SMSL D1 - ROHM DAC for everyone

[kazuviking]

I'd be confident in a blind test I could pick between the SMSL and my current CD player running though same amp and speakers.

Spoiler you wouldn't. With no switching indicators your brain have no bias or stimulation to differentiate. IMO in a proper blind test you should be asked WHEN it switched and NOT write down which one you think its A or B.

 

[RandomEar]

I'd be confident in a blind test I could pick between the SMSL and my current CD player running though same amp and speakers.

Statements like that are always baffling to me Did you ever even conduct a level-matched blind test or maybe at least a blind ABX test? As in: Do you have any experience at all in the topic you're so absolutely confident about?

More then 80% of drivers in the US are certain that their driving skills are above average. And about half of them are very, very wrong about that.

I couldn't say which was which without hearing close A/B comparisons.

So you can't identify them in an uncontrolled test, but you are certain that you could do so in a much more difficult controlled test?

These may be a couple of threads which are interesting to read:

AES Paper Digest: Sensitivity and Reliability of ABX Blind Testing

This is abbreviated synopsis of the paper, Ten Years of ABX Testing, by David Clark: http://www.aes.org/e-lib/browse.cfm?elib=5549 ABX testing as you may know is a double blind testing methodology aimed at determining if someone can reliably identify A from B. Both A and B are presented to the...

www.audiosciencereview.com

Audio Blind Tests and Listener Training (video)

I see so many people claiming to have done blind tests in youtube videos recently without knowing what it means to perform one. Also, the topic of training comes up with many abusing the term. So I decided on a whim to create a video on it. It is rather long at 44 minutes but you can speed it...

www.audiosciencereview.com

Audio Blind Testing - You Are Doing It Wrong! (Video)

Just uploaded a video on the basics of performing controlled tests in audio. It was motivated by saving myself text in having to write all of this down when telling someone who to do these tests right. And as a counter to a few online personalities to keep saying they do "blind" tests yet when...

www.audiosciencereview.com

 

[ICIETDIYEUR]

Once again, 'skitron' on diyAudio said:

"...A curious statement to make for one clinging to flimsy claims of absolute proof of human inabilities with respect to hearing sound...
As in all forums, don't start a mud-fest unless you're prepared for someone to reveal your errant thoughts for all the internet to see..."

 

[Roland68]

More then 80% of drivers in the US are certain that their driving skills are above average. And about half of them are very, very wrong about that.

No, 100% are wrong.
Human reaction times when braking do not vary significantly. Even Formula 1 drivers have a reaction time only 0.1 seconds faster than average in normal traffic—a fact that has been impressively demonstrated.
If someone is driving at 100 km/h and maintains a gap of only 20 meters (or less), they will crash into the car ahead if it performs an emergency stop—hitting it before their foot even touches the brake pedal. Every time. Unless, of course, they can swerve to avoid it.
Even the slightest distraction—such as listening to the radio, talking to a passenger, making a phone call, or being lost in thought—can double that reaction time, which explains the high number of rear-end collisions that occur even with a 30-to-40-meter gap at that speed.

When it comes to evasive maneuvers, however, driving skills and experience in such situations are what matter; raw reaction times don't help and—without the necessary experience—can actually make the situation worse.
Average drivers can only gain this kind of experience through advanced driver training courses, not in everyday traffic.

This is admittedly off-topic, but it might just save someone from a serious accident.

 

[antcollinet]

I'd be confident in a blind test I could pick between the SMSL and my current CD player running though same amp and speakers.

Everyone is - right up the point they try it (when level matched and blind etc)

 

[JDub]

Ok , I'll do more homework and prepare.myself to be humbled

 

[JDub]

Statements like that are always baffling to me Did you ever even conduct a level-matched blind test or maybe at least a blind ABX test? As in: Do you have any experience at all in the topic you're so absolutely confident about?

More then 80% of drivers in the US are certain that their driving skills are above average. And about half of them are very, very wrong about that.


So you can't identify them in an uncontrolled test, but you are certain that you could do so in a much more difficult controlled test?

These may be a couple of threads which are interesting to read:

AES Paper Digest: Sensitivity and Reliability of ABX Blind Testing

This is abbreviated synopsis of the paper, Ten Years of ABX Testing, by David Clark: http://www.aes.org/e-lib/browse.cfm?elib=5549 ABX testing as you may know is a double blind testing methodology aimed at determining if someone can reliably identify A from B. Both A and B are presented to the...

www.audiosciencereview.com

Audio Blind Tests and Listener Training (video)

I see so many people claiming to have done blind tests in youtube videos recently without knowing what it means to perform one. Also, the topic of training comes up with many abusing the term. So I decided on a whim to create a video on it. It is rather long at 44 minutes but you can speed it...

www.audiosciencereview.com

Audio Blind Testing - You Are Doing It Wrong! (Video)

Just uploaded a video on the basics of performing controlled tests in audio. It was motivated by saving myself text in having to write all of this down when telling someone who to do these tests right. And as a counter to a few online personalities to keep saying they do "blind" tests yet when...

www.audiosciencereview.com

Hi RandomEar,

Thanks for the reply and for posting the very informative links.

