Did YOU know why analog sounds better than digital?

TRANSISTORS, OP-AMPS AND TUBES.

D&R started long ago (1972) making mixing consoles equipped with tubes.

One of the nicest parts of these hot valves were that they sounded great.

The sound was pleasantly warm and overload was not an issue with over 300 volts on the power rails and a bandwidth of up to 100kHz.

Then we experimented with transistors and could not get the same sound as we had with tubes.

Up to today we are using in most of our consoles integrated circuits mostly known as IC’s.

There is an enormous offer of IC’s on the market and they all have their specific pro’s and con’s.

They are different from tubes and transistors and sound different. Some sound hard and others more smoothly. But connected to a high end measuring system such as System-1, specs are pretty much the same. So what causes the differences we are experiencing?

We human beings are capable of perceiving sound in extremely small details.

We can even notice extremely small amounts of distortion in the order of 0.001% of the nominal signal level. We are extremely unpleasantly sensitive to odd harmonics such as the 3rd, 5th, 7th, 9th 11th and so on of the fundamental frequency.

Another problem in IC’s is the crossover distortion in the output stage producing not only dissonant harmonics but also switching transients when using a not so good op-amp.

We have selected our op-amps to behave in class A/B towards class A resulting in a minimum of distortion that we are so extremely sensitive to.

From a well known designer in our industry, the well respected Mr. Rupert Neve, I was pleasantly informed about the results of the following test, that anyone can repeat when interested.

This test mostly confirmed what we already knew by experience but we could not prove that designing our consoles this way improved the sound dramatically as it did.

WIDEBAND WIDTH DESIGN.

Imagine listening to a sine wave of 1kHz, this should be a nice pure round sound like a pure tone of an old Hammond organ. Then switch this 1kHz frequency to a square wave, now you are listening to a sine wave plus on top of it lots of odd harmonics such as 3rd, 5th, 7th and so on .

Actually you are listening to 1 kHz plus on top of this on a very low level frequency 3khz, 5kHz , 7kHz 11khz and so on. So the difference in perceived sound is quite clear to any listener, nothing mystical here.

Now switch the fundamental 1kHz sine wave to let’s say 12kHz. Again a pure very high frequency tone could be noticed.

But now the funny part of it. If this 12kHz sine wave is switched to a square wave we all still can hear the difference between sine and square wave.

THIS IS AMAZING.

If we all agree on this, it means that we can hear or at least notice signals beyond 20kHz.

Remember the first harmonic content above 12kHz is 24kHz , and then 36kHz and so on.

These generated frequencies above 20kHz (even in small amounts) prove that it is important to have an audio system that has a bandwidth well over 20kHz.

If you repeat this test for a fundamental of let’s say 16kHz, the first order harmonic is around 32khz and higher.  Even on this frequency most of the experienced professional listeners could easily determine when they were listening to a sine wave or a square wave!

Amazingly is not it? At least I was amazed and immediately knew why we should continue making our console having a bandwidth of 100kHz and higher.

We trim our op-amps on the board for as long as I can remember to be stable at 40kHz square waves without overshoots and frequency roll off.  We are convinced that if we tune our op-amps this way they are capable of amplifying any sum or difference of the fundamental frequency within the audio band without any coloration. Our reputation for perfect sounding consoles proved we were right.

The simple test described above proves that we are capable of perceiving sound information well above 20kHz and that this information absolutely leads to a warmer and richer sound . How we humans are doing this is still a miracle to me and many others I heard.

It is absolutely a fact that a small lift in frequency response of audio equipment well above 20kHz could easily give you the impression of giving you more air or transparency. Based on this principle we have designed our equalizers in a way that the upper band is lifting the fundamental frequency well above 20kHz if needed., resulting in a smooth breeze of air in your control room sound wise.

DIGITAL SHORTCOMINGS

Can you imagine why most digital consoles today sound harsh and can not even touch the smoothness of well designed analog consoles. This is easy understandable now with frequency responses that sharply fall off at 20kHz. No information above 20kHz means no warm open sound.

Imagine what a digital upper shelving high frequency control is doing when lifting those frequencies by 16dB just before they sharply fall off at 20kHz.

I think that digital technology has along way to go before it can even touch analog audio sound wise.

Think about this when you are ready for a new console!

Duco de Rijk

president