• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Serious Question: How can DAC's have a SOUND SIGNATURE if they measure as transparent? Are that many confused?

antcollinet

Master Contributor
Joined
Sep 4, 2021
Messages
7,409
Likes
12,294
Location
UK/Cheshire
A very unstiff power supply regulation for an OP-amp : slightly higher distortion at full music levels, current clipping in extreme cases, possible lower power voltage driving the OP and for sure some minor compression sound effects . In the original Linn akurate DS the output OP amps lm4562 only have 9 volts because of this - read more here:
Bloody hell. Trying to impact the sound of a DAC by putting impedance into the power supply would be a ludicrously uncontrolled way of impacting the frequency response - or any other measure.

Even if it makes a difference (which, given the high impedance most op amp circuits are driving I'd be very doubtful - it would only have significant effect if the psu voltage into the op amp dropped to the level the opamp was supposed to output - and then would hard clip) it would very from part to part just because of component tolerances. If you want to impact the sound, put a frequency dependent circuit in line (ie an actually designed filter specified to make the exact change you want).

I call your un-evidenced description of impedance modified PSU designed to impact sound signature.... err..... bullshit. Either because you've made it up - or if you've actually genuinely found something designed that way - because it would never work properly, and the designer himself was unable to come up with something not containing bullshittery.

Have a nice evening :p
 

SIY

Grand Contributor
Technical Expert
Joined
Apr 6, 2018
Messages
10,386
Likes
24,749
Location
Alfred, NY
I call your un-evidenced description of impedance modified PSU designed to impact sound signature.... err..... bullshit.
It doesn't even rise to that level. This is a rehash of the same nonsense Gary Galo and Walt Jung were peddling forty years ago.
 

Tangband

Major Contributor
Joined
Sep 3, 2019
Messages
2,994
Likes
2,789
Location
Sweden
One could design a test where you hear noise levels and use DACs having slow filters. What almost identical means is a bit subjective. Some early DACs and CD players could have suboptimal implementation. Modern DACs with normally good implementation, I would say, forget it.
Yes, according to LTS , a slow filter is one of the biggest reasons a dac can be detected by ear in the ” before and after” testing. The reconstruction filter must be steep.

Said in another way - a DAC with a slow filter WILL be detected in a LTS blind test. You can hear it.
Sometimes I see DACs tested at audiosciencereview that have slow filters - and also recommended. I wouldnt buy such a dac - If my goal was an uncolored sound.
 
Last edited:

Tangband

Major Contributor
Joined
Sep 3, 2019
Messages
2,994
Likes
2,789
Location
Sweden
Seems like you could describe much (subjectivist-beloved) audiophile equipment that way.
Yes- in the highend market its important to sell products that sounds slightly different than the cheaper gear.;)
Because of the flawed stereo system- I dont even see anything wrong with it, as long as you like the sound and understand the coloration. It can in certain cases make the stereo system less flawed, ie the perceived illusion can be bigger adding some coloration and compression.
 

Blumlein 88

Grand Contributor
Forum Donor
Joined
Feb 23, 2016
Messages
20,524
Likes
37,057
Yes, according to LTS , a slow filter is one of the biggest reasons a dac can be detected by ear in the ” before and after” testing. The reconstruction filter must be steep.

Said in another way - a DAC with a slow filter WILL be detected in a LTS blind test. You can hear it.
Sometimes I see DACs tested at audiosciencereview that have slow filters - and also recommended. I wouldnt buy such a dac - If my goal was an uncolored sound.
Yes when I've blind tested myself dacs with non standard filters are mildly detectable. That appears to be simply due to FR. Nothing exotic.
 

Tangband

Major Contributor
Joined
Sep 3, 2019
Messages
2,994
Likes
2,789
Location
Sweden
Yes when I've blind tested myself dacs with non standard filters are mildly detectable. That appears to be simply due to FR. Nothing exotic.
In such a case with a slow filter and not enough attenuation below nyquist freq, the distortion also goes up in the higher frequencies in the audible area. This can be seen in Amirms reviews.
Many audiophiles seems to like the sound of ”slow” filters. Or think they do.
 

