Building a Pearl 2

Slimline 1U with front plate printed to order to match the ACA font and central positioning.
The problem with it is the height restricts your choice of caps quite a bit. However a 5mm standoff placed between top or bottom covers and the chassis is just enough to bring top or bottom lid flush with the front face and give you the height needed to open up your options on caps.

My build in progress uses two DIY store slimline 1RU chassis. I trimed the 25.4mm H regulator heat sinks just a wee bit on a bench grinder and used 30mm diameter supply caps. PCB standoffs are 4mm. Caps are Vishay 30X30 10000 MFD 35V
https://www.mouser.com/ProductDetail/594-MAL225640103E3
The 3300 MFD electrolytics are Nichicon audio grade UKW rated at 25 VDC to keep the height within limits. They are all in the circuit after the 24V regulators.
https://www.mouser.com/ProductDetail/647-UKW1E332MHD
Front panel has a 3-position gain switch using a Glass Audio Select-2.
The preamp chassis was ordered with the rear panel IEC cutout to accommodate two 8-position DIP switches for cartridge loading. Perfect fit (vertically) no filing required!
DIY PSU board has the CX snubber caps and 25.4mm H heat sinks on the diodes, just because they were only 97 cents each (!) and they look cool
https://www.mouser.com/ProductDetail/532-513002B25G
And yes, that is a 50 watt Antek AS-0522 transformer, which will fit with both rubber washers in place.
 

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Supply impedance doesn't matter once it hits the regulators. More filtering (bigger R) in the raw supply will make things quieter in general, which helps downstream. :D

Will do.

As long as you're on the line, any advantages/disadvantages to using a CL60 as a chassis ground breaker instead of the bridge rectifier? I used the bridge but I am just curious. I did add some CL60s in series with the transformer primaries to reduce PS turn on current surge when charging up the 20,000 MFD per rail caps (40,000 MFD per rail if you include the main circuit boards). Wanted to keep the slo-blo fuse at 500 mA and so far, so good.
 
Oh... more photos of the RIAA chassis / layout please! It looks great so far! :yes:

Too late to go out to the shop w/ camera but here's one more pic.

Have not stuffed the DIP switch cart loading board yet but it is next to the input jacks to keep runs minimal.

Ground post (anodizing has been removed at the mounting hole) will connect to the PCB ground planes per your previous drawing.

Interconnect cable for the XLR4 power jacks is Canare 4S8 star quad with four 16 ga conductors, wired with red plus 30V, white minus 30V and the two (lt. red and lt. wht.) "negative" conductors carrying power supply ground.

The Canare is very tight in the Neutrik shell, I had to leave out the internal strain relief. If I did not care about the style and look of the connector, I would use Neutrik NL4 speakons next time. Big & ugly but easy to wire.

Front panel Glassware Select-2 is a 4-pole 3 position switch which will allow direct insertion of 3 different values at the R14 position. I'm going to start with 1200, 1000 and 300 ohms for MM, MI and MC carts, respectively.

Will post more when project is complete.
 

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Sorry to post this here but I've emailed passdiy and gotten no response. I'd like to get a set of Pearl 2 boards but don't necessarily want the JFETS (have a few in the stash) and $200 seems steep just to get the boards.

Is it possible to get just the boards somewhere (any group buys still active or any members want to get rid of theirs?) or even gerbers?
 
Hello DIY enthusiasts. I am not too experienced with DIY but love building things and audio. So far I have build a Bottlehead Reduction and Folsoms 7297 Amp. Bottlehead has great instructions and the folsom AMP instructions were pretty straight forward.

I know I can build a Pearl II but I have to admit I am a little intimidated, I will need to look to this forum for guidance. Going through this thread I am seeing power supplies with added circuit boards. Over all I feel more comfortable with Kits, is there a power supply Kit for the Pearl II? If so can someone advise which one to buy.

thanks in advance
 
Hello DIY enthusiasts. I am not too experienced with DIY but love building things and audio. So far I have build a Bottlehead Reduction and Folsoms 7297 Amp. Bottlehead has great instructions and the folsom AMP instructions were pretty straight forward.

I know I can build a Pearl II but I have to admit I am a little intimidated, I will need to look to this forum for guidance. Going through this thread I am seeing power supplies with added circuit boards. Over all I feel more comfortable with Kits, is there a power supply Kit for the Pearl II? If so can someone advise which one to buy.

thanks in advance

The Pearl 2 required a basic unregulated supply which is pretty easy to build with a proto-board. There are also many regulated supplies available on eBay in either pre-built or kit form, and in that case you just need a case and transformer.
 
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Too late to go out to the shop w/ camera but here's one more pic.


Front panel Glassware Select-2 is a 4-pole 3 position switch which will allow direct insertion of 3 different values at the R14 position. I'm going to start with 1200, 1000 and 300 ohms for MM, MI and MC carts, respectively.

.

Could you post a good picture of the selector switch once you have it all wired up? I'm interested it in how you make that work. I want to do the same thing on mine but I couldn't quite wrap my brain around how to make it work with that switch.

Thank you!
 
You got those into a 1U case? I thought for certain my transformer wouldn’t fit and couldn’t find caps on the RIAA short enough but apparently I didn’t try hard enough or know how to measure. I’m gonna have to build another level on the hifi rack to fit my 2U cases

It's the smaller diameter caps i'm struggling to find at a height that enables them to fit in the 1 u case i bought. Even with 5mm standoffs for the boards i'll still need 5mm standoff on the lid or base to get stuff to fit.