Consider Upgrading the CD, DVD or Blu-Ray Player you
have now?
The last few years has seen an amazing revolution.
We are now able to get digital sound right and that largely means not to
sound digital at all. What is more amazing is that the solutions to make
digital audio playback of CD and higher resolutions have all been
analogue. This may well explain why it has taken more than 25 years.
Anybody can make a player
sound better, easy. We could just as easily take your money and make
superficial changes such as Op-Amp upgrades and parts substitution.
Boring. Our aim is not a better player, but a great player. If your player
does not have that potential, then don't be surprised if you are advised
to hang on to your hard-earned money and given suggested alternative
options.
Our Priorities
First, the so-called
digital clock is none of the sort. The oscillators used have been around a
lot longer before digital audio came around and used in all sorts of
non-digital applications. Clocks are analogue.
Secondly, noise is the
single biggest enemy of digital audio. But especially where in the chain
that it shows up. Again this can only be fixed by analogue means. The
current crop of "modders" are into all sorts of parts upgrading using
lower noise parts. This is often concentrating on the SMPS (Switch Mode
Power Supply) - which may not be a conventional linear power
supply but is nevertheless also of an analogue designation.
But the
secondary noise created in the power supply often overlooks the
primary destructive noise that has little to do with the power supply,
indeed even the best power supply is vastly incapable of dealing with it.
Indeed improving the power supply may actually make it worse.
The solution that is both elegant and most effective
does not involve costly parts substitution. We don't make you pay for
expensive parts. We create a second order filter effect that attenuates
power supply noise while also creating a small black hole for the primary
source of destructive noise, the D/A Converter itself!!!
Thirdly, the most
destructive source of noise is that which imbedded in the clock signal, I
am tempted to call this the source gremlin jitter as it is the
source of that which is most ugly in digital sound. This contamination is
singularly the one source of digital sound that is the hardest to
eliminate.
In fact, our target of decent digital sound cannot
be achieved without tackling this gremlin.
Other clocks may make some improvement but not in a
focused attempt that is needed. The sound can be improved (the sound can
always be improved, sometimes even with a magic wand) without it,
but a totally relaxed sound devoid of any vestiges of digititus is
impossible to achieve. Our solution to this is
Terra Firma - and there is quite a bit of info on this site.
Player Types and DAC Types
Does the player you have now got suitable potential?
Or the player you have in mind to acquire? This is not possible to say
with certainty unless it is a player that has already passed
through our upgrade program. There is a near ninety percent probability
the answer is a positive yes.
Let us discuss what type of players that are
available:
Some have said that a multi-player cannot sound as
good as a dedicated audio only player. This is an over-generalisation,
indeed I have heard multi-players like the Oppo Blu-Ray BDP-83 sound far
superior to most dedicated audio players.
There are two types of Digital-to-Analogue
Converters, or DACs.
-
The 'Current' Output
DAC
-
The 'Voltage' Output
DAC
There are really on these two types (although the
first generation Sony CD/SACD Players were unusual that the DSD signal
could be diverted from the Digital Filter VC24 chip and processed as a
voltage source).
Knowing the two types of DACs is important to
understand what is required by the post-DAC audio stages. Each will
have quite different optimum solutions and we shall discuss ours and why.
Current DAC: The
current has to be converted to voltage. This necessitates the use of an
I/V Converter, where I is current and V is voltage. This is
one of the great challenges in audio. Rarely is an audio stage put to the
sword as it is here. Again we have two different methods, Active
and Passive. The former uses a high feedback technique to create a
Virtual Earth. The reason is that our DAC likes to a dead short, but of
course how do you get a signal from a dead short. Well, you can't and
hence a Virtual Earth is used. This is a method that we are not keen on
and yet is used 99+% and chances are that it what your player uses if it
has a current DAC. The other method is Passive. Here the problem is that
the DAC will not see an ideal short and the voltage signal generated will
need to be buffered and amplified by audio stages that still sees a very
hot (lot of high frequency energy) signal that can cause Slew Rate Induced
Distortion, as in I/V Converters.
So what is the solution? Being flexible helps and
understanding that even Virtual Earths are not real earths anyway. Our
solution is Passive but at a much lower impedance level than usual and
fairly close to a short. We use our Moving Coil Phono Cartridge as a
model. These have very low impedance coils and we can simulate that
resistively. The small voltage signal generated now needs a lot more
amplification, but we already have the technology to do that as Moving
Coil Phono Preamplifier designers. The JLTi Phono Stage is adapted and the
source impedance is about 6 Ohm and simulates that of a high quality
Ortofon Moving Coil Cartridge.
What about the Slew Rate problem. Our JLTi Phono
Stage design is no negative feedback design, has huge bandwidth and entire
immune to high frequency overload. So here we have a solution that is both
simple and elegant. But the audio stage also needs a high quality power
supply to power it. We use a variation of our Constant Current SuperRegs.
The "Current" DAC Solution
Voltage DAC: The best
solution here is a 1:1 transformer of the highest quality. The key to this
type of DAC is to go entirely Passive, in this sense no active circuitry
after the DAC, no transistors or opamps etc, and be able to listen to the
DAC itself, but with some filtering added. Typically a single-output
voltage DAC outputs from 0.6V and 1.3V RMS. This is lower than the regular
2V RMS that commercial players are supposed to output, but still healthy
enough in most cases. But if you use a so-called passive preamp it may not
have enough gain in the system. Take the output which usually sits on
+2.5V via a coupling capacitor and a series resistor and smaller capacitor
to ground, this forms a low-pass filter. This we call
Level 1 and is inexpensive to implement,
unless you want to spend ridiculous amounts on the coupling cap.
But the best solution is a special purpose
transformer such as our custom designed QuadFilar transformer. Most, but
not all voltage DACs have differential outputs. Yes, they have two
outputs. If so the transformer is ideal as it also doubles the
output. A couple of examples is 2.45V in the Oppo and nearly 2V with the
also excellent Wolfson DAC. This is our Level 2
upgrade.
The ideal "Voltage" DAC
Solution - coin reference to size.
Summary: We now have
workable solutions with both
kinds of DACs. With current DACs we use Terra Firma Lite and our
I/V Converter, and with differential voltage DACs we use Terra
Firma Lite and QuadFilar transformer.
Are all players suitable?
A high percentage are eminently suitable. It
depends on the details such as layout and in some cases what data
is available for the player in tricky situations. What is certain
is this, if your player has certain fundamentals right (and there
is no way we can go into full depth on this page), the existing
sound may give no indication whatever of what the end result will
be. The total removal of cheap opamps (operational amplifiers) and
their attendant poor power supplies, poor noise management and
lack of clean clocking, all these can totally transform the
performance.
But please do not be surprised if by chance
your player is knocked back and you are told to save your money.
We have no intention of making a player sound better, only
great!
Cost?
In most cases for a full-out conversion is
between A$1300 and A$1500. If Level 1 in voltage DAC player's is
$880. Usually the QuadFilar option can be made later at a nominal
A$550. Please note issues re Warranty with original manufacturer
is beyond us to comment on (the Oppo BDP-83 is an exception), but
our Warranty is 3 Years.
Re-Cycle?
Absolutely. Players only lasts so long, but the add-on
parts are as valuable as the player itself, often more. The Terra
Firma Lite module, the I/V Converter module and QuadFilar
transformers are all re-usable in your next player. You are truly
investing in the future with your first upgraded player. Good to
keep that in mind.
Joe Rasmussen
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