Can anyone please explain the filters on the Stellar Gold DAC in plain English? I’m hearing impaired And have no idea what “LinSlow” means, for example. I’m a lost soul attempting to find a simple explanation that I can understand.
I found this AI explanation via Brave browser:
Linear phase filters are designed to be non-dispersive, meaning they maintain the integrity of the audio signal’s phase, which can result in clearer and more accurate sound reproduction. However, some users report that linear phase filters can introduce audible ringing into the audible frequency range, which can be perceived as a negative effect.
Minimum phase filters, on the other hand, are designed to minimize pre-ringing, which is the distortion that occurs before the main audio signal. While they can reduce pre-ringing, they may introduce other types of phase distortion that can affect the sound quality.
Slow roll-off filters are known for their gradual transition from the passband to the stopband, which can help reduce the harshness that some listeners perceive in the audio signal.2 However, they may not provide as much rejection of ultrasonic frequencies as other filter types.
The choice of filter can be highly subjective, and many users prefer to disable filters altogether to achieve a more neutral and “pass-through” sound, similar to what an excellent DAC would produce without any processing.
1 Like
Not sure if this helps but i have three filters available.
Fast rolloff, Slow rolloff, or Minimum Phase .
To me and my ears…
Fast roll off was bright.
Slow roll off was fine (its what i have selected)
Min phase collapsed my sound stage
Best just experiment and see what if anything you notice
If the manual doesn’t define the various filters, it must at least state what PS Audio considers the standard default setting. If they do, pick that one. The default should represent the essential sound of the DAC.
Then, if you care, experiment with different filters and see if you hear a difference and if so, which one you like. See @roninaudio response above.
2 Likes
Thanks everyone! The DAC is factory set to the first of seven possible choices which is where I have it set now. Because of my poor hearing I can hear no difference in the other options. I’m curious what they do?
I found this info helpful from this page–about the Oppo UDP-205 which shares DAC from the same family:
I have TONS of info on DAC Filter Characteristics for you!
Howdy everyone!
This is long, but you asked for info, so you got it. I could just provide the links & let you read & draw your own conclusions - but you’ve already proven you want others to do the work for you by asking the question, rather than looking it up yourselves.
What will make this really hilarious is if I am totally off base. I mean, that would be priceless.
Rather than just provide the links, I make an attempt to simply explain some of the content & relate it to the 205. Not being an engineer or any sort of expert, I laughed at myself for trying & thinking I can/should do that for you. Pretty brazen. LOL
But.. I think I got it mostly right.
First, all of this “filtering” - DACs require it. Don’t ask why, it just is. Or read the articles - it’s ALL in there & it’s AWESOME info. The 7 filter settings are variations of the required DAC filtering. These variations are all about tweaking the sound to mitigate distortions that contribute to that “digital sound” everyone hates. Except me. I also like circus peanut marshmallow & peeps.
Now that you know from where I am coming… here’s my take on all of it.
LINEAR VS MINIMUM PHASE: “linearity” is all about frequency dispersion - or delay, which is time distortion. Linearity (linear filter) means all frequencies share equal delay. No dispersion, or time distortion. Seemingly desirable, right? Linear implies “correct”, right? Well… maybe yes & probably no.
Scientifical reasons beyond mere mortal comprehension (means I can’t explain it) say that phase linearity introduces a lot of pre-ringing. Pre-ringing is perceived as unnatural, “off” sound - distortion - because it’s not how sound occurs & our brains are wired to hear how sound naturally occurs: there is a cause & there is a resulting sound. Pre-ringing - sound is produced before it’s supposed to be. Imagine if you heard a bell begin to peal before it is struck, then it is struck & you hear the intended sound. It’s a head-scratcher your brain tells you is “wrong”.
Some genius figured out that pre-ringing can be mitigated by introducing “phase” distortion - frequency dispersion/delay. But, too much dispersion is not desirable because unwanted, additional artifacts can occur. So we have minimum phase filtering.
