View Full Version : Technics 1210 mk2 pitch fader fix (and instructions on its removal)
dantheman91
27-01-2012, 12:39
Hi
is the pitch fader an easy fix. i have been offered one of these for £60 is it worth it.
Dan
Dingdong
27-01-2012, 12:46
Do you really need it? You could always wire it out. There is a pot inside I believe to set the speed right.
dantheman91
27-01-2012, 12:51
Hi
no i wouldnt need it. but the owner says it now running a constently at a fast speed. would it be easy to wire it out?
dan
Dingdong
27-01-2012, 13:13
I think so. Somebody with some experience of the innards should be able to instruct you.
Beobloke
27-01-2012, 15:09
Easy to wire it out, even easier to replace it. £60 is a no-brainer - go for it!
I have removed it since I will not use it, and it was in a bad shape anyway.
I read the instructions somewhere in a long forum topic, can't find it now, but it's very easy. You disconnect "pitch connector" from the main board:
http://santeria.sakura.ne.jp/takeout%20conect%20pitch.JPG
And then you connect the two middle connections on the main board pitch connector. That has the same effect as pitch control in the middle position (which bypasses pitch slider). You can use the "jumper" from a PC motherboard if you don't want to solder around main board.
I don't know if any of the wires from the main board to the pitch board connects the grounding, or is the ground carried through the chassis? Best to ground the main board from a proper position:
http://i273.photobucket.com/albums/jj220/kingbusoms/1210input.jpg
This shows the back side of main board, if viewed from above the ground is under bottom left screw.
Dingdong
27-01-2012, 15:22
Is it running a little bit fast, or a lot fast?
Does the fader thingy make any difference to the speed?
I have just had a look at the service manual and it should be able to adjust the pitch with VR301 on the pcb.
Hopefully someone with experience of doing that will pop along soon.
Hi Blaz,
Excuse my hard of thinking, but could you explain what you mean by:
And then you connect the two middle connections on the main board pitch connector.
Where are the two "middle connections" you're referring to? And also, if you could show exactly how one "grounds the main board from a proper position", should this be necessary.
Some nice arrows on pictures pointing to exactly what you're talking about, in the form of a step-by-step guide, would be great - cheers! :cool:
Marco.
Sorry for my unclear English, not my native tongue. Also I'm not an electrician, I'm just following the propositions made by others. I'll try to be more clear this time, and try to find the sources for the claims. And sorry, no step by step picture book, I'm not dismantling my 1200 now, still waiting for a few parts before I install the new "Mains Cables 'R' Us" PSU and KAB fluid damper.
Technics SL1200 MkII main board, with pitch control bypass and proper earth point described:
http://i84.photobucket.com/albums/k26/Bwaze/Removepitchslider.jpg
I followed the "thedelihaus's (http://www.audiokarma.org/forums/showpost.php?p=3914305&postcount=51)" advice from Audiokarma forum about removing pitch control:
Regarding the pitch control- you can remove and bypass it- unplug the connection of the pitch control wires/plugs and join the 2 center pins of the socket together. - Connecting the pins 6 and 7 has the same effect as placing pitch control in the centre detent, which is a switch that bypasses the potentiometer.
Here's the diagram of the pitch control PCB from Technics SL1200 MkII Technical Service manual, Supplement, page 21 :
http://i84.photobucket.com/albums/k26/Bwaze/Removepitchslider2.jpg
As far as I can see earth cable that connects to the pitch control PCB screw only connects to the main board earth through a conductive chassis, and that is not optimal - coating and oxidation can even prevent the connection. So I think it would be better to connect it to the proper earth wire tag on the bottom left of the main board - extend the earth cable and solder it to the underneath of PCB. Link to the explanation why this is the proper point to earth the Technics: The final Words and Music on the earth point (http://theartofsound.net/forum/showpost.php?p=176536&postcount=141).
Not as clear as I hoped it would be, but it will have to do for now. :)
Hi Blaz,
That's spot on, mate. I understand exactly now, and many thanks for taking the time and effort to explain things properly! It'll act as an excellent reference point for others wishing to do the same :cool:
What did you find was the best (neatest) way of joining the two centre pins, and did you notice any sonic improvement after you did the mod?
Marco.
I have used "jumper" from a PC motherboard - it fits almost perfectly and is removable.
