Question(s) Regarding Technics Pitch Calibration/Zero Point

Discussion in 'DJ's, MC's & Turntablism' started by Kevdino, Jan 23, 2009.

  1. Kevdino

    Kevdino Member

    Joined:
    Sep 1, 2008
    Messages:
    93
    Likes Received:
    0
    Howdy!

    Alrighty, So to begin heres a little summary of recent events:

    I noticed that one of my 1200 MKii's had two "zero points" (the large dots standing still at both the centre 'click' and once again around +1). Upon further investigation, I also noticed that the other dots were well off from the rough estimations given on the legend beside the on/off knob.

    So, I took it upon myself to recalibrate both the pitches on my pair of technics so they are (roughly) in sync. However, the initial two Zero points still exist on the one unlucky turntable.

    Now, upon reading various 'how-to guides' Ive noticed that some suggest the use of a multimeter in accordance with adjusting the potentiometer located on the bottom of the table, (note: NOT the same 'PITCH' screw adjustment used to recalibrate the pitch).

    I was wondering, had anyone attempted todo this? I read that the desired Ohm reading is 2.7kOhm, but im still not sure where to hook everything up.

    So yeah, these two projects, recalibrating both pitches so that they were relativly close (which seems to have helped with the mixing) and the removing the second zero point, have been my first attempts at handyman work on this suckers. Overall im pretty pleased with it, but as stated, id like to remove this annoying extra zero point, which is essently rendering my +1% point useless.


    My quick fix as of now has been to basically pitch my mixes up around +3-4% so that Im not ever really using the slider around the +1% area. ( I hear most people do this anyways to avoid the apparently 'pull' twowards 0 often associated with quartz-lock)

    In short, Im just looking to see if anoyone hase experience with using the multimeter to remove the two zero points, and if anyone has an easier method to remedy the problem stated.

    Thanks in advance

    (Ive only been djing since the summer, but this board has been a great help with keeping up to date on tunes and my mixing!)
     
  2. Dustek

    Dustek Finished the PhD

    Joined:
    Oct 18, 2004
    Messages:
    5,914
    Likes Received:
    15
    Location:
    London on the Wisla
    Man, you're Yoda asking 8 year old Anakin for wisdom.
     
  3. Kevdino

    Kevdino Member

    Joined:
    Sep 1, 2008
    Messages:
    93
    Likes Received:
    0
    lol, I didnt know much about this stuff prior to last night, this was just something I thought Id try todo, I was surpsied how easy it was todo some of the stuff I mentioned, honesly the hardest part was lifting those beastly turntables!

    dont listen to the horror stories you hear, try to save some bucks and DIY!
     
  4. Dustek

    Dustek Finished the PhD

    Joined:
    Oct 18, 2004
    Messages:
    5,914
    Likes Received:
    15
    Location:
    London on the Wisla
    Shit man, multimeter and OHM readings, I'd rather suggest debating set theory vs Platonian completeness.
     
  5. SH81

    SH81 Member

    Joined:
    Oct 21, 2008
    Messages:
    100
    Likes Received:
    0
    You gotta strip your deck and remove the pcb with the pitch control attached. Make sure your multimeter is on the correct setting and that your pitch control is set at 0; ie, its 'clicked' in the middle. Then take the reading from the legs on the potentiometer next to the slider. Its fiddly but with very fine adjustments to this potentiometer you'll be able get it to read 2.7k which should solve your problem. Ive done it on a couple of decks in the past and its worked a treat :)
     
  6. Kevdino

    Kevdino Member

    Joined:
    Sep 1, 2008
    Messages:
    93
    Likes Received:
    0
    Thanks!

    I was wondering, instead of removing the PCB with the pitch control, is it possible to just detach the brown, red, orange and yellow wires that connect the pitch slider to the main PCB on the top of the deck?

    Im just a bit lost as to why I cant just hook the multimeter to the legs and turn the pot.

    EDIT: For example: "locate the hole, which is situated near the pitch fader's area of the circuit board. You should see a small pitch pot beside it. Connect one probe of a multimeter to the center lead or the pot, and the other probe to the lead nearest the edge of the board. Use a small screwdriver to adjust the output reading to 2.7 kΩ. (If you don't have a multimeter, you will have to rely on trial and error.) Adjust the setting, hook everything back up, and try it; then readjust until you have fine-tuned it accurately".
     
    Last edited: Jan 24, 2009
  7. SH81

    SH81 Member

    Joined:
    Oct 21, 2008
    Messages:
    100
    Likes Received:
    0
    If you can get to the potentiometer without taking the pcb out then theres no need to remove it. Although if you've already stripped the deck far enough to get to the pitch pcb, its only 2 more screws to remove it so just makes access easier.
     
  8. RUSSLA

    RUSSLA DNBF Monarch

    Joined:
    May 23, 2008
    Messages:
    6,264
    Likes Received:
    886
    Location:
    BH1
    Yeah its all about how much access you actually to the pins. Personally i'd take it out, set you multimeter to have as many decimals as possible to get it super accurate.
     
