Tube versus SS



Since I just installed some rather expensive NOS 6922 Telefunken tubes in my Phono-preamp, that yielded outstanding results, I decided to compare CD to Phono.

From the best of "Jacintha", CD, I selected "Danny Boy". Her voice emerged deep center stage from a jet black noise free back ground. It sounded more like what I expected from the analog.

That was followed by special LP's of Dinah Washington that had recently arrived. Those LP's were everything I expected with the NOS 6922 Telefunken Tubes in the Phono, but the surprise was the fact that I couldn't tell the two apart; both were outstanding.

What may surprise you, is the fact that I attribute these outstanding results from the COVID 19 "lock-down" which has given us the quietest "grid" ever in history. That means those of us with lesser means have the same AC power as the richest who can afford expensive AC power "clean uppers".

BTW, I have made extensive comparisons to recordings made before and after, the lock-down that confirm just how much of a difference it's made. I must admit that I had doubts about expensive power conditioners, but this confirms that fantastic results come from taming the wild AC.

It's my belief that we can not achieve better results than we have from the current "quiet grid", which means power conditioner or no power conditioner, we are all presently getting the same results.

Could it be that the dominant factor when comparing tube and SS when they both are of comparable quality is "The quality of the AC"?
   
orpheus10

Showing 1 response by alexberger

My two cent, to people who like transistor sound "without distortions".
Most of these people like to talk about science, measurements and distortions - having zero engineering and technical background.

Here is the great article about tubes vs transistors:
https://spectrum.ieee.org/consumer-electronics/audiovideo/the-cool-sound-of-tubes

1. Transistor as amplification elements has much higher level of distortions compared to triode. 
In addition to that, transistors have temperature dependence distortions that tubes don't have. This kind of distortions have inertia that make them even worse for human brain perception.

2. "Good characteristics" of transistor amplifiers achieved by using feedback everywhere, that causes to replacing of low order harmonic distortions to high order harmonic distortions. Human brain recognises of a smallest amount of high order harmonic distortions because they are unnatural.

3. The single advantage of transistor amplifiers is lack of output transformers.

4. Our brains perceive distortion in a completely different way than instruments. There is a whole science of psychoacoustics that deals with this issue.

5. High power amplifiers are useless, cause compression and distortion of speakers.
Here is an example:
https://www.linkedin.com/pulse/power-compression-vs-thermal-distortion-loudspeaker-alexander-wilson/
"

Taking an example of a voice coil using 10 meters of 0.2mm Copper with a typical resistance of 5.5 Ohm at 20 degrees C.

Apply power (music signal) & the voice coil jumps to 120°C and the resistance rises to approx. 7.5 Ohm….Now the resulting current flow through the voice coil drops by approx. 35% ….So does the SPL….This is a 35% distortion!

Orders of magnitude worse than the usual suspects of THD or IMD which loudspeaker manufacturers like to quote.

With passive crossovers in multi way systems thermal power compression will shift XO frequencies when the voice coil resistance changes – resulting in summation errors between the two drivers involved, depending on program and listening level.

The same holds true for notching out resonances or compensating impedance….The more complex the passive crossover the worse the TD effect becomes.

Why 120 degrees C?

This is a safe or medium range voice coil temperature, many voice coils hit double or triple this temperature on a regular basis.

The energy involved is as follows:

The weight of our VC wire is slightly below 3g if we calculate length multiplied by cross sectional area multiplied by specific mass of copper.

We require approx. 1 Watt for 1 sec for each Kelvin temperature increase (no cooling assumed here), looking at the thermal material constants for copper

To heat up this < 3g of copper wire our voice coil is made from, we only need 10 sec of 10W input to finally arrive at a 100°C increase – or – if we have fortissimo playing – a very short 1 sec of 100W input."