Linear: no frequency dispersion (delay) but inherent pre-ringing and post-ringing.
Minimum Phase: introduces a small amount of frequency dispersion (delay = distortion) to mitigate pre-ringing and some but not all post-ringing.
Post-ringing… sonic artifacts that occur (for scientological reasons) after the desired sound - think… echos. This is natural; we expect sounds to “echo” & so this type of distortion is less objectionable, but only to a point. Too much “echo” sounds unnatural, so post-ringing needs to be controlled, too. We don’t want to hear that bell ring on forever, right? Which brings us to…
SLOW VS FAST ROLL-OFF:
NOTE: We’re not talking major slope differences here when fast/slow roll off is used to describe these filters; it’s a relative measurement. Doesn’t take much to tweak these unwanted bugs out of the system (based on what I’ve read). A -6dB slope is shallower than a -3dB slope, but is still steep/fast. And these distortions are barely audible; the brain just about perceives them as off-putting sound. Maybe… someone else’s brain might tell him “sounds awesome, man!” (Probably also tells him baby corn & water chestnuts are delicious.)
Steep (or fast) slope/roll-off means frequencies are attenuated quickly/sharply at the cut-off point. It’s as if a… brick wall (!) was in the way, not letting you hear the frequencies beyond the cut off. A “brickwall” filter has a very steep (fast) slope at its cut off frequency.
Shallow (or slow) roll off is the opposite. Frequencies are slowly/less sharply attenuated beyond the cut-off point. So instead of a solid brick wall, we have a slightly open door. Some frequencies on the other side of the wall will now come through that door - which ones & how loud they are depends on how far that door is open (how steep or shallow the slope or roll off is).
Steeper roll off, fewer frequencies pass & you have to be closer to the brick wall to hear them. Shallower roll off, more frequencies pass & you can get farther & farther away from the brick wall & still hear them.
Open the door too much (roll off is too slow) you defeat the purpose of the necessary filter (you reintroduce the unwanted frequencies & distortions!) Once again, it’s all about compromise.
So, if distortion is more likely to occur in ultra-sonic frequencies, you might think a steep (fast) roll of right at say, 20khz is ideal - just flat-out get rid of (stop, or cut off) frequencies we can’t hear, and also get rid of this nasty distortion. Well, what I’ve read seems to indicate steep slope = introduction of the dreaded “digital harshness”! (Booga booga! Scary!)
Slow/shallow roll off softens that digital harshness. It also mitigates post-ringing.
And now you’re thinking - just make & only use the slowest roll-off, stupid!
NOPE!
Here’s why: slow/shallow roll off introduces aliasing, which is ANOTHER type of distortion. Hence we have…
APODIZING: this hocus-pocus mitigates aliasing! So sayeth the articles - and they don’t say much more about apodizing, except that it means “cut off at the foot”. So, cut off your foot & your music will sound better.
If I was to draw a (feeble) conclusion based on everything I’ve read so far,
theoretically speaking ,
we would most want Santa to bring us good little boys and girls a:
- MINIMUM PHASE (to “best” reduce pre-ringing),
- SLOW ROLL OFF (to “best” reduce post-ringing & eliminate “digital harshness”),
- APODIZING (to “best” reduce the aliasing distortion)
filter. And a puppy.
Assuming all of that is “the best”. What if it’s not for you? What if they don’t even make a mini-phase, slow roll off, apodizing filter so all we get is a fast one? I dunno these answers, man!
That’s just me drawing a conclusion for poops & gigs. I haven’t done any listening tests because . And for god’s sakes - don’t write Oppo asking if the 205’s apodizing filter is linear or mini-phase & why it’s not slow roll off “because some mo in the forum said…”
Now, if I was to make a guess like I learnt somefin, based solely on what I’ve read, I would put my money on MY final A/B comparison of the best of the 7 to be between the Fast Apodizing vs Minimum Phase Slow filters. I would also bet it’s a toss up over which one I liked better. (It’s circus peanuts.)
