Technics SL-1200 DC Power Supply

Jump to Latest
#81
Yes that is true. My tape was also torn, so I replaced it with some Teflon discs I had from dissecting 10nF FT-1 russian teflon capacitors. These are around 10mm in diameter and less than half a mm thick. It still goes without issues. There is a minor squish in it by the axle, but it still runs smoothly. I have also seen some people using teflon balls, but I would not use anything thicker than half a millimeter. The ball is not going to run fully squished and it will introduce some bouncing to the axle
 
#83
Here is a fast photo of what it looks like. You can see some curvature on the teflon disc, because I did not properly cut it to fit within the 3 metal posts and the axle is pushing it down in the middle.

attachment.php


I believe 3M is selling such discs, even with sticky tape on the downside.
 

Attachments

  • DSCF0605.jpg
    DSCF0605.jpg
    123.1 KB · Views: 1,821
#89
6L6 I used your crcrc combo on another psu on my shigaclone and using leda for the reference I found out some very interesting stuff. Mainly that 10R resiators are VERY big and are acting like brick walls for the current. I noticed the issue by seeing the leds flashing when the cd powered up and wrote to Martin from acoustica. He included the big resistor in his possible problems without even knowing about the rest of the setup.

We should use something really lower. Like 0R1 or 0R47

I just got my sl1200 back so I will make the psu very soon
 
#90
The 10R are not much of a problem in the PSU as designed for the SL-1200, as the unregulated supply is almost 20V higher than the regulated output.

If you had a supply where there was only a few volts for dropout, I could see some problems.
That said, if yo wanted to use a lower value resistor, it will work wonderfully. The filtering is more about the multiple stages than the R value. 🙂
 
#91
Cool 🙂

By the way, anyone with a european mk2?
I tried to hook it up with its own pcbs, but I am getting only 6v on the output without load. I missing something on the power switch. How do we short the pcb to work without it?

And how do we connect the primaries for 220v? Black and white together and power goes to brown/blue? My secondaries are both yellow.
 
#95
It's DC in the umbilical.
I just did not include the small 100nF caps, and used 10000uF panasonics with 0R47 resistors.
You think the 100nFs make a significant difference? I have some around... I m just a bit lazy after a working Sunday...
I think I will try the 317 next...

By the way, the pretracking reg works wonderfully in my shigaclone 🙂
 
#96
Nah - I just used the 100nF because I had them and people expect to see a film bypass on electrolytics.

The regulator does help - it makes everything cleaner and clearer.

I never got around to making a pretracking reg because 1) the normal reg works great, and 2) I could never figure out a layout -- it makes my brain hurt, there is some layout logic that I'm just not seeing...

Anyway, as you have probably figured out, the external PSU is the best single mod you can do the SL-1200.
 
#97
I could not find my zeners for the reg, so I decided to give a try at upgrading the local decoupling caps.

I replaced C1 with a Panasonic FC 1500uF/63V and C3 with a 47uF/25V Panasonic FR

The difference was more than obvious. The sound is much more dynamic. Bass is tighter and nicely timed with cymbals and other stuff, and the sound is full of harmonics. You can clearly hear finger changing in strings, and deep stuff in voices and horns.

Overall a very nice change... Got me wondering what else we can replace 🙂
 
You must log in or register to reply here.
Top Bottom