Restoring a pretty old -and dirt- Technics SL-1200Mk2

[morfeora]

Hello friends,
Some months ago I was bitten by the idea of buying a turntable and to start a record collection. My first choices were mostly Technics turntables which are very common over here in my city, but after realizing the price for a second hand Technics SL-1200MK2 I wanted to give a try to restore this very old one that I have since 20 years ago. I thought I would prefer to spend the money restoring this one that to buy one.

The entire tone arm assembly was missing (I used in another turntable 20 years ago when I was DJ), also foots were, and the worse... not spinning.

So far I have spent some days buying things and also was checking all the circuit with help of the manual. Bought a second hand AN6675 drive IC that turn out to be shorted (it seems I am not learning from experiences and some of you which already told me not to do that on that known site), whether because it arrived like this (shorted) or because I did the mistake and put a wrong transistor as rectifier... any way I learned a lot, and now I am waiting for a new AN6675 (from 1200.com). I hope this solves the not spinning problem, if not, has to be the AN6680. I already check some voltages and every thing seams fine with the AN6680 (I don't have an oscilloscope, so I only check voltages). The other little transistors around seams ok.

So far these are the things I have bought:
1. A complete tone arm assembly (second hand with the arm bent). Apart from the arm bent, is in a good condition, and bearings are ok
2. Arm tube.
3. Tone arm balance
4. A new start stop button
5. New AN6675
6. A set of feet

I don't have a dust cover, but I have no plans to buy one. My idea is to create a wood base and in the way also some kind of cover too.
After I have this table working I will change all the electrolytic capacitors. Also have heard of an external Power supply mod, but it seems the only noise thing in the power supply is the Transformer, so I have plans to leave it outside and build an external wood box for it. (what do you think about these guys?). I am also thinking if I try to find the original color to paint it (Something that will be difficult here specially because I am limited to spray paint), or to paint it in black.

This turntable was given to me for parts from my brother 20 years ago, before that the turntable was in a radio station, it suffered a lot there. I am a little afraid, because I am putting too much work and money in this, when with may be the same money I was able to buy one in a very good condition, but I like to restore things instead of put them in the garbage...

Well guys thank you for the reading and for the future company in this new project.
Cheers,
Rodolfo

These are some pics before disassembly (today wile I wait for the AN6675 to arrive (I order to be shipped to my sisters house in The States, and then she sends it to me to Colombia, as everything I need, so this is mainly a waiting game








And this is the second hand tonearm I got:






More pics of the disassembly in the next post...

 

[Ilikevinyl]

Get the KAB Fluid Damper for sure.

 

[morfeora]

This is after putting all apart:




I guess a lot of liquid was pull inside this...





How many hits you need to turn that button to this:




This is all for now guys... wish me luck!

Cheers,
Rodolfo

 

[Ilikevinyl]

Good Luck! You'll have that looking brand new when finished.

 

[morfeora]

Get the KAB Fluid Damper for sure.

Hi Steve, I was looking their site, and as I am new to turntables, wondering if this updates really worth the investment, but now that you mentioned and that I read from many others this is a great improvement, I will added to my "wish list after restoration".
Thank you for the good vibes Steve.
Cheers.

 

[warrjon]

Yes it is worth it. I made a damping trough and paddle for my EPA100 and it makes a difference. Technics arms are pretty good. Other mods worthy are:

Damping the arm wand with 3m foam ear plugs. Cut 3x 5mm slices and place them both ends and in the middle where the bend is.

I also replaced the CW and stub with one I made that cleaned up the CW resonance.

 

[WaynerN]

Why is this a problem? I can run a Grado with my Technics and not have any hum issues whatsoever. If a Grado doesn't hum, there is no problem with any other cartridge.....just sayin'

 

[morfeora]

Awesome thread. Nice project! Do all the KAB mods and you'll have a really excellent table!

I was thinking of one of these for one of my tables. Silver, black, or white. Pretty nice alternative to painting: https://www.etsy.com/listing/948891...nics-1200?ref=related-1&variation0=1831255461

Here is my external supply. I just moved the stock transformer out of the table and into an ABS box. Still outputting 30V AC to board. I have a DC one on another table but don't hear a single difference either way and just moving it out and into box was relatively easier. I selected the electrical plug and socket for safety reasons since it's AC and it works out great. Excellent insulation from wall socket to the table board.