Blumlein 88

Grand Contributor
Forum Donor
Joined
Feb 23, 2016
Messages
20,524
Likes
37,057
In such a case with a slow filter and not enough attenuation below nyquist freq, the distortion also goes up in the higher frequencies in the audible area. This can be seen in Amirms reviews.
Many audiophiles seems to like the sound of ”slow” filters. Or think they do.
I actually don't like that DACs now offer these filters. I know it is offered because it is easy and looks like a feature to differentiate one product from another. I do have recording interfaces that have minimum phase filters, but they do that for lower latency. They also aren't exceptionally slow roll off filters like some that are available.
 

Rottmannash

Major Contributor
Forum Donor
Joined
Nov 11, 2020
Messages
2,969
Likes
2,606
Location
Nashville
Linear phase is closer to an ideal reconstruction. For this reason alone, it should in my opinion be the default choice unless something else is specifically required.
on that subject, my Hiby R5 has 4 filters, 2 fast rolloff and 2 slow rolloff with the option of either "low latency" or "phase compensated". Which is closest to linear phase? The DAC chips are CS43198's.
 

majingotan

Major Contributor
Forum Donor
Joined
Feb 13, 2018
Messages
1,511
Likes
1,781
Location
Laguna, Philippines
on that subject, my Hiby R5 has 4 filters, 2 fast rolloff and 2 slow rolloff with the option of either "low latency" or "phase compensated". Which is closest to linear phase? The DAC chips are CS43198's.

Phase compensated = group delay being equal (or constant) across frequencies so this must be linear phase
Low Latency = minimum phase
Use Phase compensated, Fast Roll off for the best filter performance
 

Rottmannash

Major Contributor
Forum Donor
Joined
Nov 11, 2020
Messages
2,969
Likes
2,606
Location
Nashville
Phase compensated = group delay being equal (or constant) across frequencies so this must be linear phase
Low Latency = minimum phase
Use Phase compensated, Fast Roll off for the best filter performance
Thank you-that's the one I usually use. Now I know it's the more "correct" filter.
 

solderdude

Grand Contributor
Joined
Jul 21, 2018
Messages
15,891
Likes
35,912
Location
The Neitherlands
Speaker cables affect damping factor. Damping factor affect sound in the bass.

For that to happen it needs to be either a long cable or a thin lampcord when just a few meter long.
 
D

Deleted member 48726

Guest
For that to happen it needs to be either a long cable or a thin lampcord when just a few meter long.
Mostly correct. I have a sheet where you can see the difference between cable gauges and length. It does make a difference.
 

solderdude

Grand Contributor
Joined
Jul 21, 2018
Messages
15,891
Likes
35,912
Location
The Neitherlands
Of course cable resistance matters for DF and this is very measurable.
How much it matters also depends on the output R of the amplifier, the load impedance as well (and how much it varies).
DF would have to be worse than 10 to really make an audible difference though.
 

Julf

Major Contributor
Forum Donor
Joined
Mar 1, 2016
Messages
3,004
Likes
3,998
Location
Amsterdam, The Netherlands
Before and after listening :

Sonos : could be detected in the bass area
Oppo sonica : detected , but measured very well
Benchmark DAC2 : could not be detected
Yamaha wxc50 used as dac without preamp : could not be detected.

This is just 4 of many examples of tested dacs that LTS has made.
Any possibility of a description of how the test was conducted and what the test setup was?
 
D

Deleted member 48726

Guest
Of course cable resistance matters for DF and this is very measurable.
How much it matters also depends on the output R of the amplifier, the load impedance as well (and how much it varies).
DF would have to be worse than 10 to really make an audible difference though.
Yes, DF being a product of output impedance and load impedance (cables included). Worsens with low impedance loads. My calculations with an amplifier with DF=10 and a 4-2 ohm load, 13 ft 14 AWG cable returns an attenuation of max. 3.12 dB. 18 AWG returns 3.42 dB error.

DF = 160 returns an error of 0.9 dB (18 AWG)
DF = 80 returns an 1.1 dB error (18 AWG)
 

solderdude

Grand Contributor
Joined
Jul 21, 2018
Messages
15,891
Likes
35,912
Location
The Neitherlands
The only (speaker) amplifiers that have such a poor DF are some tube amplifiers or 'specials' and in such case that poor output R is part of the 'charm' of the amp.
Those amps usually are not recommended for speakers dipping to 2 ohm in the bass area anyway.
Combine that with a wild varying speaker impedance and long or thin cables and yes it will be audible.

