PDA

View Full Version : M3D/MK5 pitch control in MK2 table



_rt_
06-10-2013, 09:40 AM
Question to those that have completed the M3D/MK5 pitch faders in MK2 mod.

I recently completed a table restoration that I am quite happy with.
Included in the restoration was the installation of M3D/MK5 pitch faders.
I did this because the old ones were filthy and rather than open the up to clean everything out, I figured I would replace them and get rid of the click at zero. I also planned to eliminate the quartz lock during the mod.

Long story short:
I replaced the faders and the LED on the board.
When everything was put back together, the pitch control works great. I'm calibrating the pitch tonight.
The one thing that is throwing me off:
The LED light isn't coming on at the zero location.
Considering I replaced all the lights on the table with LED's, I'm hesitant to thing I screwed up on the easiest one. But before I replace it again, I wanted to ask the following questions:
1. When pitch faders are replaced with M3D/MK5 faders, is the quartz lock automatically eliminated? This could explain the light not working.

Thanks all-

Mark_Spit
06-10-2013, 10:50 AM
I've done the mod myself, and found that the LED doesn't work anymore either. Doesn't affect the operation though, so I didn't worry about it.

_rt_
06-10-2013, 02:51 PM
But does that mean that quartz lock has also been eliminated or do I need to do that mod?
I get the sense that quartz lock ends up removed as well once the new fader is used.

I'm also wondering how easy it would be to run power to the LED. If it isn't going to come on at the zero point then maybe I'll just have it permanently on when there is power.

BOWNSIR
06-10-2013, 05:00 PM
I get the sense that quartz lock ends up removed as well once the new fader is used.



http://i26.photobucket.com/albums/c115/bownsir/th_cleanpitchzero_zps01238b60.jpg



You're correct and no need for the mod. The true quartz lock point (that also enables the led to turn on) on a regular mk2 pitch fader is dictated by the center notch on the carbon track like in the picture above. The carbon track on the M3D/MK5 pitch fader is slightly different in this area and doesn't enable the quartz lock or led because it's controlled by the reset button. I also used M3d/Mk5 faders when I had my MK2's and experienced what you described. Once I got my M3D's I compared the actual pitch fader PCB carbon tracks of both pitch faders and saw they were different which explaind why the led wasn't turning on with the M3D pitch fader.

If you want to leave the led permanently on you can power it from a 12V source with a 1kohm resistor in series on the positive leg of the led.

DTR
06-11-2013, 05:12 AM
But does that mean that quartz lock has also been eliminated or do I need to do that mod?

The "quartz lock" at 0% is actually a common misconception. The pitch on any 1200 / 1210 is quartz locked across the entire pitch range. On a M3D all the button does is bypasses the fader and forces the table to run at 0%. On a Mk2, the centre position of the fader switches in the bypass so that the pitch is a true zero, not governed by the resistance of the fader pot (it's possible for the actual zero position to move away from the zero position on the scale).

Incidently, a Mk2 fader can be easily modified so that the 0% bypass is removed (this makes the fader more accurate around 0%) but the light still comes on at zero.

djpenguin
06-11-2013, 12:29 PM
The "quartz lock" at 0% is actually a common misconception. The pitch on any 1200 / 1210 is quartz locked across the entire pitch range. On a M3D all the button does is bypasses the fader and forces the table to run at 0%. On a Mk2, the centre position of the fader switches in the bypass so that the pitch is a true zero, not governed by the resistance of the fader pot (it's possible for the actual zero position to move away from the zero position on the scale).

Incidently, a Mk2 fader can be easily modified so that the 0% bypass is removed (this makes the fader more accurate around 0%) but the light still comes on at zero.

:love:

:school:

BOWNSIR
06-11-2013, 02:22 PM
Learned something new, thanks Dave. I always thought the frequency of the crystal was enabled/disabled and not constantly on. I stand corrected.

"You must spread rep..."

_rt_
06-11-2013, 03:02 PM
The "quartz lock" at 0% is actually a common misconception. The pitch on any 1200 / 1210 is quartz locked across the entire pitch range. On a M3D all the button does is bypasses the fader and forces the table to run at 0%. On a Mk2, the centre position of the fader switches in the bypass so that the pitch is a true zero, not governed by the resistance of the fader pot (it's possible for the actual zero position to move away from the zero position on the scale).

Incidently, a Mk2 fader can be easily modified so that the 0% bypass is removed (this makes the fader more accurate around 0%) but the light still comes on at zero.

Not that I doubt you, but where does the info come from?
I've seen so many accounts that are the opposite of this that I just don't know what it true anymore.

djpenguin
06-11-2013, 03:45 PM
Not that I doubt you, but where does the info come from?
I've seen so many accounts that are the opposite of this that I just don't know what it true anymore.