  9. Kevdino

    Kevdino Member

    Joined:
    Sep 1, 2008
    Messages:
    93
    Likes Received:
    0
    Okay thanks, I didnt notice that it was only two screws, so I took those out.

    Now... those "legs" I connect the probs to on the multimeter, are those the 3 little silver things connecting the pot to the pcb?

    If so, they are basically set up in a triangle fashion; now, do I just connect the probs to the top one and the bottom right one?

    I ask this because of this quote "Connect one probe of a multimeter to the center lead or the pot, and the other probe to the lead nearest the edge of the board"

    This is assuming the 'legs' are the 'leads'.

    Thanks!
     
  10. SH81

    SH81 Member

    Joined:
    Oct 21, 2008
    Messages:
    100
    Likes Received:
    0
    Yep, thats what i meant by the legs, thats prob not the technical name but oh well! Off the top of my head I can't remember which two to connect the multimeter to, but I've a feeling you're right. If its the wrong legs you will prob just get '1' reading on ur multimeter so you know to connect to the others. Theres only three combinations so wont take long with a bit of trial and error
     
  11. Kevdino

    Kevdino Member

    Joined:
    Sep 1, 2008
    Messages:
    93
    Likes Received:
    0
    thanks buddy!

    from what Ive read, I'll need to recalibrate the 'PITCH' pot aswell after doing this.

    Now, to figure out how to remove the his from my bloody monitors!
     
  12. SH81

    SH81 Member

    Joined:
    Oct 21, 2008
    Messages:
    100
    Likes Received:
    0
    No worries, has it worked ok?
    The way i've adjusted the pitch pot is to move the pitch fader as close as possible to where +6.4% looks like it should be, then make small adjustments to the pitch pot on the main PCB until you get the top level of dots staying still on the platter when its spinning. There might be a more acurate way of doing it, but as far as I know its just trial and error again until you get it right.
    Remember to turn the deck off before you remove the platter as you can cook the motor if you were accidently to press start while the platter is removed!
     
  13. Kevdino

    Kevdino Member

    Joined:
    Sep 1, 2008
    Messages:
    93
    Likes Received:
    0
    Okay, so far Ive been unable to get a clear reading; the numbers are constantly jumping around. I assume this is because my multimeter lacks alligator clips to clamp onto the legs.
     
  14. Kevdino

    Kevdino Member

    Joined:
    Sep 1, 2008
    Messages:
    93
    Likes Received:
    0
    I finally got it to read 2.7, but the zero point still exists!

    Could this possibly mean I should attempt to clean the pitch slider?

    If so, what would be the best method?
     
  15. SH81

    SH81 Member

    Joined:
    Oct 21, 2008
    Messages:
    100
    Likes Received:
    0
    Wont do any harm to clean your pitch control, use some long nose pliers to gently bend the 8 or so lugs on the metal casing of the pitch slider and lift it off to get access. You can then also remove the little ball bearing to get rid of the centre click as well while its stripped down.
    I wonder if the zero point problem is something other than just the calibration, one way to solve it good an proper is with this........http://cgi.ebay.co.uk/TECHNICS-PITC...14&_trkparms=72:1301|66:2|65:12|39:1|240:1318
     
  16. Kevdino

    Kevdino Member

    Joined:
    Sep 1, 2008
    Messages:
    93
    Likes Received:
    0
    Whole new slider eh, well I guess it wouldnt hurt.

    Would I need to go in do redo all the fiddling ive done on the new one as well? such as adjusting the two pots? or would that be good to go with the new one
     
  17. SH81

    SH81 Member

    Joined:
    Oct 21, 2008
    Messages:
    100
    Likes Received:
    0
    That link is to the pcb as well so it will have the potentiometer already calibrated properly, I think if you were just to replace the slider it wouldn't solve the problem.
    Alternatively here's a walk through of removing the quartz lock- never tried it myself though

    http://technics.junglist.pl/hacking_technics.html
     
  18. Kevdino

    Kevdino Member

    Joined:
    Sep 1, 2008
    Messages:
    93
    Likes Received:
    0
    Cool, thanks man

    Im def considering purchasing the new slider/pcb combo, although id like to figure out how to remove my current slider first!

    the 4 coloured wires that run onto the larger PCB on the top of the deck wont seem to budge. However I've read they just 'pop off'

    Once I get comfortable with this i may consider replacing the rca's aswell. In comparison to my newer 1200, this one sounds lackluster
     
  19. robhicks1

    robhicks1 Nuts about Zoo

    Joined:
    Feb 6, 2008
    Messages:
    2,530
    Likes Received:
    7
    Location:
    Southampton
    Also do note that in the instruction book it says that the values that the dots stay stationary at are estimates.
     
  20. Kevdino

    Kevdino Member

    Joined:
    Sep 1, 2008
    Messages:
    93
    Likes Received:
    0
    yeah, for the dots im not to worried, I figured they were estimates; as some look spot on but others are say, .2-4 off.

    Im more concerned with the extra zero point!

    But thanks!