View attachment 2172581 View attachment 2172582 View attachment 2172583 View attachment 2172584 View attachment 2172585 View attachment 2172595

Thank you GPJ for showing me your External Supply, this is exactly what it was in my mind. I think I will use a wood box as I feel more comfortable using wood, and I like finishing, I can use oak and give a finish that goes well with my speakers and the wood base I plan to do for the turntable itself.
As I can see in your External Supply you are avoiding the power switch on the turntable itself, don't you? I was thinking to try to find a cable with 5 wires that allows me to keep using the power on/off switch on the turntable, but your solution is more simple and also like that.

About the painting, now that I see your turntable (which look gorgeous!!) think the black painting will be very nice, but I think yours looks that nice because the base for the tone arm is also in silver, as the clamp, and that the pitch surround is in black.... those three details likes me a lot in your table creates a very aesthetic view.
What clamp are you using?
And I like a lot that headshell too, what is the reference?
Thank you GPJ, very inspiring to see your turntable and what you have done with the PS.

Why is this a problem? I can run a Grado with my Technics and not have any hum issues whatsoever. If a Grado doesn't hum, there is no problem with any other cartridge.....just sayin'

Hi Wayner. In my case it is just some kind of fun... fun on thinking I can turn this into a more "audiophile" version, it's a kind of snobbish think I guess, because here is a big chance I will not notice the improvement... but I also have done things that never though will change sound and at the end the improvement was obvious. For example, now I can't live without a weight on top of my cd player... never though this could be a big improvement, but it was... any way, mainly all this extra work, is for fun, is because I enjoy a lot tweaking and building things, and if at the end gives some improvement, cool.

I also have my doubts about to turn into an external transformer, specially because this power supply is not involved in audio, and the vibration that can pass from the transformer to the platter it will be minimum.. In that way, probably no cartridge will be able to pick any of this vibration, but sure will be vibration at some degree, even when not important... if this vibration can be avoided, well, we can think there will be an improvement... even when we can't hear it... may be at the end is more about feeling than hearing... it's about playing with these things.
Cheers,
Rodolfo

 

[OMGCat!]

Looks like a great project so far.
One thing I’d do is inspect the leads on the capacitors. I recently had my 1800mk2 apart and found about 60% of the caps had fuzzy green leads due to electrolyte leaking. The caps all tested out of spec too. This was a pretty low hour unit especially compared to yours. If a cap has gone leaky it could account for at least some of your issues.

 

[morfeora]

Looks like a great project so far.
One thing I’d do is inspect the leads on the capacitors. I recently had my 1800mk2 apart and found about 60% of the caps had fuzzy green leads due to electrolyte leaking. The caps all tested out of spec too. This was a pretty low hour unit especially compared to yours. If a cap has gone leaky it could account for at least some of your issues.

Hi OMGCat, you are right, you make me realize that I already know this, but somekind afraid of not make it spin again I am afraid of place the order for the caps, which are not big deal, they are just a few.... I am going to place that order soon. Yes!
Cheers.

 

[Bratwurst7s]

Hi OMGCat, you are right, you make me realize that I already know this, but somekind afraid of not make it spin again I am afraid of place the order for the caps, which are not big deal, they are just a few.... I am going to place that order soon. Yes!
Cheers.

Exactly which cap values do you need?

Cheers,
James

edit: Never mind, I found the service manual.

 

[Bratwurst7s]

What is this cap?

This doesn't look right. It looks like someone took a radial cap, lengthened 1 lead, and installed it where an axial cap was originally installed.

Cheers,
James

edit: Is this C1 = 470µF/50v?

 

[beej]

You've come to the right place, Rodolfo. The expertise you'll find here is absolutely tip-top. I wish you good luck with the project and look forward to reading about your success with it.

 

[morfeora]

What is this cap?
View attachment 2172893
This doesn't look right. It looks like someone took a radial cap, lengthened 1 lead, and installed it where an axial cap was originally installed.

Cheers,
James

edit: Is this C1 = 470µF/50v?

This cap was there since I have the turntable, I checked and measured and the valued was right, I know measure is not enough, but I haven't anything on hand to changed it. Voltage is right on the check point for the power supply 20v at TP5. So I was not worry about it yet.

edit: Is this C1 = 470µF/50v?

Yes James, is C1.

This is the list of caps I created visually by looking at the board. Checking some leftovers from my two past restorations I end up having almost half of the caps I need (in blue).


Edit: The 11mm gap is wrong, actually there is a 20mm gap between the board and the cover that goes under the platter.

I am going to prepare this order plus some resistors, I fell tempted to change them all, but so far I am going to start with some of them which are clearly suspicious, painting falling or little burn.


After this photo I realized haven't clean the board... will be the first task next time.

