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Advice for Lehman power supply upgrade… or not

G

greggor

New Member
So I have an original Lehmann Black Cube (from early 2,000’s) with standard wall wart peer supply. I have 2 Rega TT’s, an older 3 with Goldring 1042 MM & new P6 with an Ania MC. The P3 w1042 plays quiet but I’m getting a 60 hz hum through the P6 Ania (yes I am adjusting the dips for MC). I suspect this is due to the Lehmann standard power supply. Upgrading to the better Lehmann Pwx will cost me $400 (new). Since there is no returns allowed I’m on the fence. Would I be better served looking at a better Phono stage or will I not find a better phono stage for less than about $600?
 
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I'd deem 400 bucks for an upgrade power supply too much, if returns aren't allowed and you can't be sure, that it'll definitely solve your problem. I wouldn't risk that.

Greetings from Munich!

Manfred / lini
 
greggor said:
So I have an original Lehmann Black Cube (from early 2,000’s) with standard wall wart peer supply. I have 2 Rega TT’s, an older 3 with Goldring 1042 MM & new P6 with an Ania MC. The P3 w1042 plays quiet but I’m getting a 60 hz hum through the P6 Ania (yes I am adjusting the dips for MC). I suspect this is due to the Lehmann standard power supply. Upgrading to the better Lehmann Pwx will cost me $400 (new). Since there is no returns allowed I’m on the fence. Would I be better served looking at a better Phono stage or will I not find a better phono stage for less than about $600?
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Rega connects the ground cable through the interconnect cable, some phonostages will not like that, and with low output of Ania it will be more noticable. I don't doubt upgraded power supply will improve sound, just check beforehand will it eliminate hum, if you can't return it.
 
CrSens said:
Rega connects the ground cable through the interconnect cable, some phonostages will not like that, and with low output of Ania it will be more noticable. I don't doubt upgraded power supply will improve sound, just check beforehand will it eliminate hum, if you can't return it.
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Yes I’ve tried alternate grounding techniques and none have worked, also tried sound conditioning power strips. But can’t eliminate this hum which makes me believe it’s coming from the Lehmann power supply. So I my question is ultimately can anyone recommend a great phono stage in the $600 USD range. Or would you drop $400 on the PS?
 
unplug the power supply and see if it goes away. That would at least be a clue as to whether its related or not. If no change in the hum, a new power supply isn't going to do it for you
 
To me if the table with the 1042 on it does not hum on the Lehmann then it is not the power supply. Sounds like a ground issue between phono stage and tone arm wiring. I would be tempted to turn everything on and run a ground wire from a cartridge pin to the phono stage and see if the hum changes.

If I were shopping for a new phono stage I would consider the Darlington or the new SOTA. If I were opportunistic and could find a Dynavector P75 on the used market that would probably be one I woud seriously consider.
 
greggor said:
Yes I’ve tried alternate grounding techniques and none have worked, also tried sound conditioning power strips. But can’t eliminate this hum which makes me believe it’s coming from the Lehmann power supply. So I my question is ultimately can anyone recommend a great phono stage in the $600 USD range. Or would you drop $400 on the PS?
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Maybe you can test by putting the Lehmann in MC mode and connecting P3 and Goldring to it, but without playing music, just listen if the hum appears when in high gain. Did you try reversing the wall wart plug polarity to mains (rotate plug 180 degrees, if possible, or use adapter to eliminate ground pin, if Lehmann has it).
 
I had a Grado phono stage that hummed while in it's "normal" orientation (feet on ground).
When I put it on its side, the hum disappeared.

Edit:
How are the signal wires (L/R) run relative to any AC power lines?
They should never be running parallel to each other, any crossing should be at 90° (ideally).

Likewise with the Lehman's supply from wall wart to the cube. No power cables should run parallel with signal cables, especially if the wall wart is stepping mains AC down to a lower voltage AC.

What I don't know is if the wall wart steps AC down to reduced AC (120VAC:20VAC), if it steps AC down to DC (120VAC:16VDC) or if it steps AC down to dual rail DC (120,VAC: +16VDC/-16VDV). Since the problem doesn't occur with all turntable, my gut tells me the power supply is not likely the (entire) problem. This might be something cheap and simple.
 
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What is the voltage out of the power supply. There are lots of CHEAPER & most likely better options than spending $400.

Cheers
 
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