I tried to run through the archimego blind test for an exercise but the links to download the sample tracks are old and defunct, no matter.

Undoubtedly, the driving analogy applies in many cases. Without a mention of above average hearing,
I shall rephrase it to "I am confident I could tell the difference between the DAC and CD player currently plugged into my amp without confirming levels are exactly matched" and just drive away oblivious to my mediocre skills. I admit pointless.

I could hear a difference between each source, realising now that it was down to small differences in sound levels between the DAC and the CD as they reach my Amp.

I couldn't say which was which without hearing close A/B comparisons. Understanding more about sound reproduction from some fine postings on this site, the ability to detect will be due to influences outside of the DACs... such as small differences in sound pressure level or distortion.

I wasn't implying I would be fit to tell which was playing if I walked out of the room and back in again.
I had quickly switched between sources so many times I could safely say I couldn't determine which was which but was detecting a fuller sound on the same option.

Did you ever even conduct a level-matched blind test

Nope

or maybe at least a blind ABX test?

Yep - but agricultural in design and execution.

Do you have any experience at all in the topic you're so absolutely confident about?

Having not stated being "so absolutely confident" either, merely "confident".
I'm now reneging on that confidence as levels were not accurately controlled.

I've since watched the Amir blind test guide and am now more informed.
The CD player outputs 0.1V more via RCA than SMSL meh
I wished on my cherished CD player to sound as good as my budget DAC (which I use with an old gaming PC.) The SMSL has a more appealing sound so I understand now that is only due to increased volume not sound quality.

I realise I wasted money on a cable from the CD player to the DAC. (And maybe a DAC). At least my curiosity led me here, and with thanks to you, to:

Audio Blind Tests and Listener Training (video)

I see so many people claiming to have done blind tests in youtube videos recently without knowing what it means to perform one. Also, the topic of training comes up with many abusing the term. So I decided on a whim to create a video on it. It is rather long at 44 minutes but you can speed it...

www.audiosciencereview.com

That's the kind of content I was looking for. Colour me converted. I'm still happy with my little DAC and I appreciate the forum here.

I didn't intend to baffle anyone - consider yourself un-baffled

 

[_MAX_]

Heard here and there the following: Can't hear the difference using one USB input or both. While some can.
Perhaps their auxiliary PSU has reverse current protection.

SMSL D1 is limited otherwise. Current flows back to the PSU from the DAC.
When I sorted that, the performance significantly improved. Especially bass dynamics, strings and SQ in general.
Soldered in a Schottky diode (discovered this due to my custom PSU, which supplies my amp as well), unlocked the performance.
Which wasn't expected, was just annoyed by the fact that LEDs on the PSU were lit when it was off.

Also installed a USB isolator from PC to DAC. It would be interesting for someone to compare the unmodified output (s/n etc).
On my system (upgraded Alpine amplifier (OPA1656)), bookshelf x 4 and sub; most engaging. My E30II is superb, but I haven't switched it back in yet.
Think I'll use it for DAW .

 

[RandomEar]

SMSL D1 is limited otherwise. Current flows back to the PSU from the DAC.

Sorry, but how did you establish that?

 

[VientoB]

Heard here and there the following: Can't hear the difference using one USB input or both. While some can.
Perhaps their auxiliary PSU has reverse current protection.

SMSL D1 is limited otherwise. Current flows back to the PSU from the DAC.
When I sorted that, the performance significantly improved. Especially bass dynamics, strings and SQ in general.
Soldered in a Schottky diode (discovered this due to my custom PSU, which supplies my amp as well), unlocked the performance.
Which wasn't expected, was just annoyed by the fact that LEDs on the PSU were lit when it was off.

Also installed a USB isolator from PC to DAC. It would be interesting for someone to compare the unmodified output (s/n etc).
On my system (upgraded Alpine amplifier (OPA1656)), bookshelf x 4 and sub; most engaging. My E30II is superb, but I haven't switched it back in yet.
Think I'll use it for DAW .

Yes and you verified all this with blind listening tests...

 

[VientoB]

Sorry, but how did you establish that?

New member, joined today, very first post...

 

[_MAX_]

Connect D1 to PC.
Plug a USB lead into Aux power on the D1 and the other end into a rechargeable torch for example.
The reverse current provides charge.
Another DAC in my collection, Sanskrit 10th MK3, doesn't route power through Aux.
On that device, the additional 5V input doesn't provide a dramatic boost.

Got the D1 to check out the ROHM. Didn't expect what developed.
It's so good, not motivated to mod it. Bought another.

Image: PC, USB isolator, D1.