I received my used SL1200 in pretty bad shape, and I did the mod before I had the chance to seriously listen to the deck so I had no "before and after" comparison. I don't expect this mod to do anything to the sound quality, but you never really know - member of the TimeStep forum JuanPabloCuervo measured the pitch stability of his Sl1200, and found out that Technics had a bit better pitch stability when the stylus illumination light was on. And he also found out that when he replaced the incandescent light of the SL1200 for the LED diodes of the later models, this "positive effect" was lost, so the pitch was worse with the LED on...
Nice. I wanted to bypass the pitch control, but have been too lazy to research how it should be done. Next time my platter is off to lube the bearing, I will probably do it.
Just one less variable to cause error in the pitch control circuit.
Hi Blaz,
I don't expect this mod to do anything to the sound quality, but you never really know - member of the TimeStep forum JuanPabloCuervo measured the pitch stability of his Sl1200, and found out that Technics had a bit better pitch stability when the stylus illumination light was on. And he also found out that when he replaced the incandescent light of the SL1200 for the LED diodes of the later models, this "positive effect" was lost, so the pitch was worse with the LED on...
Interesting... My thinking behind this is that I notice a discernable improvement (a clearing up of the sound and a removal of 'hash'/ noise), particularly through headphones, whenever I disable the red strobe light, which one can do when the strobe disabler mod has been fitted.
Therefore, perhaps the effect will be the same with the lights on the pitch control? I guess that one could disable the LEDs, but taking the whole pitch control out of the circuit, when it's never used, seems more thorough! :)
I will do this next time my T/T is near someone who possesses the necessary soldering skills.
Marco.
An off-topic question about the "SX-1200 KAB strobe disabler" - after inspecting schematic diagram of SL1200 wiring I noticed the only function it does is it breaks and connects one of the two wires to the strobe diodes. The whole "SX-1200" circuit is there just so you can operate this by pressing start/stop button for 5 seconds. So one could achieve the same function by installing the switch on one of the wires? The switch could even be hidden beneath the turntable - you only need to check the platter speed every now and then... And if you replace the platter so you don't have the strobe dots not even then...
INSTALLATION INSTRUCTIONS FOR SX-1200 (http://www.kabusa.com/sx1200i.htm), SL-1200 Strobe Lamp Disabling Circuit.
http://i84.photobucket.com/albums/k26/Bwaze/Strobedisabler1.jpg
http://i84.photobucket.com/albums/k26/Bwaze/Strobedisabler2.jpg
SX-1200 KAB strobe disablers connects between the following wires: 12 - brown (one of the wires that go to strobe LEDs, for disconnecting the strobes), 4- orange (one of the wires to the start/stop button - for sensing the 5 seconds long press.
I'm not saying SX-1200 isn't wonderfully elegant solution, but it could be done much simpler if one does not need the convenient access to enabling / disabling the strobe.
moodybuilder
31-01-2012, 11:23
http://i1079.photobucket.com/albums/w516/moodybuilder/DSC01921.jpg
http://i1079.photobucket.com/albums/w516/moodybuilder/DSC01926.jpg
http://i1079.photobucket.com/albums/w516/moodybuilder/DSC01907.jpg
first of all remove the platter when you remove the pitch controller by the plug you solder or connect by watever means you like the 2 pins (when looking down from the arm side of plinth and counting from L to R number 2 & 3 together this will them stabilize the pitch
moodybuilder
31-01-2012, 11:24
please ask if you have any questions
Wakefield Turntables
31-01-2012, 19:13
Bloody hell is that all you do :eek: If i'd have known this i'd have done this long ago, this has been on my list of tweeks to do for ages. Cheers mate. :cool:
moodybuilder
31-01-2012, 19:23
no problems and its as easy as that if you do it and totally remove the pitch slider and fill the hole can you let me know any sonic differences you notice please
Wakefield Turntables
01-02-2012, 19:41
Sure thing. I honestly dont think there will be any sonic differences. I went through a phase of getting rid of as much crap from under my platter as possible of the PCB. I honestly cant say that I noticed much difference :( But when I do the mod if I spot something you'll be the 1st to know! ;)
Just noticed this, Phil - thanks! I can see from the circuit diagram that it just bypasses the pitch control assembly switch. However, I always leave mine in the centre detent (locked) position anyway - are you saying there is a sound quality improvement?
