1. 1960’s – Tubes to Solid State
2. 1980’s – Vinyl to Digital
3. 2000’s – R-2R DAC’s to DELTA-SIGMA
When you look at the above list the first two are quite obvious – it made sense for the mass market of audio consumers and retailers to move from tubes to solid state during the 1960’s – more power , less heat , more reliability etc. etc.. Tubes would move to the smaller boutique audiophile market
Vinyl records started to change over to CD’s in the 1980’s – everyone started unloading their record collections and started re-buying everything on CD! Hey they took up less space -there were no ticks and pops – no stylus replacement or setting up cartridges – for the mass’s it was a great move and vinyl moved over to the audiophile corner
The third one might be a little more difficult to understand because it is not very obvious to the consumer. Back in the 80’s and early 90’s computer horsepower was not what it is today – the internet did not even get started at a consumer level until the mid 90’s with faster and faster computers. Back in the 90’s when digital was becoming stable the chips that were used to convert from digital to analog used resistor ladder circuits – basically real electrical circuits made up of voltages, resistance and currents that actually converted binary numbers to voltages that we listen to – in other words an actual circuit was used and corresponding analog voltages were generated via a real circuit. This soon became an expensive process to continue and with the explosion of computer based sound in everything from home theater, satellite tv, video camera, car stereos etc, the Delta-Sigma chip was born. Now computer horse power took over the job of converting digital to analog, a computer algorythm read in the binary numbers and through a series of calculations derived what voltage should be in our audio signal and what we should listen to. This was an excellent decision for cheap low cost digital sound for the masses! Once again R-2R DAC technology was moved over to the audiophile corner!
The problem however was that the low end and even many high end DAC manufacturers were also moving to Delta-Sigma processing. What about the high end audiophile with single ended tube amplifiers? For these applications Delta-Sigma will just not cut it. As mentioned Delta-Sigma digital to analog processing is fine for 99% of musical applications that we deal with in every day life! Delta-Sigma will just not cut it for high end audiophile listening!
Resistor Ladder DAC technology is used exclusively in all the Audio Note DAC designs. R-2R Audio Note DAC’s support Redbook 16/44 and 24/96 recordings but no higher. The reason is that you can’t implement resistor ladder dac with higher level resolution due to the resistor ladder implementation – its been proven that the higher level resolution does not bring anything to the table when it comes to digital audio. Simply increasing the number of bits does not solve the problem of listening to digital music without fatigue – that’s why you can buy 24/192 and higher dac’s for less than one hundred bucks!
It’s interesting how the audio world in 1960 was extraordinarily advanced while the video industry was very basic when you think of the tv’s in those days – 55 years on music technology had been drastically dumbed down while video technology had made extraordinary leaps!