PROJECT IV: PART 3 / Dual DC +-15 / LibreELEC / Toroidal T.+ LM317/337
as said, burnt my Philips BDP9500-powerboard with these fabulous dual DC (+-12V) ->(see post before) but i didn´t give up 😉 and so i tried another way to get my wonderful dual DC 😉 ..
okay, as i have now only straight/normal +12V DC (via another line on the powerboard (have still of course the toroidal Dual AC (18V1 + 18V2, more later)) i thought why don´t buy a single DC to Dual DC-converter !! ? (found it by chance, didn´t knew its possible)-> 5,50€ Aliexpress-> https://de.aliexpress.com/item/32924044001.html
and so i could test-out again the “benefits” from dual DC..
okay, the dc-dc converter runs a little bit hot (had to screw the poti a little bit up (from 12V to +- 15V)(use a little 5V-fan to cool it) but again, such a nice sound/tune from dual DC (absolutely better channel separation etc., see also post before) (and now with the, for me missing, “push” from the +-15V instead of +-12V before !!) + and this time i used “LibreELEC“->https://libreelec.tv
because i´ve got the Rasberry Pi Zero 2 earlier, (and wanted to check the usability as a media-center with only 512MB Ram from the Zero 2) and voilá also a nice sound via Pi 4->Skysong XMOS-USB-bridge->I2S->ES9038Q2M; really a little bit “airier” maybe better as with “Volumio” for example (but also a little bit more “distorted”, have to evaluate it more), but absolutely nice, these better dual DC-sound 😉 ..
and because i´m an absolutely dummy/noob concerning electronical things like these whole dual AC/DC.-thing (but made these site also for people with no knowledge in these things 😉 , to learn about it) i also found out by connecting the toroidal 18V1/18V2 to a simple dual AC to dual DC-converter (see post before) that i got a massive voltage drop under load (means: set to +-15V out, dropped under load extremly about 4-5V (to 11V for example), had not such a drop with the single DC-rail/line, discussed it with some friends and yes, absolutely clear, u need some capacitor to “buffer”, like with these ->”regulated LM317 + LM337 power supply board AC-DC” with some 35V/2200uF capacitors for example ! 😉 (as said, totally clear for some electronical-hifi-freaks but not for me till this point); there are a lot of them around, also with greater capacitors, but just to learn about)..this thing cost about 9€ ->https://de.aliexpress.com/item/32570124466.html
(Voltage input-range: Dual AC28V (three lines), Voltage output-range: ±DC1. 25 V to 30 V adjustable.)
good 😉 ,
so, and now we´ve learned:
you have to use/need a regulated power-board behind some toroidal transformer !! 😉 (and some “thermistor” before, another time..)
more to come + greets for now 😉