Do you think it is necessary to remove start and speed buttons from the deck? Does this improve smth? Because if you don't have any buttons on that external PSU you can put it somewhere further apart from a beautifully looking TT
Not at all. In fact if you did, it would be a major pain.
He did so because his turntable is filled with concrete or liquid metal or something like that - he basically took the original plinth and used it as a mold for a new plinth, and all the electrics save the motor are outboard as there is nowhere to mount them.
Hi guys
Just to add a bit of my experience here. I did my SL1200 outboard PSU mod back in 2010 after reading an article in HI FI WORLD magazine on the upgrades done by Sound Hi Fi on a SL1200. Pretty easy to figure out what they did in that article.
The difference to this post's mod is that I used a higher current transformer (50VA i think) to provide a bit more torque to the motor instead of the original transformer. It can now handle a 500gm steel puck.
I also mounted an old Magnepan Unitrac arm instead of the crappy original.
The only puzzle left was the bearing, To get a new one made costs a bomb and I wasn't willing to spend silly money on this but something had to be done. So reading this thread about using Teflon tape or plumbers tape and fishing reel oil solved that.
Thank you very much.
Here are some pics of my SL1200.
The PSU
Early stages
Just to add a bit of my experience here. I did my SL1200 outboard PSU mod back in 2010 after reading an article in HI FI WORLD magazine on the upgrades done by Sound Hi Fi on a SL1200. Pretty easy to figure out what they did in that article.
The difference to this post's mod is that I used a higher current transformer (50VA i think) to provide a bit more torque to the motor instead of the original transformer. It can now handle a 500gm steel puck.
I also mounted an old Magnepan Unitrac arm instead of the crappy original.
The only puzzle left was the bearing, To get a new one made costs a bomb and I wasn't willing to spend silly money on this but something had to be done. So reading this thread about using Teflon tape or plumbers tape and fishing reel oil solved that.
Thank you very much.
Here are some pics of my SL1200.
An externally hosted image should be here but it was not working when we last tested it.
The PSU
An externally hosted image should be here but it was not working when we last tested it.
Early stages
An externally hosted image should be here but it was not working when we last tested it.
mating with the pearl
6L6, thanks a lot for the effort. Recently a Technics 1310Mk2 fell into my hands on a recycling facility. I tried it at home, and it worked! But I liked the sound too. Then I read your guide and had to try it all. During tinkering with what I thought could work, I tried a damper diode (EY500) in the negative rail of the psu. That is, the part which powers the motor (I understand, this differs from the Technics 1200, as this only has one rail of 21 volts). I did that, because I had too much voltage to drop. But to my surprise I now had too little voltage for any active regulation. In fact the psu settled at about 20 volts. I tried it anyway - my jaw dropped and I just sat there listening. Really good music, a wonderful flow. It measured rather poor, drops of up to 10 volts at start/stop. But the music was much better than with the LM317, which sounded veiled an congested compared to the tubed supply. Now the Pearl from Wayne Colburn came to my mind. I tried its regulator, set to 21 volts, with a 4R7 resistor at the end (the drain of the Mosfet), followed - and this ist important - by a cap of 6800uF. - Wow. Punch, Tone, Timing and lots of detail. Just great. Try it! (the best would be perhaps the pearl-regulator with the damper diode. but a bigger transformer is needed).
Cheers, Merten
6L6, thanks a lot for the effort. Recently a Technics 1310Mk2 fell into my hands on a recycling facility. I tried it at home, and it worked! But I liked the sound too. Then I read your guide and had to try it all. During tinkering with what I thought could work, I tried a damper diode (EY500) in the negative rail of the psu. That is, the part which powers the motor (I understand, this differs from the Technics 1200, as this only has one rail of 21 volts). I did that, because I had too much voltage to drop. But to my surprise I now had too little voltage for any active regulation. In fact the psu settled at about 20 volts. I tried it anyway - my jaw dropped and I just sat there listening. Really good music, a wonderful flow. It measured rather poor, drops of up to 10 volts at start/stop. But the music was much better than with the LM317, which sounded veiled an congested compared to the tubed supply. Now the Pearl from Wayne Colburn came to my mind. I tried its regulator, set to 21 volts, with a 4R7 resistor at the end (the drain of the Mosfet), followed - and this ist important - by a cap of 6800uF. - Wow. Punch, Tone, Timing and lots of detail. Just great. Try it! (the best would be perhaps the pearl-regulator with the damper diode. but a bigger transformer is needed).
