Watts Up...?
Oct 17, 2020 at 8:01 AM Post #1,981 of 3,523

Amberlamps

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The increasing sales are no surprise to me. It is an awesome DAC and I take my hat off to you for nailing the DAVE so successfully that it doesn’t need an updated model.:relaxed:

Everything needs an updated model, it's just a matter of time.

6 years later is multiple lifetimes ago when it comes to moores law.
 
Oct 17, 2020 at 11:33 AM Post #1,982 of 3,523

Triode User

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6 years later is multiple lifetimes ago when it comes to moores law.

Hey Steve, how are you? I thought Moore’s Law had underlying health issues even before it caught Covid and was of declining health.:stuck_out_tongue_winking_eye:

Anyway, you don’t fool me. I know you are just trying to manipulate the market so you can pick up a cheap Dave.

You sly dog!
 
Oct 17, 2020 at 4:18 PM Post #1,984 of 3,523

Triode User

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You didn't know that he is the person ahead of @musickid in the DAVE order queue?
His special paint job will take a year, so musickid has a long wait.
:wink:

The man with the Golden Gun Dave. :stuck_out_tongue_winking_eye:
 
Oct 18, 2020 at 4:18 PM Post #1,987 of 3,523

alxw0w

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@Rob Watts Recently I switched to the Dave.
And have question about usb vs optical and RFI thing.
I've done many test switching between USB and optical using the same streamer (raspberry pi with hifiberry digi+pro - battery powered)
And my observations are:
- USB sounds a bit more colorful (?) sound pops out more, has more of WOW effect
- optical sounds a bit veiled in comparison doesn't have this WOW effect is calmer/smoother (?)
BUT
Whats more important using optical I can listen for very long time. I Don't get any fatigue, with USB after some time (about hour)
my ears feel tired, music isn't so smooth. Even though for first 5-10 minutes of listening you would prefer USB input it's not my option I'm sticking with optical.

As I understand correctly this wow effect with usb and fatigues can be due to RFI noise getting into the chain ?
Or maybe something else is going on ?
 
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Oct 19, 2020 at 1:17 AM Post #1,988 of 3,523

Rob Watts

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Yes what you are hearing is exactly consistent with random RF noise increasing noise floor modulation within Dave.

My only very big surprise is that it is so obvious for you; my own listening tests with Dave USB against optical revealed a barely audible tiny change, certainly not one that would give listening fatigue. Another puzzling feature is a Raspberry Pi is power efficient, and you state it's battery operated - which should improve things dramatically. Remember too Dave has galvanic isolation on it's USB inputs, so RF ground currents are (almost) eliminated.

But then the problem with this hobby is your mileage will (or may) vary - either because of different systems, or different listeners!

I am always open to the possibility of something else going on, but I think in this case it's unlikely. RF noise is very pernicious, and the brain seems incredibly sensitive to minute changes in noise floor modulation. In this case it would be unmeasurable as USB has identical measured noise floor modulation as optical - and I can resolve the noise floor at -180dB with Dave. I have also heard noise floor modulation that was easily audible that was well below -180 dB - and I knew it existed from digital domain measurements. And what you are hearing is completely consistent with the audible effects of noise floor modulation.
 
Oct 19, 2020 at 4:32 PM Post #1,989 of 3,523

miketlse

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And my observations are:
- USB sounds a bit more colorful (?) sound pops out more, has more of WOW effect
- optical sounds a bit veiled in comparison doesn't have this WOW effect is calmer/smoother (?)
BUT
Whats more important using optical I can listen for very long time. I Don't get any fatigue, with USB after some time (about hour)
my ears feel tired, music isn't so smooth. Even though for first 5-10 minutes of listening you would prefer USB input it's not my option I'm sticking with optical.

As I understand correctly this wow effect with usb and fatigues can be due to RFI noise getting into the chain ?
Or maybe something else is going on ?
I know what you mean.
Maybe 4 years ago, I did a similar comparison with my Mojo.
I listened to recordings of choirs accompanied by lute, playing in churches or large rooms.
I tried using both optical and usb cables.
Like you, I felt that optical sounded slightly dulled, but usb gave a slightly brighter 'more alive' sound.
The analogy I concluded was that optical sounded 'like a recording' but usb sounded like 'being in the audience listening to live music'.
I easily decided that I preferred the usb cable.

A few weeks later I had the opportunity to listen to a choir accompanied by lute, playing in a local church.
To my surprise I discovered that the choir and lute, did have that slightly dulled edge to the music, which reminded me of the optical cable.
My initial conclusions had been wrong, so since then I have used optical cables.

You will read many posts from owners who prefer that brighter 'more alive' sound, and they spend thousands on cables, power supplies,... in order to achieve that sound.
Rob is correct about RFI, but I am sure that occasionally he must despair at some of the posts he reads.
 
