Technics SL-1200 DC Power Supply

[dimkasta]

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

 

[6L6]

What kind of tape? Plumbers thread tape?

As for wire from cartridge all the way to photo preamp? I want to try it.

 

[dimkasta]

What kind of tape? Plumbers thread tape?

Yeap exactly. The really really thin kind. I cannot even measure mine, and it is even more squeezed from the bearing. I have tried some thicker discs, like 1mm and 2mm and they did not work that nicely, probably because they have some strength and elasticity making the platter kind of bouncy. But the super thin one is just crashed flat by the bearing.
Run it diagonally. From the upper side of the left screw to the lower side of the right one, so that it passes nicely on top of the the ceramic cap and the bottom cover holds it tightly in place.

I left it spinning for a bit, and the time is now 33 seconds

 

[dimkasta]

Oh and just add a drop of whatever oil you are using on top of it.

 

[dimkasta]

By the way I just found this zener that comes pretty close to what we need for a single 19,20ish volts

PTZTE2530B ROHM Semiconductor | Mouser

That's 12ohms max impedance for the reference and 1W rating

I also wanted to ask if you have tried the preregulator thingy on the article. It sounds VERY promising...

 

[6L6]

I have not tried the tracking pre-regulator. But I will - it seems very cool.

 

[dimkasta]

By the way, do you see any issues using bigger caps in the CRCRC filter? I currently only have 10000uF caps

 

[6L6]

None at all. I used the 4700uF because I had them.

You might have to use a bigger fuse due to inrush.

 

[dimkasta]

Cool

I ve been working a bit on the prereg schematic to apply all the goodness from the first page to it.
I came up with that

I have included the filter caps, the protection and thermal drift diodes and selected a few values for components]

Any comments?

 

[dimkasta]

BTW I do not see a reason why not to use LM350

It s ~3 times cheaper than LM117, has 5db better ripple rejection and can go up to 3A. And of course it is a direct replacement... no changes required on the other components...

 

[audiostar]

Is anybody familiar with the external Paul Hynes SR7EHD power supply. This is suppose to be the best external power supply for the Technics. Can you make
something similar?

 

[6L6]

This is rather similar.

When it's all said and done 75% of the improvement from any external PSU is getting the transformer out of the turntable. Then having really clean DC to the table is another 20%. Everything past that is the last 5%, and you can do it any way you would like.

 

[vinylkid58]

Paul Hynes SR7EHD power supply.

Are these just oversized mains transformers with shunt regs. in a fancy box?

jeff

 

[audiostar]

I have no idea how the SR7EHD compares to other power supply but is offered for 680 british pounds. Are all external power supply for a turntable created equal? Can one power supply be superior and one inferior?

 

[Zen Mod]

well - 680 greenies is blasphemy ( at least on DIY site ) , if we are talking about PSU for 1200 , which can be only basic PSU with pre-reg , except in case of total redo of TT electronic itself , and multi-feed arrangement

 

[bozakdla]

There are more expensive PSU here, Shunt £995, LM317 £450.

 

[6L6]

I tell you what - send me your SL1200 and $1500. I will do all sorts of awesome mods to it, PSU and others, and I will send it back. You will be astounded at the improvement, as there will be quite few modifications made to the deck. It will sound just like mine, genuinely better, a significant and marked improvement from stock.

I also have a service for $2000 - it sounds better because it costs more.

 

[Zen Mod]

There are more expensive PSU here, Shunt £995, LM317 £450.

well , last sheep is not dead yet , I suppose

 

[Zen Mod]

I tell you what - send me your SL1200 and $1500. I will do all sorts of awesome mods to it, PSU and others, and I will send it back. You will be astounded at the improvement, as there will be quite few modifications made to the deck. It will sound just like mine, genuinely better, a significant and marked improvement from stock.

I also have a service for $2000 - it sounds better because it costs more.

naah

my option is better - send me just 499,99$ , keep TT at home and I'll do everything with my brain power

 

[6L6]

No, you must realize that the best option is to do both - I will do the Physical modifications, Zen will to the Metaphysical modifications.

All the best of both disciplines rotating at a perfect 33.3RPM. (Or 45, if you have some of those records...)