The fasterst Sansui amp known to man

It's good to have an amplifier with a rate of change higher than required for powering capacitive loads, but there is no viable data supporting the requirement of hundred of volts per microsecond. Thre are two reasons for this, first, because the rate of change follows the square law in relation to the voltage magnitude. A 400W/8ohm amplifier only needs a slew rate of 10V/µS for full power 20kHz use. Secondly, the big one is that no recorded music containing transient swings that large at a corresponding frequency - most recordings attenuate a minimum of 6dB and commonly 12dB from 20Hz to 20kHz. This reduces the requisite maximum rate of change. An excessive slew rate open the amplifier to instability, mandating the use of frequency compensation early in the circuit and there should be an inductor on the output to maintain EMI & RF stability. But, if one can have a high slew rate without sacrificing anything else, then there should be no problem.
 
Nikko75 said:
It's good to have an amplifier with a rate of change higher than required for powering capacitive loads, but there is no viable data supporting the requirement of hundred of volts per microsecond. Thre are two reasons for this, first, because the rate of change follows the square law in relation to the voltage magnitude. A 400W/8ohm amplifier only needs a slew rate of 10V/µS for full power 20kHz use. Secondly, the big one is that no recorded music containing transient swings that large at a corresponding frequency - most recordings attenuate a minimum of 6dB and commonly 12dB from 20Hz to 20kHz. This reduces the requisite maximum rate of change. An excessive slew rate open the amplifier to instability, mandating the use of frequency compensation early in the circuit and there should be an inductor on the output to maintain EMI & RF stability. But, if one can have a high slew rate without sacrificing anything else, then there should be no problem.
Click to expand...


A slew-rate of 10v/us is indicated for PA amplifiers (public address) for HI-FI amplifiers 10V/us interferes greatly within the audio range for those who use speakers with good tweeters and good audio tracks with harmonious content up to 40khz a slev-rate of 10v / us is unacceptable.
The minimum would be around 80v / us for HI-FI.
 
DVNOBLE said:
A slew-rate of 10v/us is indicated for PA amplifiers (public address) for HI-FI amplifiers 10V/us interferes greatly within the audio range for those who use speakers with good tweeters and good audio tracks with harmonious content up to 40khz a slev-rate of 10v / us is unacceptable.
The minimum would be around 80v / us for HI-FI.
Click to expand...
Crown Macro-Tech 5002VZ (2500watts per channel 2Ω) has a slew rate >30VµS.....So I don't know where you are getting this incorrect information from......
 
A while back I was communicating with John Siau of Benchmark and regarding slew rate he told me that-

"Slew rate is a function of output voltage and bandwidth. Rise time is only a function of bandwidth. For this reason, you can only compare slew rates when the amplifiers have identical output power. Use the rise time instead of slew rate to make comparisons between amplifiers of any power.

A 400W amplifier with a 200 kHz bandwidth will have twice the slew rate [as a 100W amp with the same bandwidth] (but the same rise time).This is exactly what you get when you run the AHB2 in bridged mono. This illustrates why slew rate can be misleading. Use rise time and not slew rate when making comparisons unless the amplifiers have exactly the same power.

4X power should have 2X the slew rate for identical bandwidth. Slew rate increases with the square root of the power for a given bandwidth."

Hope this helps.
 
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Stene said:
Slew Rate and Rise Time

There are some other amps having high figures and fast Rise Time.

Au-G90X and B-2102
Slew rate: 350V/µSec.
Rise time: 0,5µSec

But here is the King
AU-D11 II
Slew rate: 400V/µSec.
Rise time: 0,5µSec
Click to expand...

^^^
Slew Rate and Rise Time

There are some other amps having high figures and fast Rise Time.

Au-G90X and B-2102
Slew rate: 350V/µSec.
Rise time: 0,5µSec

But here is the King
AU-D11 II
Slew rate: 400V/µSec.
Rise time: 0,5µSec
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Ancient thread but I am trying to track down the slew rate of the AU-D11 ii (it is not show in the Operating Instructions). This comment above is all I can find, and it completely confirms my bias in trying to figure out why the AU-D11 ii sounds so energetic and fast! Maybe that's because it is! Prepared to be wrong here. Maybe there is more to the AU-D11 ii's magic than slew rate, or maybe that is it. 400V/uSec ???!!!

Can anyone verify?

AU-D11 ii listed specs

Screenshot 2024-11-30 at 7.54.52 PM.png
 
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AU-D11ii is one of the only x balanced/alpha type's that had a true dual mono power supply, like the AU-G99X & AU-D907x decade.

So that might be a factor ppl are unaware of when listening.

All 3 of those are pretty similar, all high slew rates too. although the D11ii had different output transistors than the other two.
 
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