[jlbrach]

everything sounds exactly the same no matter the price point,there now can we move on to something else?

 

[dougq]

https://shenzhenaudio.com/collectio...ldac-hi-res-audio-support-up-to-dsd512-768khz
This looks to make the stealth affordably portable now.

 

[Currawong]

I don't understand what you mean

....is what seems to be the case. Listen to actual instruments and how the notes decay, and what you hear. My main amp is a tube amp with vastly worse measurements than the A90D, yet I can hear the decay of notes -- the reverberation of strings and the like, far more clearly with it. It's not harmonic distortion either. It's also audible on the better solid-state gear I have. This is what I spent half my life hearing from a piano. You could describe actual music as distortion of the air, which in that case, your suggestion that I'm hearing distortion would be correct, but not in the sense you mean it.

The problem we have is, "good measurements" are being described as the THD or THD+N from a full-output (or 4V) 1kHz signal. This is like racing a car down a perfectly constructed flat test track at full revs, measuring the speed it is going at the 100 yard mark, then deciding that the performance of a car should be judged by that alone. If I were to compare cars this way, and do little else, I'd be laughed off the internet. Yet, here we are with much the same thing being done with audio gear.

BTW, the IMD of the Topping amps is several orders of magnitude higher than the THD, yet nobody points that out. Realistically, the best they can market themselves if they weren't be deceptive, is "Distortion better than 0.05%".

The most ironic thing about this is that as the Stealth has much lower distortion than other headphones, these things are all the more audible.

 

[theveterans]

....is what seems to be the case. Listen to actual instruments and how the notes decay, and what you hear. My main amp is a tube amp with vastly worse measurements than the A90D, yet I can hear the decay of notes -- the reverberation of strings and the like, far more clearly with it. It's not harmonic distortion either. It's also audible on the better solid-state gear I have. This is what I spent half my life hearing from a piano. You could describe actual music as distortion of the air, which in that case, your suggestion that I'm hearing distortion would be correct, but not in the sense you mean it.

The problem we have is, "good measurements" are being described as the THD or THD+N from a full-output (or 4V) 1kHz signal. This is like racing a car down a perfectly constructed flat test track at full revs, measuring the speed it is going at the 100 yard mark, then deciding that the performance of a car should be judged by that alone. If I were to compare cars this way, and do little else, I'd be laughed off the internet. Yet, here we are with much the same thing being done with audio gear.

BTW, the IMD of the Topping amps is several orders of magnitude higher than the THD, yet nobody points that out. Realistically, the best they can market themselves if they weren't be deceptive, is "Distortion better than 0.05%".

The most ironic thing about this is that as the Stealth has much lower distortion than other headphones, these things are all the more audible.

The first paragraph can be summarized in one word as "plankton" which to my experience is only unveiled on audio chain that has that capability

 

[PointyFox]

....is what seems to be the case. Listen to actual instruments and how the notes decay, and what you hear. My main amp is a tube amp with vastly worse measurements than the A90D, yet I can hear the decay of notes -- the reverberation of strings and the like, far more clearly with it. It's not harmonic distortion either. It's also audible on the better solid-state gear I have. This is what I spent half my life hearing from a piano. You could describe actual music as distortion of the air, which in that case, your suggestion that I'm hearing distortion would be correct, but not in the sense you mean it.

The problem we have is, "good measurements" are being described as the THD or THD+N from a full-output (or 4V) 1kHz signal. This is like racing a car down a perfectly constructed flat test track at full revs, measuring the speed it is going at the 100 yard mark, then deciding that the performance of a car should be judged by that alone. If I were to compare cars this way, and do little else, I'd be laughed off the internet. Yet, here we are with much the same thing being done with audio gear.

BTW, the IMD of the Topping amps is several orders of magnitude higher than the THD, yet nobody points that out. Realistically, the best they can market themselves if they weren't be deceptive, is "Distortion better than 0.05%".

The most ironic thing about this is that as the Stealth has much lower distortion than other headphones, these things are all the more audible.

Nearly all tube amps will have transformers for matching the high impedance of the tube’s anode to the low impedance of a speaker; most solid-state amps will not have a transformer in the signal path (yeah, I know about Futterman amps; to a first approximation, nobody has one).

That transformer, both because of its first-order performance (all transformers behave like bandpass filters) and also because of its effect on phase and the difficulty that presents for the feedback loop, creates a serious limitation on transient response. Bottom line: it’s not at all difficult to find a solid-state amp with better transient response than even a top-of-the-line tube job

Almost all tube power amplifiers use transformers, which may limit the low bass notes to a degree (and impact speaker damping in the low range), they can provide a pleasant "burnished" mid-range tone, just where the important parts of human voices, pianos and guitars exist.

The dynamic nature of tubes causes them to pass through slightly different operating conditions, over their range of output wattage. The result is a hint of natural compression that takes a little of the edge off of transients, as the volume goes up.

I guess it has to do with the output transformers in tube amps "smearing" the sound according to the above two posts?

 

[Currawong]

I guess it has to do with the output transformers in tube amps "smearing" the sound according to the above two posts?

No. That's not how transformers work. If that were the case, then the isolation transformers would "smear" the signal in network switches and cause drop-outs, as they operate at much higher frequencies. Please go and discuss it with someone who has some decades in audio electronics design about how things work, that is, if you really want to know and learn.

