Hi everybody,
I have been playing around with various power supplies for my SBT in
recent weeks, and thought I'd share my experiences here.
(My setup is a pretty revealing one, bordering on the analytical, but
still musical enough: SBT fed via Ethernet from a WLAN bridge. All
"Soundcheck" mods applied with the exception of the Vol100 mod which I
find too harsh. SBT digital-out into an rDAC, into a Krell 300 iL
(modded with better caps), into NHT speakers (modded with Bybees and
better internal cables). Power-wise, the digital stage is fed from a PS
Audio P300 power supply, and the amp is on a massive industrial
isolation transformer. Cabling by Elrod, Rosinante Pursang, Harmonic
Technology and DIY)
A few of my experiences in no particular order:
* Actually, I could live okay with just the SBT stock power supply
plugged into my P300 power conditioner. Treble is okay though wooly,
mids are okay, just the bass is not all that extended. Overall, the
presentation is somewhat unfocused and muddled when compared to a
high-end CD player. Not sure whether this is due to the DC power that
goes into the SBT, or whether the SBT stock supply simply contaminates
power for everybody else, i.e. my rDAC.
* Yes, the SBooster added to the stock power supply makes a huge
difference. Bass is extended, treble is neater and a little more
pronounced (not always a good thing), dynamics are improved. I perceive
mid-range as a little harsher than before ... this is something I have
observed with network filters before. Still, on balance, this was a
no-brainer improvement in my system.
* I then tried the linear power supply that you can order together with
the SBooster ("Best of Two Worlds" PSU for 140 Euros). I must say that I
had an initial crush on this setup ... the combo sounded clearer and
more transparent than anything I had listened to before. After a while,
though, listening became fatiguing. In my setup, the whole frequency
spectrum is tilted towards treble. Break-in did not improve things. A
number of recordings sounded harsh no matter what I did. Lower midrange
was just a tiny bit washed-out.
* The linear power supply operated without the SBooster is clearly even
worse; no sense losing time on this setup.
* The solution I now have is superior to all of those above. I bought
an extremely high-quality, medical-grade switching (!) 5V, 2A power
supply from an electronics store (around 55 or 60 Euros), and plugged
the SBooster into it. This is a very quiet supply. Now everything is
extraordinarily well balanced. Strong bass but not overbearing and
well-controlled, dynamic and liquid midrange, all the detail is there
(and I am a sucker for detail!), spatial imaging with a "Wow"-effect.
Nobody seems to hiss or spit into microphones anymore.
* I tried this same setup, but without the SBooster: Still good, but
not as good. Not all that extended, a bit woolier. On the plus side,
things are a little more liquid = a little less edgy (I am talking
relatives here, both setups are pretty good actually).
* Let's take one step back: At first, things had not sounded all that
great in the 50-Euros-switcher-setup. Treble was not well resolved, and
bass was too heavy and out of proportion. What helped?
a) A better power cord for the switching power supply. I first tried an
exotic super-high-price powercord by Elrod, and yes, that one worked out
rather okay. Dear Trolls: This was just an experiment for baselining!
One does not plug a 1600 Euro powercord into a 60 Euro power supply
into a 200 Euro streamer and leaves it at that. What got surprisingly
close to this setup was a 1m piece of my old stock Krell amp cord, with
high-quality Kimber plugs on both ends, the shielding connected to
ground at the source end only (!), and all the contacts shrubbed really
well. The Elrod cord is still better (more liquid, better dynamics), but
hey.
b) A replacement for the power cable on the DC side proved essential.
The 50-Euro-switcher came with an un-shielded, un-twisted braided
copper run on the DC side, which I swapped for a shielded cable nicked
from an old Toshiba Laptop computer PSU. Around this, another run of
Aluminium foil, surrounded by copper wire, grounded at the source end.
Looks horrible, sounds fantastic.
c) Scanning the room for misbehaving power supplies was important, too.
My system only started to behave REALLY well after I switched off the
Television and DVD player (doh!), and after I replaced the power supply
for my WLAN Adapter (remember, I run a WLAN bridge into the SBT via
Ethernet) with another high-quality switcher (60 Euros). I may also be
the only madman in this group who operates a WLAN adapter on Bybee
filters on both AC power lines ... sorry about this one, but they just
cleaned up things a little more. Whatever these Bybee filters do (on a
good day, I still think they are just resistors in a voodoo shell),
they seem to isolate the WLAN power supply a little more from the rest
of my system, so they do not pollute power lines or the ground all that
much. Some of you will will say that a simple network filter does more
of the same thing, but I disagree, I am trying to avoid network filters
on my lines as they reduce dynamics. Others will say that if you have
Bybees lying around in the first place, you might apply them to the SBT
power supply for greater effect, and I tried. Sounds horrible. I'll
spare you the details.
d) Oh, and I made sure that there was only one ground running into all
of this. This ground is also connected to a water pipe that goes REALLY
deep into the ground.
* I am going to baseline this whole setup against a Teddy Pardo PSU in
the coming days. A package is on its way. I was so overwhelmed with the
quality of that (at 320 Euros rather costly) supply on my rDAC, that I
just had to try. I might also try to plug another SBooster into the
Teddy Pardo PSU for the rDAC ... I'll keep you posted.
Have fun. I realize that parts of this post are highly trollable, and I
do not have time to answer to everything. Just sharing. Try it out by
yourselves,
Thomas
--
Tom186
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