CD Timecode Control and Momentum

DJChadG 5:02 AM - 21 January, 2009

In SL, I've always felt that undesired drifting occurs whenever the platter or pitch slider on my CDJs has been touched.

This effect is most noticeable when moving the platter back and forth while watching a virtual deck: when moving the CDJ platter and stopping promptly, the scratch reference line on the virtual deck continues to move slowly in the direction in which the deck was pushed. This occurs in both Relative and Absolute modes regardless of buffer size, key lock, etc.

Another odd behavior is that moving the deck forward, back, forward will cause the deck to slowly move backwards, in the opposite direction of the "momentum."

In theory, shouldn't the virtual deck stop playback as soon as the timecode signal is not being sent? How can there be progression within the track when playback is stopped by removing my hand from the CDJ? It seems as if SL has built in momentum. Beatmatching could be much more efficient if one did not have to take compensate for this behavior, as I am sure that the tempo slider also affects this behavior.

Any ideas?

My laptop is a Lenovo T61p w/ XP SP3, 2GB of ram and a Core 2 Duo processor @ 2GHz.

victor_M 2:20 PM - 21 January, 2009

Try moving the threshold to the left. MY CDJ's do the same thing at 75db try setting it to 35db which might eliminate that "Momentum" your talking about.

victor_M 3:30 PM - 21 January, 2009

sorry Move the threshold to the right.

Chad S. 4:38 PM - 21 January, 2009

Sounds like to you would need to calibrate the cdj's in the set-up screen.

Turn off the keylock / master tempo on the cdj. If you need that feature, it is in the software. It will appear as a musical note next to each virtual deck.

Can you adjust the braking on the cdj?

DJChadG 6:20 PM - 21 January, 2009

Moving the slider all the way to the right seemed to have fix the problem, thank you! Although this goes against the advisory in the help screen (CDJs are not really subject to vibration as a turntable would be).

For the record, breaking is adjusted to its sharpest setting. Master tempo is always turned off. But it seems fixed. Perhaps the help documentation should be revised to reflect CD timecode behavior?

victor_M 7:26 PM - 21 January, 2009

if you play the tone you will notice when you stop the platter it still plays for a little bit just really low. It's something on the CDJ's... maybe it's buffering to avoid the cd from skipping.SSL picks it up when it's all the way to the left.

Chad S. 8:03 PM - 21 January, 2009

usually cdj's dont need to be calibrated. Seeing that that did, there is a problem with them. Could be the RCA cables, try replacing them. Usually when you have to bring the slider to the right there is a grounding problem. Oddly enough, they don't have ground cabels like a turntable would.

DJChadG 8:40 PM - 21 January, 2009

Well I have tried standard RCA cables and those special high-quality cables that come with Traktor Scratch. Problem is the same both ways. And this happens for Victor as well.

Chad S. 9:20 PM - 21 January, 2009

What type of cdj do you have?

how about you victor?

DJChadG 9:22 PM - 21 January, 2009

cdj 1000 mk3 x2

Chad S. 10:00 PM - 21 January, 2009

hmmm, I've used those a million times. hmmm.

DJChadG 2:59 AM - 22 January, 2009

I tested Victor's findings that the control signal is audible during SL's momentum playback. I could not hear the control signal whatsoever during this tested momentum playback (even after increasing the volume quite a bit right after moving the platter). This implies that the issue is related to SL and would happen with other CD players.

I have a feeling that it's always been this way and it's gone unnoticed. So should it be a recommendation for all users of CD timecode use -24dB as the recommended threshold setting?

Is this unavoidable due to the resolution of the CD timecode (maybe SL vinyl has a higher output volume for the threshold to deal with)?

Also, assuming the control signal changes in tone to communicate the absolute mode playback position, would this have any affect on the momentum (beginning of control CD track 1 as compared to last couple of minutes)?

victor_M 3:28 AM - 22 January, 2009

I have 800's Made in 08.. didn't have issues with my 1210's plugged in.

don't hate Chad S..."jokes of course"

DJ chadG. Just tried it again. do the following

stop the platter
jerk it a little you will hear like a whoosh...very faint.

victor_M 3:35 AM - 22 January, 2009

and when I mean stop the platter not with the play button...pretend like your going to scratch and jerk it a little.

Chad S. 5:19 PM - 22 January, 2009

chadG, if this was a common problem, we would have heard more about it. Thousands of people use both of these together every day. Something odd is happening for you. Can't put my finger on it as of yet, but I'll ask the other guys what their thoughts are. They might have seen this before, I haven't.

DJChadG 6:44 PM - 22 January, 2009

Okay, thanks for your help. This seems more like a software / Serato problem.

=)

Zach S 5:10 PM - 28 January, 2009

ChadG,

Please recalibrate your setup.

Make sure the control disc are in the players and press pause on the players.

Now, put one virtual deck in INT mode, load a song, and play the song through the speakers as loud as your going to be playing.

Now go to the setup screen and hold down the estimate tabs for each side for about 4 seconds.

Take note of the number in the upper right corner of each scope view.
This number should be stable at 0.0 or -0.0.
If this number is fluctuating then that will tell us your picking up interference somewhere in the chain.

If this is the case, try dragging the estimate slider to the right until the number in the upper right corner of the scope views stops fluctuating.

If you've moved the estimate slider all the way to -24 and the number in the upper right is still fluctuating then there is an interference issue.

If this is the case, make sure that your SL1 interface isn't sitting next to a power source such as a power strip, and that the rca cables coming to and from the SL1 aren't sitting across something that conducts power.

Let us know your findings.

DJChadG 3:26 AM - 29 January, 2009

Followed directions as described:

- Virtual deck playing in internal mode without timecode signal stays at constant 0.0 in scope view (never fluctuates).

- Holding down the estimate tab does not do anything - pressing it moves the slider all the way to the left (-72 dB)

- Power cord is below plastic table about 4 feet away (through table).

In case it matters, with both CDJs playing, the number in the upper right corner of the scope view is 33.3 (with tempo reset engaged). Also, output of SL1 is through LINE and goes into LINE input on my DJM 800.

Chad S. 5:17 PM - 29 January, 2009

any improvement? None at all?

DJChadG 6:29 PM - 29 January, 2009

No improvement with his instructions - I believe they were only to diagnose the problem (with the belief that the issue was caused by interference).

Moving the slider all the way to the right seems to be the only solution. My point is that the documentation should be updated if this problem is widespread (and not unique to my setup). Also, there's probably a lost of senstivity due to this "fix."

DJRR 6:53 PM - 29 January, 2009

I have a problem when spinning back on my Denon DNS3500's... When I spin back very fast sometimes the waveform on scratch live just freezes up stoping me from spinning back...

How can I correct this?

Chad S. 10:12 PM - 29 January, 2009

Quote:

I have a problem when spinning back on my Denon DNS3500's... When I spin back very fast sometimes the waveform on scratch live just freezes up stoping me from spinning back...

How can I correct this?

DJRR could you please start a new thread. Different problem, different controller. Thank you ;)

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CD Timecode Control and Momentum

CD Timecode Control and Momentum

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