Bitcrusher?

Is there a unit or combination of units in the ER-301that will allow me to add bitcrusher style effects to audio?

Thanks!

You can use the Quantizer !

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Yep. Quantizer for bit crushing, audio into S&H triggered at audio rate for sample rate reduction.

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I get what you mean by the S&H trick, but wouldn’t it produce a stepped or stair case wave form while with a reduced sample rate it would still be continuous but would contain less information to interpolate the higher frequency content and sharp transients? I have not tried it yet though it should sound different, shouldn’t it?

The S&H trick does create a stair case wave form visually on a scope if you set the sampling frequency low enough. Very similar to what would be produced by the Grid Quantizer. I guess the difference is that the Grid Quantizer would let only a discrete set of voltages through whereas the S&H would allow any voltage through - just depends on what the input is when it grabs the sample.

The S&H trick doesn’t have any effect, I don’t think, until you set the sample rate below the Nyquist frequency.

Any digital signal is a staircase signal

That’s a common misconception - digital audio is not stair cased but continuous.

I don’t know if that’s accurate…it’s not staircased, but it’s not continuous. When it comes out of the DAC, it is a continuous signal after that conversion, but all digital information is discreet by it’s nature, right?

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I would say, the concept of digital audio is that discrete numbers are representing a continuous wave form, which is different from applying quantization or S&H to an audio signal (even when it is implemented in a digital environment like the ER-301) to get a wave form that is stepped while being continuous. Those are different levels.

p.s.: I like that video!
:smiley:

A low pass filter in and around 1/2 the sample rate smooths out that staircase and eleminates any weird artifacts and odd harmonics created by those immediate squarish jumps… from what I remember.

i think it’s not that different, only more complex because of the techniques involved in modern signal sampling. (oversampling, interpolation, etc…)
so the s&h trick is very similar, only a bit more primitive.
anyway if you try it yourself you’ll see it is very similar sounding.
i have the doepfer bitcrusher that does sr reduction too, and the dual s&h also from doepfer. i tested the reduction on both modules and sounds very similar to me, almost undistinguishable.

I really hate that above video because from everything I gather , that ONLY applies to audio that has been run through a DAC that has the antialiasing taking place. which as we know … isn’t always the case. digital audio is indeed staircase but of course by the time it hits our ears those acoustic waves are smoothed no matter what by this thing called physics of the real world.

Hi. I just want to make sure I’m thinking correctly here:

Sample Rate Reduction:
S&H after the input, triggered by a modified Clock (Hz) unit, with the max multiplier set to 320 or so. Running 64 Hz w/ a 200 mult provides the S&H with a 16KHz trigger input.

Right? This seems to work as predicted.

Bit Strength Reduction:
To emulate, say, a 12-bit converter I need a grid resolution of 4096 (2^12). So I modify a Grid Quantizer to a maximum of 2048 levels (since from the wiki it looks like it’s 2*levels for total steps between max and min). This has a no real effect. Then I thought “hmm, if that’s for -0.5 to 0.5, maybe I have to reduce by 10 (as audio is typically 10Vp-p) to get the effect?”. At 205 levels it definitely does does something, I’m just not completely confident I’m interpreting the wiki correctly.

You see where I’m going with this, I would just like to package this up for my chains as ‘bitcrusher’ with sample rate and bit reduction controls.

I noticed the same thing with the grid quantizer. It is surprising how few values you need to recreate a signal.