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Arpeggiator Timing - Slight Irregularities?

Arpeggiator Timing - Slight Irregularities?

2014-11-15 by jim@saltlands.com

Anyone ever experience any slight timing issues with the polysix arpeggiator? Usually for me it only occurs when i have the arp in full range setting of 2 octaves UP/DOWN.. There is a slight hiccup after going UP, just before it begins to come DOWN. It seems like the down begins a dozen or so milliseconds late while it processes the upcoming information. The funny thing is this even happens with the ARP being triggered externally via the TRIG jack. 

Is this a result of digital lag time in the microprocessor? Or is this actually something i can adjust or repair?

Re: [PolySix] Arpeggiator Timing - Slight Irregularities?

2014-11-15 by Bob Grieb

The arpeggiator is code inside the key assigner.   An interrupt
signal is generated by an edge either on the remote trigger or the
oscillator on the front panel board.   When this interrupt comes in,
if the arpeggiator is enabled, the key assigner advances to the next note.
So I think the delay when changing direction is probably in the code,
and would be the same for internal or external trigger.

    Bob

From: "jim@saltlands.com [PolySix]" <PolySix@yahoogroups.com>
To: PolySix@yahoogroups.com
Sent: Saturday, November 15, 2014 3:12 PM
Subject: [PolySix] Arpeggiator Timing - Slight Irregularities?

 
Anyone ever experience any slight timing issues with the polysix arpeggiator? Usually for me it only occurs when i have the arp in full range setting of 2 octaves UP/DOWN.. There is a slight hiccup after going UP, just before it begins to come DOWN. It seems like the down begins a dozen or so milliseconds late while it processes the upcoming information. The funny thing is this even happens with the ARP being triggered externally via the TRIG jack. 
Is this a result of digital lag time in the microprocessor? Or is this actually something i can adjust or repair?


Re: [PolySix] Arpeggiator Timing - Slight Irregularities?

2014-11-15 by Bob Grieb

I already have a PIC design that replaces the key assigner and adds
MIDI, but it's based on the Korg code, and seems to have the same delay
as the original MCU, so it must be built into the code.  It's hard to trigger
the scope on the direction change, so I can't be sure.   Probably I should
trigger on the interrupt and see how much the envelope of the note
moves around.    Guess I could look at the code too and try to see where
the delay comes in, but that's more effort...

Bob

   

From: "jim@saltlands.com [PolySix]" <PolySix@yahoogroups.com>
To: PolySix@yahoogroups.com
Sent: Saturday, November 15, 2014 5:03 PM
Subject: Re: [PolySix] Arpeggiator Timing - Slight Irregularities?

 
Alrighty, so it is what it is I suppose. I guess a long winded solution would be fully replacing the arp system with a custom designed version such as an Arduino based device or similar.


Re: [PolySix] Arpeggiator Timing - Slight Irregularities?

2014-11-16 by chipaudette@yahoo.com

If you felt like replacing the Arpeggiator's microprocessor (which is also the Key Scanning and Voice Assigner microprocessor), you can do it with an Arduino.  I've done it.  It's pretty sweet.  I replaced this microprocessor not because of the Arp, but because I wanted other features...


If you do this kind of mod, you'll have total control over the Arp, you can fix any timing issues that you don't like, and you can add new Arpeggiator modes.

If you don't feel like replacing it yourself, I believe that the KiwiSix upgrade replaces this microprocessor, so it's Arp behavior will be different/better, too.

Chip