Before the audition of the Reference
1.1 preamplifier from Opera Audio, I noticed several
things. Firstly, this is the first reference series
preamplifier from Opera Audio since their establishment.
The selling price is RMB 10,000. - Secondly very seldom
Chinese made preamplifiers are being sold at this
price level. It is because the imported brands such
as Audio Research LS8, Sonic Frontiers SFL1 and Matisse
Atom already enjoyed a very good reputation in the
market. The most appealing factor to me is, this preamplifier
has been selling very well since launch although the
factory only puts up the information in their web
page (www.operaudio.com.cn). Orders just keep coming
in and this is very rare when the current Hi Fi market
is very weak.
After receiving the R1.1, I realize its appearance
is really special, unlike any other preamplifiers
made by Opera Audio. Like other products from Opera
Audio, the R1.1 uses wood as part of the chassis but
skillfully utilize the cherry wood to form the chassis
cover. Not only does it look nice; it is part of the
damping system. The front plate is made of well machined
aluminum with a curved upper edge in sync with the
cherry wood cover. Its outlook scores well in terms
of elegance and dynamics. The four silver knobs in
the front panel are for power on/ff, input selector,
and volume control and mute control. The mute control
has only two positions, normal and mute. When in mute
position (-10dB) there is still sound output and the
reason for this design is to reduce the use of the
expensive volume control (like when you need to reduce
the volume when the phone rings). R1.1 uses plated
brass as equipment feet as well. The attention to
detail is good in such an area too. You could select
up to three inputs and there is one set of output.
All the connectors are RCA since R1.1 is not a full
When the cover is removed, the content of R1.1 is
quite surprising. This is a preamplifier that uses
very Hi End construction and components. A lot of
preamplifiers use hard wired construction. What about
R1.1? There is a large PCB. However the factory said
it is only acting as a mounting frame for components
like tube sockets. Underneath it is hard wired. In
this way, not only it uses hard wired construction;
the layout of the components is very neat too. On
the left hand side of the chassis lies the EI type
power transformer and the filtering choke, shielded
by a metal cover. They are made of high grade silicon
steel in order to obtain better high frequency response.
Power supply rectifying does not use vacuum tube rectifier
and this is after special consideration. Filtering
capacitor is using Solen non-polar MKP, with one at
47uF/400V and the other at 100uF/400V. One more Philips
electrolytic capacitor 47uF/400V is added for the
consideration of sound performance. R1.1 is using
very Hi End components. The common Rel-Cap and Multicap
coupling capacitors used by ARC and Sonic Frontiers
are used in R1.1 and this is rare in Chinese made
amplifiers. The circuit used by R1.1 is very simple.
It uses two 12AU7 in classic SRPP configuration. Although
the circuit is very simple but implementation is very
thoughtful. Apart from using a heavy duty power supply,
the choice of components is also very strict. R1.1
uses very good coupling capacitors and resistors.
The internal hookup wire is from VDH. The volume control
is very special. It uses 24 steps ELMA and best resistors
available. Stepped volume control has good separation
and life span but its adjustment is not continuous.
Opera Audio understands this and in the most frequently
used ranges there is no problem of too big a step.
The vacuum tubes used are NOS RT 12AUT made in France.
Two tube coolers are supplied to help reduce any microphone
effect. In order to test R1.1, I tried to borrow other
famous tubes like Mullard and Telefunken but in vain.
I only get hold of the 1960s RFT tube made in Germany.
Originally I tried to borrow an ARC LS8 MKII for comparison
purpose but also not available.
The audition uses Aragon 8008B power amplifier, Meridian
506, Original A9 CD player and Audioquest cables.
I also have Krell KAV500i and Meridian 551 integrated
amplifier that has preamplifier output for comparison
R1.1 belongs to the high price Chinese made preamplifier.
What about its quality? Before listening to R1.1 I
have been using Krell KAV500i and Meridian 506 to
drive Dynaudio's Contour 1.3SE bookshelf speaker.
This combination gives high density and great dynamic
sound. With so much clarity it is perfect for listening
to guitar and piano. With symphonies it is very good
in imaging and soundstage presentation. After changing
to R1.1 and 8008B I can feel the increase of smoothness
with more meat and glamour in middle frequencies,
The soundstage is smaller but with good transparency.
