Chord Hugo M Scaler - Stereophile Review (measurements also)

[mansr]

Like this?

Review and Measurements of the Chord Hugo 1 DAC & HP Amp

I tested a Hugo 2 a while back but it was with my old analyzer. So a member kindly sent me an original Hugo DAC and headphone amplifier to remeasure. I wa shocked to find out that the Hugo cost US $2,500 when it came out!!! Man that is expensive for a portable DAC and Amp. Here is a shot of...

www.audiosciencereview.com

Exactly like that.

 

[Music1969]

it is easy to achieve much better stop-band rejection using only a few hundred taps.

Then Robert W will say something like, you've now compromised the transients to achieve better stop-band rejection.

Then (as per one of his slides) a piano may sound like a trumpet...

Watts Up...?

The audioquest seems to be a splitter, i.e. if you want to run 1 output to two inputs e.g. biamping. But are you sure you need any special cable, most sub-woofers has a stereo input and a internal conversion to mono, hence a standard stereo cable is all that is needed? Yes that's my...

www.head-fi.org

 

[Veri]

Then Robert W will say something like, you've now compromised the transients to achieve better stop-band rejection.

Then (as per one of his slides) a piano may sound like a trumpet...

Watts Up...?

The audioquest seems to be a splitter, i.e. if you want to run 1 output to two inputs e.g. biamping. But are you sure you need any special cable, most sub-woofers has a stereo input and a internal conversion to mono, hence a standard stereo cable is all that is needed? Yes that's my...

www.head-fi.org

View attachment 162388

That image LOL

 

[RustyGates]

Have you ever looked into how sampling theory works? You seem to think of it as a connect the dots exercise, with more dots always better than less.

If you're interested, here's the oft referenced 'Monty' video (mentioned by @SIY ) that does a nice job of making some sense of it.

No, that's not what I think. Your assumption is wrong.

I don't know why this guy is using a Tektroniks scope from pre 1995 to measure the output signal, but anyway, if you measure any NOS DAC in the time domain there is going to be stair steps and a massive aliasing frequency at the sample rate, which is created by the zero order hold of the DAC.

One of many examples, you can see from a SYS2722 Holo May measurement:

HoloAudio May (Level 3) D/A processor Measurements

Sidebar 3: Measurements

www.stereophile.com

Its obvious this Emagic DAC he's using, is using oversampling to some extent to get the waveform back as a relatively smooth (using a time div of 10uS, as accurately as that old scope can garner) 1kHz signal, I don't understand the point of this video.

Lastly, if you're pushing the whole "ditch oversampling" thing here, i.e. pro NOS, I'm out.

 

[mansr]

if you measure any NOS DAC in the time domain there is going to be stair steps

Wrong. Here's a scope screenshot of a 1 kHz sine wave reproduced by a Sony D-50 CD player:

Do you see any stair steps?

 

[RustyGates]

Wrong. Here's a scope screenshot of a 1 kHz sine wave reproduced by a Sony D-50 CD player:

View attachment 162390

Do you see any stair steps?

And your evidence to show Sony completely ditched any form of filter is....

where?

It is not NOS.

 

[mansr]

And your evidence to show Sony completely ditched any form of filter is....

where?

It is not NOS.

Is this enough evidence for you?

 

[audio2design]

It is simple. What Rob believes, and others as well is that high res recordings sound better. I will not argue if they do - but these people think they do. They believe 96k sounds better than 48k, 192k is better than 96k etc. - up to many MHz - with a law of diminishing returns, of course. Why is this if we can only hear up to 20khz - most people lower? They think it is time smear. The higher the sampling rate, the less time smear. So upscaling as much as possible makes things sound better by reducing time smear. Rob, in his DAC's, sometimes upsamples to many MHz. He uses a sinc filter to upsample because Shannon's sampling theorem says it reconstructs a limited frequency signal perfectly. However, he also believes the quality of the sinc filter is of vital importance especially during the early upsampling stages. His calculations showed that a 1 million tab filter was necessary for at least 16 bit-perfect accuracy in the upsampling process. The question is such perfect accuracy essential?

It's like analog post filters don't exist. They have infinite taps ... essentially. But lets make all our arguments in the digital domain and ignore what comes out the analog output. Then let's distract with nonsense time domain claims which our speakers and room will obliterate (and even for those have questionable value due to how our hearing works).

In the first page someone said the point of this thread was entertainment. Still the best answer.

No level matched blind tests and sorry Rusty what you did was not. Defined sequence is not random blind.

There is no mathematical proof this will do anything audibly better than the what's inside the average modern DAC chip (THD with 16bit depth is a good indication). You have to assume super human hearing (also never proven) to justify.

It's a solution in search of a problem.

 

[RustyGates]

Thanks. Its using analogue LC filtering for lowpass at the output.

