Why does Delay go silent with high feedback?

I have a question, as i’ve just updated to 0.6.11 firm, but this always happened with previous firmwares: every time i push the feedback control of any delay unit (native or bespoke) over 0.9 the sound disappears completely after deteriorating, i should expect a feedback “scream” or noise , but instead the sound disappear, so strange.

It sound like your input signal has a DC offset which is getting amplified thus making the output clip 100% of the time. This would result in silence.

To confirm: Press ENTER on the fdbk control so you can watch the unit’s output scope while tweaking the feedback.

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Do you mean the gain of the input is too high?. Anyway, looking at the scope for a visual feedback, the waveform goes above (and/or beyond if the source is stereo), it feels like a phase cancellation(?) or i’m far from the point?

Anyway seems a normal behaviour, as i tested it on another er301 module and it acts just the same.
Of course a droning oscillator through a delay with a cranked feedback it’s not my everyday use case :slight_smile: , but i’m experiencing problems when i use CU’s where there are network delay feedbacks, i use the module like that often to achieve raw reverberations, which i love to do on er301.

No. I mean that you have small offset in your input (this especially common for external analog signals) and that gets amplified by the feedback. You will need to remove the offset using a high-pass filter such as the Fixed HPF.

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No it is not phase cancellation. It is clipping like I said. For example, if you have a signal oscillating around 2.0 (say 1.9 to 2.1) you will not hear it because it will be all clipped to a constant 1.0 (the maximum output value of a digital system like the ER-301).

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Yes, this is normal behavior. Large feedback networks are very sensitive to small constant offsets in their inputs. You will have to combat this with HPFs to remove offset (i.e. growing signal bias) and even sometimes limiters (for when you run out of headroom).

Ok perfect, thanks, i’ll try with the HPF

Oh ok, very clear, thanks Brian.