[sdiy] PLL question

Mon Mar 17 21:56:42 CET 2003

Phase shift can be a four, or five letter word...

The 4046 has two phase comparators... One is an exclusive or that has
limited lock range, high noise immunity, and guaranteed phase shift
in lock. The other is an edge sensitive detector that has high lock
range, limited noise rejection... but no phase shift when in lock...

You will be OK as long as you do not change tempo after you acquire
lock.  (with the edge detector)

H^) harry

--------Original Message--------  

From: frankentron at hotmail.com
To: madhun2001 at yahoo.com, synth-diy at dropmix.xs4all.nl
Sent: Mar 17 2003 15:32
Subject: Re: [sdiy] PLL question

>Hmmmm, phase shift should be a 4 letter word ;-) I guess if the phase shift 
>is 180 degrees I'll wind up with alternating 1/8 notes, or more specifically 
>16th notes when the 2 machines play together (only the sequencer responds to 
>start/stop). maybe it would make sense to derive the 24PPQ from the 12Xclock 
>for the sequencer. this will complicate things a bit but in the end I would 
>have synchronized machines right?
>~M
>>From: Tim Ressel 
>>To: Michael Ruberto , synth-diy at dropmix.xs4all.nl
>>Subject: Re: [sdiy] PLL question
>>Date: Mon, 17 Mar 2003 11:51:56 -0800 (PST)
>>
>>Michael,
>>
>>There are two issues here. The first is syncing these
>>two devices. If they both use a MIDI start command,
>>then they will probably be in sync. The second issue
>>has to do with phase shift within the PLL. There is no
>>guarantee that the 12x clock will be in phase with the
>>24PPQ clock. If there is phase shift, then you will
>>see a slight delay.
>>
>>PLLs are pretty easy to make. Whomp one up out of an
>>HC4046 and see how it works.
>>
>>--Tim
>>
>>--- Michael Ruberto  wrote:
>> >
>> > I need to take the 24PPQ from a MIDI to DIN Sync
>> > converter and speed it up
>> > by a factor of 12 with a PLL to clock another device
>> > which requires a higher
>> > clock rate.
>> > Now if I also have a normal sequencer being clocked
>> > by the straight 24PPQ
>> > will it be in perfect sync with the device whos
>> > clock is coming from the
>> > PLL? with a constant tempo, will 1/8 notes generated
>> > from both machines have
>> > acceptable timing to each other assuming the one
>> > device will divide down the
>> > higher clock rate to generate the 1/8 notes?
>> >
>> > I apologize for being so vague but I am just in the
>> > conceptual phase and
>> > haven't put anything to the breadboard yet.
>> >
>> > I appreciate any input :-)
>> >
>> > ~M
>> >
>> >
>>_________________________________________________________________
>> > The new MSN 8: advanced junk mail protection and 2
>> > months FREE*
>> > http://join.msn.com/?page=features/junkmail
>> >
>>
>>
>>__________________________________________________
>>Do you Yahoo!?
>>Yahoo! Platinum - Watch CBS' NCAA March Madness, live on your desktop!
>>http://platinum.yahoo.com
>_________________________________________________________________
>The new MSN 8: smart spam protection and 2 months FREE*  
>http://join.msn.com/?page=features/junkmail