[sdiy] Re: Harry's BBD rant (for newbies...)

[René Schmitz]

Hi Harry (et al)!

>you are correct in ignoring my BBD bashing... its mostly for fun...  ;^P

Sure! Actually our opinions aren't so far apart, its just we draw 
different conclusions. 

>my POINT is that the BBD is the method of choice (like knife, gun, poison)  ;^P
>for the newbie who wants to make an "echo unit" like a tape delay...
>
>...often as a first DIY project.

I doubt that a bit. 

>The BBD (as the more experienced are well aware) is not a simple, magic delay
>chip. The companders, and anti-alias filters etc are often overlooked, or
>underestimated, by the novice.

Agreed! And often the designers try to squeeze out the BBD to the last bit, i.e. 
very low clock rate to get long delays, no bandwidth and lots of aliasing, because 
the filters are dimensioned for an "average" clock frequency. 

>If they DO get the BBD working (and they are NOT forgiving chips, a simple
>error will fry them dead, right now...).. they are often disappointed with the
>performance.  (I sure was....)

Just as they are when their oscillators don't work! Sure, without help this is 
difficult. But thats why we have S-DIY, its about learning stuff like what 
aliasing is, and what constructive measures one must take to avoid it.
Learning how to use the BBD right can be a milestone on the way of becoming an 
analog Master. 

>For me, its a matter of 'bang for the buck'... it might be more effective to get
>a used digital delay, and spend your DIY time on a VCO, or VCF instead...
>especially for a novice.  I'd consider buying one of those cheap, new, digital
>delay pedals from Danelectro and hack that to start with...

Well you can buy VCOs too! So why DIY at all?! I guess we all have different 
motivations, some like to do everything on their own. I don't see a difference 
between building a filter on your own or building a flanger or chorus on your 
own. (BBDs aren't suitable for real delays, thats why I left them out here!)

>(those newbies reading this, check out JH's 'Storm Tide Flanger' for an idea of
>how much external circuitry you need to do a BBD right.  If you don't do it
>right, you are wasting your time imho...)

Right!

Cheers,
 René


-- 
uzs159 at uni-bonn.de
http://www.uni-bonn.de/~uzs159