LSA Voyager GAN Amplifier

What the 15khz test tone could potentially do is put strain on the amp, which in turn worsens the harmonics from the 1khz test tone. As well as increase the noise floor of the amp. Because performance within the audible band is what audiophiles care about. But some folks must only listen to music where all the tones are at 1khz. So this test would be meaningless for them.

🤦‍♂️🤦‍♂️🤦‍♀️

It’s not. And that’s what confuses people with no hands on experience. I read that thread over on ASR and the answers from the armchair engineers were to increase the bandwidth so harmonics out of the band of human hearing would tell us what was needed to know. Poor answer. That wouldn’t tell us any meaningful information.

What the 15khz test tone could potentially do is put strain on the amp, which in turn worsens the harmonics from the 1khz test tone. As well as increase the noise floor of the amp. Because performance within the audible band is what audiophiles care about. But some folks must only listen to music where all the tones are at 1khz. So this test would be meaningless for them.

Would there  be harmonic distortion from a 15khz tone that humans could hear or a band limited amp would amplify? Anyway this Voyager amp uses 2 stereo modules bridged which doesn't make sense to me, I think one could find a better amp for less mony.

You know very well we are talking about electronics here......of course, certain measurements of speakers are very important. 

That isn't what your statement said. You said:

What is so funny is that these "science is truth" people have no truth.   There are no double blind linstening tests that confirm one measurement is better than another.

Saying that this applies only to amps and preamps after saying something like that is changing the argument- the first statement remains false.

That old junker maxes out at -80dB THD+N. Useless for modern audio gear engineering. Especially for class D design work. No wonder you didn’t know Johnson noise existed.

To be clear, the conclusion isn't supported by the opening statement. You don't know anything about me; the conclusion is not only unsupported but also false. And I made my statement in the context of crossover components in a loudspeaker. I would be really interested if you could show that they make even a 10th of a dB difference to the noise floor. In practice that seems difficult at best since you'd need an anechoic chamber to prove it. Regarding the analyzer, its proven itself very useful during the class D project as have differential probes, smart tweezers and a decent thermal camera plus a fair amount of simulation.

With my analyzer cheap dummy loads have a -92dB noise floor.
 

Lol! This statement suggests that your analyzer isn't being run properly or its broken. 

The answer to that question is simple. Do a 2 tone test with 1 tone @ 1khz, and the other at 15khz. Then run the THD+N test. Then follow by the standard test of 1khz on its own. Then compare the THD+N results between the 2 tests. If the 2 tone has higher THD+N, it was obviously due to the influence of the 15khz tone. But thats not in the text book. So it's not possible.

🤦‍♂️🤦‍♂️🤦‍♀️

Looks like you’re making things up. Unlike you I actually posted some measurement results. Rather than just blindly trusting in your god Amir’s word.

Looks like to me whoever said that over on ASR was just testing to see if anyone knew what they were talking about. Because over on ASR, they only listen to music at 1khz. The answer to that question is simple. Do a 2 tone test with 1 tone @ 1khz, and the other at 15khz. Then run the THD+N test. Then follow by the standard test of 1khz on its own. Then compare the THD+N results between the 2 tests. If the 2 tone has higher THD+N, it was obviously due to the influence of the 15khz tone. But thats not in the text book. So it's not possible.

Over on ASR they don’t care about wide band distortion and noise. I was just reading over there about a new Topping amp. The sycophant’s were all jumping for joy because of the 1khz 5w THD+N. Because that’s what god Amir told them is the most important. So they completely ignored that the amp actually sucks using measurements that matter.

I was demonstrating how an audio analyzer can measure inconsistencies between cables. When you have hands on experience rather than just reading what the clowns on ASR say you can learn a few things. I measure stuff all the time with balanced connections and the consistency is spot on.

Pretty obvious from my replies AmplifierDude that I have more than enough experience when I can look at your numbers and know whether they are "real" or there is a flaw in them.

I’m kinda new with my analyzer. How do I measure to figure out the THD in the audible band with a 15khz signal? I’m using the dScope software.

https://www.audiosciencereview.com/forum/index.php?threads/what-tells-us-more-practice-or-theory.28502/

These were your exact words from Saturday, November 27, 2021. So you have become a measurement expert in the last 3 days? I stick to my previous comment. I do not think you know how to use your tools properly. Asking how to measure the audio band THD of a 15KHz reinforces that you do not understand the measurements (hint, there are 0 harmonics of 15Khz in the audio band, hence you cannot measure it). The last post even brings up your name. You may want to try to understand a multi-tone IMD test it will prevent saying things you may regret later. Will you grace us with your list of "measurements that matter" ?

