DETAILED DESCRIPTION & FAQ:
2017 Oppo Level 4.2 - Oppo BDP-105/D
Level 4.2+ACB "Analog Clock
From $1990.00 to $3590 Upgrades (Australia)
Clock Buffer (or Booster) - for a little while yet, we shall be a
little coy, but it has to do with how the Clock Input of a D/A Converter
works. There is a glitch that can only be overcome by a buffer, a
non-switching buffer, hence an analog buffer.
The Terra Firma
'Heavy' Clocking - The Terra Firma incorporates a servo control that is
tuned to a few millionth of a Hertz. The end results is that it gets rid
of the worse kind of jitter that occurs at ultra-low frequencies.
All Clocks are actually Oscillators and they are not digital
devices at all, they are very much analogue. Conventional Oscillators are
actually of the BAW type and are harmonic oscillators. BAW means Bulk-Acoustic-Wave and while they
never specify themselves as BAW, it is the default if nothing is
mentioned. But there is also the SAW type Oscillator. These are
fundamental oscillators. Here SAW stands
for Surface-Acoustic-Wave and they were not originally intended for audio
use, but being non-harmonic makes them a more correct oscillator. They are not available in frequencies used in digital players and DACs
- in fact, with modern manufacturing methodologies, they can make SAWs working up in the GigaHertz
ranges. We first saw them in brochures slated to the military and they
are also more sturdy than conventional oscillators. They praised their
superior 'stability' and digital playback and Clocking is all about
'stability'. Only the Sabre DAC is compatible
with SAW technology. The SAW Clocking is a winner, it just really makes
the music swing, superior audible timing. We now use two SAW Clocks in the Oppos,
one for the Sabre DAC and another for the Master Clock. For the latter,
we had to get them custom made by Seiko Toyocom of Japan, as 54MHertz
was not available. We then put that through a divide-by-two circuit to
get 27MHz, the Master Clock frequency.
Post-DAC Circuit - Diamond Transistor.
Want the sound that is more associated with tubes? Diamond Transistor
theory. It is recognised that the humble Triode is the most linear
voltage device we know and that transistors are not as linear in their
native current device mode. The Diamond Transistor is not a transistor
perse' - but rather is circuit method or topology, that achieves an incredible level of
accuracy and works as a transconductance amplifier, where input is
voltage and the output is current. Literally one point in the circuit
emulates a near perfect Collector, and another point is the Base (high impedance)
and finally the Emitter (low impedance). I do know one very high-end
manufacturer that uses Diamond Transistors in their very best designs,
and we have a lot of respect for this designer.
Circuit - SuperReg. Basically can be described as a two-stage
Regulator, a Constant Current Shunt Regulator. The first stage locks in
the current and hence establishes a huge Power Supply Rejection Ratio
(or PSRR) and trust me, this is a good thing. This isolates the Voltage
Regulator from the worst noise. Then the Shunt fixes the
Voltage. So this is effect a Class 'A' Regulator in a similar way that
some Amplifiers are called Class 'A' and the speaker is the Load. Here
the Load is the actual Post-DAC Circuit. The implementation is not brute
force, but simply clever engineering. We first did the SuperReg way back
in 1980 and now it is much more commonly used by other high-end DIY'ers
New Post-DAC Filter
- This is a controversial when it came out. Initially 1st Order
and later 2nd Order. Most modern DAC chips are of the Delta-Sigma
variety. These are essentially single-bit processing (or low bit) and
have inherent noise issues that are dealt with using things like 'noise
shaping' and dither to overcome the problems. Musically more authentic,
more expansive midrange, better layering of depth, larger soundstage,
and bass that seems to more pristinely balanced and less glare
Supply Noise Reduction: The worst noise is the noise that
impinges directly on the DAC. There is some level of recognition by the
manufacturers of DAC chips and their Technical Data Sheet has
recommendations, but they are woefully inadequate. There are many
upgraders that will milk you for expensive components, as power
supply upgrades, that have minimal benefits when other glaring problems
are ignored. Hence, not just to be cost-effective, but be clever and use
actual engineering solutions. In our case, we concentrate on absorbing
the back-EMF noise of the DAC and while affecting a 2nd order filter
effect. The former treats by far the worst kind of noise, just as we
ourselves breathe in oxygen and breathe out carbon dioxide, and if you
don't get rid of the carbon dioxide, it will in effect poison your
environment and you. This is what back-EMF (or sometimes called
'switching noise') does. The second is to attenuate the noise
that originates from the power supply. The components used, were for
some times rare and expensive, but thanks to the computer industry,
these devices are now highly cost-effective and even more important,
they are effective!
