goes high enough that sidebands are added, then what is "misrepresented" is overall envelope amplitude, not instantaneous amplitude.  That, I would put more in the analog camp.

Mark, even if the rate is very slow, "sidebands" are added. Only as the rate goes slower, these "sidebands" get closer and closer to the "main band", until they get more and more overlapped.

[Mark Hammer]

OK.  Gotcha.  Sidebands you notice and sidebands you can't detect are both still sidebands.