Film
Capacitor Universal Power Supply
The DIY HiFi Supply Universal Film Capacitor
Power Supply has been designed to offer a State
of the Art power supply for tube amplifiers
and tube preamplifiers.
Due to its compact size it can be used both
for retro-fit upgrades in many tube amplifiers
and preamplifiers as well as for new designs.
Compact 60 mm x 60 mm x 220 mm, easy to place
in chassis.
The Universal Film Capacitor Power Supply tracks
the transformer secondary voltage just like
a choke filtered/choke input supply. The “electronic
choke” circuit basically tracks the lowest
point in the rectified and first capacitor stage
filtered supply and drops another around 6V
to allow it to operate under all conditions.
Thus any losses are set to the minimum required
for the circuit to function.
The
Universal Film Capacitor Power Supply has on
board a “schottky-enhanced” solid
state rectifier bridge, or halve bridge for
use with centre tapped secondary transformers.
Additionally any form of external tube rectifier
can be used.
Of course heater windings for tube rectifier
must be present on mains transformer. Traditional
(dual anode) tube rectifiers such as 5U4 can
be used even if the mains transformer used lacks
a centre tap for the high voltage winding.
The Universal Film Capacitor Power Supply is
for use with input voltages of no greater than
380V AC for Solid State rectifiers and 420V
AC for Tube rectifiers.
On the output side the Universal Film Capacitor
Power Supply provides +B (high tension/anode
supply) and Ground, -C (negative bias/helper
voltage) and Ground.
The negative bias voltage supply can be set
from -80 volts or -140 V. (There is no need
for a separate negative voltage winding on the
power transformer).
Additionally a line for connecting to the ABS
over current sense circuit forms, if used, a
protection against of the amplifier against
faulty output valves.
There are two sets of terminals usable to add
external capacitance. One set adds capacitanace
after the rectifier, the other set adds capacitance
after the electronic choke. Maximum output current
is scalable from about 100 ma up to 300 ma depending
on additional capacitance available.
Supremely quiet power supply, output
noise should be in the 0.0x mv range.
Can be used all the way up to delicate applications
such as a phono stage (one extra RC at the output
recommended for input phono stage).
Application
notes (pdf)
Film
Capacitor Universal Power Supply.
|
| €
172.25
ex.VAT |
€
205.00
incl.VAT |
each |
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CLCLC vs FCUPS
Noise:
The FCUPS (Film Capacitor Universal Power Supply)
gives 115 to 120db of 100hz ripple rejection.
To get that with traditional CLC networks would
need a 20uf/20h/220uf/20h/220uf network.
Performance:
Of course all that CLCLC capacitance is going
to make for a very slow and soggy sound since
it is inductance that gives speed and attack.
The above supply only has 40h - practical limit
for size that would fit into an already huge
and heavy chassis.
The FCUPS? Equivalent 500H ! with a 60 x 60
220mm footprint. And sound that has attack,
transparency and bass that goes WAAAAY down
low.
Features:
On board negative bias voltage supply. Configurable
-80 or -140v.
Flexibility:
Ever wonder about those low DCR or battery supplies?
Easy. One jumper switches between virtual battery
or virtual choke. Now you can be your own judge.
virtual battery:
output impedance is 10 ohm at low frequencies
and falls with the 20uF capacitors impedance
above around 1KHz. It certainly qualifies as
“low DCR”, the “virtual”
capacitor on the output of the circuit behaves
like a 820uF capacitor, film at that!
virtual choke:
the output impedance is several dozen KOhm down
to very low frequencies, just as if a giant
choke was used. In this mode an extra external
capacitor must be used, as the only capacitance
on the side feeding the amplifier is the 20uF
on the board. Add a pair of 47uF Film Caps and
your PSU will be fine for most cases.
Another little detail -- the
rectifier.
FCUPS: on board Schottky diode bridge. Of course
the bridge can be bypassed and a tube rectifier
used.
Portability:
CLCLC: major 5 to 10kg adder to amplifier weight
and don't even think about trying it in different
applications.
FCUPS? 350gr. Easy to remove and install as
all screw connectors.
Adrenaline For Your Power
Supply
power supply: we know that fast recovery and energy
storage are prime ingredients for a good sounding
power supply; unfortunately the two qualities
seem to be mutually exclusive. Add tons of capacitance
and you get energy storage BUT very slow recovery
and sluggish sound. If we go with small film caps
we get very fast recovery but with just a few
successive transients and we quickly run out of
steam . Depending on priorities different paths
are taken. In Asia it is very common to see power
supplies with 10 micro farad film capacitors in
the pi filter with their characteristic sound.
in the West is common to see huge electrolytics
or banks of oil caps, 200+ micro farad per leg.
One
way to enjoin these two qualities is to use
an electronic choke. This, along with a few
other tricks, is what we have in the FCUPS (film
capacitor universal power supply). The last
capacitor is 10uf film and has the the speed
and clarity of the fastest power suppliers.
Between we have a solid-state choke with equivalent
of 500H of inductance! Maximum input voltage
is about 380 V directly on the Schottky diode
bridge or 420 volts if from a tube rectifier.
We
may have heard power supplies with huge amounts
of capacitance but very unlikely we've ever
heard a power supply with 500 H inductance because
the choke would be absolutely huge! what would
such a thing sound like?
We
have installed two of the FCUPS into our resident
Ella. I must say I am surprised and impressed.
It's like hooking Ella up to an adrenaline drip--
everything is bigger bolder more dynamic, and
because of the added quiet more low-level detail
is resolved. It's been running in the past week
and the initial edge that all film capacitor
power supplies have at the beginning is starting
to recede; we are hearing more bloom and swell
around transients. I'm just using the little
5 inch Feastrex field coil drivers which are
impressive in their own right, but now they
sound unbelievable for their size.
it's
also nice to have a pure ripple-free DC bias
supply generated onboard the FCUPS. this powers
the ABS and also interfaces with the "protect"
feature so that if current should start to run
away the B+ rail will be shut down stone cold
dead.
I
also now have two empty slots for a couple of
47 micro farad film capacitors which can be
used to replace the last remaining electrolytics
and then we will be living in a truly electrolytic-free
zone.
Regards
Brian
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