The imaging is not as sharp as the 500i. While listening
to violin solo R1.1 brings out more air, harmonics
at ease with softer sound than 500i and is more human.
With vocals and strings it is even more touching.
Although it is not very "tube" sounding
but I can easily tell the fundamental difference between
solid state and tube sound. After more than a months
auditioning I have the following major observations:
Firstly R1.1 is very balanced, neutral and natural
sounding. It has the capability of a reference level
preamplifier performance. Its sound is open; transparent
while it tonal character is neutral and smooth. There
is no obvious deviation or coloration. This is what
a "reference" preamplifier should be. R1.1
has very simple circuitry, best choice of components
and as a result exhibit very low coloration, high
resolution and soundstage clarity. The frequency extension
of R1.1 is very good. While listening to violin solo,
the vacuum tube preamplifier presents more realism
of the instrument sound at ease with rich harmonics
and air. This is very difficult for a similar priced
solid state preamplifier to achieve. Comparing with
R1.1, Meridian 551's preamp output is also very full
and smooth with good vocal. However the special richness
and delicate, airy high frequency sound unique to
vacuum tube cannot be reproduced with the Meridian
551. R1.1 does not have the characteristic "sweetness"
or "thickness" of certain vacuum tube preamplifier.
It's frequency response is very flat from high to
low. From the neutral, balanced and relaxed foundation
it brings in a bit more of the vacuum tube flavor.
You can listen to it for a long time.
Secondly R1.1 has good resolution. Not only does
it sound real and natural; it also reveals clearly
the minor details in music. Its dynamic response is
very good. From chamber music involving only several
instruments to symphonies with lots of players, R1.1
reproduces them at ease even during high level playback.
R1.1 is fast and clean sounding, balanced in any frequency
range. Its frequency extension and resolution is comparable
with some other more expensive import preamplifiers.
The usual "misty" behavior in lower priced
preamplifier cannot be found on the R1.1. Although
the R1.1 presents a smaller soundstage comparing with
Krell and its imaging is not as sharp, the resolution
power is very good. Tonal character of R1.1 is also
better than Krell's preamplifier section.
In addition, R1.1 is a very sensitive preamplifier.
If you change a tube or add a tube cooler, the sound
changes. When the R1.1 is first turn on, its sound
is a bit bright and tight. This improves after 1 to
2 days of breaking in. I tried removing the tube cooler
and the sound becomes more relaxed but not as focus
as before. However the tube cooler is designed to
reduce microphone effect and I suggest to leave it
untouched. Later I change the tube into RFT 12AU7.
The sound then becomes richer in middle frequency
and feels more relaxed. However resolution is worse
than before with less glamour in the high frequencies.
Since R1.1 is a reference preamplifier and is designed
to be neutral with high resolution, you should leave
the stock components alone.
R1.1 is neutral sounding with high resolution and
beautiful tonal characteristic. Opera Audio's designer
thinks a "reference" preamplifier should
not be colored and has too much character of its own.
It has to focus on the overall performance such as
"simple, natural and neutral". According
to this R1.1 is heading the right path.
What should be the right amplifier to match R1.1?
I think either solid state or vacuum tube is suitable
since it is a very high quality preamplifier.
Before finishing this review, I have opportunity
to hear the R1.1 and R9.9 combination playing in two
different occasions. R9.9 is a 845 single end 30W
class A power amplifier. It matches very well with
R1.1. The R1.1 and R9.9 combination features a rich,
relaxed and transparent sound way ahead of the R1.1
and 8008B combination I have in my review. The density
of sound, the ease of playing is truly musical. Although
the speed and power is weaker than 8008B but all else
are better. Hearing the R1.1 and R9.9 driving a floor
standing speaker consisting of Scan-Speak drivers
the 30W output is not weak at all. Smoothness of sound,
lively reproduction , density and frequency extension
are all very good.
While using R1.1 and 800B I thought R1.1 is a very
good top of the range preamplifier. But after hearing
R1.1 and R9.9 I am deeply attracted by this reference
series amplifier. I remember in 1999 Spark's 9084D
845 amplifier once gave me a shock and I was attracted
by it. Now in 2000 Opera Audio's R1.1 and R9.9 gives
me the same feeling. A customer already buys the R1.1
and R9.9 I listen to. Next time I would really like
to audition them again in my listening room.
High Fidelity 2000 issue 11, China