torque enhancing on Technics SL-1200/1210

[jeantalban]

DubcutterManual03.pdf

Hi everyone,
I intend to enhance the torque on a Technics (original model).
As described on the vinylium manual, the brown, blue, orange, resistor required is a 150Kohms.
B.U.T, contacting Mantisamusements.com to get it the so colored resistor is listed to be a 16 Kohms.
So, wich part is true from the vinylium description the color code or the ohms level ?
Would someone that did the operation could confirm one or the other?
Greetings.


here the answer of kerry from mantis :
brown blue orange is 16K ohms . . .

150K and 330K in parallel will net 100K total . . . however why not remove the resistor and put in a 100K resistor? That makes little sense to me.

The big resistor with the gray and orange band is a 1watt or maybe a ½ watt. The others are ¼ watt. What does this upgrade do?

I’d be very nervous about instructions to upgrade that had a wrong resistor value by color to start with. I’d want second opinions from people that have done the upgrade.

Having said all that I’m happy to sell you what you need if I have it . . .


Kerry Stair

Mantis Amusements

[markrob]

Hi,

There does appear to be a difference between the instructions and the photo. The resistor shown in the photo is 82K (Grey Red Orange), not 16K. Perhaps the photo was an earlier version of the mod and they finally settled on 100K as the correct value. If we assume that the stated value is correct, then ignore the photo and either bridge a 150K (Brown Green Yellow) or remove R209 and replace with a 100K (Brown Black Yellow). I assume they elected to bridge the resistor because it is easier than removing the existing part (with the potential for damage of the PC board) and it allows you to easily go back to the factory value if you run into problems. It looks like the purpose of the mod is to increase the gain of the phase detector feedback. So going with the 100K value would be less feedback than the shown value in the photo (65K or 330K in parallel with 82K). BTW, I don't think there would be any danger in trying the 82K to see if that works better.

Mark

[Ben]

How did this turned out finally??

I'm looking to do this mod on my turntable also, that would be amazing if you could do a little follow up!!

Thanks
Ben

[fredbissnette]

me too bumpity bump

[davorvenom]

Hi. I have done this but you will find that 100 k is too much for Technics. Result is that you get much more torque and a lot of wow and flutter. What i did is placed 200 k resistor instead and i got some torque which is enough to run cutterhead without wow. I hope this helps.

[drdub]

We also just did it to one of our SL-1200 MKII. There was a 330k resistor in there - I added a 160k in parallel (about 108k total)
Voila - works like a charm. Also no hearable wow or flutter.

-dub

[talbanjean]

dear dr dub,
i am about to make that precise change on my beautiful sl-1200 mkII and i still wonder about one thing: the number of watts of the resitor in 160kohms.
is it 1/4w 1/2w 1/8w or 1w or more that you added to the 330k in parrallel for instance?
thank you for your kind answer by advance.

spires are made of the golden number....

[markrob]

Hi,

Not at all critical. Use any wattage you have that will fit. The power dissipation is next to zero.

Mark

[Vinylfan]

Hi,
Interesting:
In the original version of the SL-1200MK2 service manual R209 is listed with 150k. In a later version (supplement) R209 was changed to 330k. So I assume that early versions of the SL1200 were produced with almost the "correct" value.
Which may have been the reason for Matsushita to increase the value?

According to the dubcutter manual the upgrade may only work for the MK2 Version. I use a MK5 model that looks exactly the same in that area of the board
Does anyone have any idea why the upgrade should only work on MK2 models?

Vinylfan

[talbanjean]

thank u so much mark, i will proceed right away and put the 160k 1/2w in parallel to the 330k a pray for a torque betterment.
i have one 1200mkII and one 1210 mkII to modify.
I will keep you informed in this topic when i have recieved the resistor and put it on the turntable.

Greatings from paris

[cutz]

The new 1200 MK7 has a torque adjustment feature on it. I’ve heard about converting a 1200 into a lathe, I’m a newbie to this board and lathes in general.

[Vinylfan]

I only heard that so I can't confirm:
The new SL1200 MK seems to have weaker bearings.
Only the much more expensive SL1200G has stabler bearings so that the plater is well balanced.

[drdub]

Anybody already tried the SL1200GR for cutting?
it's supposed to have a bit more torque stock 2,2 kgs.

[PLD]

e3sa934 on here is using one.

[flozki]

we did a nice teardwon of a SL1200GR beginning of this year.
i cant confirm more torque right now. maybe its has a little torque but
during cutting behavior in regulation not really better.
nicely built but comparing them 1:1 the original one make a better impression. technically.
i will see if i find the torque measurments somewhere.

one possibility is to raise voltage of the motor controller . but that needs more examination, reverse engineering.
so far i havent seen a service manual.schematics.

at the moment still the SP10MK" is best for torque for money.although the 7mm spindle is quite small and you can bend the turntable a few milimeters.


happy cutting
f.

[drdub]

Hey flo,

Thanks for sharing! We'll stick to a SP-10 MK2 for the new studio then. Costs a bit less and is great (if working).

-the dubs