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Driving sample playback position with CV (aka turntable simulation)

is it possible to do this on the er301? i know you can use offsets to control speed and direction, but it seems it always has to be playing, not just static like it is in this video, where the tapes not moving, your just moving the playhead. https://youtu.be/-Z3v_W-s2rI

not in front of my 301 right now (and haven’t had time with my system for a few weeks :cry:),
but i’d try to assign a continuous control to the position; then the same control through a comparator (i think there is one in the accents library (“motion sensor”)) that outputs a quantized 0 or 1 value, will control the speed of the player (maybe with a slew to get thing more “natural”). Probably the motion sensor should also be used to trig the “reset/sync” control of the sample player.
Not sure if that’ll actually work.

Put your offset through a high pass filter to calculate its velocity, then from the high pass into the speed control. Tune the high pass cutoff and speed gain to taste. There will be some drift so you will probably want to add a clutch.


I’m not sure this will get me what im trying to do.
let me re explain: im looking to have the tape (sample) completely stopped and just move the play back head around on the stopped tape with a dc voltage.
similar to the effect of moving a vinyl back and fourth with your fingers on a stopped turntable.
does that make sense and is it possible?

Did you at least try what I suggested?

yes, i tried it but wasn’t able to get it to behave right. i couldn’t get no drift for one, and second of all the full voltage range only let me use a very small portion of the sample, hoping to get more of the sample in the swing of the voltage, more flexibility.

This isn’t a problem. Having drift is usually considered inconvenient in this situation.

This implies that you need to increase the gain on the sample player’s speed control.

Also, your choice of controller is going to be pretty important. Just using the knob on the ER-301 is not going to work well. I would use an external offset module to provide the CV, like the Planar or similar. High resolution is the goal.

i have the gain turned all the way up and it still seems like not enought are of the sample is covered.
and when i move the voltage very slow, it just cuts off or stops, it not behaving right. im using a intellijel planar.

What about your cutoff on the HP? Too high and the slow movements will be ignored.

tried adjusting it, i just cant get it feel/react right.
edit- i got it a little better with slow sweeps but also, with really fast sweeps it dosnt seem to be moving fast enough. maybe its just a matter of spending more time finding the exact spots.
and id like to get a few seconds of audio within a single voltage sweep, and be able to do very slow to very fast sweeps.

Just tried it again here and I found it to work pretty well…although our expectation might not be matching of course.

I was able to cover a 10s sample and position/scratch at will within it with the following

Planar into A1 into Fixed HPF into Variable Speed Player (speed).
FixedHPF(f0) = 1.375Hz
Variable Speed Player (speed.gain) = 100x
Variable Speed Player (speed.bias) = 0
Planar in bipolar output mode.


Thanks, will give that a shot!

By the way, to “address” longer samples with “short throw” controllers like joysticks and knobs, I can suggest patching the other axis of the Planar into an Offset that is inserted after the Fixed HPF. Set the gain on the offset to about 0.2x. This 2nd axis becomes turntable speed.


works! thanks again for the suggestion!
nothing impressive here but just vids showing it works:


Sounds great! Now let’s figure out how to get it playing at a constant speed, accept nudges from the ribbon, and only stop the record when you apply enough pressure. Bonus points if the pick-up point on the ribbon is the current playback position. My early thought experiments with this involved phase modulating a ramp wave…

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