[sdiy] BBD help

[Harry Bissell Jr]

<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
>