Article: LessLoss Echo’s End Reference DAC Full Review

[mansr]

2 hours ago, Louis Motek - LessLoss said:

The USB input, however, does play 384 kHz sampling rate files, not that any truly exist.

What is that supposed to mean?

[mansr]

5 minutes ago, Louis Motek - LessLoss said:

I mean that ADCs typically aren't used to convert at 384 kHz. 96, yes, this is ubiquitous, 48 kHz, too, but in recording scenarios it is not a professional standard to record at 384 and therefore anything you see on the music market which claims to be a 384 kHz sampling rate recording is likely a mathematically contrived version of the originally recorded material.  This is a heated discussion in the audio recording arena.

 

There might be some scientific applications for recording at 384 like recording bats, but in order for this to be justified, all the gear in the chain needs to have extremely low noise even at ultrasound frequencies in order for the intermodulation effects not to add even more noise to the audible spectrum that we humans can indeed hear. Maybe some rare labs have this capability but for the world of audio this type of extension of sampling rates simply does not add value and can even be (due to interpolation distortions) detrimental to the result. 

 

If you ever compare a high jitter recording at high sampling rate vs. a low jitter recording at a low sampling rate, you will always prefer the low jitter recording. In terms of hierarchy of importance with direct relation to sonic quality, low jitter is much, much more important than the difference between, say, 48 kHz and 96 kHz. Today there are even ADCs (AK5397 for example) which can do 786 kHz but it remains disputed as to its usefulness in real-world (human ear) audio applications. 

Sure, recording music at such rates is of dubious benefit. Nevertheless, such recordings are not hard to find. For the purpose of this discussion, I'm regarding 352.8 kHz and 384 kHz as equivalent, the former for some reason being far more common.

[mansr]

5 minutes ago, soekris said:

I'm a little tired of people claiming that with 0.01% resistor it can't be more than a 13-14 bit DAC, while the measurements of my dam1021 module show a dynamic range of at least 130 dB....

Dynamic range is not the same thing as linearity.

 

8 minutes ago, soekris said:

We can agree that the pcm1704 was the best audio DAC chip ever made

No, we cannot. If it was, they'd still be making it.

 

8 minutes ago, soekris said:

So I couldn't make a DAC based on the pcm1704, and then started to think, it can't be that complicated to make a discrete sign magnitude DAC.

Complicated, no. Accurate? Also no.

[mansr]

15 minutes ago, soekris said:

You need the linearity to get the dynamic range. And the key here is level linearity, which is where the sign magnitude DAC really shines....

Crossover distortion is just one of many problems with a ladder DAC. At full scale, the distortion of a discrete resistor ladder is at best equivalent to 14 bits or thereabouts.

 

15 minutes ago, soekris said:

Just because the pcm1704 was the best, does not mean that TI was making money on it.... And semiconductor manufacturer like to keep their expensive fabs used for money making parts....

If it was that great, they could have raised the price enough to make it profitable. In actuality, they made a better and cheaper DAC, presumably resulting in higher profits.

 

15 minutes ago, soekris said:

So what DAC chip do you consider the best?

Who cares?

 

15 minutes ago, soekris said:

And the dam1021 is accurate enough to that the customers like it, just read the dam1021 thread at diyaudio.com....

I'm sure it's good enough that the sound is acceptable. A THD+N of 70 dB or so is sufficient to beat vinyl, after all.

 

15 minutes ago, soekris said:

Seems like the audio community is divided in two parts, those that trust their ears and those that believe in numbers....

I think you mean eyes (on the price tag), not ears.

[mansr]

6 hours ago, Louis Motek - LessLoss said:

Panzerholz (Tankwood) is used as the base of the core chassis of F1 cars.

Supposing that's true (which I'm not going to take your word for), what is the relevance for a DAC enclosure?

[mansr]

Just now, STC said:

Some say it produces organic sound.

In the F1 car?

 

Just now, STC said:

Seen old amps made of wood too. 

There's nothing wrong with using wood for aesthetic reasons.

[mansr]

I want a DAC with a V8 engine.

[mansr]

5 hours ago, BrokeLinuxPhile said:

A log cabin home would probably work great keeping out RF compared to gypsum/frame construction.

Mobile phones work fine in my log cabin.

[mansr]

9 minutes ago, Madra said:

I was referring to its' anti-vibration properties. Some manufacturers go to great length to treat vibration using special footers, enclosures carved from solid aluminum blocks..... They claim that it affects the performance. You may obviously disagree.

Vibration properties matter for speakers, turntables, and anything with tubes in it. This DAC fall in neither of those categories.

[mansr]

44 minutes ago, Superdad said:

Well there is something (subtle) to be said for reducing vibration on clock oscillators.

Can you quantify the effect with some measurements? I suspect the DAC would physically break apart before you could hear any effect of vibrations in the output.

[mansr]

23 minutes ago, Superdad said:

Plenty of technical reference sources discussing the adverse affects of vibration on phase-noise performance of crystal oscillators:

 

https://tf.nist.gov/general/pdf/2328.pdf

 

https://pdfs.semanticscholar.org/0ebe/814dbe61c8cd51515552d1da100c6bf95f51.pdf

 

http://www.wenzel.com/documents/vibration.html

I don't see anything in those sources suggesting that vibration would be an issue in domestic audio applications.

[mansr]

6 minutes ago, BrokeLinuxPhile said:

You seem to be misinterpreting me.  I studied mechanical engineering and fully understand material properties, including tank wood.

The mechanical properties are of very little interest for a DAC enclosure. Almost anything will have sufficient strength and rigidity. The electromagnetic properties are the interesting ones here, specifically the ability of the enclosure to shield the interior from potentially harmful interference. Metal does this very well, wood and plastic not so much. Wooden cases on old equipment often have a copper lining for this reason.

[mansr]

8 minutes ago, BrokeLinuxPhile said:

The purpose of material choice in this case still escapes me though?   All we heard from the builder is that the reasoning is similar to use of this material in speaker cabs.  Which still doesn't make sense to me.

Now we agree.