 

[RandomEar]

Connect D1 to PC.
Plug a USB lead into Aux power on the D1 and the other end into a rechargeable torch for example.
The reverse current provides charge.
Another DAC in my collection, Sanskrit 10th MK3, doesn't route power through Aux.
On that device, the additional 5V input doesn't provide a dramatic boost.

Got the D1 to check out the ROHM. Didn't expect what developed.
It's so good, not motivated to mod it. Bought another.

Image: PC, USB isolator, D1.

OK, that may not be the best design choice by SMSL. However, during normal operation you would have a PC and PSU connected and both would provide very close to 5 V, so there would be very, very little current flowing between them. Assume you've got a 100 mV difference between the 5 V sources and your cables and connectors add up to 2 Ω, you'll end up with around 5 mW of power. That is totally irrelevant for a PSU which can provide 10 to 15 W at 5 V.

There is also no connection between this, your diode mod and the sound of the DAC. A PSU provides power, it doesn't "make" the sound. And as the example above showed, there will be no relevant difference in the amount of power available to the DAC. You need to take into account that your comparison involved a very long switching time where you disassembled the device, soldered in the diode and reassembled it again. So maybe an hour? Our echoic memory which stores details of the sound we hear is only a couple of seconds long. So in your case, there is no way the comparison delivered reliable results. Any impression you got from that mod is most likely pure placebo.

 

[Roland68]

Connect D1 to PC.
Plug a USB lead into Aux power on the D1 and the other end into a rechargeable torch for example.
The reverse current provides charge.
Another DAC in my collection, Sanskrit 10th MK3, doesn't route power through Aux.
On that device, the additional 5V input doesn't provide a dramatic boost.

Got the D1 to check out the ROHM. Didn't expect what developed.
It's so good, not motivated to mod it. Bought another.

Image: PC, USB isolator, D1.

After more than 30 years of experience modifying audio equipment—and 26 years conducting level-matched blind tests—I can tell you that in most of these tests, you are simply fooling yourself and wasting your time.
Without a second, unmodified unit to serve as a reference for a blind comparison, such tests are completely worthless.

Your theory regarding back-feeding current is also incorrect.
All you’ve done is create a connection between the USB power adapter and your rechargeable flashlight—essentially just passing the line through. Naturally, the flashlight charges this way.
However, that has nothing to do with connecting two power adapters or connecting the device to both a PC and a power adapter simultaneously.

 

[_MAX_]

Never intended to promote the idea that the PSU is making the sound. It does contribute by being as silent as possible. Pitch black background. Supply distortion does without doubt, hinder sound quality, even if it's not obvious, while the audio is output. A noisy supply can cause damage. Got a knackered Sanskrit (1 of 2) waiting for an SMD soldering kit to arrive. It was Aux powered by some cheap DC kit grabbed from ebay. Managing the supply from the perspective of efficient utility, available current does affect sound quality, if/when the circuitry demands.

The whole idea of a custom PSU for me was to build it without much compromise. As far as filtering, regulation and capacity beyond demand are concerned (behind cabinet, out of view; PC ITX case entirely filled with PSU workings). The system shall want for nothing.
This solved the desired connectivity visualised and interference from appliances that caused pops, cracks as well as hum.
Built on the fly (thought about building it for a long while), good clean power, minimal ripple. 5V, 12V and 9V center negative for pedals. 70A on tap for the amplifier. The bass can rattle the windows in the house, without the sub. On test only of course. Mission QX's can push deep bass. This wasn't possible with a 48V ZA3. Hence current matters. Sure, the DAC sips it, but it's enough to make a difference.

Auditioned my DAC collection for days, after the fix, the D1's performance was noticed.
Hearing, without any wishful hoping; significant, perceived SQ dynamics. I did not expect to experience audio that makes me wonder how much better can it get.
Especially when eminating from such a cost effective device. Dimensionality was not so pronounced before.
That's not what I was putting my foot down for.
The objective was to correct the 'anomaly' of reverse current flowing from D1 towards the PSU when it was powered off.
DAC on via PC USB, PSU off = PSU LED lit via USB cable. Hence diode mod.

 

[RandomEar]

You should really look into how to test audio components and why proper controls are 100% required for any plausible result:

Audio Blind Testing - You Are Doing It Wrong! (Video)

Just uploaded a video on the basics of performing controlled tests in audio. It was motivated by saving myself text in having to write all of this down when telling someone who to do these tests right. And as a counter to a few online personalities to keep saying they do "blind" tests yet when...

www.audiosciencereview.com

Concerning the "black background" stuff: You can either hear noise, or you can't. If there is no audible noise while no music is playing, you don't have a noise problem and don't need any magical PSU upgrade.

"Supply distortion" on a device which comsumes a flat two or three Watts and where the actual output power is close to zero is just audiophile fairytales.

Sorry, I get that you like tinkering with stuff and it's fun and OK to do that. But this is getting into audiophoolery territory.

 

[_MAX_]

Hi Roland68,

Like it haha. You make me laugh (I should be decorating the lounge). