Is it time for the traditional 1kHz tone test for amp power to go? (brief Amir name drop)

[Bruce Morgen]

 

[Blumlein 88]

He is either incompetent or intentionally deceptive.

 

[Bruce Morgen]

He is either incompetent or intentionally deceptive.

At one point in the video he does admit to being "blackout drunk" on at least one occasion, so there is that -- and his shot at John Darko was well aimed. As for the rest? I'll leave that to folks who have more technical chops -- and patience -- to deconstruct.

 

[Blumlein 88]

At one point in the video he does admit to being "blackout drunk" on at least one occasion, so there is that -- and his shot at John Darko was well aimed. As for the rest? I'll leave that to folks who have more technical chops -- and patience -- to deconstruct.

We could start the deconstruction, but damn this BS is tiring. As the saying it takes an order of magnitude more effort to refute BS as it does to spout BS. Brandolini's law. I can spot a few problems even without him telling you enough to know what he is really doing with his test. Do I want to bother when it is obvious he is probably lost in what he is doing? Or worse if it is just throwing crap out to get noticed.

For starters is he doing his measuring with a cheap multimeter. One which might respond pretty well to 1 khz or 2 khz, but which would be deaf to 20 khz or all those higher frequencies in a noise signal. Is the noise signal pink, white, what is it? How is he setting level, setting it with a 1 khz tone and then switching to noise?

 

[valerianf]

It is the first time that I watch a SA review.
Well what the reviewer found may be accurate:
The load dependency was noticed by Amir.
The low amplifier gain was measured by Amir at 20.9dB.
The channel crosstalk issue is obvious on the SA video.
I can even listen high frequencies distorsion characteristic of bad class D amp design.

Regarding the issue driving a complex load, it is possible.
Alas Amir did not use a complex load (he has one) during his test.
Did this missing test avoided a bad rating for this Wimm amp?
Only Amir can answer as he has a power load that can simulate a complex load.

Regarding the 1khz test, it is an industry standard.
By itself it is far from sufficient to characterize a good amp.
Many other tests are needed.

 

[Blumlein 88]

It is the first time that I watch a SA review.
Well what the reviewer found may be accurate:
The load dependency was noticed by Amir.
The low amplifier gain was measured by Amir at 20.9dB.
The channel crosstalk issue is obvious on the SA video.
I can even listen high frequencies distorsion characteristic of bad class D amp design.

Regarding the issue driving a complex load, it is possible.
Alas Amir did not use a complex load (he has one) during his test.
Did this missing test avoided a bad rating for this Wimm amp?
Only Amir can answer as he has a power load that can simulate a complex load.

Regarding the 1khz test, it is an industry standard.
By itself it is far from sufficient to characterize a good amp.
Many other tests are needed.

No it is not accurate. The amp in question probably has issues, but not the way shown in this video.

Having glanced at this guys videos on a couple other items I have no idea why he calls it Scientific Audio. He doesn't do any real testing, and from what I can gather does not know how.

 

[Ze Frog]

The guy's attitude and demeanor preaching away thinking he's being really clever is pretty annoying. He's the type of person who Springs to mind when somebody says 'audiophile'. He makes a couple of fair points, but he isn't someone I'd follow or look to for advice. Sad thing is, he probably genuinely feels he's one upped those he mentioned and somehow is the greater authority, poor guy.

 

[Ze Frog]

No it is not accurate. The amp in question probably has issues, but not the way shown in this video.

Having glanced at this guys videos on a couple other items I have no idea why he calls it Scientific Audio. It doesn't do any real testing, and from what I can gather does not know how.

Yeah, he hasn't done any science, he's only borrowed such from others and then tries to pan them. Considering his channel name he's a joke really, no information is his own and even his opinion you have to wonder if he's even managed to form that by himself.

 

[pkane]

No it is not accurate. The amp in question probably has issues, but not the way shown in this video.

Having glanced at this guys videos on a couple other items I have no idea why he calls it Scientific Audio. He doesn't do any real testing, and from what I can gather does not know how.

