MB808 tighter as a TR808...

MIDIbox SEQ
1

…might be interesting for some of you… i stumbled across this site innerclock

so i ran a little test with my MBSeq808-Build…120 bpm, rimshot each quarter…and ended up like this:

22.029|22.072|22.075|22.025|22.077|22.028|22.079|22.030|

22.077|22.027|22.071|22.030|22.075|22.030|22.071|22.031|

…so the largest distance between two quarters is 52 samples…the tested 808 is 87 (on their site)

so a 1,18 ms drift compared to 1,97 ms…

what i was thinking of is , what cause the drifts? (not that i´m not satisfied with the results)

would it be an improvement when the two 33pF caps (C1, C2) will be matched as close as possible?

…this is just a guess…since i´m noob when it comes to electronics (but learning everyday ;))

nik

2

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Faster update rate for the trigger pulses

??

3

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Faster update rate for the trigger pulses

??

…mmm…is this just a guess?..or do you think its the only way to avoid the jitter?..i assume then its more a programming aspect rather than selecting components, right?

ok…why i ask is because i thought of building such a “sync-lock” on my own (i would buy this- but it´s soo expensive for “just” a midiclock…also like to have more midiouts, like they announced with the cinq-lock)…so when it depends on “just” programming, thought it may be possible with a pic (maybe even with mios ) to get a stable samplebased midiclock via a trigger input…

i searched this forum and also the www and stumbled across several projects (pic and arduino-based), but they all seam to be kinda “dead”, not further developed… :unsure:

the clockboxproject is great, but it also is heavily dependent of a stable midiclock from its source…would be great to have such a trigger-feature added to this…

cheers, nik

4

…might be interesting for some of you… i stumbled across this site innerclock

so i ran a little test with my MBSeq808-Build…120 bpm, rimshot each quarter…and ended up like this:

22.0029|22.0072|22.0075|22.0025|22.0077|22.0028|22.0079|22.0030|

22.0077|22.0027|22.0071|22.0030|22.0075|22.0030|22.0071|22.0031|

…so the largest distance between two quarters is 52 samples…the tested 808 is 87 (on their site)

so a 1,18 ms drift compared to 1,97 ms…

what i was thinking of is , what cause the drifts? (not that i´m not satisfied with the results)

would it be an improvement when the two 33pF caps (C1, C2) will be matched as close as possible?

…this is just a guess…since i´m noob when it comes to electronics (but learning everyday ;))

nik

And how did you measure this ?

5

And how did you measure this ?

did u read the article on the innerclock site posted above?..they describe the procedure there…

i put the mb808seq as master at 120bpm with a rimshot each quarternote…in soundforge i sampled 4 measures…so 16 rimshots in total…the distance between two rims should be exactly 22.050 samples @ 44.1Khz…the results are posted above…i know its not 22.0029 …should read 22.029 and so on, with a zero less (my fault, was a copy paste error :ahappy: ) <- corrected the readouts