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Technics 1200 refurb help

markshan

markshan

Sir Thrift a Lot
I decided to put this in DIY instead on turntables because I eventually will be asking for help with power supplies and other general audio questions that aren't specific to just turntables. I know the skilled craftsmen here will be a wealth of information.

Some of the people who post in DIY are pros who are putting their handywork on display. Not me, I am a hack tinkerer who will be looking for guidance and direction.

Anyway, I bought a 1200 MK2 off Craigslist for $2 (yes, two dollars). It has been treated very badly and needs a great deal of work both functionally and cosmetically. I will be posting pictures and questions as the project goes on. The picture below is from the Craigslist ad.

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I first tested the motor and made sure it was still functional and stable. It is. So my next line of action was to make the plinth look pretty. I looked into having a body shop paint it, but they wanted over $100. I didn't want to spend that kind of money on an experiment. So the guy recommended some "pro grade" primers and paints. They would have cost me $70. So I ended up going with plain old Rustoleum.

The first step was to sand out the filth.

Primer1.jpg


I removed any burrs and got rid of the brown stuff, but if I were doing this again I would have sanded more aggressively. In particular I would have done much more to remove the logos. After priming an a few coats of paint they were still visible. On the other hand, it did force me to use many light coats rather than rush the job.

After sanding, I did a heavy prime just at the scratches.

Primer2.jpg


I then sanded this to try to create a smooth surface. Then I did several additional layers of primer to get it like this (note the way I carefully masked the middle with a paper plate).

Primer3.jpg


Next came several coats of Rustoleum yellow. I don't have any covered area to do this, and it was windy, so between coats I had to pick out bugs and debris, sand lightly and recoat. I used about 3/4 of the can.

Paint1.jpg


I then applied a waterslide decal with "my logo" (this probably seems narcissistic, but if I'm putting this much effort into it...) and did several coats of clear coat. This step did not come out perfect, as I am up against a Pennsylvania winter and knew I was running out of time. Some sanding was done before the surface was ready, and some coats were heavier than they should have been, causing runs.

ClearCoat1.jpg


The final job isn't 100% perfect, but I give it a strong 90% and feel really great about doing it so inexpensively and keeping the "DIY ethic" by not farming the job out.

PlinthFinished.jpg


The fuzziness is my camera, not the logo.
 
Hmm, does look like a project, but a great deal at 2 bux! What are your plans for it? Bring it back to stock, or slap a different arm on it? Best of luck with it, Nick
 
Trower said:
What are your plans for it? Bring it back to stock, or slap a different arm on it?
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That is one of the many things I will be asking for advice on. Before I worry about the arm, however, I will be asking lots of questions about the bearing and power supply. I want to make sure I have those right before I waste time and effort on a table that I may very well destroy during those steps! Once it is running again, we will talk arms.
 
Mark-

That looks great. I wouldn't have picked the Steelers colors, but I understand that you're a fanboy.:thmbsp:

The nice thing about your project is that even if you use the stock arm with this, you'll be able to rewire it and, as long as you've got that baby apart, I'd recommend installing some Petra RCA cable upgrades, etc. It would be much more fun to try to Frankenstein/mod a $2 table than to try to "fix" a $150+ one. Definitely keep the posts coming!
 
dodog said:
I wouldn't have picked the Steelers colors, but I understand that you're a fanboy.:thmbsp:
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Actually, I debated between yellow and purple. Either way it is in homage to my beloved AT 440 MLA. I went with yellow and will be doing the LEDs and trim pieces in purple (plum, actually) to match the cartridge. I decided that plum was too dark to use as the primary color (plus Rustoleum didn't offer it) so the yellow seemed the natural choice to set off the plum. Perhaps I should have made my logo plum, but I knew the speed strip would also be black (those bastards at Technics don't offer it in plum!).

at-440mla.jpg
 
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dodog said:
It would be much more fun to try to Frankenstein/mod a $2 table than to try to "fix" a $150+ one.
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That's the bottom line for me. I would be afraid to do this to a new deck, but ripping apart a $2 table is fun!
 
Applauding your efforts on this, it's one thing to write, " I applied several coats of paint and sanded" but the work takes a wee bit longer than typing.:D

Did you craft the logo yourself ? How does one go about that ?

Stand by for advice on the PS and upgrades to the Technics, there are guys in this section of the Forum that will get you through that.
 
westend said:
Did you craft the logo yourself ? How does one go about that ?
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The logo has a short but moderately interesting story. For about ten years now my wife (Gale) and I (Mark) have made Christmas mix CDs and sent them to people in lieu of Christmas Cards. When we made the first one I wanted people to understand that what they were holding was "a musical Christmas card" so I adapted the Hallmark greeting card logo. I found a clipart crown that was close to the Hallmark one and added the slightly modified (but mostly stolen) tag line "Galemark: When You Care Enough to Send the Very Best". Once I started needledropping, I simply used that logo as my "needledrop label".

