Vari+ PSU Setting

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oran.outan

Well-known member
Joined
May 12, 2021
Messages
100
Location
France
Hi all

During working on a custom 500 series pre, I used Volker PN48PSU I have for an other gear, which I have to say is great! and no noise at all... then I put the pre on a (old) vacant fredenstein bento2, and... it's noisy°°°
So, I'm planning to customise the bento...
Sadly, not enough room to fit volker PSU and transformer inside the case.
From few times, I have a Vari+ pcb from PCB grinder which is smaller, so time to work on but can't find much info, side to the schematic on the website.
I have to set the PSU to +15/-15/+48 but a bit confused...
Maybe @Gustav could bring me some clarification !

- the circuit is +V/-V/double on the positive rail
does that mean for get the 48v i will need a secondary 2x 24v !?

- I have to set K+ and R+ for the desired voltage.
I see some calculator on the internet but :
--> do I have to calculate a bit higher ? like it will drop a bit when in charge...
calculation say : R+ = 240 R / K+ = 2.7k ==> 15.3v
or R+ = 220 R / K+ = 2.7k = 16.5v

And 200R / 7.5k = 48.1v
what will be your opinion !

thanks for your help !
best
F
 
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