Any thoughts, Martin, that by disabling the lights on the pitch control, it may remove noise from the cricuit, in the way that disabling the strobe light does? :)
Marco.
It's part of the clock circuit so it might have an effect. It's easy to try, with a motherboard jumper. I'll give it a go in the weekend.
moodybuilder
02-02-2012, 16:55
as i said in a previous thread I did this for looks but when it was removed and sealed up i did notice some sound improvements, a solid sound wether this is because of removing a circuit or through filling a hole I dont know look forward to your findings Martin
Wakefield Turntables
02-02-2012, 20:07
why not removed ALL the bits which are not needed, just like I did ages ago? i.e. dismantle the strobe light, get rid of the pop up light and also the pitch slider??? Less stuff working from the PCB the better.
I don't use the strobe or pitch, but I do like the pop-up light (converted to LED) as it helps me cue accurately.
It's part of the clock circuit so it might have an effect. It's easy to try, with a motherboard jumper. I'll give it a go in the weekend.
Please do - I'd value your opinion :)
Marco.
Hi Martin,
Have you had a chance to try this, matey? I'm curious to see if you can hear any difference :)
Marco.
I have the PCB jumper in my pocket. Back home tonight, will try it then.
I'm a bit knackered after a huge drive down the A1(M) and M25 through the snow last night, three hours of white knuckle slipping and sliding.
Ammonite Audio
05-02-2012, 17:20
I have the PCB jumper in my pocket. Back home tonight, will try it then.
I'm a bit knackered after a huge drive down the A1(M) and M25 through the snow last night, three hours of white knuckle slipping and sliding.
Not much slipping and sliding with my Michelin Alpin (winter tyre) shod BMW; however I do have to admit that yours is a tad more powerful than mine! It's almost nice to have some adverse weather so that I can smugly drive past everyone without any drama. Those tyres were an absolute godsend last year.
Ok, this was a very simple mod to try out. Required: one standard PCB jumper as found on many motherboards and PCI cards. Remove connector CN102 and insert the jumper connecting pins 6 and 7 of the PCB socket. Easily reversible, and negates the useless pitch control and centre detent switch. You lose the LED indicator, too.
What this does is ground pins 9, 12 & 13 of IC302 (pitch control), effectively crystal locking the deck's speed.
http://www.mtc.me.uk/images/Pitch_Jumper.jpg
Listening to it, I can maybe hear a further cleaning up of the soundstage making everything that little bit more vivid. It's not a night and day thing, but every little helps. A nice, cost-free mod. Thanks Phil and all the others for pointing it out.
prestonchipfryer
05-02-2012, 18:28
Ok, this was a very simple mod to try out. Required: one standard PCB jumper as found on many motherboards and PCI cards. Remove connector CN102 and insert the jumper connecting pins 6 and 7 of the PCB socket. Easily reversible, and negates the useless pitch control and centre detent switch. You lose the LED indicator, too.
What this does is ground pins 9, 12 & 13 of IC302 (pitch control), effectively crystal locking the deck's speed.
http://www.mtc.me.uk/images/Pitch_Jumper.jpg
Listening to it, I can maybe hear a further cleaning up of the soundstage making everything that little bit more vivid. It's not a night and day thing, but every little helps. A nice, cost-free mod. Thanks Phil and all the others for pointing it out.
Hello Martin. Where could I obtain one of the said jumpers? Only I'm a bit thick with electronics. Would somewhere like Maplins stock them?
John
These: http://www.ebay.co.uk/itm/25-2-54mm-PCB-Motherboard-Disk-Drive-Pin-Jumpers-/180807734611?pt=UK_Computing_CablesConnectors_RL&hash=item2a18fb1553
But you only need one! Don't you have any old PC kit waiting to be scrapped? You can frequently find them on old circuit boards and peripherals.
prestonchipfryer
05-02-2012, 18:37
These: http://www.ebay.co.uk/itm/25-2-54mm-PCB-Motherboard-Disk-Drive-Pin-Jumpers-/180807734611?pt=UK_Computing_CablesConnectors_RL&hash=item2a18fb1553
But you only need one! Don't you have any old PC kit waiting to be scrapped? You can frequently find them on old circuit boards and peripherals.
No old stuff. Thanks for the link.
John
John, I'm sure I've got loads of the jumpers lying around - PM me your address and I'll put one in the post to you straight away.
prestonchipfryer
05-02-2012, 19:19
Cheers Keith. PM on its way.
