Newbie issues with clicks when using Feedback Looper and Manual Grains

Hi there everyone, recent buyer here who is blown away by the ER-301. Managing to work my way around it pretty well but have come up with a problem today that I can’t seem to work round.

Basically I was working up a patch with manual looper and manual grains here (I started out modifying ultraviolet in 0.3.25 to update a few bits and change how the trigger worked, found this behaviour, and then tried some simpler setups to reproduce, as well as under 0.4.01/48kHz).

I seem to have the issue that when I use Feedback Looper and Manual Grains together with some pitch shifting on manual grains I get really quite significant clicks. These persist despite a lot of experimenting with trigger frequencies, duration, and position parameters, so I don’t think they relate to end of record buffer problems… and it doesn’t seem to relate to hitting the polyphony limit.

Switching the looper buffer for a (static) sample on the SD card, and everything work brilliantly with no clicks. Am I doing something wrong?

Tried two (front) cards and both the same (I am guessing that loop buffers are not stored there anyway). Lots of effort on gain staging and testing out a lot of stuff here today - but it is happening in a very simple configuration with only looper and manual grains loaded in a stereo chain.

Any ideas to help me out?

John

How long is the looper buffer?

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i assume it’s the problem discussed in these threads where record and play head collide and create clicks…:

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Thanks @rbeny and @kilchhofer for the replies… To deal with the first one, I started with 1 second but have tried longer ones (5 and 20 seconds). Really glad you pointed out those threads @kilchhofer - I was sure I had seen something on here, but my search terms didn’t throw them up.

Pretty sure that the clicks are due to grain playbacks crossing the record head in the buffer file. I had actually discounted this for incorrect reasons, I guess I had assumed that with start=0 grains were sown from a point in the recorded loop relative to the record head. Of course with feedback looper that isn’t the case (Manual Grains has no idea where the record head is).

I think to do what I am thinking of here (pitch shifted grains from a live input buffer) without clicks I would need to be able to attach the manual grain playback unit to a moving buffer rather than a looping sample. Wouldn’t it make sense if it was at least possible for the start position for manual grains to refer to a position a given distance ‘behind’ the record head in a loop? I suppose this would mean exposing the record head position as a parameter… or some new unit to deal with this.

I guess we do have other modules in Eurorack land that do this function already :smiley:, but given how awesome pitch shifted grains sound on samples in the ER-301 I was hoping to achieve this kind of sound against a live input stream without clicks.

I guess there are a couple of options for mitigation, I at least thought of

  • adjusting the dry/wet of the looper so that a pass of the record head doesn’t sound as discontinuous.
  • sequencing or clocking the looper reset parameter to control the record head position away from where the playback magic happens :smiley:

Thanks again both for the replies.

John