power supply for a beresford dac

cressy · Post by **cressy** » Wed Jan 04, 2012 11:43 pm

just musing with regards to the power supply in the squeezebox power supply thread, and seeing on fleaby that there seem to be plenty of expensive psu's for beresfords, i assume a variation on the one mi old man did for the sb could be done for the beresford im using with the apple tv?

im musing because this beresford has the passive mod done, and as it reduced the gain and im currently driving long cables, i was using the variable output. switching to the modded output the quality has taken a leap forward.

having heard mi old mans sb with the old psu (incedentally exactly the same variable output maplins switcher im using with the beresford) and with the new ugly-but-so-much-better psu i wondered if this was the first step towards better better better digital for me.

have any other beresford users on here tried any psu upgrades? googling seems to provide mixed views. id rather hear someones views whom i know tbh...........

Neal · Post by **Neal** » Thu Jan 05, 2012 7:38 am

I tried linear supplies on my Caimen but found the best improvement was to replace the 2 internal regs with something better and continue to use Stan's upgraded external SMPS. The linear supply on its own made little difference to my ears over the SMPS.

I made up these regulators with a cap multiplier (gyro) on the front end which seemed to work well, space is tight as you can see above...

Andrew · Post by **Andrew** » Thu Jan 05, 2012 9:01 am

Nice job there Neal, a VBE/gyro is a nice way to reduce the noise.

Ant, you only really get 60-sh db from a 3 legged reg so a second layer of filtering is often useful.

Andrew

cressy · Post by **cressy** » Thu Jan 05, 2012 2:13 pm

cheers neal i'll look into that option

Max N · Post by **Max N** » Thu Jan 05, 2012 3:04 pm

Ant, there are pre-built regulator replacements as well if you want to go that route:
http://www.hificollective.co.uk/compone ... d_reg.html

http://www.hificollective.co.uk/compone ... shunt.html

little eddy · Post by **little eddy** » Thu Jan 05, 2012 8:56 pm

Neal wrote:... but found the best improvement was to replace the 2 internal regs

Do you have a schematic of your improved 'gyro' regulators?

bostod · Post by **bostod** » Thu Jan 26, 2012 12:16 pm

After some research the i found the value for the regs 12v reg and 5v reg.
Can anyone explain what the 12v and 5v feed.
At the moment i have bought a class d 12v voltage regulator. i will replace this today and feedback my results.
What effect will the the 5v reg change bring?
there is a niggle in the back of my head that changing both regs are not necessary with the Gator "direct out" board as it bypassess the op amp stage.
can anyone clarify this

bostod · Post by **bostod** » Fri Jan 27, 2012 1:59 pm

deleted

Mike H · Post by **Mike H** » Sat Jan 28, 2012 2:53 pm

Just to be pendantic, a 'gyro' (gyrator) is a thing that simulates the behaviour of an inductor (so you don't have to use a real inductor, especially for large values).

If you had made a real gyro you'd have something whose impedance is frequency dependent, but which I don't think you have, it's a capacitor multiplier.

I only mention it 'cause of seeing frequent mentions of 'gyros' around here lately, but they're not true gyros, so far as I can tell.

<end of mini-rant>

I'll get my coat

pre65 · Post by **pre65** » Sat Jan 28, 2012 2:59 pm

I'll be gyrating tonight at the bike club dinner.

colin.hepburn · Post by **colin.hepburn** » Sat Jan 28, 2012 5:01 pm

This link maybe of help to diy voltage regulators
For CD supplys look in diy projects near bottom of page 317/337 regs
http://www.raylectronics.nl/index_en.html

Ali Tait · Post by **Ali Tait** » Sat Jan 28, 2012 5:02 pm

pre65 wrote:I'll be gyrating tonight at the bike club dinner.

Mind your back!!

Dave the bass · Post by **Dave the bass** » Sat Jan 28, 2012 9:59 pm

Ali Tait wrote:
pre65 wrote:I'll be gyrating tonight at the bike club dinner.
Mind your back!!

Our-Phil + half pint of Shandy Bass =

DTB

Mike H · Post by **Mike H** » Tue Jan 31, 2012 3:23 pm

Dave the bass wrote:

Our-Phil + half pint of Shandy Bass =

DTB

Dave the bass · Post by **Dave the bass** » Tue Jan 31, 2012 3:33 pm

Mike H wrote:
Dave the bass wrote:

Our-Phil + half pint of Shandy Bass =

DTB

Was this.

DTB

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power supply for a beresford dac

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