John
Cheers Keith. PM on its way.
John
Replied!
prestonchipfryer
05-02-2012, 19:33
Replied!
Okey doke.
Hi Martin,
Thanks for the link - just bought one of those little chaps! :)
Glad to hear that there was a small improvement. I thought that there might be, as LEDs in circuits (such as on the pitch controller) are usually quite noisy, which I suspect is where the sonic improvement is coming from.
Marco.
moodybuilder
05-02-2012, 21:53
Glad you found the infomation both helpful and benifical, so Martin are you going to remove the slider altogether and fill as I have ?
No Phil, I'm not worried about the standard Techie's looks. It's only the sound that matters to me.
Not much slipping and sliding with my Michelin Alpin (winter tyre) shod BMW; however I do have to admit that yours is a tad more powerful than mine! It's almost nice to have some adverse weather so that I can smugly drive past everyone without any drama.
I've now got rid of those godawful run-flats and have a nice set of Avon ZZ3s - not winter tyres, but they have better grip in the snow. However, on Saturday we were in Ruth's RAV4 and we needed it - we only just got away with not having a night on the M25 by dint of driving over the snow and virgin bits when everyone else was well stuck.
moodybuilder
06-02-2012, 07:03
I will agree first and formost its the sound, but with all luxury items aesthetic beauty and customisation (dont know if thats a word) must play its part, the same as the cars we drive.
RobbieGong
06-02-2012, 13:08
Hi Martin / all - thanks for this. I will be looking to short out the pitch fade lights as per the picture above with the little clip thing. I definately heard a difference when I decided to turn off the spectrum analiser blue light show on my equalizer (lights are definately noisey as Marco has pointed out). Thing is there is no on and off for the idividual red lights on each eq slider, I'm sure there must be away to short those out too cause they must be imparting a fair bit of low level hum into my soundstage too. Anyone able to assist ? Is it a case of using one of the clip things in the right area of the eq pcb ? Thanks in advance :)
Hi Martin,
These: http://www.ebay.co.uk/itm/25-2-54mm-PCB-Motherboard-Disk-Drive-Pin-Jumpers-/180807734611?pt=UK_Computing_CablesConnectors_RL&hash=item2a18fb1553
But you only need one! Don't you have any old PC kit waiting to be scrapped? You can frequently find them on old circuit boards and peripherals.
I ordered these jumpers, and they've just arrived. They're absolutely TINY and look much smaller than what you used in the picture you posted earlier (about a quarter of the size), and also I'm sure will be too small to fit where they need to do on the PCB... Is 2.54mm meant to be the right size?
Any thoughts? If they're unsuitable, which I suspect they are, any chance of sending me one of yours, since you appear to have easy access to these jumpers? :)
Marco.
I ordered these jumpers, and they've just arrived. They're absolutely TINY and look much smaller than what you used in the picture you posted earlier (about a quarter of the size), and also I'm sure will be too small to fit where they need to do on the PCB... Is 2.54mm meant to be the right size?
Yes, that should be right. Hang on while I measure one here in the office...
Yep - 2.5mm pin spacing is standard. One should just slip over pins 6 & 7 as described. Remember that my photo was pretty highly magnified!
Ah, that'll be why the jumper shown below looks so big!
http://www.mtc.me.uk/images/Pitch_Jumper.jpg
Okies, if you say it's fine, I'll try it. So, there are four 'slots' in the jumpers I've got, does it matter which two I use, in order that the plastic housing doesn't foul the other pins?
It looks like you've got one of the pins at the end going over the top of the jumper housing.
Marco.
Ok, let's go through this slowly:
1. Gently pull off the white connector, revealing pins 5, 6, 7, 13. There is a pin between pins 5 and 6 but it is not connected and there is no corresponding wire in the plug. You cannot quite see pin 13 in my photo but it is there.
2. Now take your jumper, and holding it at the end with the groove all the way round, push it onto pins 6 and 7. It will slip on nicely and be a snug fit. It should look roughly like mine although they do vary and mine doesn't have a groove, it has a ridge (which are just for getting your nails into to pull them off).
Once done, that's it. You leave the connector permanently disconnected. You will have no pitch adjustment and no LED, the speed will be crystal locked as it was when the slider was in the centre detent position.
