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diyAudio group buy Paradise R3 phono stage boards

I was considering an arrangement where I replace the heatsink with a bit of aluminium angle that bolts to the top of the case. Also wondering whether it would work to drill out a metal bar (aluminium or copper) with 5mm holes for the input transistors as a heatsink/thermal coupling.

All of this is in the future though, first I need to match a buttload of transistors and solder all the things :)
 
The input stage trannies need to be at a constant temp, as close to working temp as possible. So do your matching with the final design in mind. Mine sit under a little perspex bus shelter made for me by Ynwan. (Not the best photo)

14404762473_47b905d174_c.jpg


Al, my psu runs 28.5 volts into the shunt on the Paradise boards, with the Calvins fitted everything runs a touch cooler as they suck up 30mA from the shunt.
 
I must clarify something as I am not using the pre reg boards so that's why I can get away with a lower voltage transformer. I just have a conventional Cap6 type arrangement with inductors and resistors between the caps for filtering.

paradise 1 by 337alant, on Flickr


If you use the pre reg board then those chokes will drop your DC supply voltage when the power supply is under load so you would need a higher voltage transformer to accommodate those losses and you would most likely have much better filtering of the DC than with my supply

Si I agree, I am getting about 26V into the shunt regs and that is trimming down nicely to 18V and gives a nice stiff supply with not much heat at all.

mcai7et2 I dont know if you can see on the photo above but I filled the gap between the shunt heat sink and my case side panel heat sink with a piece of aluminium bar with compound either side, I have a bolt that pulls the shunt reg heat sink hard up to the side panel. I needed this to spread the heat out as by putting both boards in one case I have given myself the additional problem of twice as much heat in the same space :rolleyes:



Alan
 
I like the cheeky heatsink spreader Alan, nice thinking. You defo want them in two boxes though for least thermal pumping of the input stage.
 
sq225917 said:
The input stage trannies need to be at a constant temp, as close to working temp as possible. So do your matching with the final design in mind. Mine sit under a little perspex bus shelter made for me by Ynwan. (Not the best photo)



14404762473_47b905d174_c.jpg




Al, my psu runs 28.5 volts into the shunt on the Paradise boards, with the Calvins fitted everything runs a touch cooler as they suck up 30mA from the shunt.
Click to expand...

And mine with heated bus shelter for trannies - ooh err missus!

A516B038-CDB8-483C-A84B-E50D6F6BACC4_zpsasz64cfa.jpg


Calvin buffers since fitted :).
 
Spent a couple of hours bent over a soldering iron fitting resistors to the tiny pads on the boards. Did all the resistors in the shunt regulator, and a few of the others, as well as the diodes and zeners. Before I go futher, I wanted to double check which components needed to be matched, of course there is the transistors in the input stage and the current mirrors, and the RIAA components, but is there anything else that should be critically matched either per channel or otherwise?

Cheers,
Ed
 
I tested all the 33Rs and they were all a great match already (<1%) so I added those to the boards too :), soldered in all the LEDs on the shunt as well, and all the SMT caps on the bottom of the board.
 
I'm sure you'll enjoy it. Did you go down to 8.5ohm for the shunts? I found they got way too hot so stuck with the 10ohm
 
16051736484_dd1e3607db_h.jpg

Assembling another, this time Markus's. Should be a nice build, better than 1% match for all transistors, input stage and current mirrors. OPA627 to fit and the psu uses the new CREE SiC diodes. Should sound very good.


Ed, have you finished yours yet?
 
Having finally admitted to myself that a) I wasn't going to get around to building the Paradise anytime soon, and b) it was never going to be a build anywhere near as tidy as those I've seen from Simon, it was a really easy decision to contact him about this.

Simon, thanks. Is anything missing?
 
Pre-Reg boards, I could use a pair of those !

I saw a post by someone that said on the Paradise R3 boards the Calvin buffer had been incorporated, truth or myth ?.

Just waiting for my boards to arrive from the US. :)
 
sq225917 said:
16051736484_dd1e3607db_h.jpg

Assembling another, this time Markus's. Should be a nice build, better than 1% match for all transistors, input stage and current mirrors. OPA627 to fit and the psu uses the new CREE SiC diodes. Should sound very good.


Ed, have you finished yours yet?
Click to expand...

Nice work Simon.

I have the CREE in my build and to my ears they make a difference.:cool:
 
16486824158_1b51d54034_b.jpg


They have virtually no switching noise so the psu output should be a little cleaner than a standard build. I wouldn't worry about it Mark yours are built with similarly low switching noise types as are mine, just not Cree, they didn't exist at the time.

Markus, You're missing a couple of op-amp sockets for the opa627 swap, but I have plenty of those in my spares box. All you need to do is make a call on RCA sockets and front panels.
 
Hi Mark

Take a look here:

http://www.cree.com/Power/Products/Diodes/TO220/C2D05120A

Especially at the data sheet and switching times.

They are a little expensive but worth the cash IMHO especially for low level signal stuff like Phono stages.

As Simon said.

They provide a cleaner, quieter supply.

To my ears they are a little better in terms of detail and sound a little smoother.

Not by huge margins but every little helps.
 
misterdog said:
Pre-Reg boards, I could use a pair of those !

I saw a post by someone that said on the Paradise R3 boards the Calvin buffer had been incorporated, truth or myth ?.

Just waiting for my boards to arrive from the US. :)
Click to expand...

I have a spare pair of pre-reg boards (unpopulated). PM me if you are interested in them.
 
Re calvins on R3, myth, it merely has the resistor pad overly fixed.

I'll give mrdog first shout on those boards, if he doesn't want them can I have second dibs.
 
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