We can say that SpeedMatrix invention is a great achievement of the whole digital audio industry, its forward evolution. If we look back at DAC history we will see R2R resistor network, we will see binary weighted resistor DACs which are practically impossible to implement and we will see a lot of hybrid, compromised approaches, like Delta-Sigma modulation or DSD, which are cheaper to manufacture but are deficient in one way or another. Our invention is a next logical step which gives a straightforward and effective solution to all the problems associated with previous designs.
fig.1 Conventional R2R architectures
Based on new digital-to-analogue conversion logic together with new resistor array architecture, SpeedMatrix avoids all R2R weaknesses. The core of digital part in SpeedMatrix engine built with FPGA, where FPGA executes the new digital-to-analogue conversion algorithm developed by Leonardo.
R2R is pretty good in theory, in reality have several disadvantages that come from the resistors array architecture and resistors structure.
Asymmetric R2R architecture has different signal path length for each of digital signal bits. Lower signal levels that correspond to lower bits pass the farther R2R array route with delay in relation to higher bits. The lower bit - the bigger delay, with all these delays together influence the final result in analog sound of course.
Another factor, the lower signal levels have to pass through the longer route that consist of more resistors. So the lowest level signal has to go through the longest route overcoming all the barriers in form of resistors on its way.
Each of the resistors consist of multiple transitions between different metals, the more transitions between metals signal gets through - the more it degrades. All this means the lower level signal has to pass through hundreds of one to another metal connections, with each of these connections negatively influence the signal.
Based on alternative more proper more optimal algorithm, SpeedMatrix architecture consist of several times less resistors array with all the bits go through much shorter path almost similar length.
Positive side effect of the array with less resistors, that also proves our solution, SpeedMatrix has powered output, it can work directly to headphones, so no headphones amplifier is needed, which is another big advantage!
fig.2 Comparison R2R to SpeedMatrix
Another our important invention the unique SpeedMatrix resistors, that we are using for higher versions of SpeedMatrix DAC module.
As it has already mentioned above, resistors influence the sound signal a lot. The fact is that the less metal-to-metal transitions in the resistor and the more proper type of metal used - the better sound.
SpeedMatrix resistors are a handmade coil resistors made with specially selected constant metal wire and coiled in a special way. That’s a whole one piece of special wire that don’t have any material transitions in it. The method of resistors winding allows to avoid occurrence of any parasitic electrical appearance.
Using of SpeedMatrix resistors help us to get rid of any other slight influence on signal.
fig.3 Parasitic effects in the resistor
Both these inventions SpeedMatrix DAC architecture and SpeedMatrix resistor together result in the best DAC solution ever!
The perfection of our solutions was proven in Milano LaVerdi. Please have a look at the videos in our website. That’s why we state it’s revolutionary, no other DAC have pass this test before!
If you are high quality sound equipment manufacturer, we welcome you to evaluate SpeedMatrix for further use in your audio products to make them even better.