Building a Pearl 2

Member
Joined 2019
Paid Member
Just finished soldering, testing, and hooking the Pearl 2 into my system. So far I’m really liking the sound. Not sure about him or noise since the kids jump house was on and drowned out some of the sound. I’ll report back on that later. Right now it feels good to have this build in the books. Thanks to everyone and to itsikhefez for the great layout inspiration on the back panel.

Good looking build!
 
Thanks itsikhefez an codyt! I was just listening to some Junior Mance Live at the Village Vangaurd. Great sound! Imaging and detail is the best I've heard with my vinyl yet.

If anyone's curious my setup is: Yamamha P-550 TT with an LPGear Vessel A3SV cart, through the Pearl 2, to WHAMMY preamp, to F7 clone, to Lii Audio Crystal 10's on open baffle with GRS-15PF-8's for bass support.
 
Thanks 6L6! And thanks for your help from the build guide and comments on getting my power supply moving along. When this whole COVID thing has settled you’re more than welcome to come over and have a listen. :D

I was concerned that I would pick up some hum with the short umbilical and the cases on top of each other but so far, nothing. At normal listening volume this setup is silent in my listening chair. That said, I will make a longer umbilical one of these days. ;)
 
I’ve been involved with the Pearl 2 since 2011, and finished my first build in 2013. This was a version on perfboard. Since then I have done many tweaks to the PSU, voltage regulators, RIAA section and loading options. In 2019 I finally decided to do a rebuild on the official boards. I had held this off for a long time due to cost (almost 300 euro for the boards including shipping and taxes). Hiss was slightly less in this build (small point of criticism on my perfboard version). Recently I did a small modification which will probably be the last (never say never :) ). I changed the values of the RIAA correction back to stock. I always had the impression that the modified RIAA values made it sound a bit too lean in my system. I prefer a slightly fuller sound, so I went back to the original values. The difference should be pretty small and I can’t a-b the two, so I might just be fooling myself :) I also added the capacitor to R14 to stabilize DC offset (which indeed is now 0.000V). See pictures below of how it looks now.


PSU is pretty standard. 2x22V Amplimo transformer 50VA with CRCRC. Rectifier diodes are Power Integrations LQA (fast/soft). The Pearl itself is set for about 57.5 dB gain, this works great with my cartridge (Benz Wood SL). 10k uF caps in the amp are Mundorfs, voltage regulators are Sigma 78 and 79 from AMB audio (soldering smd resistors is a real pain in the a**).


Oh, and just in case you wonder: I enjoyed listening to it in every incarnation. The Pearl will see use for many years to come! I will keep reading this thread, hopefully it will not infect me with the tweaking-bug again ;-)


PSU outside:
PSU_outside.jpg


PSU inside:
PSU_inside.jpg


Amp outside:
Amp_outside.jpg


Amp inside:
Amp_inside.jpg
 

Attachments

  • PSU_outside.jpg
    PSU_outside.jpg
    170.7 KB · Views: 416
  • PSU_inside.jpg
    PSU_inside.jpg
    333.1 KB · Views: 405
  • Amp_outside.jpg
    Amp_outside.jpg
    172.9 KB · Views: 425
  • Amp_inside.jpg
    Amp_inside.jpg
    354.3 KB · Views: 414
@Wellerman, how are you switching power for the PS? I can't quite make out what's going on with that small perf board or the wiring at the switch.


Wiring is hidden away a bit in the left side panel. You can see the blue and brown wire that come out of the mains filter/IEC inlet appear again at the front panel going to the power switch. From the switch a blue and black wire go to the small perfboard. On the small board are a fuse, 2 NTC's in series for inrush current limiting and a small 0.0033 line rated capacitor. After that, white wires go to the transformer.
 
I have Pearl I boards old enough that the instructions to connect the power supply ground to the signal ground were on an instruction sheet tucked in with the boards, not on the actual silkscreen. In my confinement I decided to (finally) build it and have almost got everything I need to stuff the boards and complete the power supply.

The thing is, once it's done I'd love to be able to lug it over to a friend's place and have him try it out in his system. If there's any chance of it blowing up anything just because he didn't follow procedure then all bets are off.

KatieandDad's diode clamp seems like essential equipment on a unit that might "make the rounds". Are there any other "necessary frills" I should be contemplating?
 
I had a problem that my Pearl 2 destroyed the power amp due to its nature of driving the output to Vcc when powered up.

This is a known issue with the Pearl 2 and can be corrected with either a diode clamp or delay relay on the output.

It isn't an issue here. I powered up my power amp a few minutes after powering Pearl II.

Looks like I'll have to check everything from the start.