# DAC Noise Modulation: Chord DAVE vs Topping DX7 Pro+

#### HarmonicTHD

##### Major Contributor
Forum Donor
So Rob wants to eradicate art now? The man is clearly even more evil than even I dared to assume
We all don’t know what is going on at -300dB - maybe unknown eternal bliss and Nirvana. Some achieve it after a lifetime some will never.

#### RayDunzl

##### Grand Contributor
Central Scrutinizer
Note: these tests are pushing limits of physics and instrumentation. Distortion measurements at -150 dB and lower is just crazy!

In linear terms...

If the 0dB (signal voltage) were the height of Mt Everest...

The noise level would be 0.0110168694036009 inches.

That is, according to the scribblins I made on the back of my nakkin.

That's 0.27982848285146283418 mm for the folks on the other sides of the borders.

Last edited:

#### Geert

##### Major Contributor
It's simple. Air is made of N2, O2, Argon, and small amounts of CO2, H2O, and other stuff. "Air pressure" is created by those molecules individually bouncing off the surfaces of things. INDIVIDUAL MOLECULES doing that.

This means, at the lowest level, air pressure consists of noise. Because the "averaging" is enormous, the DC component is what we call air pressure. Obviously.

But, now, let's talk about the AC component. Without going into a whole lot of mathematics that is impossible to type in ASCII, the answer is

"For an average sized eardrum, the noise due to the molecular nature of air is somewhere around 6 to 8.5 DB SPL white noise." Yeah. Really.

Now detectability of noise goes by how much energy there is in every ERB, an ERB being the cochlear filter bandwidth around any chosen frequency between about 20Hz and 19000Hz (hearing above that is limited to the very entrance to the basilar membrane and the filter bandwith at the entrance). At low frequencies, an ERB is about 40Hz wide, give or take. When 1/4 octave is wider than 40Hz, then it grows more or less by 1/4 octaves.

Using all that established knowledge, we figure out that the atmospheric noise is JUST below the absolute threshold of hearing at the most sensitive point in an undamaged person's ears.

Using other established knowledge, we know that a tone is masked by noise in an ERB when it's about 5.5 dB lower than the noise in the ERB. There are some circumstances that may make this number 8dB.

So, let's make this 10dB (being conservative). Using a very narrow estimate for ERB's (that has to be over conservative), the noise floor in the most sensitive band is at about -20dB SPL. This means that detecting tones below -30dB SPL is, frankly, not going to happen.

#### Peternz

##### Active Member

1. DAVE is obsolete and it is not fair to compare it with a new product that costs less than a 10th of what it costs.

2. DAVE is only worth buying if you prioritize brand, styling and hype above sound quality.

3. People are different and they have their own priorities. It is their money and how they spend it is up to them. Insisting that everyone do their utmost to get the greatest bang per buck in terms of sound quality is pointless.

4. If you must have a DAVE you might be able to pick up a used one up for a reasonable price.

5. I am so glad that I never really fell for the Chord hype. (I admit I did once own a Mojo but I found the experience annoying.)

And while I am here, let me thank Amir for his wonderful work. It has enabled me to assemble a system that gives me a very satisfying sound while remaining well within my budget.

#### Axo1989

##### Addicted to Fun and Learning
We all don’t know what is going on at -300dB - maybe unknown eternal bliss and Nirvana. Some achieve it after a lifetime some will never.

Have you watched Martyrs? It's had work getting there.

#### Rottmannash

##### Major Contributor
Forum Donor
A Topping DAC after couple of years ain't worth much, a Chord is!
Not that you mind in Toppings case, since it was cheap enough.
But in Dave's case, if you suddenly are told, that it is crap and you have been done by some science forum, THEN!
you can count your lucky stars that it has a good resale value!
Which still should be good enough to buy few box fulls of Toppings.
You don't think my D90SE won't be worth much in a couple years?

#### Blumlein 88

##### Grand Contributor
Forum Donor
You don't think my D90SE won't be worth much in a couple years?
I believe the D90SE likely will bring 50-60% of its original cost in a couple years. Which is about what the Chord gear (or other expensive high end brands) do. I used expensive DACs for probably a couple decades. Purchased a couple or three years old, kept for a couple years, and resold usually for what I paid or very nearly so. The big drawback to selling even good inexpensive items is shipping is too large a fraction of selling price so you have to stay local for it to make sense. A used item for \$6k makes shipping only a small portion of the cost.

