Jump to content

Pass 'Pearl' phono stage restoration


andyr

Recommended Posts

Cameron ( @ericd) has a Pass 'Pearl' phono stage which was built by a member here.  It is built very well - using top quality parts - and has the PS in a separate case ... with an umbilical between the two.  Unfortunately, though, for some strange reason the guy who built it decided to put the DIN sockets on the front panels of both cases - so the umbilical is on full display ... instead hiding it at the back of the cases.  :classic_ohmy:

 

I had been helping Cameron with a little job for the new Funk F5 arm he'd recently purchased and suggested I could rework the Pearl to:

  • put the umbilical connectors on the rear panels
  • change the silver front panels to black, to match the rest of his system
  • add an earth terminal to the back of the case, to take the arm earth wire on the F5.  (The Rega arm he'd been using has the earth wire connected to the ground on one of the arm cable's RCA plugs - so the earthing was fine between his Rega arm and the Pearl.  However, when I fired up the Pearl in my system ... I got a nasty buzz which only went away when I clipped the arm wire to one of the input RCA barrels.  So an earth terminal which is insulated from the case but connected to an input RCA ground lug, was needed for my arm ... and I suspect, Cameron's Funk F5.)
  • and ensure the twin power transformers in the PS case are a. mounted on Sorbothane pads and b. both oriented correctly wrt mains Active & Neutral.

 

Attached are front & back pics of the re-worked phono stage case; relocating the umbilical connector to the back panel of the Modushop Galaxy case which houses the PS is tomorrow's task.  :)

 

I was very impressed with the sound of the Pearl in my system - I thoroughly recommend it to anyone who's looking for a top-class MM phono stage (and can't afford my 'Muse'  :lol: ).  One for you @catman?

 

PCBs - and (genuine!) matched jfets - seem to be available from here:

www.passdiy.com/store/product/pearl-2-pcb-board-plus-6-matched-jfets

 

Andy

 

 

Cameron - Pearl FP.jpg

Cameron - Pearl BP.jpg

Edited by andyr
  • Like 4
Link to comment
Share on other sites



Thanks for your work on this Andy. Looks fantastic, that front-facing umbilical cord is the one thing that has always bugged me about the Pearl!

 

In case any one is curious, the link Andy provided above is for the revised Pearl 2, I am pretty sure the one here is v1. Not sure what the differences are but you could search pretty easily I'm sure.

Link to comment
Share on other sites

  • 2 years later...

I'm thinking of building a Pearl 2. Have built the F5, I'm currently ramping it into a Turbo V1... 50W @ 8Ω Class A

I love the Pass sound so my thinking here is the Pearl would be a great add-in. Currently using GS Era Gold V and the GS Elevator for MC's.

I'm curious to know if either of you have heard GS products, if so how does the Pearl sound in comparison please?

 

Thanks

 

 

Edited by Allan
Link to comment
Share on other sites

  • 9 months later...


Pearl 3 Phono Build Notes

June 2024 Doc Rev 1.0d

 

The Pearl 3 is the latest phono preamplifier generously offered to Do It Yourself audio enthusiasts by Wayne Colburn of Pass Labs. This circuit was first presented at the 2023 Burning Amp Festival. The Pearl 3 phono stage is a composite amplifier featuring a low noise parallel JFET front end, driving a passive-feedback, split RIAA EQ, in the loop with a bipolar output follower stage. An optional, balanced line driver can be mounted on the board for those who wish to use balanced / XLR outputs. The circuit employs several strategies to minimize noise, such as, parallel JFETs (Q1-4), an active capacitor multiplier with low noise transistor (Q8), voltage regulation (U3-4), and connections for an external/separate raw power supply. The Pearl 3 offers flexibility in parts selection allowing builders to experiment and explore options to find their preferred sonic flavor. Builders can choose between many surface mount or socketed DIP8 op amp options. Builders can also select between several surface mount or traditional through-hole front-end JFETs options

 

The Pearl 3 has a jumper to switch between low gain (MM) and high gain (MC) settings. Default settings are: Jumper out = 2k2 (R9) 70dB total gain + 6dB on balanced out Jumper in = 220R 49dB total gain + 6dB on balanced out Those builders who use phono cartridges with “medium” gain may want to build with an alternate gain configuration

 

image.png.951980360d105eeaf5a4034116a90e2b.png

 

 

image.png.ebab0991825374eab6f381e6eaf9a1c6.png

 

Edited by Allan
  • Like 1
  • Thanks 1
Link to comment
Share on other sites

1 hour ago, andyr said:

Interesting ... no tubes?  I had thought that previous versions did use tubes - which was why I couldn't cope with the hiss level. 

 

 

to date none of the Pass Pearl's have used tubes.. they've all been SS, all Jfets.

People are commenting how quiet this V3 is

 

 

Edited by Allan
  • Like 1
Link to comment
Share on other sites



  • Recently Browsing   0 members

    • No registered users viewing this page.




×
×
  • Create New...
To Top