Analogue-sequencer

Hi Colin,
Some while ago I told you that the midi2din was working perfect, but 
not on the cr-8000. The cr-8000 "swinged" like hell, but not in a 
musical way. You told me that I should compare the clock signals on a 
scope from the devices I run my cr-8000 with. I did and I found out 
that the sbx-10 (Roland syncbox) has a "square wave pulse" as a clock 
signal, and that the midi2din produces a really narrow pulse as a 
clock signal. You told me that it was not a problem to make the pulse 
less narrow, but that that would affect the timing accuracy, or 
something. I would really like a less narrow pulse so how should I do 
that? I use an external powersupply with the thing, so power is not a 
problem.
Cheers,
Roel

> Some while ago I told you that the midi2din was working perfect, but 
> not on the cr-8000. The cr-8000 "swinged" like hell, but not in a 
> musical way. You told me that I should compare the clock signals on a 
> scope from the devices I run my cr-8000 with. I did and I found out 
> that the sbx-10 (Roland syncbox) has a "square wave pulse" as a clock 
> signal, and that the midi2din produces a really narrow pulse as a 
> clock signal. You told me that it was not a problem to make the pulse 
> less narrow, but that that would affect the timing accuracy, or 
> something. I would really like a less narrow pulse so how should I do 
> that? I use an external powersupply with the thing, so power is not a 
> problem.

The original Roland clock oscillators in something like a TR808 or TB303
generate a true square wave.
I did a fair bit of research into the importance of this, especially
with respect to the TR909, as I knew it was doing it's shuffle at a
48ppqn resolution, and I thought it may have been using the trailing
edge of the din clock as a reference. But I found that the 909 only
cares about the start of the clock pulse, and interpolates the middle
position.
For the other devices I looked at, I found that as long as the pulse was
more than 2ms long, it would work fine. I had reports of some older
Roland gear having trouble, so I increased the length of the pulse to
4ms.
Do you know if your m2d2m is doing 2ms, or 4ms ?
Making a longer fixed length pulse, which reduces the maximum possible
tempo, is a poorer solution than doing a 50% duty cycle square wave
clock, but that is probably beyond the capability of the PIC 12C508 I
used for the convertor.
Funnily enough, the P3 outputs a true 50% duty cycle square wave sync
pulse, as it has to do clock multiplication of the incoming midi sync to
it's internal 48 ppqn resolution, so it's an easy matter just to toggle
the din clock line on the off at every other 48ppqn pulse, whether
running from midi or internal clock. Does the Cr8000 work OK from P3 ?
I guess you could use another P3 just for this ;-)
Or you could plead with me to do a simple sync convertor with true 50%
duty clock output.

Cheers,
Colin f

Hi Colin,
This morning I downloaded the midi2din2midi HEX-file again, asuming 
that it will give a 4 ms pulse, and putted into a new pic and still 
the cr-8000 did the swingy thing, and it seemed to run on half tempo. 
After the cr-8000, I tried it with a mc202 and a tr606, and both 
machines synced very well. After that I tried the cr-8000 with the 
sync from the P3, and that also works very well. And yes I will order 
an other P3 for that, cause I also like the other features from the 
machine. Some friends of my also want such a great midi to din 
device, so I let you know this week if I order 1,2 or even 3 P3 
boards! So this problem is solved and I'm very content with the 
midi2din2midi device as it is. 
By the way I found out that I can run the Korg kr55 from the midi2din 
device so I don't use a 48 ppq sync output anymore. But I got an 
other problem with that. I want to use the 5 Volt start/stop signal 
from the midi2din to start and stop the Kr-55. It has an jack input 
for start/stop, but this input uses a 5 volt pulse to start and an 
independent pulse to stop ( or shorting to ground instead of a 
pulse ) So when I start the P3  the Kr-55 starts running, but when I 
stop the P3 the Kr-55 just keeps on running, and when I start the P3 
again the Kr-55 stops running. Does anyone got a solution for this 
problem?
Cheers,
Roel


--- In analogue-sequencer@yahoogroups.com, "Colin f" <colin@c...> 
wrote:
> > Some while ago I told you that the midi2din was working perfect, 
but 
> > not on the cr-8000. The cr-8000 "swinged" like hell, but not in a 
> > musical way. You told me that I should compare the clock signals 
on a 
> > scope from the devices I run my cr-8000 with. I did and I found 
out 
> > that the sbx-10 (Roland syncbox) has a "square wave pulse" as a 
clock 
> > signal, and that the midi2din produces a really narrow pulse as a 
> > clock signal. You told me that it was not a problem to make the 
pulse 
> > less narrow, but that that would affect the timing accuracy, or 
> > something. I would really like a less narrow pulse so how should 
I do 
> > that? I use an external powersupply with the thing, so power is 
not a 
> > problem.
> 
> The original Roland clock oscillators in something like a TR808 or 
TB303
> generate a true square wave.
> I did a fair bit of research into the importance of this, especially
> with respect to the TR909, as I knew it was doing it's shuffle at a
> 48ppqn resolution, and I thought it may have been using the trailing
> edge of the din clock as a reference. But I found that the 909 only
> cares about the start of the clock pulse, and interpolates the 
middle
> position.
> For the other devices I looked at, I found that as long as the 
pulse was
> more than 2ms long, it would work fine. I had reports of some older
> Roland gear having trouble, so I increased the length of the pulse 
to
> 4ms.
> Do you know if your m2d2m is doing 2ms, or 4ms ?
> Making a longer fixed length pulse, which reduces the maximum 
possible
> tempo, is a poorer solution than doing a 50% duty cycle square wave
> clock, but that is probably beyond the capability of the PIC 12C508 
I
> used for the convertor.
> Funnily enough, the P3 outputs a true 50% duty cycle square wave 
sync
> pulse, as it has to do clock multiplication of the incoming midi 
sync to
> it's internal 48 ppqn resolution, so it's an easy matter just to 
toggle
> the din clock line on the off at every other 48ppqn pulse, whether
> running from midi or internal clock. Does the Cr8000 work OK from 
P3 ?
> I guess you could use another P3 just for this ;-)
> Or you could plead with me to do a simple sync convertor with true 
50%

> duty clock output.
> 
> Cheers,
> Colin f