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View Full Version : aikido octal acf powered via world audio designs psu3



smithie
02-01-2018, 19:44
hi all
i wondered if any one knows the max current a world audio designs psu3 can put out via its pre-amp output feed while still powering the wd phono 3.
im toying with trying to use it to power a aikido 6sl7 octal acf buffer that im attempting to build,i know the voltages are suitable but i got a hunch i could be dreaming regarding the current side of things:D
anyone use a wd psu3 and may have that info....

regards
paul

Primalsea
02-01-2018, 21:00
I can check when I get a chance. If I remember correctly you are supposed to change a resistor from 10k to 1k if you plan to power both the Pre3 and Phono3.

smithie
02-01-2018, 21:15
hi paul
that would be great if you can....im thinking it probably wont produce enough current for two octal valves..but im hoping:)
i did remember it being mentioned about a resistor change when both items are being used...ive got loads of notes somewhere,just cant find em:D

on another note...loving your work and experiments...keep it up:cool:
and your phono3 is boxed up just the way i was thinking of doing it....was going to go with oak and satin black top metal mesh for mine,after seeing yours.
i feel spurred on to get off me arse and do it:stalks:

Primalsea
02-01-2018, 22:29
As a rough guess the Phono 3 idles just under 5 mA and the Pre 3 just under 20mA. Heater current of both amps wil be around 1.33 amps.

I guessed the current of the 2nd stage of the Pre 3 as it was not obvious from the manual. I assumed it was about the same as the 1st stage and then rounded up thetotal for both channels to the nearest 5mA.

smithie
02-01-2018, 22:49
paul your a star,
a big thank you for that.
it might be a bit tight but i might get away with that:lol
from the spec sheet of a 6sl7 the heater draw was 0.30 ma
anyhow...whats the worse that can happen?:lol:
once again many thanks for your help

RothwellAudio
03-01-2018, 09:07
from the spec sheet of a 6sl7 the heater draw was 0.30 ma


Seems extremely unlikely - more like 300mA.
My guess is the HT won't be problem. It's the heaters that will need more than the PSU will deliver.

smithie
03-01-2018, 11:21
hi andrew
yes you are indeed right,thanks for pointing that out,trust me to pick a spec sheet with a print error:)
so with that correction sorted it looks like ill have to go with plan b or c,d,e....
i could try ac on the heater side i suppose,or maybe a smp little power supply,or maybe just look out for a complete separate ht and heater supply to go with this project,maybe valve rectified just for the hell of it and bling:)

RothwellAudio
03-01-2018, 11:43
I don't really know what an Aikido octal acf is, but you're right, you can treat the HT and the heater supplies as two entirely different power supplies and that may allow you to do something unusual. For example, a 6 volt DC smps could be a cheap and convenient option for the heaters. 6 volts is close enough to 6.3 to get away with it.

Primalsea
03-01-2018, 12:29
The PSU3 uses a LM317T to regulate the heater supply. The heater supply floats at around 40v. The LM317T has a limit of 1.5 amps.

smithie
04-01-2018, 11:57
I don't really know what an Aikido octal acf is, but you're right, you can treat the HT and the heater supplies as two entirely different power supplies and that may allow you to do something unusual. For example, a 6 volt DC smps could be a cheap and convenient option for the heaters. 6 volts is close enough to 6.3 to get away with it.

hi andrew
the aikido acf in my case is going to be used just as a valve buffer,although it can be used and modded for various over projects.
regarding trying other arrangements on the heater power arrangement,i will certainly do that,this project is more to do with having a "play" and "trying out" as i have no need for a buffer....or do i?:D
i was just hoping to get away with the wd psu3 to get me up and running quickly and at least expense...as i already have it:)

smithie
04-01-2018, 12:03
The PSU3 uses a LM317T to regulate the heater supply. The heater supply floats at around 40v. The LM317T has a limit of 1.5 amps.

paul
thanks once again for the information...i was trying to see if it was a lm317t,the way i've built and thrown my phono3 clone together makes it very hard to see,not to mention strip down and have a peak:)
i should really stick a picture up here of it...but it could be to scary for alot to view:lol::lol::lol:
i really do need to find my notes and information on this,its all here somewhere,that's the trouble with to many projects on the go:D