Some pictures. The power supply is dual-mono with 50VA trafo and 2x15KuF for each channel (I know, way overbuilt).
I did not use bridge rectifier to ground the power supply, just connect earth to PS chassis, and PS ground floating to Pearl chassis.
I did not use bridge rectifier to ground the power supply, just connect earth to PS chassis, and PS ground floating to Pearl chassis.
Attachments
My DIY setup is like this -
TT (Technics SL-1200MKII)->Pearl 2->[Pass B1->LDR based Volume Control->PassB1]->Pass F5 turbo V2 -> GR Research Lab DIY Bookshelf speakers
Tested while ears are close it speaker, full volume, stylus rested on record surface and no record playing. My Pearl 2 has absolutely no Hum (very faint hiss) till I power ON TT. As soon as I power ON TT I can hear barely audible hum as same conditions.
About TT->Phono cables I use 1 meter piece of Amazon Audio cable "AmazonBasics 6 feet 3RCA Component Video Cable". Also my all interconnects are Audioquest cables which shielded ground at source end.
TT (Technics SL-1200MKII)->Pearl 2->[Pass B1->LDR based Volume Control->PassB1]->Pass F5 turbo V2 -> GR Research Lab DIY Bookshelf speakers
Tested while ears are close it speaker, full volume, stylus rested on record surface and no record playing. My Pearl 2 has absolutely no Hum (very faint hiss) till I power ON TT. As soon as I power ON TT I can hear barely audible hum as same conditions.
About TT->Phono cables I use 1 meter piece of Amazon Audio cable "AmazonBasics 6 feet 3RCA Component Video Cable". Also my all interconnects are Audioquest cables which shielded ground at source end.
Nice looking setup! I really like the DIP females on the loading pads. Great idea!
First - get the Pearl 3 feet away from any transformer. Next, put the lids on.
If you short your inputs you should have no hum. There is a bit of hiss (actually popcorn noise) from the front-end Jfets if you really crank everything up. I need to listen with headphones, with everything turned all the way up to hear that.
There are lots of places for hum to sneak into a turntable rig. If your Pearl is grounded properly, it shouldn't be the culprit.
First - get the Pearl 3 feet away from any transformer. Next, put the lids on.
If you short your inputs you should have no hum. There is a bit of hiss (actually popcorn noise) from the front-end Jfets if you really crank everything up. I need to listen with headphones, with everything turned all the way up to hear that.
There are lots of places for hum to sneak into a turntable rig. If your Pearl is grounded properly, it shouldn't be the culprit.
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6L6 - The DIP sockets were your suggestion 
My current setup:
VPI Traveler - Pearl2 - Conrad Johnson PV10 - Aleph2 clone - B&W 805.
Digital source: M-audio Audiophile 192 and Opus DAC.
I have just added DPDT (on-off-on) switch for each PCB with resistors wired parallel to R14 and R16. Now I can select either 45dB, 55dB, or 65dB gain.
45dB sounds just the right gain for my Ortofon 2M Blue.
The VPI/Pearl combo easily blows my digital setup out of the water, even with 24/96 files. Certainly more than worth the $$$ and effort. Wondering what kind of branded phono stage at what price point would be comparable to the Pearl 2.
Now I can move on with my Mesmerize project
Thank you Papa and Wayne for the wonderful projects!
My current setup:
VPI Traveler - Pearl2 - Conrad Johnson PV10 - Aleph2 clone - B&W 805.
Digital source: M-audio Audiophile 192 and Opus DAC.
I have just added DPDT (on-off-on) switch for each PCB with resistors wired parallel to R14 and R16. Now I can select either 45dB, 55dB, or 65dB gain.
45dB sounds just the right gain for my Ortofon 2M Blue.
The VPI/Pearl combo easily blows my digital setup out of the water, even with 24/96 files. Certainly more than worth the $$$ and effort. Wondering what kind of branded phono stage at what price point would be comparable to the Pearl 2.
Now I can move on with my Mesmerize project
Thank you Papa and Wayne for the wonderful projects!
Attachments
6L6 - The DIP sockets were your suggestion
It was? Ha! Even then, it's pretty cool...
Again, very nice. (That wasn't my idea, was it?)
Duh.
The Pearls are seriously good. You are now part of a very exclusive club.
I still think mine is noisier than other people's builds. With the volume turned up, I have no difficulty hearing hiss. With the volume WAY up, I can even hear it from my listerning position 2.5m away. Then again, when playing music with the volume in this position, it would produce earshattering levels. It is a bit noisier than the built in phono in my amp, but this can only be heard with my ears next t the speaker. No hum in my build.
