'Swell' mode in Binson Echorec

[mudmen]

I found this quote in a interview with Gilmour:
"The selector accessed either echo (one repeat), repeat (more than one repeat) or swell (reverbs cleverly devised by feeding the outputs of the heads back to themselves)"

First two modes are pretty obvious but is there a way to recreate that 'Swell' mode using normal delay pedal (or pedals)? How can I feed the delayed signal back to the pedal's delay line?

http://www.youtube.com/watch?v=1layrwUW54U
Around 4:17 and 6:26 he demonstrates this mode in a slightly different model, but it's still Echorec so I guess it works similar...

Any help appreciated!

[petemoore]

http://www.youtube.com/watch?v=M-6k-8GgtsM&feature=related
  Along in this video the cat seems to be adjusting by ear the balance, it appears he may be balancing by adjusting the distance the playback heads are from the disc.
  Very interesting !
 

[ZiggyZipgun]

Schematic Heaven has three Binson Echorec schematics posted; I'm sure someone with more training than myself could identify the inner workings of that mode, and if they were fairly clever, adapt it to a nice analog delay.  In any case, I'd love to hear the results!  My stomp-box to-do list is a little long to be tacking that on.

[slacker]

To recreate that you need 4 delays, either 4 pedals or a circuit with 4 delay lines in it, and some sort of mixer.
Connect the inputs in parallel and set the delays to 4 different times fast to slow, they're your 4 playback "heads", if you're using 4 pedals turn the "feedback" all the way down so you just get one repeat.

Then for echo you just mix the output of how ever many "heads" you want with the dry signal.
For  repeat you do the same but also take the output from one of the "heads" and mix that back with the input signal to get some feedback.
Like he says in that clip swell is basically the same as repeat but using all 4 heads for playback with one of them feeding back to the input.

Something along those lines would get you close anyway, even if that's not actually how it works.

[mudmen]

To recreate that you need 4 delays, either 4 pedals or a circuit with 4 delay lines in it, and some sort of mixer.
Connect the inputs in parallel and set the delays to 4 different times fast to slow, they're your 4 playback "heads", if you're using 4 pedals turn the "feedback" all the way down so you just get one repeat.

Then for echo you just mix the output of how ever many "heads" you want with the dry signal.
For  repeat you do the same but also take the output from one of the "heads" and mix that back with the input signal to get some feedback.
Like he says in that clip swell is basically the same as repeat but using all 4 heads for playback with one of them feeding back to the input.

Something along those lines would get you close anyway, even if that's not actually how it works.

I don't know if I get your idea right but here's what I've just done. I used some free VST plugins to simulate that multi-head delay. I connected 4 delay lines into VST instrument - so it's more like a signal splitter than mixer but for 'Echo' and 'Rep' modes it doesn't sound bad:

Here's the signal path:
http://img513.imageshack.us/img513/954/delay1sk4.jpg

And some clips:
'Echo' mode: Feedback at zero:
http://odsiebie.com/pokaz/1395580---4007.html

'Rep' mode: Feedback at more or less 75%:
http://odsiebie.com/pokaz/1395636---e742.html

To get various head combination I simply bypass those delay lines which shouldn't be used. In both clips all 4 delay lines has the same settings for feedback and volume (Echorec has only one feedback and volume control)

Please (if possible), write me once again how should I use a mixer for that. Especially how can I feed back a signal that goes from 4 delay lines back into one of them to get that 'Swell' mode. This time more idiot-proof version... 

Thanks in advance!

[slacker]

Nice samples, that's the basic idea.

Here's a block diagram showing what I mean.



The input buffer splits the signal and sends the dry signal straight to the output mixer.
The signal goes to the 4 delays that I've called head 1 to 4, head 1 is the shortest and head 4 is the longest. The 4 Playback switches then control which heads you hear and sends the signal to the output mixer. They are the the top row of switches in the video.
The output from all the heads also goes to the feedback switch which sends the output of one of the heads back to the input of all of them, in echo mode this is disconnected. This is what I think the bottom row of switches does in the video.
I haven't shown the feedback pot but some way to control the level would be between the switch and the inputs.

You might be able to do this with your VST instruments if you've got some sort of mixer plugin. Send the output of one of the delays into it and send the output to all the inputs.

Hope that makes sense.

[mudmen]

Wow! Now everything is clear! Once again, big thanks for your help!

[Ben N]

To recreate that you need 4 delays, either 4 pedals or a circuit with 4 delay lines in it

Akai Headrush has separate outputs for its virtual tape heads. With a little outboard circuitry you could easily do this. I wonder if the "swell" in question is self-oscillation resulting from the feedback signal being unattenuated.

[mudmen]

Well, this quote (swell - reverbs cleverly devised by feeding the outputs of the heads back to themselves) and video posted on YT is all I know. Maybe someone here has a Echorec and will help us a bit? 

[sjaltenb]

oh wow i had no idea how good that thing sounded! I want one now!!!!!