A quick visual guide to externalising PSU from your Technics SL 1200

[Frankyc2003]

Well, what I have noticed for sure is that it starts and gets up to speed in less time than before (maybe less than a quarter turn, not measured it precisely).

Bear in mind that I have and upgraded 'Inspire Hifi' platter which has a 1in billet of Aluminium underneath, so considerably heavier.

So I would say that it has helped the speed control definitely.

Also since the platter is heavier, as mentioned above I had to adjust the brake to slow the platter down harder. I don't really want to fly wheel the platter for no reason...

[Marco]

Excellent stuff, Francois! Hope that you feel that the sonic results were worth it

The only thing I was disappointed about was that you didn't show a picture of the 'externalised' PSU housed nicely in its new case... Any chance we could see a pic of that, so that people can observe how neat it looks after the job has been done?

Churz!

Marco.

[Frankyc2003]

Thanks Marco, and well spotted, indeed the finished PSU is the only thing I didn't photographed...

Hopefully these few pix will correct this...





I used a temporary solution for the feet... Insulating tube from B&Q, it does a pretty good job at isolating the PSU from ambiant vibrations... But some sorbothane pods are on their way!

I am creating a new post about my impressions on the actual sonic results! So watch this space!

[Marco]

Nice one, Francois. That makes all the difference, as it shows people what the finished item looks like!

Yup - would love to know what your impressions are of the sonic improvements gain from the modification, so I look forward to reading about that

Marco.

[Qwin]

Ready to start on the PSU al la Franky.

OneyedK - "A lot of decks are equipped with a 470µF/50V, while the schematic still states 1000µF (the correct value)."

I checked the service manual (PDF on Vinylengine) C1 is listed as 470uf/50v.
Where are you getting the value of 1000uf from and is it a worthwhile upgrade?

[UV101]

I would go bigger if you can fit it!!!

Im not looking at the manual but is It's a power supply reservoir (pre regulator) bigger will help to quickly deliver any current pulses needed to stabilise the platter. If you are looking at it from a psu noise point of view, you can always add smaller value caps in parallel to deal with this.

In my psu I'm using massive mundorf caps pre reg (I think 2 x 22,000uf from memory) and smaller 470uf in the techie.

[OneyedK]

I checked the service manual (PDF on Vinylengine) C1 is listed as 470uf/50v.
Where are you getting the value of 1000uf from and is it a worthwhile upgrade?

Have a look at the right schematic of the mk2:

http://www.vinylengine.com/ve_downloads/index.php?technics/technics_sl-1200_1210mk2_supp.pdf

And yes, C1 should be as large as possible (rectifier and transformer should not be overloaded).

[Qwin]

Ah - It's in the mkII supplement.

Still says C1 is 470uf on the ammended parts list but I see the circuit diagram says 1000uf.

Note the mk IV service manual also shows C1 as 470uf in both the parts list and the circuit diagram. That's confusing

Thanks for clarifying the point.

[OneyedK]

Note the mk IV service manual also shows C1 as 470uf in both the parts list and the circuit diagram. That's confusing

When you're into mass production (like Technics), certain compromises need to be made.
In this case, the 1000µF that fitted the original holes/soldering pads was no longer made by Panasonic. Next best thing was to use a 470µF.
Luckily we're not into mass production
So we can use any part we want...

[Qwin]

OK - Would this item do the job?

http://uk.farnell.com/nichicon/tvx1h...50v/dp/8823715