Some of yet realized models of the HIFI & ART
All models are originals. The copies are not made.
The amplifiers use electric circuits of the same type as for example the Mark Levinson No.38
and volume regulators potentiometers ALPS.
The construction is made of profiles of the American firm Nielsen. The surface of these profiles is
formed with gold, black or titanium cut frozen elox with an extra hardness and a resistance to a
mechanical damage.
Used filter capacitors are of a very good quality (usually the Computer Grade) and their capacities are
from 27,000 μF to 1,000,000 μF.
They are usually equipped with a fully automatic input switch which does not contain any
unlinear or mechanical switches, analog multiplexers or relays. As a matter of fact it is a part of a
professional mix board. It automatically choses as active the signal source which is plugged in.
This solution was chosen because practically every first-rate signal source as a CD player, a tuner, a
satellite receiver etc. is operated by remote control. Because of the inner construction of all first-rate
signal sources, the output of an unplugged signal source is automatically either directly earthed
with a contact or a relay (like more "better" CD and DVD players work) or connected with the
earth through low impedance.
Some more information are on the following address
E-mail: Petrik@KOF.ZCU.CZ
www.gmx.cz, CZ High End, prezentace výrobců, Czech(&Slovak] made II, HI FI & ART
www.gmx.cz, recenze, HIFI&ART Machine No3
www.gmx.cz, Teorie & Praxe, Teorie zesilovačů třídy A (theory of amplifiers class A)
Gold Black Dream
This amplifier works in the pure Class A with the
output power 2 x 30 W / 8 Ω (2 x 56 W / 4 Ω).
The central part contains a mechanically and
electrically detached source part with a switch, which
is operated by a key, optically avowed feeding 2 x
250 VA transformers and effacing 2 x 1,000,000 μF
capacitors. The resource part is energetically
exacting and susceptible to a radiation of
disturbing magnetic fields. Although any relays for
a delayed connection of systems of loudspeakers
are
not used, there is not audible any disturbing noise
when the amplifier is plugged and unplugged. This
quality is a part of a perfect function of the amplifier.
The achievement of such a good quality is not quite
easy because the monstrous condensers cause a
"bursting" of a great charging current. Everyone can
use a delaying relay. Above described way to a perfection is more difficult and a lot of experience in
constucting and work with circuits is necessary. Output power circuits are located in the refrigerators
by the sides of the amplifier.
The bottom part of the amplifier consists of two visible filter 10,000 μF capacitors (for a feeding of
voltage circuits), stabilizers on optically avowed refrigerators, excellent gilt input clamps with a Teflon
insulation, electric circuits of a voltage elaboration of the signal which are of the same type as the
directive amplifier Mark Levinson No.38, and a volume regulator potentiometer ALPS.
The framework is made of profiles of the American firm Nielsen with a surface formed with gold
cut frozen elox with an extra hardness and a resistance to a mechanical damageThis amplifier
maybe the first on earth which use effacing capacitors with a total capacity 2,000,000 μF for its
function in the Class A.
Every part of this amplifier (and of the other models) is perfectly functional, nothing is only decorative.
All constructional elements of a perfect design and function need not be covered with any further
chest.
Because of electrical qualities of the used effacing capacitors it was necessary to adapt the electronic
circuits, i.e. to use a bridge arrangement. This arrangement not only doubled the number of active and
passive components but also improved the electrical qualities of the amplifier (smaller harmonic
distortion) and the dynamic qualities.
RAMESSE
The model Ramsess is for customers with the highest demands. The model is on the picture. Its
proportions ( 65 x 45 x 45 cm ) and its weight (80kg) imply that the electrical parameters are not
insignificant.
The presupposed output power in the pure Class
A will be around 2 x 60 W, his output power with a
continuous transititon to the Class AB will be more
as 2 x 150 W.
A feeding toroidal 1,000 VA transformer is placed
separately at the bottom of the middle part and is
even covered with a circular cast with ventilating
openings because of disturbing fields which are
caused by the big quiescent current even in a state
without the signal. All the middle bottom part
contains every output power and non-output power
feeding sources. The feeding voltage for circuits of a
voltage adjustment of the signal, which are placed
in the upper opticaly and constructively separated
part, is led by a tube in the middle.
Silver Monster 1
On above-mentioned picture is again one of "big"
amplifier working into achievement 2 x 50 W / / 8 Ω in
class A and into achievement 2 x 120 W in class
AB.
It is made in DUAL-MONO and again thoroughly
symmetrical wiring. The incoming unsymmetric signal
is translated on symmetrical signal and in this forms
is processed on output.
Power supply contains two 450VA toroidal
transformators,
exterminatory
capacity
of
achievement parts is 264 000 µF.
Amplifer has 16 output power transistor , loudness
regulator is controller with "cosmic" resistors Vishay.
Binding posts WBT illustrate uncompromise
constructional resolution.
Construction from 10 mm strong brushed Al
warrants resistance against mechanical negative
influence and helps to steady heat removal.
Quiescent power drain 320W without signal is
the same how in Model ACCUPHASE A50.
On picture S_Monster1a is a look inside
amplifier,where voltage, output power and supply
parts are separated.
HI FI MACHINE No 3
Amplifier HI-FI MACHINE No 3 works in pure class A, output power is 2 x 40 W / 4Ω.
Actually it is an amplifier of the output power
2 x 200 W but it works in a special regime.
The reqiured value of the quiescent
current for the input output power 40W/4ohms
in the pure Class A is
1 40
Ib  
 2  2, 24 A .
2
4
If we chose a value of 2.5A for a channel, the
value of the quiescent current for both
channels is 5A and there is necessary to
divert a losing output power higher than
300W from the amplifier in a state without the
signal.