Your point?

Its as ancient as it gets.

In NOS fanatic speak, "its not true NOS"

 

[mansr]

Thanks. Its using analogue LC filtering for lowpass at the output.

Your point?

You seem to believe that having an analogue low-pass filter somehow makes the DAC oversampling. That's absurd.

 

[audio2design]

Rusty, your cut and paste of what others have wrote has much improved in the last year. A year ago someone would have known immediately your digital audio knowledge was thin. Your posts of late stepped that up. Then you had to respond to the Sony CD posts and show that you don't really understand digital audio.

 

[Music1969]

Thanks. Its using analogue LC filtering for lowpass at the output.

Your point?

Its as ancient as it gets.

In NOS fanatic speak, "its not true NOS"

View attachment 162406

The web page you got that from mentions twice that both Mk1 and Mk2 had no digital filtering...

 

[RustyGates]

You seem to believe that having an analogue low-pass filter somehow makes the DAC oversampling. That's absurd.

Note how I said, "in NOS fanatic speak" NOS fanatics don't just want no Oversampling, they want no filtering whatsoever and thereby "true NOS". Just go ask them on audiogon or whatever.

I know its not oversampling, but it is a filter nonetheless. Not that an analogue filter can touch a digital filter in performance, and thus its slow rolloff and weak supression results in other measurement issues.

My point is without filtering you are going to see stairsteps. And in a "true NOS" dac, you will see it.

 

[RustyGates]

Rusty, your cut and paste of what others have wrote has much improved in the last year. A year ago someone would have known immediately your digital audio knowledge was thin. Your posts of late stepped that up. Then you had to respond to the Sony CD posts and show that you don't really understand digital audio.

Uhh... right. I can see the low pass filters on the bloody schematic. Maybe read my previous reply too.

I am an electrical engineer. No, I dont work in audio.

 

[audio2design]

Just go ask them on audiogon or whatever.

Audiogon is a bastion of ignorance. Anything said there is meaningless.

NOS - non over sampling. No more , no less.

I has nothing to do with analog filters. Never has. The NOS claimers are that it is bit perfect and hence better. They wish and wash over filters.

 

[solderdude]

And in a "true NOS" dac, you will see it.

Nope is a filterless DAC will see it.
NOS = Non Over Sampling.
The first Japanese CDP DACs were NOS.
Philips was the first one to use oversampling (4x) and did this because they could only make 14 bits DACs and wanted 16 bits resolution.
The Japanese folks could make 16 bit DACs. Of course the LSB's had issues but so did the 14 bit Philips chips.
Those NOS CD DACs had quite steep analog filters which were laser tuned on substrates.
That's why they appear to be a simple block in a schematic when in fact they were very complex.
As there was only 44.1 sample frequency this was easy.
Every designer soon found out digital OS filters were the way to go making the active post filtering much less complex and steep and thus much cheaper to mass produce.
The oversampling and because of that greater bit depth race was on.
CDP's that had 20 bits and 8x oversampling became the norm.
All CDP's were oversampling after the very first generation in 1982 (40 years ago).

Oversampling became synonymous for most folks to filtering. That doesn't mean we should not use proper naming anymore.

The folks you refer to as 'NOS fanatics' are total idiots. Still ... under the right conditions it can sound good enough for folks to like it.

 

[RustyGates]

Nope is a filterless DAC will see it.
NOS = Non Over Sampling.
The first Japanese DACs were NOS.
Philips was the first one to use oversampling and did this because they could only make 14 bits DACs.
Those NOS CD DACs had quite steep analog filters which were laser tuned on substrates.
As there was only 44.1 sample frequency this was easy.

The folks you refer to as 'NOS fanatics' are total idiots.

Yes they are total idiots.

Yes it should be referred to as a filterless DAC.

You should probably head over there and explain it to them. I am merely talking in their "speak".

 

[audio2design]

.. as well as winning the best DAC in the world two years in a row at Rocky Mountain.

I'll have fun prodding all the jelly beans who can't afford one though (you can tell who they are, because they make threads such as this).

Being called "best DAC" at an audio show is sort of like being called best dressed at the local hoedown. Nothing says I am full of crap like claiming you can extract the sound of only a DAC from unfamiliar speakers, with unfamiliar amplification in an unfamiliar and awful room. Audio reviewers claim that all the time. It's meaningless.


You will excuse me if I doubt the engineering chops of anyone who would post those two paragraphs or who spends more on a DAC then their car.

 

[mansr]

I am merely talking in their "speak".

You should probably stop doing that if you want to be understood.

 

[solderdude]

You should probably head over there and explain it to them. I am merely talking in their "speak".

You shouldn't talk here in their speak. They should not even be quoted or mentioned here.
You will be punished immediately

edit: as usual mansr beat me to it.