hmm. ah, okay, that's common sense. I should have picked up on that. Thanks for helping me out a second time on the same issue, haha. That will work for the main thing I have in mind.

However, one thing I'd like to do eventually is have two oscillators running at independent frequencies and one phase modulating the other. So it would be useful for me to have a control that would reset the phase on a note-on message. That way I could toggle the control to have either free-running oscillators or oscillators that start at a specific phase each time a note is produced.

to realize this should I just use a master phasor~ by default and toggle in additional phasors as independent frequencies become necessary? I feel like at that point I would still be lacking note-on phase syncing.

The note-on phase syncing is handy for realizing predictable note attacks when the difference in frequency is relatively small. It's a feature in Ableton Live's Operator, for example (I don't own this actually).

Thanks for bearing with me on this. The relative nature of phase has always confused me to a degree.

Well, I was about to refer you to a post on hard syncing I did, but I realized it was in response to you. So now I'm thinking I don't fully understand your question. Syncing oscillators should always be done with a master [phasor~], so you wouldn't really toggle it so much as you would alter the output of the master [phasor~]. (Just in case my earlier response didn't make that clear.) Are you maybe asking about phase offset? If so, you can do it like this:

[phasor~]
|\
| \
| \
| [tabread4~ mywave]
|
[+~ .5]
|
[wrap~]
|
[tabread4~ mywave] <--will be synced to above oscillator,
but 180 degrees out of phase

Hello,

I'm trying to make something that sounds like C64 SID chip. One particular property of that chip is that, it is possible to hard-sync two oscillators, so that the slave oscillators phase is reset to zero every time master oscillators phase returns to zero. I couldn't find a a way to implement this in pd.

Trying to capture the zero crossings on the master oscillator seems to be a dead end, because i'll have to turn it into a control signal somewhere to connect it to the phase input on slave phasor. And control signals are much too slow to catch every zero crossing.

Any ideas?

If you plan on using [xerox~] to phase sync two oscillators, it probably won't cut it. Generally, you want those things to be sample accurate. [xerox~] will give you a click corresponding to zero crossings out its right outlet, but, as far as I know at least, Pd's oscillators can't really use that for phase syncing ([xerox~] is actually based on a Max object, yet strangely Max's oscillators can't use it either). It would require a conversion to message rate to reset the phase, which kills sample accuracy, not to mention the fact that the phase input of [phasor~] quantizes to block boundaries (default 64 samples in Pd), which also kills sample accuracy.

However, if you know the ratio between your two oscillators, phase syncing can be achieved using a master [phasor~] to run both oscillators. Use the master sync frequency to drive the [phasor~], then multiply the output of the [phasor~] by the ratio between the synced (slave) oscillator and the master one. In other words, it should be multiplied by:

slave frequency / master frequency

Then, you just [wrap~] the signal and viola, you have a new synced phasor signal to drive the slave oscillator. The attached patch should hopefully clarify.

http://www.pdpatchrepo.info/hurleur/phase-sync.mmb.pd

Hello I installed Pd, jackd and Alsa via apt-get i have debian 5.0(lenny)

Sometimes the sound works, when work it appear an error message:

audio I/O error history:
seconds ago error type
0.14 A/D/A sync
1.00 unknown
1.52 A/D/A sync
5.76 unknown
5.76 unknown
tried but couldn't sync A/D/A
audio I/O error history:
seconds ago error type
1.40 A/D/A sync
3.38 A/D/A sync
3.69 A/D/A sync
7.12 A/D/A sync

when don't works appear this:
couldn't open MIDI input device 0
couldn't open MIDI output device 0
opened 0 MIDI input device(s) and 0 MIDI output device(s).
audio I/O error history:
seconds ago error type
4.69 unknown
4.69 unknown

thnx

ha ha, it's not very scientific. but anyway...

[noise~] outputs a random value between -1 and 1 every sample.

we then multiply the output of [noise~] by a number between 2000 and 20000

this means that going into the frequency control of the [osc~] object will be a signal between -2000 and 2000 at the lowest setting, and -20000 and 20000 at the highest setting.
sending negative frequencies into [osc~] is just the same as positive ones, but the oscillator wave flows in the opposite direction.

so, every sample, we are changing the frequency of the [osc~] oscillator. if we only oscillate at frequencies between -2000 and 2000, then the maximum frequency output will be 2000hz. however if we ramp it right up to 20000, then the oscillator will oscillate at higher frequencies.

it still sounds like noise though, because the frequency of [osc~] is changing so rapidly that there is barely any periodic content in the output waveform.

Hi,

I'm just getting started with Pd on Fedora Core 3; installation was pretty painless thanks to the CCRMA repositories, but I've run into an issue when I first tried to make some sounds with Pd. I recreated Miller Puckette's example of a constant amplitude scaler. When I start the audio, the signal seems to take a few seconds to 'settle' into a constant frequency; I get a few seconds of static that eventually turns into the sine wave I was expecting. When I click the DIO errors button, I get a bunch of A/D/A sync errors, as follows:

audio I/O error history:
seconds ago error type
0.73 A/D/A sync
0.73 A/D/A sync
0.75 A/D/A sync
0.94 A/D/A sync
0.94 A/D/A sync
0.95 A/D/A sync
1.01 A/D/A sync
1.01 A/D/A sync
1.10 A/D/A sync
1.10 A/D/A sync
1.11 A/D/A sync
1.11 A/D/A sync
1.17 A/D/A sync
1.17 A/D/A sync
1.17 A/D/A sync
1.17 A/D/A sync
1.27 A/D/A sync
1.31 A/D/A sync
1.31 A/D/A sync
1.36 A/D/A sync

If I let the steady sine wave tone continue, eventually there's a bit of a 'hiccup' in the sound, and then I get the following errors:

audio I/O error history:
seconds ago error type
1.25 DAC blocked
1.25 data late
1.25 data late
1.25 data late
1.25 data late
1.25 data late
1.25 data late
1.25 data late
1.25 data late
1.25 data late
1.25 data late
1.25 data late
1.25 data late
1.25 data late
1.25 data late
1.25 data late
1.25 data late
1.25 data late
1.25 data late
1.25 data late

Can anyone help me out in diagnosing this problem and fixing it? Where should I start looking to fix this?

Thanks!