Bucket Brigade via VST delays

[kkissinger@kevinkissinger.com]

Last week the "Bucket Brigade" topic came up and I worked out a way to  
accomplish in Cubase SX.

Cubase SX includes some VST delays -- very useful because sync is  
assured and they go up to ten seconds.

In Cubase, VSTs can be inserted into: Input strips, FX strips, and  
(so-called) Group Channel strips.

(this next paragraph is Cubase SX specific)

All the strips have SENDS.  In Input strip can send to an FX channel,  
Group channel, or output buss.  An FX channel can only send to the  
output busses.  However, the Group Channel can send to downline Group  
Channels, FX Channels, and the output busses.  A "downline Group  
channel" is a Group channel that is the most recently created.  Thus,  
a group channel can send to another group channel, provided the other  
group channel was created after the sending channel.
(Quirky, huh?)

I am using multiple instances of the "Delay Modeler" VST plugin --  
each instance of "Delay Modeler" occurs in its own Group channel  
track.  The Group Channel strip's main output is assigned to an output  
buss (a virtual hardware output, that is).  The send goes to the next  
"Delay Modeler".

Here is a sample diagram that shows the concept:

. Input
.   |
.   |-- (send) ---> Delay (A)
.   |                 |
.   |                 |-- (send) ---> Delay (B)
.   |                 |                 |
.   |                 |                 |-- (send) ---> Delay (C)
.   |                 |                 |                 |
.   |                 |                 |                 | -- (send)  
---> (etc)
.   |                 |                 |                 |
.   V                 V                 V                 V
. Center            Right             Right Surround     Left Surround...
.

Thus, with only a 10-second delay plugin, I can create a bucket  
brigade of unlimited channels (limited only by memory, CPU,  
PCI/Firewire capacity, and hardware).

Now, how about feedback?  After all, we can't SEND a Group or FX  
channel back to an input.  Fortunately, I can accomplish the trick via  
the software that comes with the RME800 -- without tying up bandwidth.  
  The RME800's driver allows you to route an output buss to its  
corresponding input strip.  For instance, if I have an unused hardware  
channel (say, the SPDIF channel), I can the SPDIF output directly to  
the SPDIF input.  In Cubase I would, in turn, create an input channel  
strip and assign the SPDIF input to it.  That channel, then, would  
SEND to Delay (A) -- and would create feedback.  The nice thing: if  
you utilize "bandwidth limiting" on the RME, you can use the unused  
channels for this.  All this happens in the driver and never actually  
goes out to the RME hardware.  For example, you could use an unused  
ADAT channel for this.

As cumbersome as this writeup is, it only takes a few minutes to set  
all this up in Cubase.

The same concept could be used to create "Long Loops" in Cubase -- by  
cascading the delays I can get around the 10 second limitation on loop  
length.

Why do I continue to use Cubase SX?  The main reason is that I compose  
everything -- that is, I write out every note.  Since CUBASE SX has  
built-in scoring, I can switch between the piano roll editor (my  
editor of choice) to the score editor (so I can read the notes and  
memorize/perform the music).

I have this "vision" of melodies that echo around the listeners and  
with this "bucket brigade" configuration, I can make that happen.

-- Kevin