Doepfer

Hallo group,

are there any disadvantages in a BBD having more stages ? is 512
"better" than 256 ?

cheers,

stu

> Hallo group,
>
> are there any disadvantages in a BBD having more stages ? is 512
> "better" than 256 ?
>
> cheers,
>
> stu

From the technical point of view the quality is worse for longer BBDs as the
signal losses, noise and clock suppression are worse due to the higher
number of "buckets" represented by very small capacitors in the pF range.

Another point of view is the sound that can be generated with a longer or
shorter BBD. As the typical clock frequencies are in the 10kHz...100kHz
(200kHz for shorter BBDs) range for all BBDs one obtains different delay
times for BBDs with different numbers of stages. Shorter delays are used for
flanging or chorus effects and Karplus-Strong-Synthesis. Longer delays cause
audio delay effects. You find a detailed list of delay times with reference
to clock frequencies and number of BBD stages in the A-188-1 user's manual.

The most flexible solution is a tapped BBD (as used in the A-188-2) as one
has available six taps with stages between 396 and 3328.

Best wishes
Dieter Doepfer

thanks for that.i just ordered an a188 - not being a fan of flanging
and having leanings towards lofi, i went for the 4096 stages :)

the advantages of the tapped version are obvious enough (at least,
after reading your comments dieter), but i did wonder, why the
irregularly spaced numbers of stages ? if i only had one clock speed
on such a unit, i think i'd find a lot of uses for mixing, say, 1024
and 2048 stages to produces rhythmic patterns. but any
mathematical/musical relationships between 662 and 396 (etc.) remain
hidden to me.

maybe a question of what's available from the bucket factory ? not
important, i'm just curious.

second question. i notice the 188 is available as module without the
buckets. are the various BBDs available separately (i.e. without
module), and would it be possible for a user (without physics degree)
to swap them ?

cheers,

stu

--- In Doepfer_a100@yahoogroups.com, <hardware@...> wrote:
>
> > Hallo group,
> >
> > are there any disadvantages in a BBD having more stages ? is 512
> > "better" than 256 ?
> >
> > cheers,
> >
> > stu
> 
> From the technical point of view the quality is worse for longer
BBDs as the
> signal losses, noise and clock suppression are worse due to the higher
> number of "buckets" represented by very small capacitors in the pF
range.
> 
> Another point of view is the sound that can be generated with a
longer or
> shorter BBD. As the typical clock frequencies are in the 10kHz...100kHz
> (200kHz for shorter BBDs) range for all BBDs one obtains different delay
> times for BBDs with different numbers of stages. Shorter delays are
used for
> flanging or chorus effects and Karplus-Strong-Synthesis. Longer
delays cause
> audio delay effects. You find a detailed list of delay times with
reference
> to clock frequencies and number of BBD stages in the A-188-1 user's
manual.
> 
> The most flexible solution is a tapped BBD (as used in the A-188-2)
as one

> has available six taps with stages between 396 and 3328.
> 
> Best wishes
> Dieter Doepfer
>

Hi Stu

> but any
> mathematical/musical relationships between 662 and 396 (etc.) remain
> hidden to me.
I remember my little sister playing something on a recorder which 
sounded mostly like Arnold Schoenberg in 396/662th.
To hers excuse I have to say, that this Arnold Schoenberg experience is 
36 years gone and she now did her doctorate in Art of the 19th century, 
is a mother of two children and wisely stayed away from all musical 
instruments but a CD player.

;-)

Florian

> the advantages of the tapped version are obvious enough (at least,
> after reading your comments dieter), but i did wonder, why the
> irregularly spaced numbers of stages ? if i only had one clock speed
> on such a unit, i think i'd find a lot of uses for mixing, say, 1024
> and 2048 stages to produces rhythmic patterns. but any
> mathematical/musical relationships between 662 and 396 (etc.) remain
> hidden to me.
>
> maybe a question of what's available from the bucket factory ? not
> important, i'm just curious.

The taps are predetermined by the BBD chip but not our choice. But the
irregular taps make sense as the chip was planned for reverb effects. And
for a dense reverb you do not want taps which are multiples of each other.
But even for non-reverb applications (like chorus/flanging) the irregular
taps generate a very dense sound - much better than taps which are multiples
of each other.

> second question. i notice the 188 is available as module without the
> buckets. are the various BBDs available separately (i.e. without module)

yes, as spare parts. The price for the BBD chip can be calculated from the
difference between the module without BBD and the corresponding module with
BBD.

> and would it be possible for a user (without physics degree)to swap them ?

please look at www.doepfer.de > PRODUCTS > A-100 > modules overview >
A-188-1 > A1881_adjustment.pdf

Best wishes
Dieter Doepfer

--- In Doepfer_a100@yahoogroups.com, Florian Anwander
<Florian.Anwander@...> wrote:
poor arnie ! every joke about cacophony and dissonance is at his
expense :) florian, i sentence you to Verklaerte Nacht (TWICE if your
eyes are still dry after the first time).

now there's an idea - everyone does bach with synths, but how about
schoenberg ? if there are five others in the ruhrgebiet, i can get us
a gig :)

dieter, thanks for the answer (and the pointer to the pdf - mea culpa,
but it was well hidden).

stu

> Hi Stu
> 
> > but any
> > mathematical/musical relationships between 662 and 396 (etc.) remain
> > hidden to me.
> I remember my little sister playing something on a recorder which 
> sounded mostly like Arnold Schoenberg in 396/662th.
> To hers excuse I have to say, that this Arnold Schoenberg experience is 
> 36 years gone and she now did her doctorate in Art of the 19th century, 
> is a mother of two children and wisely stayed away from all musical 
> instruments but a CD player.
> 
> ;-)
> 
> Florian
>

Hi Stu

You are definitely right to complain about my misusage of his name. I 
once sang Schoenberg Kanons in a chamber choir. I think, I can esteem 
him right. :-)

> now there's an idea - everyone does bach with synths, but how about
> schoenberg ? if there are five others in the ruhrgebiet, i can get us
> a gig :)

Do you know Joker Nies from cologne? He might be someone who is 
interested in.

Florian