Electronic "Flywheel". Sorry if this gets a bit technical. Ted
Smith, the designer of PS Audio 'Direct Stream' USB DAC makes this point
too (see him on Youtube), that the two states of PDM/DSD and Delta-Sigma
DACs is that the 'off' state is really, and hopefully, a clean ground.
the 'on' state it really just clipping the usual +3.3V supply and that
anything irregular on that supply rail goes straight into the process
and is converted into jitter. We have known and this view for years,
that any noise, even from ULF up, even below 1 Hertz, gets turned into
jitter because jitter is noise. Ted's solution is to put a filter that
filters everything above 1 Hertz. I am reading between the line, he is certainly
using a passive filter and I suspect it is 3rd order. That's very good,
but not good enough. We are
quite aware that even 1 Hertz may not be low enough - a normal filter to
have effect under 1 Hertz? we use a different solution. Store a LOT of energy near the DAC,
a HUGE amount, and that energy will act as a "Flywheel" and resist
changes and aberrations, even way below 1 Hertz. So it is not
frequency filtering in the usual sense as Ted Smith does it, but mass
filtering, resisting any change in kinetic energy; as
standard filtering theory implies, works both mechanically and
electro-mechanically. One area that stands out is the improvement to
bass definition and listening to bass textures, but there are benefits
across the board, the whole audio spectrum, a new natural perspective
emerges, so easy on the ear while also incredibly revealing and detailed.
Quality Silver-Clad Copper Wiring. I hear a lot of talk about
Silver versus Copper and there are strong opinions. We use a wire that is
sonically in neither camps and yet use both Copper and Silver. This wire
is totally down the middle, extremely clear and also homogenous
sounding, very even-handed and not at all Hi-Fi'ish. I even make my own
Interconnects from this wire, which is made by a UK company and I order
100 Metres at a time. Not cheap and not super expensive, it has never
let me down.
is the Output Level? The Stereo RCA Outputs are approximately
2.4V RMS and hence very healthy. The Red Book Standard is 2.0V RMS and
our experience shows that 2.2V RMS is the average. The Output Level on
the XLRs is the same (many will double to 4V RMS, but our output is
Asymmetrical Balanced and hence stays the same).
Asymmetrically Balanced? This basically means that both Pin 2 and
Pin 3 on the XLR Output is the same Impedance, but that the output is
only on Pin 2. This gives us good Common Mode Rejection and also
simplicity of circuit, as we can power both the unbalanced RCA and the
balanced XLR from the same high quality post-DAC module.
the Upgrade improve Video? According to the feedback we have been
given, the answer is evidently yes, serious videophiles loves what it
does the the picture quality. This is the result of the
superior SAW Master Clocking, which has benefits for both Audio and Video,
all digital and analogue outputs are enhanced.
it improve the HDMI Outputs? Most definitely yes, but keep this
is mind, when using HDMI, all you are doing is transmitting digital
signal to an external DAC that will most certainly not be as good as the
internal Sabre DAC and the full treatment of the JLTi Oppo player.
There will be an improvement, but for critical
use, the Sabre DAC's treatment is where the best performance will be. But no doubt that many
make good use of both features.
the Oppo be used as a Pre-Amplifier? For all digital sources, the
answer is an emphatic Yes! Please set the output of the Sabre DAC to
"Variable" and use the Remote Control to select from various sources,
including putting all your file music on an external hard drive (the
smaller 5V hard drives are recommended as they are powered via the USB
port and have less "sleep" problems). The Variable Output of the Oppo
works like a top class Volume Control. The built-in Volume Control of
the Sabre DAC is one of the great modern wonders of audio, it really is.
It is the only DAC Volume Control that I have ever recommended with zero
reservations. They really knew what they were doing and all I can
say is Bravo!
improvement to Multi-Channel? We make no secret that we
concentrate our efforts to the Stereo performance. But the Multi-Channel
Board does show very significant improvement, but not to the same degree
as the Stereo performance.
about Movies and Video? We are mainly interested in the Oppo
players for audio playback, but there is no denying that these Oppos are
stellar video performers. What is of course a real bonus is that
watching Movies that have well recorded sound, that the whole experience
is greatly enhanced. The added dimension that great sound makes to
watching cannot be understated. We can now also offer Multi-Channel
upgrade, contact your installer.
work in progress... almost there.