Crystal clear, Martin - gotcha! I'll probably wait until I've got the T/T off of the rack again before I do it, but when it's done I'll let you know what I think :)
Marco.
prestonchipfryer
07-02-2012, 14:51
Okey doke.
Just fitted jumper. There would seem to be a lower noise floor, so suppose the pitch controller must be putting in some unwanted noise. A tweak worth doing. Many thanks to Keith.
John
:cool:
prestonchipfryer
07-02-2012, 14:54
Crystal clear, Martin - gotcha! I'll probably wait until I've got the T/T off of the rack again before I do it, but when it's done I'll let you know what I think :)
Marco.
Marco, I was surprised how easy it was to do, although, of course, the 'jumper' is very small - I only dropped it twice :lol: although every ok.
John
:eyebrows:
Wakefield Turntables
10-02-2012, 21:09
Mod done, took 5 seconds, then 3 days for the jumpers to arrive through the post. Its a bit difficult to describe any changes i'm hearing cos i'm still getting used to my new cart. I would say that the soundstage seems more defined and maybe a little more stable. As other people have said, every little helps. I'll be removing the pitch slider from the 1210 once and for all. Soon they'll be nothing left under the hood! :lol:
moodybuilder
11-02-2012, 21:13
hi andrew so you will be removing the pitch slider and filling this as i have will you please post when you have done this to say weather you think there is any more improvement cheers
Wakefield Turntables
12-02-2012, 10:16
hi andrew so you will be removing the pitch slider and filling this as i have will you please post when you have done this to say weather you think there is any more improvement cheers
NO! Thats exactly what I wont be doing as its a waste of my time and money (no disrespect mate ;) ). I have a much bigger project planned when I get some time for the chassis. :D This is where my time and money will be going ;)
RobbieGong
14-02-2012, 13:31
Did this mod last night because removing even the slightest bit of imparted noise is going to help. Easy peasy, took literally a minute or two. Can't evaluate just yet as I did it at the same time as revisting cartridge set up with protractor etc so still need to adjust vta and get the sweetspot back first. Not sure why but I thought that this mod also disabled the illuminated blue pitch numbers above and below the green LED on the MK5g and not just the green LED. Does anyone know how to disable the blue lights on the MK5g my thinking is that this too will remove another imparted layer ?
Hi Robert,
Not sure why but I thought that this mod also disabled the illuminated blue pitch numbers above and below the green LED on the MK5g and not just the green LED.
Is that not the case, then? That's what I'd hoped would happen on my MK5G, but I haven't done the mod yet.
Marco.
RobbieGong
15-02-2012, 18:47
Hi Robert,
Is that not the case, then? That's what I'd hoped would happen on my MK5G, but I haven't done the mod yet.
Marco.
Hi Marco, funny enough I was gonna give you a shout as I know you too have the MK5g and would be definately interested in this. Unless I've done it wrong, which I'm sure I havn't as I've followed exactly as pictures and instruction, then it only outs the green LED in the middle of the other blue lights on our MK5g. If I've definately done this right then I'd like to find out how we can also disable those blue lights cause they must be pushing out a fair bit of noise too would be my guess :scratch:.
Indeed. The goal for me, was to cut all of the lights completely. I'd forgotten that the other guys who've done this only have MKIIs....
Still, one light gone I guess is better than nothing! :)
Has anyone done this mod on a MK5G?
Marco.
moodybuilder
15-02-2012, 20:56
can some whos done this mod on a MK5 please post a picture so i can see the difference of this and the MK2, thanks
"M5G comes with an all digital pitch control"
Technics SL1200 M5G pitch control PCB:
http://www.hinhuatdj.com/wp-content/gallery/technics-parts/pitchcontrolm5g_pcb_main.jpg
Technics SL1200 MkII pitch control PCB:
http://www.hinhuatdj.com/wp-content/gallery/technics-parts/pitchcontrolmk2_pcb_main.jpg
Sorry, this is quite different than MkII! Do you have service manual for them? I couldn't find it. You can try to disconnect all the wires that come from the PCB... But I'm not sure what connections to short with this one.
It seems that Technics SL1200 MK5 has a different pitch control PCB:
http://i.ebayimg.com/t/Technics-1200-MK5-Pitch-control-See-Video-inside-/02/!B0G3P0!BWk~$(KGrHqN,!hEEw5sM1PbvBMY4YOSCF!~~_3.JP G
But mod / removal should work just as with MkII - just unplug it and short the middle connectors on the main PCB.
