[sdiy] BBD help

[harrybissell]

Yeah thats the one :^P

H^) harry

Joseph Craig wrote:

> 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
> > >
> >