[sdiy] kits/schems for BBD MN3101 & MN3008?

[Scott Stites]

Hi,

Usually the BBD data sheets are a good starting point to learn how to apply them,
but I don't have one for the MN3008.  IIRC, that's a 2048 stage device, which
would make it OK for chorusing, and if you really clocked the heck out of it,
flanging.  

I use the MN3102 and MN3207 (a 1024 stage device) for flanging and chorus, and it
works fine, though I still  want to try companding it.

There's a file at this link called 'bbdementia.zip' that has a lot of BBD data
sheets (sorry, the MN3008 isn't in there):

http://hammer.ampage.org/index.cgi?I=10

BBD's can be tricky to implement decently, especially if you are wanting to
daisy-chain some for longer delays.  I've never tried that (I wouldn't look
forward to doing it), but, depending on how much you're willing to spend, there
is the MN3005 available at Small Bear which is a 4096 stage device that would
have a longer inherent delay time.  A 10 kHz clock rate would give you 204.8 ms
of delay.

The MN3005 is used in the Blacet Time Machine, and a IIRC, couple of them are
used in the Modcan delay, both devices I would give my right arm to own.

Alternately, if you are looking for a longer delay, the PT2399 delay chip, which
is also available at Small Bear, is a much simpler device to work with.  It's
quieter, has less distortion, and can be controlled with voltage.  It's max delay
time also exceeds that of the MN3005.  It may not have that 'BBD' sound, but that
can be fixed, too by putting in a compander circuit and filtering.  I haven't
gone to those lengths with the PT2399, and I think it's a dandy delay without all
of that dressing.  Plus it's a lot cheaper than a BBD.

An excellent example of the PT2399 implemented for synth use is Scott Bernardi's
design:

http://home.attbi.com/~sbernardi/elec/og2/og3_echo.html


This example of someone using the PT2399 to emulate a BBD based delay can be
found here:

http://www.generalguitargadgets.com/v2/index.php?option=displaypage&Itemid=80&op=page&SubMenu=


My personal philosophy is if you want to flange or chorus, use a BBD.  For a
longer delay, go with the PT chip, unless you can afford a couple of MN3005's
(always keep a spare).  YMMV. 

Here's Small Bear's address:

http://www.smallbearelec.com/Ordering/Stocklist.htm

Good luck in your quest for delays!

Scott

On Wed, 4 Jun 2003 12:27:32 -0700 (PDT), magic_silver_box! wrote:

> 
> these are sold on ebay often & I'm thinking of getting some.
> are there schematics or, better yet, kits/instructions for electronics 
> retards like me? Who knows of some?
> I'll probably want to use several (each has about 100ms delay time max) 
> to make a usable delay but I guess a flanger would be cool too.
> and I'm talking about bucket brigades, not constricting underwear.
> BUCKETS OF CONSTRICTING UNDERWEAR.
> 
> 
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