Author Topic: Echo Park Block Diagram?  (Read 3170 times)


Echo Park Block Diagram?
« on: March 08, 2006, 01:55:45 PM »
  If you know something about this either PM/Email me Please or publish for Line 6 such information.
  the unit has 4 jacks [2 in, 2 out], where these 'go, and what they do...any suggestions beyond the one Mark Hammer recommended would be a great benefit to my understanding of how this thing works/how to use it.
  Plug guitar into 'B' input, Bout to A in, output taken from A output to amp...IIRC...very coool...
  yupp don't have a clue what's going on, the instructions had no block diagram and are PDarn Vague...pedal of course is just great, but I wonder why I would want all those jacks...or what I'm missing by not knowing even vaguely what they're for.
Convention creates following, following creates convention.

Peter Snowberg

Re: Echo Park Block Diagram?
« Reply #1 on: March 08, 2006, 02:12:44 PM »
The jacks are just two inputs and two outputs that are common to all the stereo ToneCores so where they go is totally up to software control. Now I have played with mine totally on mono, so this is just conjecture: but I think that in the algorithms the inputs are summed, processed, and then spit out to the two channels via two different forks in the code (i.e. it's not the same to each side).

Mark is just chaining the two "sides" which is going to lead to all kinds of new feedback paths.  :icon_cool: Not quite orthodox useage.
Don't worry about the extras, just plug into the mono jack and be happy unless you want to experiment.

Here's another one to try:

Guitar => EP Left channel In/Out => chorus and/or flanger and/or delay and/or fuzz => EP Right channel In/Out => amp
Eschew paradigm obfuscation

Mark Hammer

Re: Echo Park Block Diagram?
« Reply #2 on: March 08, 2006, 02:34:08 PM »
It's in an old thread, but I was told by the chief programmer for the EP, that the dry paths are true stereo, but the wet paths are a kind of "pooled and redistributed stereo".    For clarity's sake, let's call the various signals:
AD (for A-dry input),
(for B-dry input)
AW (for the delay signalled created internally from A-D)
BW (for the delay signalled created internally from A-D)
A-O for A output
B-O for B output

So if you had, say, a Deluxe Electric Mistress with separate dry and wet outputs, and you fed them to the A and B inputs of the EP, what would happen?
First off, assuming you set the EP's mix control to have at least SOME dry signal in it, the "pure" dry signal from one of the DEM's outputs would show up at the output of whichever EP channel you plugged it into, as would the DEM wet output.  In other words, the A-D and B-D showing up at the output jacks would be whatever came out of the DEM's output jacks, with the DEM's "stereo separation" preserved.

Clear so far?

Okay.  A-D and B-D now get mixed to something like mono and the EP does its delay voodoo, depending on the program/mode you selected.  A-O and B-O, however, are each a mixture of A-W and B-W.  Here I tend to get lost, but what you'll notice is that if you only plug into ONE input jack on the EP, A-O and B-O are NOT a simple dry-wet split, but they are NOTidentical either.  Some of what came in through A-D always gets to be part of B-W (and B-O) and some of what came in via B-D always gets to be part of A-W (and A-O).

So, though a stereo image is provided at the output, it is not the same as having two entirely independent and non-interacting delay lines.

This is part of what makes the re-delay trick so interesting if you patch something in between the A output and B input. 

Let's say we set up the EP for an medium length echo-duration delay, let's say 500msec or so.  Guitar goes to A input, and B output goes to amp.  Between the A output and B input jacks we've stuck an autowah (though a harmonizer would be infinitely more fun).  Strum a chord.  A-O will contain A-D and A-W, and all of that will be autowahed before going to B.  BUT, A-W will show up as part of B-O without any autowahing.

So A-O now passes through the autowah and goes into B.  What happens?  That autowahed version of A-D plus A-W now is transformed into and treated as B-D.  It shows up at B-O, but the B-W that's pat of B-O is the delayed version of A-O.  But hold on a sec.  Some of B-W has also found its way into A-O at the same time.  And on and on it goes, like looking into the mirror at the barber's and seeing the mirror behind you.  (I'm hearing the sound of baby Bart Simpson on the clothesline going "wwww-OAH, wwwww-OAH, wwww-OAH, wwwww-OAH,wwww-OAH, wwwww-OAH" as he swings around and around.  :icon_lol: )  And we haven't even discussed what happens the second time something comes out of A-O and hits the autowah.

Clearly the textural possibilities are endless.  Stick a volume pedal in the output-back-to-alternate-input path, along with a chorus or fuzz, and the pads you could create are little short of exquisite and otherworldly.   I don't know if that is as clear as you needed it o be, but maybe it gives you a better idea.


Re: Echo Park Block Diagram?
« Reply #3 on: March 09, 2006, 10:22:31 AM »
  Thanks .. a whole lotta typing Mark !!!
  I'll re-read, then use some of the suggested routings/effects/etc. which piqued my interests.
  I'm sufficiently satisfied that the EP'll do plenty/all the Echo Trix I could stand to set up.
Convention creates following, following creates convention.