The adjusted value of the bias current 5A is
permanently controlled by two amperemeters
placed on the top part of the effacing
capacitors of the total capacity 200,000 μF.
HIFI FACTORY
This three-channel amplifier really remids of a
factory producing HI-FI tones of a high quality.
It contains two Class A amplifiers with the output
power 15W which waken ( excite) satellite systems
of loudspeakers with a characteristic sensitivity
93dB/1W/1m and a 200W amplifier for a subwoofer.
The character of the amplifier is emphasised even
optically, both Class A satellite amplifiers are placed
on the both sides of the model, a conventional Class
AB amplifier for a bass loudspeaker is in the middle
part.
Gold Black Monster
The amplifier Gold Black Monster of an
incomprehensible design works in the pure Class A
again, the output power is 2 x 40 W / 4 Ω.
Monster uses two capacitors 100 000 μF, two
separate transformers 2 x 250 VA, biwiring interface
of loudspeakers thorough high quality terminals like
for example GRYPHON amplifers. Switch is key
again, because the circuit breaker is better placed.
Volume regulator is ALPS.
HIFI ENGINE
The smallest Class A amplifier has only the output
power 2 x 7 W and it remains of an engine, which
propels the systems of
loudspeakers, with
characteristic sensitivity almost 100dB/1W/1m,
set with the profesional Electro Voice loudspeakers.
It is able to sound reliably a living room of 50m 2.
Gold Cylinder
The amplifer has output power 2 x 40 W / 4 Ω and
works as DUAL-MONO in pure class A.
Contains two classical transformers 250 VA
It is designed in beatiful harmony of like two round
panel and a cylindrical volume regulator.
In the bottom part is only a switch and a conector for
headphones.
HIFI TOWER
There are hidden two pure Class A amplifiers with
the output power 2 x 40 W / 4 Ω and a Class AB
amplifier for a subwoofer inside the tower.
There are toroidal transformers and circuits working
with big currents in the bottom part.
There are circuits for processing voltage signals
above.
There is a main volume regulator (Black ALPS) and
a subwoofer gain regulator in front.
All conductors leading active voltage and power
signal are very short to eliminate crosstalks and to
prevent degradation of active signal.
Outputs and inputs terminals WBT illustrate
uncompromised constructional resolution.
SNAKES
The amplifier in the midle price category
has the output power 2x20W in the Classs A
and 2x40W with a continuous transition to the
Class AB. This amplifier is cheaper because
the demands on refrigerators, a source and
effacing capacitors are not so great.
But the view of "a snakes' nest" on the
bottom picture showes that the amplifiers from
this price category are not neglected in any
way. All conductors for a distribution of
feeding voltages and an active output power
signalare properly elaborated.
BRIDGE
The amplifer is in the same category as SNAKES
but in DUAL - MONO.
Behind the mark are two toroidal tranformers in
permaloy case.
ACCU
Our firm can make amplifiers of a “normal” design
too.
This model with output power 2 x 40 W in the pure
Class A was made according to a customer wish..
The customer is very satisfied and he has a
maternal (better paternal) relationship to amplifier
(as many others customers)
Some models for the year 2002
All following ampliers are in "normal" and output
power is 2 x 40 W /4 ohms i pure class A.
The amplifer on right was made for VOBA
ACUSTIC. On the bottom picture is a look inside.
The power supply distribution is the
shortest
between power tranzistors and exterminatory
capacitors.
The amplifer Silver Monster 2 is designed in silver
edged elox metal plate.
The volume regulator and the switch are in one.
Silver Monster2 switches off in mimimum volume.
This is the new variant of Gold Cylinder.
It is so designed in beatiful harmony of like two round
panel and a cylindrical volume regulator.
Position of volume regulator signals the digital
display.
Supposed permormance is 2 x 40 W in class A.
GROUP1
There are three new TOWERS and the Silver
Monster 2 on this picture.
The tower on the left is a future amplifier with a
presupposed power 2 x 20 W in the Class A and 2
x 40 W in the Class AB. The massive framework is
made of stainless steel, a cut elox black aluminium
profile and a 3 mm steel plate.
The next tower named GOLD WAVE is a beautiful
combination of a cut gold panel in a shape of a wave
and side parts which are made of massive teak.
Except of a key, which is the switch, a volume
regulator and signs nothing else disturb the beauty
of the shape and material.
This amplifier can work as the previous one or its
power can be to 2 x 40 W in the pure Class A.
The amplifier next to the Gold Wave is in a
retrospective style. A more detailed view is on the
bottom picture. The front part has wooden sides and
there are circuits of an active signal elaboration, a
volume regulator ALPS and refrigerators only.
The amplifier is a pure audiophile performance
again with the shortest signal ways. The feeding
ransformer is placed in a special cast iron chest at
the back. Beautiful 2 x 100,000 F condensers and
gilt loudspeaker terminals are in the middle. The
presupposed performance is 40 W in the Class A.
The pictures of an amplifier named NOSTALGY give evidence that the firm isn´t interested in
transistorized amplifiers only. This new amplifier has a new mark Petřík and evokes the era of
beautiful warmth and shine of tubes.
The amplifier is being produced and contains two 800 W triodes RD 200b, two 8 kV rectifying
diodes, a 2 kVA feeding toroidal transformer and two output toroidal transformers. The
presupposed power in the Class A would be as much as 2 x 100 W. There will probably be the
possibility to switch over to a quarter of its power because of a longer service life of the tubes.
The amplifier is made of materials with a long service life and a resistance such as aluminium
casts, cut stainless steel, cut and elox aluminium and 15 mm glass.