 

[PointyFox]

No. That's not how transformers work. If that were the case, then the isolation transformers would "smear" the signal in network switches and cause drop-outs, as they operate at much higher frequencies. Please go and discuss it with someone who has some decades in audio electronics design about how things work, that is, if you really want to know and learn.

The first quote I posted was from a retired electrical R&D engineer, the second from someone who's made hundreds of tube amps.
It's too bad Head-fi has driven off all the engineers and scientists or we could have a conversation like that.

The problem we have is, "good measurements" are being described as the THD or THD+N from a full-output (or 4V) 1kHz signal.

Is this what you're referring to?

 

[Currawong]

retired electrical R&D engineer,

Retired from making audio gear?

 

[PointyFox]

Retired from making audio gear?

You know what I mean. Anyway, if you don't recommend the pairing of the A90/A90D with the Stealth, what do you recommend besides the weird looking $5000 tube amp?

 

[Currawong]

You know what I mean. Anyway, if you don't recommend the pairing of the A90/A90D with the Stealth, what do you recommend besides the weird looking $5000 tube amp?

I'd say (and I think I posted as much before) that if you want to get the most resolution out of the Stealth as possible, without any colouration, of the gear I have experience with I'd get a Chord rig within one's budget, or a FiiO M17. After that, you're moving towards slight degrees of coloration with a Schiit Yggdrasil OG or Audio-gd Reference or HE DAC, though not with amps from either company, such as the Master 9 or Ragnarok. There's also the Headamp GS-X (though it has been a long while, so I haven't tried it with the Stealth), then the Mini (very slightly warm-of-neutral).

What I'd like to try with the Stealth more is the Luxman P-750u, though they are unobtainable outside of Japan now, sadly, unless you can find one used. While the various $500-$700 amps I've tried (Topping, Singxer etc.) can drive them well, there is a distinct drop in resolution compared to the higher-end amps. I think it has mostly to do with the power supply. Someone else suggested that people used to designing speaker amps make better headphone amps for that reason.

 

[alxw0w]

Lately I haven't been listening to the music (I mean I was but it was a background music for working out using JBL endurance run BT earphones - so not particularly serious listening) because of other important commitments.
Few days ago I had more 'free' time to sit with Stealth and music

And oh my god. These are THE headphones to keep. So freakin clean.
With electronica/trance (obviously not only) music I'm shocked how every note is well defined. No smearing no reflections just pure tones.
It's nice to sit again and sink into the pure music.

 

[Andrewteee]

Lately I haven't been listening to the music (I mean I was but it was a background music for working out using JBL endurance run BT earphones - so not particularly serious listening) because of other important commitments.
Few days ago I had more 'free' time to sit with Stealth and music

And oh my god. These are THE headphones to keep. So freakin clean.
With electronica/trance (obviously not only) music I'm shocked how every note is well defined. No smearing no reflections just pure tones.
It's nice to sit again and sink into the pure music.

Do you run the Stealth straight our of the Dave?

Love to see your excitement for the music.

 

[alxw0w]

Do you run the Stealth straight our of the Dave?

Love to see your excitement for the music.

Yes, directly out of Dave. But keep in mind that I don't listen loud. In 80-85 db. 85 being top. Mostly it's in the 80db range.

Occasionally I turn volume up to probably close to 90db.

 

[Andrewteee]

Yes, directly out of Dave. But keep in mind that I don't listen loud. In 80-85 db. 85 being top. Mostly it's in the 80db range.

Occasionally I turn volume up to probably close to 90db.

Thanks, I was just curious. Right now I run mine direct from a dCS Bartok. Also not very loud.

 

[PointyFox]

I'd say (and I think I posted as much before) that if you want to get the most resolution out of the Stealth as possible, without any colouration, of the gear I have experience with I'd get a Chord rig within one's budget, or a FiiO M17. After that, you're moving towards slight degrees of coloration with a Schiit Yggdrasil OG or Audio-gd Reference or HE DAC, though not with amps from either company, such as the Master 9 or Ragnarok. There's also the Headamp GS-X (though it has been a long while, so I haven't tried it with the Stealth), then the Mini (very slightly warm-of-neutral).

Chord is out since after repairing a few I think they're way overpriced for what they are. Also the outputs on the back look cheap and I dislike their user interfaces.
The FiiO M17 is an expensive portable device and I don't want to pay for portability on something I'm going to be keeping powered on 24/7 on a desk or take a chance that it's not made for continuous use like the Chord Mojo.

They are also small amps and as 6PANDEMONIUM6 said, having a big amp is better.

I'll use my big amps and you can use your tiny amps.

Schiit is out since the power switches are on the back of the units and I won't be able to reach it where I'd put it, the user interfaces are indecipherable, and the performance of the Yggdrasil is a complete mess with audible distortion and mains hum. I had to send my last Schiit amp back due to mains hum.

I'm not going to buy anything from Audio-gd after hearing about how they lied about measurements and how badly they actually perform (like bottom 20% of all amps).

The Headamp GS-X Mini looks promising, it's also bigger than my A90 Discreet.

As other people mentioned already in this forum, the Singxer (SA-1) is as good as good as a GSX Mini, also full class A.

Ehhh...gsx mini is not THAT great and the Stealth really showed it. Exactly the same reason Goldensound uses it as an example to hype up the ahb2.

So I'll trust you over everyone else because you're REALLY convinced you're right and order a GS-X Mini to compare against my A90 Discreet using my DCA Stealth.
Maybe everyone else is wrong?