Building a Pearl 2

[WBS]

Thanks all!

@Mrshazbot I was worried I'd experience some of the problems others reported in this thread. However it worked perfectly, when I finally corrected the polarity on the PS!

It is dead quiet and a joy to listen to! The chassis are from HiFi 2000 and fit perfectly in the space I have. PS box is steel, the RIAA box is aluminum.

 

[codyt]

I’ve been thinking about tackling a Pearl 2 soon. Does anybody know dimensions of the Pass DIY boards? Going to get an idea on enclosures.

 

[Steve Luck]

Have my unbuilt boards to hand - Two Identical boards 5 x 7 inches or 127mm x 178mm

 

[codyt]

Have my unbuilt boards to hand - Two Identical boards 5 x 7 inches or 127mm x 178mm

Thanks!!

 

[Steve Luck]

Slimline 1U Case ordered (steel for RIA) - Thanks to some folk on here inc 6L6 I just need some 5mm standoffs and to buy short stumpy caps linked to in earlier posts and it will all fit in one long low case that I can put in front of the turntable. Systemdek with a Music master moving Iron cartridge on linear Air bearing Tonearm. Total frankenstein turntable. Project speedbox power supply too.

 

[codyt]

Nice! Also think about 1U. I have a B1 in a galaxy case, and am thinking about doing each channel in a 1U galaxy for a nice stack of signal electronics. Doing PSU in one of their economy cases and putting down below.

 

[codyt]

Anybody have suggestions/recommendations for a diy battery supply for the pearl 2?

 

[Eric]

Never really thought about this before, but how about a pair of 12v batteries that get used in grass trimmers?

Might give longer life than more "regular" types of batteries...

 

[codyt]

That’s not a bad idea - they’d be rechargeable too.

 

[6L6]

Probably wouldn’t need to charge them all that often, you’ll need a lot of battery; 24v per rail, so (4) 12v batteries.

I’d also mention that my pearl is the quietest phonostage I have. The only trick is get the RIAA chassis 3’ from any transformer.

 

[codyt]

I’ve been thinking of doing the phonostage first and starting out with wallwarts (or battery), then do a separate chassis PSU when I get around to it. I guess I’d need a wallwart for each rail, right?

 

[6L6]

Yes.

At start switch mode warts may be overwhelmed by the enormous capacitors on the PCBs.

The regulators need a minimum of 1.5v dropped across them to regulate properly.

 

[codyt]

Sounds like I just need to bite the bullet and build a proper PSU. Thanks for your help!

 

[Steve Luck]

But the Pearl requires -30 and +30 vdc can you get negative voltage from a battery supply? How would that work?

 

[Eric]

Sure! For simplicity sake, just image you have two 30v batteries. Connect the pos terminal on one to the neg terminal on the other. This is your zero volt reference point. Then, just use the remaining pos and neg terminals as your +30v and -30v supplies.

 

[6L6]

Eric is right. Ground is where we say it is.

 

[Steve Luck]

OK that makes total sense now. Ill have another look at the circuit diagrams with new eyes. Thanks

 

[Enochrome]

I am in the process of putting all the populated boards into their chassis and hooking them up for my Pearl 2 build. Do you know where there is a tutorial on how to hook up the transformer for the power supply? This is my first time using a transformer in a project, so I am a little nervous about screwing up and damaging something. Should I post pics of the transformer itself to make it easier?

Thanks

 

[Eric]

Pictures always help make things more clear. If you post a picture of your transformer, especially a nice and clear image of the wires leading in and out, this will be much easier.

 

[codyt]

Final configuration I’ve landed on is one chassis for PSU, and a chassis for each channel. Any reason I couldn’t/shouldn’t use a universal PSU board from the store?