RobbieGong
15-02-2012, 22:08
Cheers Blaz, I may well just get the platter off again and take a look to see how its connected up etc. Would be great if it was just another case of slipping one of the cap things over a particular point as was for disabling the green LED. Anyone else have an idea ?? Would be much appreciated :)
Wakefield Turntables
15-02-2012, 22:08
Indeed. The goal for me, was to cut all of the lights completely. I'd forgotten that the other guys who've done this only have MKIIs....
Still, one light gone I guess is better than nothing! :)
Has anyone done this mod on a MK5G?
Marco.
Are you going to remove your strobe and pop-up light? You could also remove the LEDS from the 33 and 45 switches if you really wanna be anal!;)
Hi Blaz,
Your first two links aren't working for me... Do you have to be signed in to the website or something?
Perhaps you could upload the images instead to Photobucket or Imageshack, so we can access them that way instead?
Churz! :cool:
Marco.
Are you going to remove your strobe and pop-up light?
No to the second one (never use it), and no to the first one, as I have the KAB strobe disabler fitted to my T/T :)
Marco.
RobbieGong
15-02-2012, 22:43
Will keep pop up light as I dont use it. Strobe light and 33/45 light will stay too as I dont really want to lose those to be honest. Do want to lose the blue lights as I most certainly dont use them AND there's a lot of blue light there which I'm sure will give me even a nats more cleaning up of sound stage if disabled.
I have the strobe light switched off (it was modified to work from the defunct on/off rotary). I do use the pop-up for cueing in low light but I replaced it with an LED.
I had forgotten that Marco has a Mk5G, it should be possible to short the link on the same PCB connector and remove all the other connectors coming from the pitch control PCBs, but a check with the circuit diagram would be in order before confirming this.
Does anyone have the Mk5G circuit diagram?
WOStantonCS100
16-02-2012, 08:12
It seems that Technics SL1200 MK5 has a different pitch control PCB:
http://i.ebayimg.com/t/Technics-1200-MK5-Pitch-control-See-Video-inside-/02/!B0G3P0!BWk~$(KGrHqN,!hEEw5sM1PbvBMY4YOSCF!~~_3.JP G
But mod / removal should work just as with MkII - just unplug it and short the middle connectors on the main PCB.
For anyone with an SL-1200M3D, I believe the pitch control is identical to the SL-1200MK5, and therefore this mod should work perfectly well with it also. I will be doing this to one of mine this weekend. Cheers!
Is there an electrician in the house? :scratch: I wouldn't be too confident in bypassing the pitch control in other versions than MkII, there are differences:
Pitch cotrol on various (more common) Technics SL1200/1210 versions:
Technics SL1200/1210 MkII
Diagram of the pitch control PCB from Technics SL1200 MkII Technical Service manual, Supplement, page 21 :
http://i84.photobucket.com/albums/k26/Bwaze/Removepitchslider2.jpg
Technics SL1200 MkII pitch control PCB:
http://i84.photobucket.com/albums/k26/Bwaze/pitchcontrolmk2_pcb_main.jpg
Technics SL1200 MkII main board, with pitch control bypass explained (shorting the pins 6 and 7 on main PCB):
http://i84.photobucket.com/albums/k26/Bwaze/Removepitchslider.jpg
Technics SL1200/1210 MK3, M3D, MK5 (adds a quartz lock button which resets pitch to 0 immediately)
Technics SL1200 MK3, M3D, MK5 pitch control PCB:
http://i84.photobucket.com/albums/k26/Bwaze/TechnicsM3DMK5pitchpcb.jpg
Diagram of the pitch control PCB from Technics SL1200 M3D Technical Service manual. Can anyone see from this what shorting the 6 and 7 pins does? Doesn't seem the same as MkII, connection wise...
http://i84.photobucket.com/albums/k26/Bwaze/PitchControlM3D.jpg
Technics SL1200 M3D, MK5 main board - is this even different than MkII? Almost no info on this on the net, might be the same as MkII...
http://i84.photobucket.com/albums/k26/Bwaze/MK3DMK5MainBoard.jpg
Technics SL1200/1210 M5G, MK5G The difference from the MK5 model is the ability to switch between ±8% and ±16% ranges for pitch adjustment, and the pitch control in this model is completely digital.