In respect of other people here, I will not respond to this more, as the thread is already off track.

I was demonstrating how an audio analyzer can measure inconsistencies between cables. When you have hands on experience rather than just reading what the clowns on ASR say you can learn a few things. I measure stuff all the time with balanced connections and the consistency is spot on. 

The one you indicated as balanced has worse channel matching. The one you indicated as unbalanced, had unrealistic channel matching. 0.005% gain difference. That is highly unlikely on anything "real" two channel.

They’re both single ended cables. Think I don’t know what measured worse?

Buh Bye Mike.

Best to ignore the sod and his partners (they are ll in his head)

@mivmike ,

This is why I prefer balanced.

The one you indicated as balanced has worse channel matching. The one you indicated as unbalanced, had unrealistic channel matching. 0.005% gain difference. That is highly unlikely on anything "real" two channel.

The other measurement was matched to 0.015db between channels.

I think you need to spend more time with your tools before posting stuff and learn to interpret what your post means.

Once upon a time, long, long ago, this thread was about the LSA Voyager.

I think some comments were being deleted regarding LSA Voyager.  Blink and you'd miss it.  Perhaps people just gave up - something fishy, to my mind..

Once upon a time, long, long ago, this thread was about the LSA Voyager.

That's about all for me. Just stopping by. 

Here’s how a proper digital input integrated amp measures. 1khz 24/192 PCM test tone played back in Roon, then over fibre Ethernet, streamer, DAC, pre, and amps. And into a proper 4 ohm dummy load. And at 1w not 5 like your god Amir uses.

Judging by this statement, and the name, I will make the wild guess that you are also "amplifierdude", so did you already get banned with that name here? How many times did you get kicked off of other websites? 

I don't believe YOU made that test with the resistor. Those numbers were taken from ASR I suspect, but not with Mills resistors. From what I can tell of your other posts, you don't know how to use your Dscope

Show me some results with your analyzer then. Sounds like you're one of those armchair engineers who learnt everything he knows over on ASR. 

When you get into high resolution measurements, even the cables can mess things up if you're not balanced. I tested a dongle DAC recently with a single ended headphone cable hooked up to it. Couldn't get a balance channel to channel

So tried another cable and got this:

This is why I prefer balanced. 

mivmike

16 posts

11-30-2021 1:56am

I’ve tried many. I’m not into crappy amps, so those dummy loads are useless for me. I have a hot rodded Dscope. Can do up to -116dB THD+N.

It doesn’t take much at all. Can’t even do a 5w 1khz THD+N measurement.

What amplifier and analyzer did you test this with?

It doesn’t take much at all. Can’t even do a 5w 1khz THD+N measurement.

People always claim that the driver distortion is so high that the quality of electronics don't matter. I'm sure I'm not the only one on here who has heard a difference between audio components. 

If you test an amplifier using these dummy loads:

https://www.parts-express.com/4-Ohm-100W-Non-Inductive-Dummy-Load-Resistor-019-015

The Johnson noise, as well as nasty distortion drowns out everything at -92dB THD+N. You need a bank of premium metal foil resistors. I use a bank of these:

https://www.mundorf.com/audio/en/shop/Resistors/MResist_ultra/

And can measure up to -116dB THD+N with them.

But most passive crossover use garbage like these:

The "noise" from these resistors wouldn't even begin to register let alone reduce your THD+N to -92db at any reasonable amp power. You didn't state what power level you were using, so claims of distortion impact are suspect.

No need for exotic and very expensive Mundorf resistors though. There are two parameters, one is thermal modulation, and that is a factor mainly of size, and the other one is voltage dependent resistance, and that just requires the right resistor material, it does not need to be at all exotic.

Of course the speaker driver THD is -50 to -60db.

Here's what you find in the top of the line Revel Salon 2's. All made by Bennic in Taiwan.

If you test an amplifier using these dummy loads:

https://www.parts-express.com/4-Ohm-100W-Non-Inductive-Dummy-Load-Resistor-019-015

The Johnson noise, as well as nasty distortion drowns out everything at -92dB THD+N. You need a bank of premium metal foil resistors. I use a bank of these:

https://www.mundorf.com/audio/en/shop/Resistors/MResist_ultra/

And can measure up to -116dB THD+N with them.

