Delay Feedback Loop

[norv]

Anyone have any luck setting up a delay feedback loop as described in this article from Sound on Sound
http://www.soundonsound.com/sos/jul07/articles/dubmixing.htm

The feedback loop

This technique is a classic example of using equipment in ways it wasn’t designed to be used! Set up an auxiliary send on your desk, and route it to a delay unit. Set the delay time to about 0.7 seconds and turn the feedback up until each repeat is heard four or five times. Route the output signal from the delay unit back to the desk on a full stereo channel (or a pair of mono channels) that has an aux send on it, rather than on dedicated effect return inputs, which do not always have auxiliaries.

Play back a sequence or a bit of a recording, turn up the aux send, and you’ll hear some delays and echoes developing, just as you would when using delay in any mixing session. Now here is the trick: gradually turn up the aux send on the return channel(s), so that you’re sending the returned signal from the delay unit back to its own input. As you turn up the aux send, listen out for an increase in the feedback level. When you hear the echoes picking up, mute the source channel to avoid interfering with your process. Finally, try playing about with the aux send pot on the return channel and see how every move up or down affects the feedback. It’s quite easy to lose momentum, but practice will help. It’s a bit like trying to keep the engine of an old car going just after you start it in the morning on a winter’s day — you need to adjust the accelerator to prevent stalling!
DubMixing4
An example of a reggae keyboard part playing both the ‘chop’ and the ‘shuffle’.

The delay time should be set so as to develop in triplets, and it will revolve around the beat even after it starts to go gradually off sync. This technique works best with an analogue desk. It can be done in a digital setup, but you need to be careful, as I explain in the ‘Digital Dub Mixing’ box.

[Maskin]

I will try this tonight with my tape echo!

I also have an analog delay from Moog and I can route the delay loop to other effects and send it back, but this is something different and definitely worth a (room) shot.
Seems like King Jammy does the same in this video: http://youtube.com/watch?v=s-KsWcv6YnM

[Maskin]

I’ve tried it in Renoise but they are right, you’re better of doing this on an analog board. When cranking up the feedback you also hear a lot of digital interference (and I work on 96KHz/24bit).
Perhaps I can try it with my monitor out on my mixer as I don’t have auxiliaries or send channels but I’ll do that tomorrow.

[norv]

Thanx Maskin…
that echo at 00:15 in the King Jammy youtube u posted is what I’m after.
I can fudge it with a filter and tweaking the cutoff and resonance… but not quite the same -
looking fwd to your further experiments!

[Foo (mr_mark_dollin)]

http://www.kvraudio.com/get/2011.html

[choice]

you can do this relatively easy with mda’s dubdelay:
pc/mac
http://mda.smartelectronix.com/effects.htm
linux
http://www.linux-vst.com/

it does get itself very cpu intensive for me though.
though this is definitely something analog circuits do best.

also,

there is a dsp chain labeled dubby by mmd (mr mark dollin?).
i really prefer the internal renoise effects, yet, i think i am not feeding it everything it needs.

i’ve been trying to get this Scientist echo:
http://www.youtube.com/watch?v=D3N3UST7oKg

and this Amazon II echo:
http://www.youtube.com/watch?v=vts6rqJHMK8

[Maskin]

Ok, I’ve tried it with the loop routing on my analog delay and it works great!
Only difference is that the sound is getting dull instead of brighter but this has to do with the analog circuitry, with a tape echo it should have the same effect as in King Jammy’s video. I will try that now.

[Maskin]

Even when routing the monitor out signal back into my audio interface causes digital interference, so the entire setup has to be analog to recreate this effect.
However, the feedback on my tape echo creates the effect with ease: http://www.stalcon.net/works/Feedback_Example.mp3

The advantage of the specific feedback loop is that you can control the amount of feedback directly with the mixer as the routing itself is identical to the routing on most machines that use feedback (reverbs/echoes, phasers, etc.).

Looks like you have to buy yourself a proper tape echo.

[jonnyz]

Using ubuntu studio, its quite easy, using jack and the jack rack

In renoise, i added some extra audio outputs to use for outputting to the delay.

On mixer track one i added a send to go to so1.
so1 is set to output to the extra outputs i added

On track 9 (or any empty track) i added (dsp…) line in device, a gainer and a maximizer (maximizer will stop you blowing your eardrums or speakers and maybe even burning your face if you turn down the threshold)
(the gainer will allow for easy positive feedback amount thats essential) At the end of this chain i added a send device routed to so1, tying up renoises end of the loop.

In the Jackrack i added a delay effect. Reverb would probably sound swell too
I connected in ‘Jackcontrol’ its outputs and inputs to the relevant places on renoise(outputs2 and the line in)

After pressing play on a bass note and twiddling with effects setttings and send ammounts, it was feeding back on itself. Dragging on delay times bends the feedback note.
Of course… i should be using less feedback for a dub reggae effect…

To make it sound more like an analogue device, an old trick is to make a sample from recording of eating some crunchy foodstuffs and play it back into the mix at a low level. I have found Salt and vinegar to be the best flavour.

Also… in the above method you dont really need to use the jackrack as you can just route renoises outputs to its inputs in Jackcontrol, using just renoises fx- although doing it this way had excessive feedback on the left channel for some reason i dont know.

Have fun breaking trying not to break your speakers… id keep one hand on you master fader/power socket