The R1.1 Reference Preamplifier
"This Preamp is
a real giant killer. A completely no compromise design"
Click for
Hi Res Photograph
The R1.1 represents the top model of Opera Audio's current range
of per-amplifiers. It is a 20dB gain line stage pre-amplifier
using improved SRPP circuit with no global negative feedback.
The equipment top uses cherry wood while equipment feet are brass
cones for improved shock absorption. Front plate is of machined
aluminum.The internal components used are among the finest available
in the world today. The potentiometer uses the single stereo ELMA
24 position series attenuator with 46 Holco 1% precision resistors.
Apart from having excellent sonic characteristic, it guarantees
the sound stage precision at any volume level. The capacitors
used for signal coupling is both the exotic US MultiCap RTX and
the Rel-Cap. Resistors used is a combination of Holco and Chinese
made precision aerospace low temperature drift version. All connections
are point to point wiring using Kimber high purity copper hook
up wire. The circuit board acts as a support frame for the tubes
and other components and actual point to point wirings are done
beneath the circuit board.
The two tubes used in the main circuit is the fabulous sounding
French RT12AU7 NOS made in the 50/60s. Due to limited supply they
are very hard to find in the market and price-wise expensive but
absolutely one of the very best. In order that users can try out
different types of 12AU7, the R1.1 is designed to use components
that has very little colored sound of their own. In this way,
during tube rolling the R1.1 can clearly show off the sound of
the tube itself. A lot of satisfaction will then be achieved by
trying out other exotic tubes like the Telefunken and Mullard.
Good quality pre-amplifier calls for a good quality power supply.
The power transformer and choke is shielded from the circuit board.
A special silicon steel EI type power transformer and choke with
good high frequency response is used together with large Solen
MKP metallized polypropylene filtering capacitor. Its filtering
characteristic is very uniform across the frequency range and
adds to the purity of the sound.
To reduce the microphone
effect, two Pearl tube coolers are used. Not only they are effective
in reducing microphone effect, they are also a very good heat
sink which can greatly extend tube life. Other convenient features
are added like the -10dB muting switch, which can reduce the usage
of the expensive potentiometer and as a result extends its life.
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Features: |
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1. |
Special made
EI power transformer and choke covered by a copperized cover. |
|
2. |
All substantial
filter/reservoir capacitors are SOLEN(100U/400V 1pcs, 68U/400V
1pcs). |
|
3. |
ELMA precision
stepped Volume control (unbalance<0.5% per channel). |
|
4. |
High quality
parts such as MIT capacitors,HOCOL resistors which are skillfully
hand wired under the chassis,using WBT solder. |
|
5. |
Every tube
uses a tube-damper for zero microphony performance. |
|
6. |
Cherry-wood
made camber for top chassis and brushed aluminium front panel
with natural color. |
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Specifications: |
|
FREQUENCY RESPONSE: |
3Hz to 150kHz
( -1dB) |
|
GAIN at 1kHz: |
21.8dB |
|
HARMONIC DISTORTION (for 2V RMS at output): |
0.08%(70Hz/7kHz
4:1) |
|
SIGNAL/NOISE: |
90dB |
|
INPUT INTERFACES: |
3 groups
(RCA) |
|
OUTPUT INTERFACES: |
2 groups
(RCA) |
|
INPUT IMPEDANCE: |
100k |
|
CONSUMPTION: |
40W |
|
VACUUM TUBE: |
12AU7(NOS)
x2 |
|
DIMENSIONS: |
430(L) x
320(W) x 120(H) mm |
|
WEIGHT: |
16kg |
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This preamp makes it hard
to believe that something this exceptional could be so cheap.
Virtually everyone who has auditioned it has bought one because
of the miraculous things it does to their system. Customers with
preamps by respected names such as Mark Levinson, Krell, Morrison,
Audio Research and many other solid state and tube designs have
marvelled at the detail, timber and soundstage width and depths
which it portrays. My previous pre cost several times the price
of the R1.1 but sounded dull and lifeless in comparison. I sometimes
wish it had a remote volume, which can be ordered, but with a
considerable loss of detail as the stepped volume control is
a work of art. (see photo.on left) Even David Wurtz,
the Australian Editor of "Secrets of Home Theater and High
Fidelity" was so stunned by his review sample he immediately
bought one, as did his co-reviewer. I use this to drive the Audio
Aero Prestige monoblocks which are arguably the world's finest
amplifiers. To beat the sonics of this unit, be prepared to pay
a lot of money. Please read the review below. |
