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Class A amps or Class D??: Which sounds better??

Amplifier performance and synergy depends on the other components, and cables in a system. I have read alot about the advantages of Class A.amps Though an older amp design, do class A amps necessarily sound better than Class D digital amps like Nu-Force, Bel Canto, and Wyred4Sound?? These class D amps supposedly run more efficiently, with less heat and noise and are smaller in size.

I have a friend who has a Musical Fidelity A3CR power amp and a Bel canto pre-amp, and a pair of Spendor floorstanders. The MF amp is at least 10 years old, and no longer made. I have listened to the amp in his system, and it does sound very good. Most noteably is its across the board smoothness. However, I think its performance is system dependent, and might be a liability in other systems. Would like to hear comments and opinions about these two amp "designs", and if one sounds better than the other, OR JUST DIFFERENT.

BTW, I am not sure that owning a 10 year old amp like the MF A3CR is a good idea, despite its class A rating, and a few positive consumer reviews I have seen. Thank you
sunnyjim

Showing 3 responses by spectron

spectron
130 posts
 
Hi Athmosphere:

Your caveat #1 negates your point, largely. If its non-OTL
tube amp then if power is needed I HEAR distortions I can't tolerate. So for easily driven speakers when low power is needed I also prefer tube.

For OTL, the power is not a big problem, absense of the output transformer make it (almost) dissapear. The problems with OTL are two fold: they have difficulties to drive low impedance speakers and require high degree of maintance. Otherwise, I am OTL lover and as you know I work with Jud Barber of Joule-Electra because of it !!!!

Regarding your caveat #2, I can't comment because we at Spectron Audio have proprietary speaker cable, we call
"Remote Sense" which negatate effects of imperfect real-life long speaker cables.

All The Best

Simon
spectron
130 posts
 
"..lack of authority that class D brings to the party is obvious "

What about vehicles with internal combusion engines ???
Once I drove Yugo and its was horrible !!!!!!! Friend recommended Ferrari but I said "Thanks but no, I know how they drive!"

The "authority" is a function of well designed power supplies be it for class D or class XYZ with BIG, BAD, headroom (and NO distortions, pleeeease!)

I piblished article on the topic in Enjoy The Sound:

http://www.enjoythemusic.com/magazine/manufacture/0708/index.html

If interested in the topic - please read, I wrote it as educational tool for non-engineers music lovers.

All The Best,
Simon
spectron
130 posts
 
"If we are to compare apples to apples, I recommend that the class D amp have the same power as the class A amp it is compared to. I think anyone will see at that point the difference in authority."

Brilliant! Brilliant idea. I am all for it ! My single question is: MOM, WHAT IS POWER?

If its continius (rms) power as most of manufacturers show in their specs then in my honest opinion its useless and misleading "digit".

If instead of bench test signal, we will use real life music then most speakers will require, most of the time - may be 10% of continius power. May be less.

A small percentage of time music is played is "filled" with loud sound (orchestral creshendo?) which to reproduce WITHOUT (!!!!) additional distortion you need 10 - 100 times more (peak) power then continus.

Compare two amplifiers with identical peak voltage, peak current, level of distortions, BW and....duration i.e. not 10 msec. Most class A amplifiers will do it with ease! Most class D amplifiers? .... try and see

All The Best,

Simon
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