decks have developed a fault!

[benjybars]

@ benjy,
i might have misunderstood your original post. If it is not a matter of the motor and more about pitch calibration then this is easily rectified with a little close work. As Stanton said, jus get a multimeter, hook it up to the pitch fader connector from the main board and adjust it to the value of resistance which they say. think its like 2.8 or something but it depends on the mark model as they are all different.

Another much simpler solution- the slow speed might just simply be down to lack of lubrication on the spindle bearing in the middle. This is the only moving part of the system- as well as the motor (rest is down to magnetic forces which is why the direct drive system is so indestructible) and a couple of drops of light oil will do just fine.

http://www.backspin.org/sl1200mk2.pdf
this might be of interest to anyone who likes the electronics of it. Technics sl1200 mk2 service manual

hope that helps, let us know how you get on

no, i'm saying i think it IS a matter of the motor (or torque?), rather than the pitch calibriation (which works normally)!

[FSTZ]

those motors rarely fail

when it sputters fast and then slow...

thats the pitch needing to be calibrated

if it is the motor...

might as well save for a new table

[benjybars]

those motors rarely fail

when it sputters fast and then slow...

thats the pitch needing to be calibrated

if it is the motor...

might as well save for a new table

no no no... it's NOT spluttering fast then slow!!!

it's just that the motor has a slight delay in returning to a clockwise motion if you spin the platter anti-clockwise.

i'm really not getting this across very well!

[concept_]

try oiling it as this is a good diea anyway.

I'm not too hot on the dynamics and electronics of the motor system. Ill ask my friend if he know what to do as he is big on this and taught me through a lot of it.

[badger]

I'm not really sure I know what he means but there is a centre click quartz lock on mk2 (and maybe mk3s not too sure) technics turntables (others like mk5 you can turn this off with the switch next to the pitch fader)
Basically, there is a switch which blocks pitch shifting at 0% so even if your pitch calibration is busted and way off it will still be 0% in the middle....if you remove the wires to the quartz lock, you can get rid of this "click" so the whole shifter gives you a true value at the centre region, even if it is fucked up...then you can recalibrate it effectively using a frequency counter. Removing the lock really isn't all that useful other than for calibration though when beatmixing is really tight around that centre spot, its nice for it not to automatically click to the 0 mark (this requires taking the whole fader out and a lot of soldering to get rid of the click though- takes a lot of time and care, but it is satisfying once it is all done.)

cheers for that concept might have a go at doing this when i sort out the earth. when you say using a frequency counter is this the same thing as using the multimeter like you mentioned above?

got a fudge with my earth atm just stuck it into the metal bit where the pop up light thing is so at least i've stopped the hum even if it looks shit. will try and do as much as possible when i get inside rather than doing one bit at a time

[mushieslushie]

Maybe get a slipmat?

You should never force the platter to spin the other way, unless its not spinning at all.

[concept_]

cheers for that concept might have a go at doing this when i sort out the earth. when you say using a frequency counter is this the same thing as using the multimeter like you mentioned above?

got a fudge with my earth atm just stuck it into the metal bit where the pop up light thing is so at least i've stopped the hum even if it looks shit. will try and do as much as possible when i get inside rather than doing one bit at a time

a freq counter is just a mroe specific type of counter. Most multimeters have instruments to measure voltage, resistance, and current but you can get one for measuring frequency in hertz and other instruments as well. Just look @ it before buying.
Whatever you do, if you are gonna modify/rectify, take your time and know what you are doing.

@benjy did you have any luck?

[benjybars]

@benjy did you have any luck?

nah not really, but it's not made the decks unusable and i'm worried i'll just fuck them up completely if i try and mess around with them

[concept_]

if it is bothering you, take it for a service. Its only 30 quid or so and they will look over it for you and then see (professionally) if anything is wrong. Sorry I can't be of more help...don't know too much about the mechanics of the the direct drive motor unfortunately.

To be honest though, Technics are near indestructable in terms of the motor, so if it is usable, then it's probably alright. Might just be something you can learn to live with (unless it really is very very slow). My decks are far from perfect in terms of alignment and braking torque etc. but still fine to use.