The info comes from the service literature for the SL-1200 series. The quartz crystal is used for timing the motor that drives the platter, and is responsible for the platter jumping instantly back to its set speed after a drag or twist. If you disable the quartz lock, the platter will take some time to return to its set speed. The pitch control is just a method of varying what that set speed is.

If you want to disable the quartz motor speed control, you need to remove a capacitor from the main PCB to break the timing circuit (I think it's C107 or C108, but I don't remember off the top of my head) and disconnect the orange wire from the pitch PCB on MK2 units.

As Dave mentioned, the button (M3D and above) or center click (MK2) is merely a switch that turns the pitch control fader on or off. The design of the MK2 incorporates two parts to the switch, the mechanical spring and ball to give the fader a detent at zero, and the switch circuitry integrated into the fader assembly. When modifying a MK2 fader to behave like an M3D fader, you would remove the spring and ball, and disconnect the orange wire from the pitch fader PCB. This will leave you with a fader that has no switch in the middle, but the LED will still light right around zero (though it will not have its former "the pitch control is turned off, therefore this is true 0% pitch" meaning.)

DjLiquitATL
06-12-2013, 10:19 AM
i'm pretty sure its tp17, but don't quote me on it...damn, I knew I forgot to disconnect the orange wire...good thing I don't beat juggle or i'd be screwed :teef:

djpenguin
06-12-2013, 11:56 AM
TP27 is the post you use to calibrate the quartz crystal to the factory frequency (262.08Hz...I'm certain about this one because I just recalibrated an M3D I'm thinking about selling yesterday), along with the ground post next to it. If memory serves correctly, those are the only two test posts on the main PCB. All capacitors will be labelled with a leading "C" for capacitor, not "TP" for test point/post.

In any event, disabling the quartz lock is something that is mainly done by/for disco DJs and others who spin music featuring human drummers. Disabling the quartz lock would be a nightmare for any sort of turntablism, but your teef smiley suggests you already know that.

DjLiquitATL
06-14-2013, 08:25 AM
i'm not that advanced as a turntabilist quite yet... I mainly mix so disabling quartz lock is better for me... with butter rugs it doesn't really effect me when scratching b/c the platter is constantly moving

djpenguin
06-14-2013, 11:10 AM
i'm not that advanced as a turntabilist quite yet... I mainly mix so disabling quartz lock is better for me... with butter rugs it doesn't really effect me when scratching b/c the platter is constantly moving

As I said before, disabling quartz lock is only useful to a small subset of DJs who mix music with human drummers. Because of the exaggerated pitch bends that come with even small platter manipulations, it's not a very good idea for DJs mixing music with sequenced drums.

CC Ricers
06-24-2013, 04:39 PM
I've done the mod myself, and found that the LED doesn't work anymore either.

Same here. And I hated the fact that the LED wouldn't turn on anymore, so I rewired the contacts so the LED always stayed on :D

_rt_
06-25-2013, 08:38 AM
Same here. And I hated the fact that the LED wouldn't turn on anymore, so I rewired the contacts so the LED always stayed on :D

Curious where you pulled the power from?
I completed a similar mod recently and I want power to that light as well.

I assume you used a resistor as well?

Also... your PM's are full. Just FYI.

DjLiquitATL
06-25-2013, 11:06 AM
you can easily pull the power from the pop-up light

DjLiquitATL
06-25-2013, 11:14 AM
and yes you need a resistor

_rt_
06-25-2013, 01:59 PM
you can easily pull the power from the pop-up light


That's what I'm planning to do.
Was just wondering if there was another option on the fader itself.

FWIW... I'm wiring it to the pop-up light so that the light is only on when the pop-up light is up.

DjLiquitATL
06-25-2013, 02:31 PM
I had an LED tonearm I got from jesse dean a few years back... It was wired to my pop-up light...I ended up messing it up after changing the led color a few times


http://youtu.be/oPHKh6o9fvI

I bought this 1200 from GC online for $100.00 shipped...sold it a long time ago

CC Ricers
06-26-2013, 09:51 AM
Curious where you pulled the power from?
I completed a similar mod recently and I want power to that light as well.

I assume you used a resistor as well?

Also... your PM's are full. Just FYI.

I don't have the 1210 anymore to check how it was done, but I don't think I had to route the power from another source. But check this video (http://www.youtube.com/watch?v=Vzzp6TTPYc0), it probably helps.

Basically the middle contact point on the green side of the PCB had to be physically connected to another point in the slider, I think it was somewhere between the light's mini-PCB and the pitch fader's. I used speaker wire to make the connection.