As far as putting the logo on the plinth, I simply printed it with my inkjet onto a waterslide decal and put it on the table over the paint but under the clearcoat. I literally used the entire can of clearcoat, so the sticker is well protected and the raised area where it sits is almost but not quite smooth.
 
So here is the first question...

I have seen that KAB and others sell upgraded power supplies for the 1200. I also get the impression that about 90% of the upgrade is simply in getting the transformer (and associated noise) off board. I don't want to spend the money on a new power supply but see no reason not to get mine off board while I have this thing torn apart.

Before2.jpg


Here you see all of the components as they are originally. The transformer and associated PCB are on the left.

Power1.jpg


This picture shows the removed transformer, PCB and main board. I would like to get the transformer and PCB into an off board project box. The only rub with this (AFAIK) is that the power switch is at the 120v stage, rather than the 24v or whatever it is stepped down to.

As I see it (please correct me in I'm missing something) I have two options in how to accomplish this.

1. I can put the "On-Off" switch on the project box, and make the switch on the table non-functional. For this I would not use the provided blade switch but an illuminated rocker.

2. I can use the switch exactly as provided.

The advantage I see with option 1 is that I would only need to run three wires from the project box to the table and those wires would be low voltage. The advantage I see with option 2 is that the table will function more closely to original. The downside is that I would have to run six wires and 120 AC into the table. This would obviously limit my options for wire and connectors, and may (I need opinions here) negate some of the benefit of getting the transformer off board.

Two more quick power supply questions...

The two yellow wires from the transformer to the main board are (I presume) low voltage. Are they still AC? I'm guessing that they are since they aren't color coded. On this picture you can see that they are connected to the main with several wraps around long binding posts rather than just soldered as most of the connections are. What is the purpose of this? I suspect that knowing why this was done could be important to my decision making.

Power2.jpg


Also, since all of these components were originally mounted to a common metal plinth, I am thinking that I should run a ground wire from a contact point on each component back to the plinth (that is why I said 3 or 6 wires, not 2 or 5). Am I correct in thinking this? Also, should I use grounded power even though the original design doesn't? It seems to me to be the best option for complete grounding in my system. I suspect that Technics left it off to avoid ground loops in mobile situations, but I certainly could be wrong.

Thanks so much for all of your great advice.
 
If it was me, and I really wished to remove the transformer fom the plinth, I'd lengthen the wires and leave the boards and the switch inside the plinth.
The wrapped posts are just a way of securing the wire in a robust manner, the designer didn't want the AC leads from the transformer breaking off and causing havoc.
I would also forgo any redesigning of the grounding design, only adding a ground to the chassis from the transformer, there is potential for a ground loop that doesn't have to be implemented.
Thanks for the details about the decal, I didn't know it was possible to simply print a decal. Do most of the office supply folks handle that type of printable decal?
 
Any other opinions on moving the transformer off board and how to deal with the power switch? Does anyone have a suggestion on a good 5 or 6 conductor connector that will handle 120v?
 
markshan said:
Do I sense scepticism in the idea that this would provide any benefit?
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No, just my inimitable way of wording a response and interjecting confusion :sigh:.
Anytime you can move an inductive field away from sensitive signal apparatus or shield it, is probably a good thing. I don't know from any personal experience if it is better or not for turntables, never done it.
 
If it were I (If it was ME is grammatically incorrect, - if it were I who were doing this, not ME is doing this) since the turntable works, any modifications could very well break this fact - I'd worry about the arm at this point, to see if any reasonable solution is available. PLUS, the arm is an important part of the grounding circuit, so any changes to the ground BEFORE mounting an arm may have to be totally redone once the arm is on. Leave the turntable motor and supply as is until the whole thing is functioning.
 
Actually, in looking again more closely at the transformer and associated PCB, I now notice that the transformer is mounted by heavy rubber grommets. This would prevent the transformer from being grounded to the chassis. I also notice that the associated PCB has no etching (no contact) at it's mounting points. So unless anyone can persuade me otherwise, my plan now is to put them offboard with five wires and keep the switch in the table.
 
westend said:
I don't know from any personal experience if it is better or not for turntables, never done it.
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I know that some Grado carts can become noisy as the move to the center of a 1200. The accepted idea is that the noise is coming from the transformer. They call it the "Grado hum". My AT doesn't have a hum issue, but I reason that if the transformer can cause a hum with any cartridge, then I am better off moving it.
 
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