Oct 26, 2020 at 4:57 PM Post #1,990 of 3,523

Reactcore

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Hello @Rob Watts, im a grateful Qutest owner.
I have been reading quite a lot in the Chord dac forums here and have seen you talking being amazed by how the ear/brains are so well at resolving space perception. Pinpointing the origin of sounds. Which can only be poorly achieved by record and play.

I wonder what your thoughts are on HRTF (Head Related Transfer Function) and research about it. Now i've been reading several interesting postings about how the brain uses reflections of sounds on ones ear shells and torso to calculate space perception based on phase and timing differences on direct and degraded reflected signals entering the ear canals. Normally these personal reflected signals are not taken into account when recording and playing. But if reproduced acurately on headphones it can sound real close to the reality where someone can actually hear things far away or behind, under, above the head.

For example just try this demo film made with a Realspace plugin in Unity software.



This demo software can be downloaded and run on a PC to try too.
(Yes i know its far from a good quality recording being a lossy youtube film but is about the technique)

Key is that ones OWN ears and torso must be used in the reflections reproduction in order to get it right. Simply using a standard model gives maybe only a few percent of what can be achieved.

In the simulation they used a 'average' virtual head model so its not too close to reality but the sense is really noticable, specially when entering the 3rd room where, on the lift, i can easily hear under and above me.

Further i came across the Realizer from Smyth research where they developed a 16 channel virtual room processor for use with headphones with which they can emulate sounds in any environment where they 'recorded' the ambiance, like a recording studio in london or a church.

They say to get it 'right' by measuring the HRTF reflections of a person using 2 tiny microphones placed inside ones ears folowing by playing calibration signals through a speaker setup. Then store this personal HRTF file to be used by this person for creating the realism.

It seems they are even selling virtual environment files for use with their equipment to recording studios.

I'm just unlucky that i could'nt have a demo myself of it yet calibrated on my own ears, but will if i get the chance.

Also i quietly guess they can improve on the DAC processing used on their product. (Assuming they use 'standard' chips)

Bottom line is that i think that reproducing the signal perfectly as the analog original is not the only condition needed to get real space (and depth) perception in replayed recordings.

Thanks for reading,
Rick
 
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Oct 31, 2020 at 7:04 AM Post #1,991 of 3,523

Pesis

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Hi,

I’ve been reading your insights here on head-fi, very interesting, thank you!

I would like to ask your thoughts about amplification - somewhere you mentioned you are not a fan of class D amplification because the switching has negative effects on transient timing. What are your thoughts on preamps and amps that employ feedback correction? There are several new headphone amps/preamps/amps that use this and achieve very good readings on noise/distortion measurements but how about transient handling/timing in these?
 
Nov 2, 2020 at 6:14 AM Post #1,992 of 3,523

Rob Watts

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If the effect of the feedback is to improve high frequency (10 kHz plus) linearity then the feedback is a good thing; but if it degrades it (which poor implementation can do) then it will be worse sounding.

The devil is in the detail!
 
Nov 4, 2020 at 2:37 AM Post #1,993 of 3,523

IgeNeLL

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I know what you mean.
Maybe 4 years ago, I did a similar comparison with my Mojo.
I listened to recordings of choirs accompanied by lute, playing in churches or large rooms.
I tried using both optical and usb cables.
Like you, I felt that optical sounded slightly dulled, but usb gave a slightly brighter 'more alive' sound.
The analogy I concluded was that optical sounded 'like a recording' but usb sounded like 'being in the audience listening to live music'.
I easily decided that I preferred the usb cable.

A few weeks later I had the opportunity to listen to a choir accompanied by lute, playing in a local church.
To my surprise I discovered that the choir and lute, did have that slightly dulled edge to the music, which reminded me of the optical cable.
My initial conclusions had been wrong, so since then I have used optical cables.

You will read many posts from owners who prefer that brighter 'more alive' sound, and they spend thousands on cables, power supplies,... in order to achieve that sound.
Rob is correct about RFI, but I am sure that occasionally he must despair at some of the posts he reads.
When you use optical pls be reminded of the process.
- Convert electrical signal to the light signal.
- Convert a light signal to an electrical signal.

Optical theoretically have more bandwidth and speed of propagation however, the signal is converted 2 times, which is more likely for error to happen in the signal chain.
 
Nov 4, 2020 at 10:36 AM Post #1,994 of 3,523

jarnopp

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When you use optical pls be reminded of the process.
- Convert electrical signal to the light signal.
- Convert a light signal to an electrical signal.

Optical theoretically have more bandwidth and speed of propagation however, the signal is converted 2 times, which is more likely for error to happen in the signal chain.
But if there were any errors, it would be immediately audible, correct? So, in practice, optical is error free in every competent setup.
 
Nov 4, 2020 at 2:56 PM Post #1,995 of 3,523

Uncle Monty

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I agree with the comments on optical vs USB - to me, optical sounds softer, more rounded, darker whereas USB is brighter and more 'in your face'. I can listen to optical without becoming tired, USB not so much.
 

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