Technics SL1200 M5G pitch control PCB:
http://i84.photobucket.com/albums/k26/Bwaze/pitchcontrolm5g_pcb_main.jpg
Unfortunately, I have no service manual and no information about M5G. Also, I have no idea where all this is connected!
Hi Blaz,
Thanks for that - most interesting.
Diagram of the pitch control PCB from Technics SL1200 M3D Technical Service manual. Can anyone see from this what shorting the 6 and 7 pins does? Doesn't seem the same as MkII, connection wise...
I think I'll wait to find out the answer to the above before doing the mod on my MK5G...
Any thoughts, Martin? :)
Marco.
Artifolk
16-02-2012, 18:47
Martin
Circuit dia for SL1210 M5G. If you need a better copy PM me.
http://i1108.photobucket.com/albums/h419/Artifolk/Technicssl1210m5gcirdia001.jpg http://i1108.photobucket.com/albums/h419/Artifolk/Technicssl1210m5gcirdia002.jpg
Wakefield Turntables
16-02-2012, 19:53
Charles,
You dont have a copy of the PCB schematic for the Mk2 do you?
Andy
RobbieGong
16-02-2012, 20:22
Hi Blaz,
Thanks for that - most interesting.
I think I'll wait to find out the answer to the above before doing the mod on my MK5G...
Any thoughts, Martin? :)
Marco.
So far having done it on my MK5g all I can see is that the green LED is off cant perceive anything else going on so lets just hope i'm not slowly messing anything up :eek: Hopefully someone who understands schematics will be able to tell us more and exactly what should (or shouldn't) be done with regards to this mod for the MK5g !!
It's all here, schematics are inside Service manual.
VinylEngine SL 1200 manuals (http://www.vinylengine.com/library/technics/sl-1200.shtml)
You might have to be registered to download, though.
Artifolk
16-02-2012, 20:28
Sorry Andy no i don't, i just bought the m5g version.
:(
I've just snuck a look in to see the diagrams. I'll peruse them tomorrow morning, chaps.
Wakefield Turntables
16-02-2012, 22:57
Sorry Andy no i don't, i just bought the m5g version.
:(
No worries!
WOStantonCS100
16-02-2012, 23:09
Is there an electrician in the house? :scratch: I wouldn't be too confident in bypassing the pitch control in other versions than MkII, there are differences...
Thanks for that correction! Crap... I'll have to look closely at that schema when I get home before trying it out.
Guys - I'm going to have to study this one at home. IC501 (pitch control) is a completely different IC in the M5G and I need better diagrams to trace through the pitch disable circuit. It's not immediately obvious which of S201 and S202 perform which function, but it looks like their connector (CN103) is different so don't go trying to perform the link mod for now.
RobbieGong
17-02-2012, 10:26
Yep, Probably not wise to try on the MK5g as pointed out by Baz and Martin until we know exactly what the differences are in schematic. I've just reversed this mod on my MK5g to be on the safe side. Thinking about it my Techy sounded slightly muted or slightly restrained would probably be more accurate when I did it but i couldn't work out if this was because I revisited arm and cartridge set up with protractor at the same time and hadn't quite found the sweetspot yet through final vta adjust. We'll see how she sounds when I plug her back in :rolleyes:
Ok, what's confusing about the M5G is the pitch control being on a separate circuit board with a different IC (C2BAED000009) instead of the AN6682 on the main PCB of the Mk.II. It even has a second crystal and its own regulator!
What I can confirm from the circuit (but not a visual of the M5G main PCB) is that the pitch reset still shorts pin 7 of connector CN102 to ground. In other words, a shorting link between pins 6 and 7 of CN102 will still work. Whether that connector appears in the same position as the Mk.II is another matter. Someone with an M5G will have to verify that.
It does not look as if you can simply disconnect CN105 or CN104 as the pitch clock signal is required to go back into the main board. So disabling the reset and pitch range LEDs will require desoldering them. Again, I'd be happy to have someone confirm that.
So: M5G owners, do try the link by removing CN102 but don't disconnect any other connectors in an attempt to disable the LEDs.
RobbieGong
17-02-2012, 22:38
Ok, what's confusing about the M5G is the pitch control being on a separate circuit board with a different IC (C2BAED000009) instead of the AN6682 on the main PCB of the Mk.II. It even has a second crystal and its own regulator!
