Bc2000 (for the BCF2000 & BCR2000)

Hey there - I'm thinking of buying a bcf200 and have a question:  does anybody know what kind of resolution the foot controller input is capable of?  I've read that it can output 14 bit pitch bend - but I'm wondering at what bit depth the input is sampled.

Most controllers seem to be 7 bit (0-127) which are then output as 14 bit numbers with large gaps between each number.  Or, as in the case of many faders (such as on the bcf2000) 10 bit (0-1023.)   Very few do 12 bit (0-4095).

I'm really hoping that the bcf2000 will give at least 10 bit.

Anyone know?

(A simple test would be to output the foot controller as pitch bend and see what the smallest incremental change is.)

Thanks!

--- In bc2000@yahoogroups.com, "budwardp" <budwardp@...> wrote:
> does anybody know what kind of resolution the foot controller input
> is capable of?  I've read that it can output 14 bit pitch bend - but
> I'm wondering at what bit depth the input is sampled.
> 
> Most controllers seem to be 7 bit (0-127) which are then output as 14
> bit numbers with large gaps between each number.  Or, as in the case
> of many faders (such as on the bcf2000) 10 bit (0-1023.)   Very few
> do 12 bit (0-4095).
> 
> I'm really hoping that the bcf2000 will give at least 10 bit.
> 
> (A simple test would be to output the foot controller as pitch bend
> and see what the smallest incremental change is.)

First of all, your "simple test" was a bit tricky to perform: the BCF's "standard" Pitch Bend setting leads to 7-bit output, since the LSB value is always 0. (See "BC MIDI Implementation.pdf" (section 16.5) at http://home.kpn.nl/~f2hmjvandenberg281/ .)

However, there is a way to get a higher resolution, namely by defining a "custom" setting for the foot control, specifying the individual bytes of the pitch bend message (e.g. "$E0 val0.6 val7.13") and specifying the full 14-bit range (0-16383).

This gave me the following output values (using my Roland EV-5 pedal):
0. 16, 34, 50, 68, 84, 101, 118, 135, ...

I've tried the same settings for two faders, each with the following results:
0, 16, 33, 49, 67, 83, 99, 117, 133, ...

Conclusions:

The fader output values differ from the foot control output, and neither has a fixed step size.
So the BCF doesn't seem to impose any limits in the digital domain: it doesn't automatically set any bits to zero.

The varying step sizes must reflect limitations in the electrical, analog domain.
In general the step size lies around 16, so that basically amounts to a 10-bit resolution (14 bits minus 4), with 1024 different values (16384/16).

Hope this helps,
Mark.

Thanks so much for doing this!  Very appreciated. I hadn't realized that the pitch bend output only included the MSB.  That's odd!  I'm glad to hear that there's a way to get around that.  

It does indeed sound like it has 10 bit resolution.  And I agree that the differences would be due to analog differences.  Different pots, etc.

It certainly did help.  However much I wish that the resolution were finer, 10 bit was the minimum I was hoping for.  Very few boxes that I've been able to find do better, most are worse at 8 bit.

Thanks again!



--- In bc2000@yahoogroups.com, "Mark" <markwinvdb@...> wrote:

>
> --- In bc2000@yahoogroups.com, "budwardp" <budwardp@> wrote:
> > does anybody know what kind of resolution the foot controller input
> > is capable of?  I've read that it can output 14 bit pitch bend - but
> > I'm wondering at what bit depth the input is sampled.
> > 
> > Most controllers seem to be 7 bit (0-127) which are then output as 14
> > bit numbers with large gaps between each number.  Or, as in the case
> > of many faders (such as on the bcf2000) 10 bit (0-1023.)   Very few
> > do 12 bit (0-4095).
> > 
> > I'm really hoping that the bcf2000 will give at least 10 bit.
> > 
> > (A simple test would be to output the foot controller as pitch bend
> > and see what the smallest incremental change is.)
> 
> First of all, your "simple test" was a bit tricky to perform: the BCF's "standard" Pitch Bend setting leads to 7-bit output, since the LSB value is always 0. (See "BC MIDI Implementation.pdf" (section 16.5) at http://home.kpn.nl/~f2hmjvandenberg281/ .)
> 
> However, there is a way to get a higher resolution, namely by defining a "custom" setting for the foot control, specifying the individual bytes of the pitch bend message (e.g. "$E0 val0.6 val7.13") and specifying the full 14-bit range (0-16383).
> 
> This gave me the following output values (using my Roland EV-5 pedal):
> 0. 16, 34, 50, 68, 84, 101, 118, 135, ...
> 
> I've tried the same settings for two faders, each with the following results:
> 0, 16, 33, 49, 67, 83, 99, 117, 133, ...
> 
> Conclusions:
> 
> The fader output values differ from the foot control output, and neither has a fixed step size.
> So the BCF doesn't seem to impose any limits in the digital domain: it doesn't automatically set any bits to zero.
> 
> The varying step sizes must reflect limitations in the electrical, analog domain.
> In general the step size lies around 16, so that basically amounts to a 10-bit resolution (14 bits minus 4), with 1024 different values (16384/16).
> 
> Hope this helps,
> Mark.
>