Not moot, contradictory, and kind of goes with some of the subtle things I've heard with cables, that the sound of an amp is much more affected by the impedance changes in a cable than we have thought up until now.Sorry, this should have been included with my prior post.
The Carver Amp Challenge and the 21st Century and it's Failure
Some of you may be old enough to remember this article from Stereophile. Bob Carver claimed he could make an amplifier audibly indistinguishable from some of the best from Conrad Johnson. A high efficiency (not class D), solid state linear amp vs. a linear tube amplifier.
https://www.stereophile.com/content/carver-challenge
Carver's approach was to feed a speaker via both amps at the same time using opposite terminals. The speaker itself was the measure of accuracy. Any difference in output between the two amplifiers would cause audible output.
What's super important here is Carver invented a new way to measure the relative difference of amplifiers with a real load.
That's kind of revolutionary from the standpoint of commonly published measurements of amplifiers before. Steady state, frequency sweeps, THD, IM and S/N all failed (to my ears) to express human experience and preference. I remember a reviewer for Audio, I think Julian Hiirsch, who claimed that these primitive measures were enough to tell you what an amplifier sounds like. The man had no ear at all, in my mind. More here:
https://www.soundandvision.com/content/reconsidering-julian-hirsch
And here was Carver in 1985 cleverly showing that two amplifiers which measured reasonably well, sounded differently. We should also be in awe of Carver's ability to shape the transfer function on the fly. That's pretty remarkable too but not the scope of this post.
My point is, really, Carver showed us a revolutionary way to examine differences between gear in 1985 and yet ... it did not become widespread. << insert endless screaming here >>
As far as I know (and that is very little) no manufacturer of any bit of kit or cable took this technique up. We are still stuck in 1985 for specifications, measurements and lack of understanding of what measures cause what effects and end up cycling through cables and amps based on a great deal of uncertainty.
My points, in summary:
Best,
E
https://www.stereophile.com/content/carver-challenge
Carver's approach was to feed a speaker via both amps at the same time using opposite terminals. The speaker itself was the measure of accuracy. Any difference in output between the two amplifiers would cause audible output.
What's super important here is Carver invented a new way to measure the relative difference of amplifiers with a real load.
That's kind of revolutionary from the standpoint of commonly published measurements of amplifiers before. Steady state, frequency sweeps, THD, IM and S/N all failed (to my ears) to express human experience and preference. I remember a reviewer for Audio, I think Julian Hiirsch, who claimed that these primitive measures were enough to tell you what an amplifier sounds like. The man had no ear at all, in my mind. More here:
https://www.soundandvision.com/content/reconsidering-julian-hirsch
And here was Carver in 1985 cleverly showing that two amplifiers which measured reasonably well, sounded differently. We should also be in awe of Carver's ability to shape the transfer function on the fly. That's pretty remarkable too but not the scope of this post.
My point is, really, Carver showed us a revolutionary way to examine differences between gear in 1985 and yet ... it did not become widespread. << insert endless screaming here >>
As far as I know (and that is very little) no manufacturer of any bit of kit or cable took this technique up. We are still stuck in 1985 for specifications, measurements and lack of understanding of what measures cause what effects and end up cycling through cables and amps based on a great deal of uncertainty.
My points, in summary:
- Most of what we consider state-of-the-art measurements are stuck in the 1970s.
- There are a number of ways to improve upon them
- No one has.
- We should be a little more humble when asserting if it can't be measured it isn't audible because our measurements are not nearly comprehensive
- I look forward to manufacturers or hobbyists taking modern equipment to pursue new measurement and new insights into our hobby.
Best,
E
- ...
- 57 posts total
"His "motel-room" modified amplifier sound was so similar, Stereophile Magazine editors could not tell the difference between his amplifier and one costing more than $6,000. This amplifier was marketed as the M1.0t for about $400.00. Bob Carver may have single-handedly debunked any number of theories about sound quality by using physics, blind and double-blind testing and unbiased measurements (such as "gold-plated speaker wires sound better than copper wires", etc.). Carver successfully copied the sound of the target amplifier and won the challenge. The Stereophile employees failed to pass a single blind test with their own equipment in their own listening room.". (Preceeding in part from Wikipedia). Enough said. Carver came through in spades. Nonetheless, keep knocking what he pulled off but first figure out which terminal is Positive and which is Negative. |
- 57 posts total