Cheers, Merten
Guys! I finally got myself a 1200 mkII and start moding it! I an planning to do smth like this Index, but maybe will cast a lower part of the plinth myself from plastic/send mix.
I have couple of decisions have to be made:
1) Should I keep a pitch control? I like the look without it more, so do you really need it?
2) Strobe. I know that ppl say on internet that a pitch circuit makes a really high noise... Any ideas what is the best way to disable it?
3) pop-up light. Do you think it can profuse any noise? I doubt it, but Ken(the guy from the link above) removed it...
I have couple of decisions have to be made:
1) Should I keep a pitch control? I like the look without it more, so do you really need it?
2) Strobe. I know that ppl say on internet that a pitch circuit makes a really high noise... Any ideas what is the best way to disable it?
3) pop-up light. Do you think it can profuse any noise? I doubt it, but Ken(the guy from the link above) removed it...
The biggest mods are (in order)
DC PSU
Acromat
Arm rewire
Feet and/or wall rack.
When you make your DC PSU, the original power switch is unused - I just wired the strobe through that switch... It's free and right on top of the strobe - it feels stock. Very easy, very cool.
Pitch control - Really useful IF you use it. But it looks dorky. Since you are making/modding your own chassis plinth, you could mount it on the side out of sight.
Pop-up light. Again one of those things that is awfully handy if you need it...
Noise? None.
DC PSU
Acromat
Arm rewire
Feet and/or wall rack.
When you make your DC PSU, the original power switch is unused - I just wired the strobe through that switch... It's free and right on top of the strobe - it feels stock. Very easy, very cool.
Pitch control - Really useful IF you use it. But it looks dorky. Since you are making/modding your own chassis plinth, you could mount it on the side out of sight.
Pop-up light. Again one of those things that is awfully handy if you need it...
Noise? None.
After looking at the schematic and determining which were the strobe leads and which were the switch leads, I cut them and wired the strobe's power with the switch in it, so you could turn it on/off. I don't remember the colors, you probably need to look at your specific deck and the proper schematic.
When you remove the AC board from the turntable you will have to disconnect a few wires, the power switch chief amongst them. Just wire the strobe positive in series with the switch leads. There's nothing to it.
When you remove the AC board from the turntable you will have to disconnect a few wires, the power switch chief amongst them. Just wire the strobe positive in series with the switch leads. There's nothing to it.
Huh... If that's so, then why is the KAB strobe disabler nothing more than a really fancy on/off switch for the strobe lamp?
It's complicated because it's using existing switches that do something else, and piggybacking another use onto that switch -- but all it does it does is cut the power to the lamp.
It's complicated because it's using existing switches that do something else, and piggybacking another use onto that switch -- but all it does it does is cut the power to the lamp.
I really like my SL1210 Mk2. Got a Achromat mat and Ortofon 2M Red cartridge installed.
I didn't want to mod too much, but things like an outside PSU is just fine for me.
The SL1200/1210 Mk2 hold a sentimental value, hence I don't want replace the tonearm, but a rewire is OK too.
6L6, what dimentions are the PSU housing you use? I'd like too look for a nice aluminium case before I take my turntable apart.
I read about the 240V things I need to look out with, so will keep those in mind when I prepare myself.
Will take a look at all the details with my dad. He's very skilled in electronics, whereas I can build and solder and read a basic schematic, but I feel safer after having him take a look at it too.
I didn't want to mod too much, but things like an outside PSU is just fine for me.
The SL1200/1210 Mk2 hold a sentimental value, hence I don't want replace the tonearm, but a rewire is OK too.
6L6, what dimentions are the PSU housing you use? I'd like too look for a nice aluminium case before I take my turntable apart.
I read about the 240V things I need to look out with, so will keep those in mind when I prepare myself.
Will take a look at all the details with my dad. He's very skilled in electronics, whereas I can build and solder and read a basic schematic, but I feel safer after having him take a look at it too.
By the way, I just added a VERY thin piece of teflon tape between the bearing and its ceramic plate, and the spinning time from power off to platter stop was increased from 19 seconds to 32
Using singer oil ATM
Damn I need to fix my phono to test how those things sound
dimkasta, how long did your teflon tweak last? I tried this yesterday with a single layer of tape around the thrust pad. My run-down time went from 25 seconds to 43 seconds. The result in sound quality was inspiring - definite improvement in bass drive with less overhang, dynamics in spades, more full midrange.
However, after only a few sides there was some mistracking happening. I checked this morning and the tape wore out. I removed the tape and now using the stock bearing as it was.