But most passive crossover use garbage like these:

Good articles here. Components don’t need to be active to add noise and distortion.

Resistors cause Johnson noise:

https://www.analog.com/en/analog-dialogue/raqs/raq-issue-25.html

Metal core inductors cause hysteresis distortion:

You could have measured distortion of 3 billion db down and still the amp would only sound as good as the execution and parts (the tons of things that cannot be measured yet make a serious difference in sound). 

There is no such thing as "distortion below audibility". What we hear is WAY way more than what we can measure.

This may not be the most out there thing I have heard in 30+ years in audio, but it ranks right up there, and certainly the top of the last year. It is probably just better to admit you are not an expert on what measurements can be made and what they can tell us.  I will let Bruno know next time I see him that you want to teach him how to design amp properly. I am sure he will welcome the input.

LOL.

And you sure share what you think is crap.....

What a joker.

So long Mr Wonderful.

Still waiting for your recommendations.

You'll be waiting a long time. I believe everyone has their own personal taste so rather than tell people what good sound should be I prefer to let people find their own way.

Rats where I’m from get hung and quartered. So shocking for me. 

@mivmike funny inside baseball. Well the way he was making friends and influencing people no shock there.

Still suspicious though.

Take care Mike…

 

Mike,

Come over to my house and bring your best open hearted love, open mind and bliss and I will show you how to do listening tests to various subtle things that improve the sound of equipment. Don’t need no alcohol to get high/low.......we are already infinite joy and bliss......live it now.....it is way more fun than being right.....way more fun....way more fun....way more fun....way more fun.....

Ok I’ll drink the whiskey, and you can just listen. Then let me know if my analyzer was able to help me make the sound better or not. In combination with listening tests.
 

When you have a fully equipped tool chest, your work doesn’t suffer.

Oh looks like he’s not banned, but blocked from posting. How come you have the only inside baseball on this Jerry?

Because when you know someone, and people are accusing you of being them, I don’t think it’s out of the ordinary to notify them of this. I’ll shoot him an email so he can respond as well. 

Not sure and why would he be reaching out to you?

Think he would be more concerned about the accusations from you shuttering your business if he was a friend.

Really a big coincidence there.

But who cares you seem to be nicer as Mike than @amplifierdude

We will see.

Yes Jerry I read the thread and responded to the same concerns anyone with an ounce of knowledge would. And @amplifierdude did notify me of this thread, and the accusations made about me. But as far as I know he’s not banned and could post for himself at any time. So why would he make a new account?

Mike,

Come over to my house and bring your best open hearted love, open mind and bliss and I will show you how to do listening tests to various subtle things that improve the sound of equipment.  Don't need no alcohol to get high/low.......we are already infinite joy and bliss......live it now.....it is way more fun than being right.....way more fun....way more fun....way more fun....way more fun.....

Why no referencing every single one of your posts Jack-A.

Not actually post anything of value.
 

Is this an example below of what you meant when you posted the above?

@mivmike Yep sure do. How are you? Was your Thanksgiving nice?
 

Yes not bad. But I live in Canada and that was back in October for me. 

@mivmike Yep sure do. How are you? Was your Thanksgiving nice?

The only double blind tests that were ever done showed that people cannot hear anything in a double blind test........so show me the results of phase shift of an amp....or .001 versus .1 percent distortion

If people can't hear a 3 dB difference in distortion when a controlled test is performed, then either your "everything matters" mantra is wrong or your tweakies produce a greater than 3 dB increase in distortion. Seems people can only hear these claimed "improvements" if they pay you for them. More "trust me" as the money changes hands.

You got Mike this time. Do you have something to say to me?

@twoleftears Yes sir I have and will probably at some point acquire the Benchmark unit it is an A/H unit. I keep looking for a used one in the $2K range.

Come over to my place with a bottle of Whiskey Ric. I can show you how an audio analyzer can be used to make better sounding gear. Most industry standard measurements are useless for anything but marketing purposes though. And the tin ears over on ASR will be the first to mislead you on what to measure for. 

Hp 8903B Old but it does the job.

Clearly some ’tube guys’ do have analyzers on hand...

That old junker maxes out at -80dB THD+N. Useless for modern audio gear engineering. Especially for class D design work. No wonder you didn’t know Johnson noise existed. With my analyzer cheap dummy loads have a -92dB noise floor. But your analyzer wouldn’t even pick that up.