Now go & read the articles - I promise, you will enjoy them & learn something pretty cool! Heck, you might even get to tell me I am totally wrong.
Nerd.
Jim
ARTICLE #1 :
This first link is to an Ayre white-paper on DAC filters & various characteristics, and even their effects (to a point). It’s written plainly & simply.
http://www.ayre.com/white_papers/Ayre_MP_White_Paper.pdf
Based on what I read, (I think) this is how the article’s filter descriptions match up with the 205’s. Note that the Ayre article only addresses 4 filter characteristics.
• Brick Wall – the 1st filter characteristic described in the Ayre article. After all of my reading, I understand this filter to be the “original” filter used way back when dinosaurs roamed da erf & listened to Sony Discmans (men?). And, it is why folks lamented the “digital sound”.
• Corrected Mini Phase Fast – Not described in the Ayre article.
• Apodizing Fast – This may be the 3rd filter described in the Ayre article, but hard to say because Oppo doesn’t mention linear or minimum phase.
• Mini Phase Slow – This is the 4th filter described in the Ayre article & the one they regard, and the majority of their beta-testers regarded, as the most musical/best sounding.
• Mini Phase Fast (default) – Not described in the Ayre article.
• Linear Phase Slow – This is the 2nd filter described in the Ayre article.
• Linear Phase Fast – Not described in the Ayre article.
ARTICLE #2:
The best, most informative article that explains exactly why DACs need filters & even described the effects of 7 very similar to the 205’s “filter characteristics”. It doesn’t tell you what’s right or wrong, or when to use what filter - there is no such guidance, just like how there are no unicorns. It’s a longer read, a bit more “scientific”, but still easy. I’m an idiot & I think I got it. Read it start to finish, skip nothing & it will definitely lift the veil.
And it’s specific to an ESS SABRE DAC (!!) but a DAC from 2012: http://www.audiostream.com/content/…al-filters-and-why-are-they-requried-todays-audio-dacs-resonessence-labs-tech-0
Here is how I think its filter descriptions match up to the 205’s settings:
• Brick Wall – filter #1 description most likely. I say that because the article refers to it as the “classic”, which could mean it’s akin to the original “brickwall” filter.
• Corrected Mini Phase Fast – no exact match in the article, could be AVS Forum .
• Apodizing Fast – filter #5 description (preferred by beta-testers, according to the article).
• Mini Phase Slow – filter description #4 (likely)
• Mini Phase Fast (default) – likely description #3 , but no exact match in the article.
• Linear Phase Slow – filter description #7; could also be #2.
• Linear Phase Fast – filter description #6; could be #1 .
ARTICLE #3 :
This last one is already written plainly & is helpful. I found it added to my understanding of what all of the mumbo-jumbo means.
4 Likes
Interesting that you hear the fast folloff as bright and the slow rolloff as ok. I would have thought the reverse would be the case.
Yeesh! Listen to vinyl.
1 Like
I do, but I love my cds as much if not more. I don’t mess with filters, I was just trying to help him out with info. I have the DSD Mk II and its proprietary digital heartbeat–sounds better than Sabre DACs to me.
1 Like
Thank you to all who responded. A lot to read but the answers I was looking for. Much appreciated!
2 Likes
The “LinSlow” setting on the Stellar Gold DAC basically refers to how the DAC processes the signal it receives. In simpler terms, it affects how smoothly the audio is processed. “Lin” stands for linear, which means the DAC will process the signal without making big jumps, keeping things smooth. “Slow” means it’s a more gradual, less aggressive processing of the audio. This can help reduce harshness or digital noise, making things sound more natural and less fatiguing for sensitive ears. It’s really just about choosing a smoother sound that doesn’t feel as sharp or harsh.
#1 and #4 do it for me. #4 cools it on the brightness a bit.