The guy is @SimpleTheater, of First Run Copper fame. You can ask him

 

[Bruce Morgen]

Right after the first comment showed up after my OP -- mea culpa -- I left a comment under his video. He nuked it.

 

[Chrispy]

Why even give this youtuber a click?

 

[Blumlein 88]

@SimpleTheater You willing to answer questions about your test methodology using stereo noise?

 

[amirm]

When you test an amplifier and only measure 0.1 watt, it is time to look at how you are measuring. No one would be buying that amplifier if it only produced 0.1 watts of power.

Here is my multitone test at 5 watts:

How come I am getting 5 watts with a signal that is far worse than any piece of music?

As noted, he doesn't remotely have the right setup to measure such things. Those meters are not qualified to measure noise and even if they were, they are too slow to respond to dynamic nature of it.

He needs to go back to satire and leave hardware reviewing to others.

 

[amirm]

Also as noted, analog crosstalk is not great:

See inset. But folks are going to use this with digital input where that is not a problem at all.

 

[sam_adams]

Why even give this youtuber a click?

Apply the jaundiced eye that we have all developed when looking at questionable content.

 

[totti1965]

How come I am getting 5 watts with a signal that is far worse than any piece of music?

As noted, he doesn't remotely have the right setup to measure such things. Those meters are not qualified to measure noise and even if they were, they are too slow to respond to dynamic nature of it.

But music can contain much more than 32 tones at the same time! What about following his suggestion and doing the test with noise from 125 Hz to 7 kHz in a propper measurement-setup with
a) an on chip digital-amp like the Fosi V3 and
b) a discrete Transistor amp with the same nominal power ratings

there is also one other thing that have to be done for science sake:

Could it be that one part of the fascination of tube amps is their behavior with extremely low voltage /power?
Normally you measure these things down to 100 or maybe 30 Milliwatts
What is the behavior of a standard transistor amp at 1 or even 0.01 Milliwatt?
Maybe a transistor is „collapsing“ then, because a transistor is an expert in current not in voltage like tubes, which perhaps can follow these finest signal perhaps quicker and with LESS noise.

A friend of mine used to use a classical Altec 604 E Driver in an 300 liter Shindo Enclosure.
He may have 95 dB at 1 meter at 1 Watt realistically.

If we hear music in a 10 food distance and the loudest peaks are at about 80 dB,
You can imagine where the music mostly realistically plays: less than 65 dB!
So we are in the „ less than some few milliwatts“ range…..


thorsten

 

[peng]

But music can contain much more than 32 tones at the same time!

But why does it matter? The amplifier will only see one value at any particular instant regardless of the "tones", or number of tones anyway. The 32 tones test Amir has been doing is already extra miles, that many reviewers don't bother with covering. To an amp, as long as slew rate, distortions etc. are not non issues, then we shouldn't have to be concerned about what waveform it has to deal with, many amps even would even do well (not perfect) with square wave (in fact, any non sinusoidal waveforms) has infinite number of tones, i.e. harmonics, not sure if SA knows that though.

 

[RayDunzl]

But music can contain much more than 32 tones at the same time!

Want more frequencies?

Feed the amp a 10hz square wave and count the harmonics and verify the levels...

 

[Blumlein 88]

Want more frequencies?

Feed the amp a 10hz square wave and count the harmonics and verify the levels...

You need to feed that into some of pkane's software. It lets you pick really, really big FFTs.

 

[totti1965]

Want more frequencies?

Feed the amp a 10hz square wave and count the harmonics and verify the levels...

Hallo Ray, hey folks,
Can you tell me, what the graph says?
For me as a non technical guy, I just want to know, if you find the thoughts of the scientific audiophile intelligent / relevant or not.
What he stated is: with real music / or pink or white noise the modern digital desktop amps don’t perform well.
This is not what I hear, if I compare the Fosi V3 with other amps. I think it sounds like a good tube amp.
But this is just subjective.
Is the scientific audiophile perhaps at least a little bit right?

thorsten