LSA Voyager GAN Amplifier

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.

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. 

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

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

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?

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. 

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

 

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.

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

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.

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:

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. 

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

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:

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

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. 

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. 

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.

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?

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. 

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.

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.

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

Funny it runs properly when I use the Mundorf resistor based dummy load. I guess the analyzer must have a brand bias. 

To be clear, the conclusion isn’t supported by the opening statement. You don’t know anything about me

This isn’t about you. It’s about the specs of the analyzer you claim to own. Unless the manufacturer is lying. There's been some innovations in this field since 1982.

I guess if a tree falls in the forest it really doesn’t make a sound. That is, only if you don’t have the ears to hear it, or the equipment to detect it.

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.

Why would an anechoic chamber be required? The proper way to measure the noise and distortion of the system before the drivers is an audio analyzer. Would you measure an amplifier though a speaker in an anechoic chamber?

The point of the 15khz tone is to see if the amp struggles with those frequencies. As most amps have a much harder time as the frequency climbs above 1khz. And there’s meaningful content in music above 1khz.

Most audio specs aren’t to prove how good the gear handles music. They’re simply for marketing purposes. And when the consumer doesn’t understand what actually matters, 1khz is enough to get the job done. ASR is a great example. The quality chart that everyone buys gear based on is all of a 1khz THD+N spec. So Amir's partners (Topping for example), just need to design gear that maximizes that spec (sound quality with music irrelevant), and the commissions come rolling in from the frenzy of sales. 

And the only thing ASR sycophants care about is 1khz SINAD. Here’s the holy grail for them. The best way to land sales is to keep the consumer dumbed down to only needing to understand 1 number.

If Amir really wanted to educate people. this chart would be of THD+N vs power vs frequency over a 20-20k bandwidth. But his Chinese partners would have a harder time winning that game.

Just noticed that Amir deleted most of my likes from my old ASR profile. He was so jealous when I had more than he did. 

Just explaining ASR to folks who don’t understand what it’s all about. There’s been lots of talk here on this thread about ASR before I arrived.

Keep adding value Jerry. Not sure what this forum would do without your vast expertise. 

I’ve known Amir for 6 years. Long before he started ASR. He made me my own section on his previous forum "what’s best forum". Because I quadrupled the amount of traffic with my posts. But then he got banned from his own forum from his own partner!

I was one of the original members back when the forum was dead. It was me who told him how to increase the traffic to the forum. It was only because he took my advice that the forum is where it’s at today. But when I seen his true motives, I had enough.

 

You just do not understand what you post.

The Hypex graph above is at one power level, 5 watts or about 1% of it’s output. There is about a 15-16db change from 200-20Khz. I don’t know what is happening below 200, seems all over the map. Even at 5W, the Topping only has about a 20db change from 20Hz - 15KHz. That is not much different from the Hypex.

If you test the Topping at 1%, or about 1W, then it has only about 2 or 3db change over 20Hz - 15KHz. That is quite a bit better than the Hypex.

You could choose to stop posting stuff that gets holes blown in it. Or not.

Obviously I understand that one is power vs distortion at multiple frequencies measured individually. And the other is THD+N vs frequency over the entire bandwidth. Which is a very useful test that should have been included in the Topping review. But it wouldn’t have been pretty. There’s a 20dB difference in noise and distortion at 5w between 1khz and 15 with the Topping! Only 20dB? 20dB is loads! with the Hypex it’s flat as a pancake. And thats a 10 year old amp design!

And with the Topping by 50w output its a 35dB spread! Horrible performance!

But the Topping is still the 2nd best amp in the world according to your mentors.

I admittedly read the graph wrong

Admitting is a good 1st step

@mivmike -- you didn't even know how to use it 3 days ago, sure your stuff went up ...

Yeah I've only had the unit for 3 years and designed several products with it. But someone who's never used one before knows better. And before I bought one I worked with people who did. 

Don't expect to get respect from Bruno when he knows what he is talking about and you do not. Hysteresis in the inductor is just yet another form of non linear distortion, like any other distortion. If you apply negative feedback it gets reduced by a compensatory amount, and his amps have a lot of feedback because the can.

The inductor is in the feedback loop, hence any hysteresis distortion is drastically reduced by the feedback.

He is not saying it does not exist at some point in the circuit, he is saying that he effectively eliminates its audible effects, which is self evident from the distortion measurements.

You just learned about hysteresis distortion tonight from the articles I shared. And you're already an expert!