#### Kollin

##### Member
What same Chord ugly.
However, like the rest of the products of this company.

#### Music1969

##### Major Contributor
ASR's Chord DAC measurements these last few months have caused Rob a bit of a headache.

Forum Donor

#### Music1969

##### Major Contributor
Conveniently omits the part about him making (presumably) a decent amount per DAC sold. Wonder what he prefers Chord customers to buy. A Dave and an Mscaler or a Mojo 2?
Sing it with me now: money money money moneyyyyy

#### Mart68

##### Major Contributor
Forum Donor
It's typically used in reference to durable goods. For example, "Due to concerns with Covid exposure, he invested in a home theater setup." You may disagree with accepted English usage, but that doesn't make it incorrect.
That is now accepted usage of 'Invested' but I strongly suspect it acquired that usage fairly recently and the usage was coined by advertisers and salesmen.

Then there is this defintion:

[countable] a thing that is worth buying because it will be useful or helpful e.g A microwave is a good investment.

Whilst a DAC could be regarded as investment in that sense of the word, in that it has a use, in the context of the statement made that usage makes no sense:

''Still, in UK a used Dave's value, after say five years, still is in 60 percent of the new.

Since once sold it ceases to be defined as an investment re the 'Useful' definition of the word and since the loss would be approximately £4K on the £10K purchase price it does not conform to the other meaning of investment either: The outlay of money usually for income or profit

#### Axo1989

##### Addicted to Fun and Learning
That is now accepted usage of 'Invested' but I strongly suspect it acquired that usage fairly recently and the usage was coined by advertisers and salesmen.

Yes, I suspect the same. You never know, though. After looking up a term I often enjoy the archaic meanings:

3 archaic clothe or cover with a garment: he stands before you invested in the full canonicals of his calling.
4 archaic surround (a place) in order to besiege or blockade it: Fort Pulaski was invested and captured.

Both the designer and our host are investing in Chord in their own separate ways.

OP

#### amirm

Staff Member
CFO (Chief Fun Officer)

#### Robbo99999

##### Major Contributor
Forum Donor
ASR's Chord DAC measurements these last few months have caused Rob a bit of a headache.

View attachment 229875
I don't know why he's got a thing about trying to turn musical recordings into sounding like "live non-amplified music". All a DAC is there to do is to reproduce faithfully what was put into the recording, it's got nothing to do with live music (nor non-amplified music). Unfortunately it's just another example of a strange misguided approach. I don't have a problem with the guy, he can do what he wants, but I wouldn't want to buy audio equipment from someone with such strange design philosophies, it doesn't fill me with confidence in the product, and we'll forget about the price for now.

#### Axo1989

##### Addicted to Fun and Learning
I don't know why he's got a thing about trying to turn musical recordings into sounding like "live non-amplified music". All a DAC is there to do is to reproduce faithfully what was put into the recording, it's got nothing to do with live music (nor non-amplified music). Unfortunately it's just another example of a strange misguided approach. I don't have a problem with the guy, he can do what he wants, but I wouldn't want to buy audio equipment from someone with such strange design philosophies, it doesn't fill me with confidence in the product, and we'll forget about the price for now.

It's a common enough expressed goal, to the point of being a cliché. Not mine specifically. When I first imagine playing some recorded music, then actually play it, I prefer the latter not be disappointing.

#### Music1969

##### Major Contributor
Then why does he post those measurements and keep talking about objective technical things? Can't sell on that basis but then say to ignore that and just listen.

Yes for years he complained that he was the only one with an APx555, and nobody elses measurements could be trusted

And now complains his feelings are hurt by APx555 measurements lol

#### Robbo99999

##### Major Contributor
Forum Donor
It's a common enough expressed goal, to the point of being a cliché. Not mine specifically. When I first imagine playing some recorded music, then actually play it, I prefer the latter not be disappointing.
I know, you hear that "cliché" quite a lot.....but those people fail to understand that it's about the recording and what the artist & engineer put into it......and your audio chain & speakers are just there to try to reproduce that as faithfully as possible without any additional colourations - thankfully the audio chain & speakers are really quite well understood "by science" and the way we measure them on this site reflects that. (Headphones are also "understood by science", but not as much as the rest).

Replies
1
Views
1K
Replies
2
Views
842
Replies
973
Views
130K
Replies
2
Views
1K
Replies
362
Views
31K