Yes, it is however possible. But be prepared to be more exposed to hum problems, because your circuit will likely get more parasitic magnetical flux losses from the transformer. You can cure this by moving / orienting the transformer in a way noise is minimized. Is distance is good enough, your circuit wil have more chances to produce quiet operation.
Best,
nAr
Gary,
This is what it looks like, and how to add in V+ and V-
There are several ground points to choose from.
If I can get this running, bout anyone can!
NOTE FOR OTHERS: The Regulator has been removed, for replacement of an off board one. This is NOT the default PEARL 2 schematic.
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it's always possible. And done all the time. As nAr said, it's just a little riskier. making a separate compartment with some shielding can help. Also, the field strength follows inverse square law (dropping off proportional to distance squared), so any extra distance you can provide inside the chassis goes a long way. If you have a big chassis this is good
If you take a bit of care in dressing/twisting wires, and chassis layout, you should not have any problems.
That said, for my current phono, and for the Pearl2 (when I get to it) I put the transformer and fuse in a small external enclosure, and just ran the low voltage AC to the preamp.
-Chris
This is always a preferred solution, even if it raises cost and complexity for supplementary I/Os. At least the phono stage can be in a closed aluminum box that is directly linked to Earth, audio ground is separated from chassis. The PSU box can be conveniently put 2 meters away the turntable and Pearl II. I push the ridiculous side to put the rectifiers and 1st pair of reservoirs near the transformer, in the PSU box, to carry only unregulated DC to the Pearl II box. As the PSU ground is also a signal ground, at this place I link audio ground to Earth via a thermistor CL60. For now it doesn't fail, ground connection but no loop. And no noise, it is totally silent !
Except for Music Today I made some internal subjective wiring tests.
For the inputs I now use 30 AWG copper silver-plated, with Kynar insulation, unshielded. It seems to suit the cartridge prolongation very nicely No noise, it is still dead silent.
For the output section, what gives best subjective result is a twist of 2 x 30 AWG Kynar insulated wires. I recall the difference between gauges :
20 AWG 0,812 mm dia. / cross section 0,5190 mm2 (standard hookup wire)
30 AWG 0,255 mm dia. / cross section 0,0503 mm2
So output section is only 0,1006 mm2.
Multistranded wire of thicker dia. proved to gave poorer results, revealing a simplified / muddied / rounded sonic result.
Best upgrade would be to use the silver ribbons. I will make them later as part of an upgrade kit
So, it leaves room for progression, still Best regards,
nAr
Completed my two Pearl 2 PCB. They worked perfectly the first time
I checked the RIAA curve accuracy, and it is almost perfect, textbook results. Great work Wayne!
And I took DC voltage measurements all around the circuit. These readings are great when you service a board. It may be usefull for some of you guys
I checked the RIAA curve accuracy, and it is almost perfect, textbook results. Great work Wayne!
And I took DC voltage measurements all around the circuit. These readings are great when you service a board. It may be usefull for some of you guys
Attachments
Completed my two Pearl 2 PCB. They worked perfectly the first time
I checked the RIAA curve accuracy, and it is almost perfect, textbook results. Great work Wayne!
And I took DC voltage measurements all around the circuit. These readings are great when you service a board. It may be usefull for some of you guys
Is there enough drop across Q3?
Mine is still working nicely and almost finished, except PSU box (grrr I hate to say it) and service led not mounted on faceplate
Actual PSU
I think the 300VA Rcore is more than enough
a Back View
From right to left : inputs, outputs, (white) ground point for turntable, and just behind is hidden the power con ( 4 pin mike robust plug with lock, carrying V+, GND, V-, Earth )
Pearl II
Enclosure is HiFi2000 Galaxy GX383 10mm silver faceplate, all aluminum, perfect dims for Pearl II boards
those chassis really are about the best value money can buy 
Best,
nAr
I'll try to measure them and report here when I get home, by the evening here ( GMT+1 )
Best,
nAr
And I took DC voltage measurements all around the circuit. These readings are great when you service a board. It may be usefull for some of you guys
Thanks very much for the measurements!
No Q3 voltage measurements yet?
Sorry, now the pre is boxed and I can't measure @ that point for now, but I think about 9V is a correct value, I think I measured it and you're about fine, this reading is different than in the AlephOno where voltage seems to be a little higher.
Sorry not to have measured again
I ended using a signal white led 3 mm plugged on the unregulated 36V or so, with a 100k series resistor, yes you read right, 100k series, and it is still bright
At night
Best,
nAr
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FWIW, i'd think twice about how these things are wound first, then forget about it.
Couple of years ago i rewound two 500VA R-cores for Bruno Putzeys ExtremA power amp design : Sheer Hell.
Rewinding smaller D/R-core transformers is less work, but just as difficult, not worth it in my book.