What I can confirm from the circuit (but not a visual of the M5G main PCB) is that the pitch reset still shorts pin 7 of connector CN102 to ground. In other words, a shorting link between pins 6 and 7 of CN102 will still work. Whether that connector appears in the same position as the Mk.II is another matter. Someone with an M5G will have to verify that.It does not look as if you can simply disconnect CN105 or CN104 as the pitch clock signal is required to go back into the main board. So disabling the reset and pitch range LEDs will require desoldering them. Again, I'd be happy to have someone confirm that.
So: M5G owners, do try the link by removing CN102 but don't disconnect any other connectors in an attempt to disable the LEDs.
Looking at your picture Martin, I can confirm that the connector on my MK5g appears to be in the same place on the right hand side of the pcb with the numbers 5,6,7,13 appearing the same.
Good stuff! Want to try it?
RobbieGong
17-02-2012, 23:42
Good stuff! Want to try it?
Hi Martin, Might leave well alone for a bit now that I've reversed the mod 'til someone comes up with instruction and pictures with regard to how to actually disable both the green LED AND the blue lights on the Mk5g :)
Indeed... I'm not sure what the heck to do now! :scratch: :confused:
Marco.
RobbieGong
18-02-2012, 11:29
Indeed... I'm not sure what the heck to do now! :scratch: :confused:
Marco.
I hear ya Marco - Basically, Re: The MK5g all I found was that only the green LED outted as per this mod for the MK11. Sonic wise I felt the sound became slightly restrained to my ears. I cant be completely sure that this was ALL down to this mod because as previously mentioned, I'd re-visted arm and cartridge setup at the same time so wasn't sure if this was a contributory factor ie: I'd not quite found the sweetspot through final vta adjust. That said I did feel the music sounded more alive when I reversed the mod :scratch: I would still like to try this mod whereby the blue lights and green LED are disabled together properly :)
I posted yonks ago that dis-abling ALL lights made the sound better, but hey who am I...:)
RobbieGong
18-02-2012, 14:31
I posted yonks ago that dis-abling ALL lights made the sound better, but hey who am I...:)
Hi Dave, I dont doubt it. Not everyone wants to lose ALL the lights though for their own reasons but do recognise that losing even some lights is gonna reduce electrical noise these things impart no matter how small, hence guys like myself and Marco would like to lose the green and the plentiful blue light show down that right hand side, which I'm sure would make a degree of 'clean up' difference :)
Rob - you could always remove the base, access the pitch control PCB and desolder the LEDs or cut their legs if you don't mind a little DIY.
RobbieGong
18-02-2012, 15:48
Rob - you could always remove the base, access the pitch control PCB and desolder the LEDs or cut their legs if you don't mind a little DIY.
Not sure if I wanna attempt that Martin without something to follow :) Also tilting the deck to unscrew / remove base not something I fancy doing unless absolutely necessary due to havin fluid damper in place, (although I could remove it). Thick oil spillage all over / inside the deck would be a nightmare :eek:
Removing the arm is pretty well a must before turning the deck over. There are a zillion screws to undo, all different lengths, which you must place carefully so that you will replace the right ones into the right holes again.
RobbieGong
18-02-2012, 17:51
Removing the arm is pretty well a must before turning the deck over. There are a zillion screws to undo, all different lengths, which you must place carefully so that you will replace the right ones into the right holes again.
Excatly, Went through all that when I first got the MK5g and fitted the dust cover brackets, a few squeeky bum moments for sure. Didn't need to remove the arm though - Thank God as I relied on a very large mega soft quilt and some super soft pillows strategicly placed and caressing all around my MK5g as I got to work :eyebrows:
Invaderevan
22-03-2017, 05:02
I really hate to resurrect such an old thread, but I have searched and searched and cannot find my answer. Would this modification of shorting pin 6 and 7 work on an M3D? I have compared the schematics, and the circuitry of the pitch fader is much more complicated on the M3D vs Mk2, so it is very well possible it will require a more indepth modification. I am working on a minimal SL-1200 that is totally blank on the top sans the arm, and I just want to nail down how I am going to handle the pitch fader removal.
Thanks for any input you have!
EDIT: This can be ignored, after sorting through the 27 pages of the external PSU thread, I found IanMac's comment about shorting pins 2 and 3 of IC201.
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