Edit: all with inputs not shorted. Never tried that.
6L6 - The DIP sockets were your suggestion
My current setup:
I have just added DPDT (on-off-on) switch for each PCB with resistors wired parallel to R14 and R16. Now I can select either 45dB, 55dB, or 65dB gain.
45dB sounds just the right gain for my Ortofon 2M Blue.
How much difference in noise can you hear between the 3 gain settings? (No music, ear next to speaker)
Still not convinced that there really is a problem. Line inputs are dead quiet (but also a bit audible hiss if you turn the volume way up). Phono adds 57dB (my Pearl) or around 60dB (built in phono) gain, so no wonder there is more audible hiss. Built in phono also hisses more than line inputs. It is only that my Pearl hisses a bit more than the built in phono stage (which by the way has very good noise specs) and other people seem to describe their Pearl as dead quiet.
From your description, it sounds like my build is as "noisy" as yours. I have both hiss and a very faint hum - my tube preamp probably contributed to the hiss, too. But most important, it is not noticeable when playing music. I think in this case time is better spent listening to records than hunting for hum.
I haven't compared the noise between the lowest and highest gain settings since I installed the switch - I will probably try this tomorrow.
Aha - hum gone (well, almost)!
I found that if I plugged all my hifi gears into the same power strip, the Pearl two is a lot quieter. Still have very tiny amount of hum/hiss at full volume, but now it is super-duper quiet at listening level.
The hum/hiss goes louder at higher gain (65dB) as expected.
Previously, my power amp went into a different power outlet.
I found that if I plugged all my hifi gears into the same power strip, the Pearl two is a lot quieter. Still have very tiny amount of hum/hiss at full volume, but now it is super-duper quiet at listening level.
The hum/hiss goes louder at higher gain (65dB) as expected.
Previously, my power amp went into a different power outlet.
I'd stick a transformer at the input of the amp, myself, but then I am a fan of transformers.
Hello guys,
here is my try at Pearl 2.
External unregulated PS and two Salas shunt regulators (half Mezmerize boards), one per channel.
The boxes come from HiFi2000 (Modushop). R-Core transformer from Selectronic. Most part of components are from
Mouser, but for the additional jfets that come from an Israeli ebayer. Shunt heatsinks from a surplus fair.
RCA sockets from hificollective.
Everything measures fine, close to Wayne's values. Offset is stable and close to zero mV.
Only noticeable difference are the Q3 tensions:
Vb=8.12V, Vc=7,58V, Ve=7.54V (the other channel is close).
So Vb is greater than Vc. Should I tweak anything?
I made a fast listening test with a very old TT and a Stanton 681 EEE cart. It's a MM with 2.5mV output, not an ideal source for the Pearl2.
There is no hiss, only a moderate buzz at high volume. Still have to work on this.
The sound, with this far than ideal set, is full, vivid, with wide image and great realism.
It lacks openness at high frequencies, but I plan to hook the Pearl to my friend's super TT set, and see how it compares to his megabucks phono preamp.
I will report the forum about the showdown verdicts
Thanks a lot to Wayne and Salas for sharing the projects, and to the forumers for a lot of useful hints. The 6L6's building thread, as usual, was of great help.
Ciao. Carlo.
here is my try at Pearl 2.
External unregulated PS and two Salas shunt regulators (half Mezmerize boards), one per channel.
The boxes come from HiFi2000 (Modushop). R-Core transformer from Selectronic. Most part of components are from
Mouser, but for the additional jfets that come from an Israeli ebayer. Shunt heatsinks from a surplus fair.
RCA sockets from hificollective.
Everything measures fine, close to Wayne's values. Offset is stable and close to zero mV.
Only noticeable difference are the Q3 tensions:
Vb=8.12V, Vc=7,58V, Ve=7.54V (the other channel is close).
So Vb is greater than Vc. Should I tweak anything?
I made a fast listening test with a very old TT and a Stanton 681 EEE cart. It's a MM with 2.5mV output, not an ideal source for the Pearl2.
There is no hiss, only a moderate buzz at high volume. Still have to work on this.
The sound, with this far than ideal set, is full, vivid, with wide image and great realism.
It lacks openness at high frequencies, but I plan to hook the Pearl to my friend's super TT set, and see how it compares to his megabucks phono preamp.
I will report the forum about the showdown verdicts
Thanks a lot to Wayne and Salas for sharing the projects, and to the forumers for a lot of useful hints. The 6L6's building thread, as usual, was of great help.
Ciao. Carlo.
Attachments
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