Not varispeed again but half speed..

[jcotner]

I've looked at the older posts about this and about decided the only way you might get there (without altering your original audio) is to supply DP with an external clock. I design hardware for a living so that's no big deal for me. However I'm looking to make this behave like flipping an analog tape deck from 30ips to 15ips. Half the clock. Question is will this cause DP to behave badly? I wouldn't think so and perhaps noboby has done this. But in the interest of not banging my head on the wall, I thought I'd see if anybody else has already tried this approach.

[David Polich]

I've looked at the older posts about this and about decided the only way you might get there (without altering your original audio) is to supply DP with an external clock. I design hardware for a living so that's no big deal for me. However I'm looking to make this behave like flipping an analog tape deck from 30ips to 15ips. Half the clock. Question is will this cause DP to behave badly? I wouldn't think so and perhaps noboby has done this. But in the interest of not banging my head on the wall, I thought I'd see if anybody else has already tried this approach.

Two questions - one, why do you want to do this? To learn a guitar or other
instrumental part?

Second - since switching a tape recorder to a speed that is 50% slower would
result in "slowed down" and therefore degraded audio, wouldn't using time-stretching produce the same result?

Third - well, to answer your question of whether sending DP a slower external clock would screw it up - my guesstimate is an absolute yes, it would - because ALL your audio tracks would be messed up, not just the ones
you want to affect with the change in clock. Not to mention, anything else
that depends on clock - plug-ins, VI's, etc.

To me, this is kind of the equivalent of downshifting to 1st from 3rd at 80mph - a recipe for disaster no matter how you look at it.

[jcotner]

OK well I used to do this on analog tape decks with the synths a long time ago. It's also a known Wendy Carlos trick (and many others). This is only for tracking and would not involve any VIs or plugs. And yes all other tracks would be half speed but when you're using this technique it's all good.

With regards to quality, say your project is 96KHz and half speed would be 48KHz. It seems to me that if you are sampling something at half the frequency and then double it for playback you won't have any nasty Nyquist issues or other artifacts. Remember a 440Hz Middle C will be 220Hz on the synth for tracking at half frequency sampling and tempo will also be divided by 2. You would need a dedicated click track to make this work, but I do that already anyway.

Some old analog gear is not MIDI and it also allows one to do some things with timbre and evelopes that is hard to do otherwise with old analog gear.
And why you might ask would anybody want to fool with this sort of nonsense with the modern tools---it's all about the sound. Good synthesizer realizations are anything but easy and the most enduring at the ones where people push the envelope. Hope that helps in understanding the motivation.

[MIDI Life Crisis]

If I am understanding you correctly, you could probably accomplish much the same effect with something as simple as a good pitch shifter like Melodyne. Better yet, you might also actually expand your pallet with a tool like the IRCAM stuff currently found in MachFive and elsewhere. The granular stuff in particular might hold some interest for you.

If you want to use the old synth sounds directly, you could sample them and just do the processing in a more controlled and more expansive working environment.

As for the G5, the sooner the bett:er. I finally took mine offline about 18 months ago and what a difference, especially in VI stability and with file exports and other CPU intensive processing. Breaking out of the 4GB RAM limit is going to change your world.

[Shooshie]

You're asking the wrong people. This is something that few people are going to know the answer to. I say install DP on a spare drive and go for it. If it breaks, it breaks. If not, then you've got a story to tell. Use copies of any important files, plugins, etc. You may have to reinstall the system if the drivers get screwed up. But that should be a no-brainer for you.

Good luck…

Shooshie

[jcotner]

I hear you on the G5 but for me it's a new Mac, new PCI-424, new Altiverb, new VIs and on and on. Little steps for little feet, if it were. I've just spent over 2K on a DAC/ADC so the move from G5 will take a while. When you take into account things like Ribbon Controllers and pedal modifying patches and all the modulation combinations sampling these old synths becomes a not very fun exercise, rapidly. For the most part I want to and do use DP more or less like I used to do things with my Fostex A-8 and my old Tascam M-312 and a bit of outboard gear. These days it's all too easy for the music to get lost in the technology.

[vsoprod]

I came from the analog world and varispeed was a major tool in our sound shaping arsenal. If you slowed the tape down a couple of cents and then doubled a synth part, when it was back to speed it had a nice sheen.
Half speed, you'd play an octave lower, when back up to speed the timbre changed and it was a nice effect. Also if you needed to play a part that was difficult it made it easier and timing descrepancies with half as far off.
Years ago I had the idea to clock DP from the Optical sync from an ADAT. It would work for a certain amount of change and then DP would quit. I'm can't remember if we ever got it to record in that mode.
Always hoped someone could figure out how to make a reliable variable clock that DP would work with.

[David Polich]

I came from the analog world and varispeed was a major tool in our sound shaping arsenal. If you slowed the tape down a couple of cents and then doubled a synth part, when it was back to speed it had a nice sheen.
Half speed, you'd play an octave lower, when back up to speed the timbre changed and it was a nice effect. Also if you needed to play a part that was difficult it made it easier and timing descrepancies with half as far off.
Years ago I had the idea to clock DP from the Optical sync from an ADAT. It would work for a certain amount of change and then DP would quit. I'm can't remember if we ever got it to record in that mode.
Always hoped someone could figure out how to make a reliable variable clock that DP would work with.

Well I've been playing and programming synths since 1972. And I've spent
plenty of time with analog tape machines in studios. Honestly, all the techniques you mentioned were the results of trying to do things with the
technology that was available at the time.

The reply above was correct, you can do all this half-speed, quarter-speed, de-tuning, whatever with Melodyne and other plug-ins (including plug-ins that emulate double-tracking).

Tape emulation you can do with UAD's Ampex and Studer tape machine plugs, or Slate's tape machine plug or the Waves MPX plug-in. You can even change the tape speed, type of tape, alignment, bias, all kinds of things. If you want to "slow things down" so you can play a tricky part, you can simply slow the tempo of your sequence down, play the part from a MIDI controller, then speed the tempo back up.

There's no need for external clock trickery, which doesn't really work anyway as you discovered with your experiment with ADAT optical sync.

[stephentayler]

I don't think any of the modern pitch shift/time stretch tools are right for this.

Assuming the idea is to record audio at half the speed so that it sounds sped up at normal speed - Wendy Carlos or Les Paul style - then what I do is to:

make a stereo rough mix of the backing -

drop the pitch 12 steps in either MachFive or (I usually use) ProTools pitch shift without time correction*, this is equivalent to halving tape speed -

do the overdub -

reverse the process on the overdub by shifting back up again.

I know you didn't want to alter the original audio, but this solution works for me. When done just trash the rough mix. You can obviously use any pitch interval for this.

And before anybody starts calling it cheating - it's a sound technique, not a trick to sound like you are playing faster!!! Also works the other way for creating deep sounds.

Cheers!

SWT

* unfortunately DP does not offer this option