In practice most amps are above DF50 and people using speakers that dip that low use short and thick cables anway. Certainly when they are enthusiasts.

But... this thread is about DAC sound signatures and has no relation to speaker cables so perhaps discuss cable resistance in one of the many cable threads.
 

Sokel

Master Contributor
Joined
Sep 8, 2021
Messages
5,844
Likes
5,787
Is it possible that the differences (if existed) occurs in different level settings?
We all can see that the SINAD vs Level measurements varies wildly amongst different dacs.
And if we consider the rapid drop of SINAD because of level/music gentre (and their need for different level settings)/placement/etc, and that sometimes level matching can favor one dac against another it's not surprising if differences occur sometimes.
It's a little chaotic anyway.

EDIT:Same with SINAD against freq.
 

antcollinet

Master Contributor
Joined
Sep 4, 2021
Messages
7,409
Likes
12,294
Location
UK/Cheshire
Yes, DF being a product of output impedance and load impedance (cables included). Worsens with low impedance loads. My calculations with an amplifier with DF=10 and a 4-2 ohm load, 13 ft 14 AWG cable returns an attenuation of max. 3.12 dB. 18 AWG returns 3.42 dB error.

DF = 160 returns an error of 0.9 dB (18 AWG)
DF = 80 returns an 1.1 dB error (18 AWG)
In your first example output impedance (amp plus cable) is dominated by the amplifier.

In your second example, it is dominated by the cable - but only because you've changed your gauge from a reasonable 14awg to a less useful 18awg. In other words - thin lamp cord.

The only important rating of speaker cables is resistance - as long as you select low enough, then cables don't matter. I don't use smaller than 13, my current cables are 11 (2.5mmsq and 4mmsq)
 
Last edited:

DanielT

Major Contributor
Joined
Oct 10, 2020
Messages
4,751
Likes
4,633
Location
Sweden - Слава Україні
Yes when I've blind tested myself dacs with non standard filters are mildly detectable. That appears to be simply due to FR. Nothing exotic.
I actually don't like that DACs now offer these filters. I know it is offered because it is easy and looks like a feature to differentiate one product from another. I do have recording interfaces that have minimum phase filters, but they do that for lower latency. They also aren't exceptionally slow roll off filters like some that are available.
Of course cable resistance matters for DF and this is very measurable.
How much it matters also depends on the output R of the amplifier, the load impedance as well (and how much it varies).
DF would have to be worse than 10 to really make an audible difference though.
In your first example output impedance (amp plus cable) is dominated by the amplifier.

In your second example, it is dominated by the cable - but only because you've changed your gauge from a reasonable 14awg to a less useful 18awg. In other words - thin lamp cord.

The only rating of speaker cables is resistance - as long as you select low enough, then cables don't matter. I don't use smaller than 13, my current cables are 11 (2.5mmsq and 4mmsq)
Speaking of blind testing. Like you Blumlein 88, you can test that with different filter settings in your DAC, if that functionality in the DAC is there.

Easier and cheaper blind test. Anyone can get a thin lamp cord cheaply, use it as a speaker cable and blind test.If you have balance control on the amplifier, you can have your usual speaker cable connected to one speaker and thin lamp cord to the other speaker.Then ask if you can detect differences between the different channels, and yes I am aware that the placement of the speakers plays a role (when listening to one or the other via the balance control), but you can switch the cables between the speakers a number of times and then see if you can identify which cable is which. But ok, maybe it was too much trouble, uncertainty about the outcome if you do that, maybe it's best to just change the cable set for both speakers and carry out a blind test.:)
Obviously hidden cable so the listener cannot see which cable goes to which speaker.:)

OT:
In my opinion, a more fun blind test would be if one person moves (or not) the position of the speakers and then the other listening test person, blindfolded, gets to say if he hears any differences. Sooner or later, depending on how much the speakers are moved and angled, you will hear differences. Real differences, not just imagined.:)

Then you might also disconnect your biases, preconceived notions about which speaker placement gives the best sound and arrive at a placement that you hadn't thought of before if you do such a blind test.:)
...then you can move the furniture around and blind test ...but that is perhaps overkill.;)
 
Last edited:
Top Bottom