[sdiy] BBD help

[Joseph Craig]

I think you were talking about...

Princeton PT2395 Enhance Digital Echo IC 

I also wanted an analog delay, but after checking prices on BBD chips and 
going through all the design work, I have decided to go with a quality 
digital solution.  Has anyone designed with the PT2395?  looks decent.  I 
just need to build a delay module for my modular synth.

-Joe


On Fri, 23 Jan 2004, Harry Bissell Jr wrote:

> <harryrantmodeon>
> 
> The BBD is indeed a candidate for a short, low quality
> audio delay...
> 
> ... and you WILL filter it heavily as well (like it or
> not)  ;^P
> 
> My rants have the following points
> 
> 1) The BBD has very low quality ~unless~ you add a lot
> of extra circuitry to it, usually high quality
> multi-pole filters at the input and output, and
> usually
> some companding (NE-570 and ilk... know what an ilk is
> dont'cha... its a small MOOSE).
> 
> 2) See the JH "Storm Tide Flanger" for an example of
> how much hardware it takes to do it 'right'
> 
> 3) BBDs are unforgiving chips, a wrong wire, or
> slipped probe is DEATH.
> 
> 4) most NEWBIES who are the least well equipped, both
> on the workbench and in experience... say "I want to
> make an audio delay as a first project" without
> knowing what they are getting into.
> 
> 5) DIGITAL delays are cheap today as well... Princeton
> Technologies makes the PT- (something help me here)
> which will do the delay better than most BBD circuits
> at the same cost.
> 
> 6) BBDs were the 'only' sub for tape echo in their
> day... but that day is long past.  Digital delays are
> going for cheap new, and cheaper used.
> 
> so if you want to explore the BBD for educational
> purposes, go for it. If you want an audio delay of any
> quality... there are better faster cheaper ways to go.
> 
> </bbdrant>
> 
> Bffzfftppssszzzzz..........
> 
> H^) harry  (who actually HAS a few BBDs in stock...
> might use them someday :^)
> 
> 
> 
> --- Shokwave <shokwave at nb.aibn.com> wrote:
> > 
> > ----- Original Message ----- 
> > From: "Magnus Danielson" <cfmd at bredband.net>
> > 
> > > From: Scott Gravenhorst <music.maker at gte.net>
> > 
> > > > Just don't mind Happy Harry when he goes into a
> > BBD rant...
> > >
> > > Actually, on rare occasions he will motivate it
> > very well, and then also
> > give
> > > you insigh into what needs to be done to make it
> > fairly decent.
> > 
> > AHA! Well, time to ask then:
> > 
> > I want to delay an audio signal by a small
> > (preferably variable, but there
> > is a possible use for hardwired) amount, and mix it
> > back in.  It doesn't
> > have to be high-quality, I'm probably going to
> > filter it all to hell before
> > I mix it back anyway, and a BBD seems like the
> > obvious place to start. By
> > "small", I mean 1-50 ms or so, maybe even just 1-20.
> > Sooooo...is there any
> > good canidate IC for this? I figured maybe there was
> > a BBD made that was so
> > short a delay that it was useless for most
> > "delay/chorus" projects, and thus
> > cheap and still easily available. Or is there an
> > easier way to go about
> > this?
> > 
> > -Darren
> > 
>