SL-1200 DC Power Supply DIY

[Firebottle]

You took the mains input to the 'output' terminals, the ones with the neon indicator connected to them.

So the indicator light is on all the time

How did you secure the electrolytic caps Francois?

Alan

[Frankyc2003]

Bingo!

That's exactly what I did!


Jim did notice the swith looked upside down, but you did mention the switch light would be on all the time which it did and that confused me a lot.

So I declare the free vinyl is going to Alan in France!

The bank of caps are tied together with zip ties, and then secured to base with more across.
They don't move...

When I come to build the real thing, the case will be aluminium, and everything will be a lot more serious looking!



PS. Alan PM me your adress and I shall post you a surprise...

[6L6]

When I come to build the real thing, the case will be aluminium, and everything will be a lot more serious looking!

I'm of the opinion that the PSU should be as far away from the cartridge as you can make it... so shoving it down on the floor, out of sight is de rigueur...

That said, having a snappy looking external box is always nice, so if you find one that is really pretty, please contact me, I might want one as well.

[Qwin]

Excelent work by you both on this, watching with interest.

[6L6]

Thanks! I'm hoping it will inspire others to do the same.

[Qwin]

I might get round to building one when I clear the decks of other projects.
Would an R core transformer be a good idea?

Jim, I noticed you grounded your DC supply screen to the Techie PCB. Is it not good practice to ground the other end instead, taking any interferance collected away from the board? I am non electrical but that would make sense to me.

[6L6]

R core are interesting. I've not used one. Some reports are very favorable, some are not. (Usually stemming form mechanical noise)

Regardless, I am still interested in giving one a go. Use the stock transformer in the meantime.

As for the shield ground... The external PSU is in an ABS case, with no mains earth. (Nowhere to attach it.) The DC PSU essentially floats. So the only "ground" potential (relative to the signal) is on the TT chassis. So might as well take it there.

Remember, there is no such thing as 'ground'. It's only a convenient term we give to the lowest voltage potential. (And it gets even weirder in bipolar power supplies....)

[MartinT]

Jim - if you didn't know it, the ground post is the front-left PCB post as you look at the deck (all the PCB tracks return there), so that is where your DC 0V return and screen should go. You should ideally connect that point to your phono preamps' earth post (and SUT earth post) for lowest noise.

[Qwin]

Jim, any chance you could elaborate on how to make/wire the rectifier section?

Where do you position the "Bleeder" resistor you mention on the caps, as it is not on your very good picture of the Capacitor assembly or the schematic?

[6L6]

Ken,

The schematic does show everything.



The Mains, fuse, AC switch.

Transformer.

Diode snubbber cap to the left of the bridge, and then the bridge.

The 4700uF caps with the 10 Ohm resistors for the CRCRC filter.

The film bypass cap and the bleeder resistor.

I will label the drawing.