CD/DVD Upgrades FAQ

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While below contains information you would like to read, we have since late concentrated on upgrading Oppo players. The reason is that it is capable of playing both discs and most imporetantly, full resolution files. That makes them much better value for the end user as the cost is little different from players that can play discs only. Also, Oppo provides the most full-proof way of playing files, since the 'codecs' are internal and hence no loss over USB2.0 and USB3.0 devices.


Consider Upgrading the CD, DVD or Blu-Ray Player you have now?

PLEASE NOTE FIRST: We still do upgrades to disk players, but one should consider that optimum value comes from players that can also play music files, such as Flac and Wave files. For the last 4-5 years Oppo Digital has made a series of BluRay Players that can both play CDs, SACD disks etc, but also at no extra cost can also play Wave and Flac files with its internal integrated music server. Naturally, when the same amount of money is paid to upgrade an Oppo, clearly it gives you for more bang-for-your-dollar to consider an Oppo player. Oppo has this market sown up and also have the greatest potential to upgrade that we have seen so far.

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

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.

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 raw power supply, indeed even the best power supply is vastly incapable of dealing with these more series noise problems. This takes real design rather than just paying for improved parts. Indeed improving the raw power supply may actually make it worse. Yet a lot of money get wasted in that direction. Be smart, be elegant, it is not enough to throw expensive components at the problem - and that is not problem solving, that is selling.

This kind of noise can be describes as "back-EMF" - a kind on Einsteinian noise caused by digital switching. Noise even below 1 Hertz are problematic. This cannot be sorted in the typical 'active' way and alternative ways need to be found. Such as our "Flywheeel" solution that is not active but passive, storing a lot of energy close to where the power supply interfaces with the digital circuitry, such as the DAC and Clocking.

The best solution is the elegant one and does not involve costly parts substitution. We don't make you pay for expensive parts. We create a second order filter effect that attenuates HF power supply noise while also reducing noise down to ultra-low frequencies via our "Flywheel" solution.

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.

More recently, this has been described as causing Uncorrelated Noise-Like Jitter. For more info on this topic, read here.

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:

  • Multi and universal Players like DVD & Blu-Ray

  • Dedicated Audio Only Format Players like CD and SACD

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 only 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. 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 perhaps added.

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 1:1 type 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!


In most cases for a full-out conversion is between A$800 and A$1800. 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, but our Warranty is 3 Years minimum.


Absolutely. The Green option - at least $400 cash-back. 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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Last modified: Saturday June 17, 2017

Just had a terrible thought. If "intelligent design" is unscientific, then who will design our audio equipment?