Technics 1210 mk2 pitch fader fix (and instructions on its removal)

[RobbieGong]

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 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 !!

[Bwaze]

It's all here, schematics are inside Service manual.

VinylEngine SL 1200 manuals

You might have to be registered to download, though.

[Artifolk]

Sorry Andy no i don't, i just bought the m5g version.

[MartinT]

I've just snuck a look in to see the diagrams. I'll peruse them tomorrow morning, chaps.

[Wakefield Turntables]

Sorry Andy no i don't, i just bought the m5g version.

No worries!

[WOStantonCS100]

Is there an electrician in the house? 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.

[MartinT]

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]

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

[MartinT]

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]

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.