What does "fast" mean with regards to an amp?

[egellings]

That will be difficult because performance measurements are quite repeatable, while subjective ones are all over the road like horse apples. Maybe with trained listeners, it could work.

 

[sq225917]

Technically, “fast” amplifier has short rise time of transient response and high output slew rate.

Name one amp so slew rate limited it can't do 20-20khz

 

[egellings]

I think that by time you get to 4 or 5uV/uSec, in a home power amp, that's adequate. More gets you nothing.

 

[egellings]

A direct drive vacuum tube amp driving electrostatic speakers may have to do better than that, since voltage swings in that setting are so high.

 

[JWAmerica]

That will be difficult because performance measurements are quite repeatable, while subjective ones are all over the road like horse apples. Maybe with trained listeners, it could work.

You just need a large enough pool of data to sample from and ignore the extreme outliers, a la Harman curve survey.

 

[Wes]

outlier rejection can introduce biases - there are "rules" on when and what outliers can be rejected

 

[Spkrdctr]

All these words /adjectives confuse me, but sometimes I analyse it instead of just getting irritated.
So it means less distortion, as in blurring of discrete sounds - iow, it sounds clear instead of blurry, and that gets interpreted as "fast"...but I think they're just hearing the speakers.

My gosh man, you have it! They are hearing the speakers. The end. All of the other stuff is rubbish. But, I do tend to paint in broad strokes on this forum as it is work to dig into the weeds and give a technical answer! Broad strokes for me!

 

[Spkrdctr]

Sadly it makes hifi really dull because the only conclusion is that any amplifier more expensive than a £300 Yamaha RN-303, which at 100w and inaudible distortion will drive just about any speaker, is a waste of time and money. Which may well be true!

Bingo! Or, very close to bingo.

 

[Trouble Maker]

I'm faster and more agile when I'm lighter.
I'm not sure it helps me be any more articulate but I can articulate better.
Class D or other digital type amps are lighter.
So they must be faster and more agile.

 

[Spkrdctr]

Name one amp so slew rate limited it can't do 20-20khz

A broken one! What's my prize?

 

[mhardy6647]

Bingo! Or, very close to bingo.

bing! ?
bingc! ?
ingo! ?

 

[Wes]

Name one amp so slew rate limited it can't do 20-20khz

from which decade?

 

[JWAmerica]

Does anyone run 85db/W speakers anymore? Mine are 89-90db@1W and those are on the low side these days.

 

[b4nt]

Does anyone run 85db/W speakers anymore? Mine are 89-90db@1W and those are on the low side these days.

Is more noise per watt better sound?

 

[wwenze]

Does anyone run 85db/W speakers anymore? Mine are 89-90db@1W and those are on the low side these days.

*Looks at my 84dB/W which is further bass-boosted to 71dB/W*

 

[levimax]

Does anyone run 85db/W speakers anymore? Mine are 89-90db@1W and those are on the low side these days.

If you read Amirm speaker tests most book shelf speakers measure between 82 and 86 dB ... Usually a little less than manufacturers spec. Very few speakers tested have been 90 dB or above.

 

[Chrispy]

Gotta love the guys who read these use of "fast" descriptions in audiophilia questioning the bullshit, tho! Keep questioning....

 

[mhardy6647]

Does anyone run 85db/W speakers anymore? Mine are 89-90db@1W and those are on the low side these days.

Really?
That is certainly not, FWIW, my impression -- not to mention that loudspeakers nowadays seem to be heavily biased towards low nominal impedance ratings (4-ish ohms), which "artificially" (so to speak) adds 3 dB relative to an 8 ohm sensitivity rating when expressed on a "per watt" basis.

Of course, we're at ca. 104 dB/watt @ 1 meter here, so we just kinda chuckle at low impedance, low sensitivity loudspeakers and the behemoth amplifiers they require for even polite listening levels.

 

[Plcamp]

The only context “fast” might make sense … describing a speaker with perfect timing between drivers, each of which shows no stored energy in waterfall plots? Can’t see how an amp affects that.

 

[sq225917]

from which decade?

Any of the last 3 will do...