 

[morfeora]

You've come to the right place, Rodolfo. The expertise you'll find here is absolutely tip-top. I wish you good luck with the project and look forward to reading about your success with it.

I already have seen what you say with my own eyes, ears and in person. I just so you are the one for one of my next repairs.. I have a non spinning Pioneer PL400 I will love to take to my office. It will be one of my next proyects .
Thank you Butch, for your good wishes.

Hello Rodolfo! Thanks for the kind words. You are correct, everything functions as normal except for the on/off switch on the table. It is replaced with the on/off switch on the external unit. I like the idea of your wood box, please post a pic when you get it put together, I'm sure it's going to look fab!

The table is a 1200M5G with an upgraded chrome armboard and tonearm (Jelco TS-550S). I replaced the thrust plate with the KAB derlin one and added the wax. I also removed the blue led's and replaced with white (same voltage so easy change ... easier on the eyes).

The clamp is just a heavy weight really (650 grams). I purchased it from a German seller on eBay but they don't seem to sell them any longer. I really like the look of it and it does affect the sound (in a good way for me).

The headshell is an Orsonic AV-101b. They are still available on eBay from 2juki (great seller) but costly. It does work great and is very rigid. Looks cool as heck too, at least in my eyes. The black one I have looks even better on that chrome arm. They may not be around much longer, all of his other Orsonics have been gone for quite sometime now.

Good luck on your journey sir! Can't wait to see the progression.

Edit: Here is a place for caps (they nicely provide a list / rating too): https://www.audiovisualspareparts.c...trolytic_capacitor_kit/p5275248_20591983.aspx

Thank you for all this info GPJ I will have all this in mind... already check the headshell, and well, I will have to keep saving... harder... and this without mention the Jelco tonearm (already check that one too

Edit: I just checked audiovisualspareparts, very good place for the ICs (unfurtunly I already paid a lot more for the AN6675... but in case I need the AN6680 this will be a good place).
Cheers,
Rodolfo

 

[morfeora]

Yes it is worth it. I made a damping trough and paddle for my EPA100 and it makes a difference. Technics arms are pretty good. Other mods worthy are:

Damping the arm wand with 3m foam ear plugs. Cut 3x 5mm slices and place them both ends and in the middle where the bend is.

I also replaced the CW and stub with one I made that cleaned up the CW resonance.

Hi warrjon, I will love to know more about what you did, I like the DIY approach. Unfortunately I do not understand pretty well "arm wand"... Damping the arm wand is something similar to put the "S" -in case of the SL-1200s- tube (what I guess now is the arm wad) in a kind of heat shrinkable tube?
Cheers.

 

[Bratwurst7s]

This cap was there since I have the turntable, I checked and measured and the valued was right, I know measure is not enough, but I haven't anything on hand to changed it. Voltage is right on the check point for the power supply 20v at TP5. So I was not worry about it yet.

Yes James, is C1.

This is the list of caps I created visually by looking at the board. Checking some leftovers from my two past restorations I end up having almost half of the caps I need (in blue).

View attachment 2173235

I am going to prepare this order plus some resistors, I fell tempted to change them all, but so far I am going to start with some of them which are clearly suspicious, painting falling or little burn.
View attachment 2173241

After this photo I realized haven't clean the board... will be the first task next time.

Rodolfo, I can most likely help you with most or perhaps all of these caps, and many resistors.

When I get home from work I'll go through what caps I have and measure for size. When you have a list of the resistors we can look at what I have. If you are not in a rush I can then send them down to you with your CD player. It would save you from having to make an order.

Cheers,
James

 

[Markoneswift]

It's funny that people jump into replacing ICs because there's a drive / speed issue with Technics DD turntables. I've done a LOT of these over the last few years and the ICs are NEVER the problem - it is always the capacitors which filter the signals from the frequency generator circuit. If any of the reference waveforms expected by the IC are missing or bad, you get all kinds of weird speed issues including (but limited to) rotating backwards!!

Do a full recap of the board - all of them - and then see where you're at before looking at replacing any ICs. I have had success on SL-Q1 / SL-QL1 / SL-10 and many others, all by doing the caps and a damn good Deoxit of all the pitch controls and switches.

Good luck!

 

[cafe latte]

Why is this a problem? I can run a Grado with my Technics and not have any hum issues whatsoever. If a Grado doesn't hum, there is no problem with any other cartridge.....just sayin'

Depends on the age of the Technics old ones are good but newer ones the transformer causes hum on Grado. I had one of the last production sl1210mk2's and Grado hummed, but Kab psu fixed it.
Chris

 

[cafe latte]

Looking forward to seeing this turntable spinning again.
Chris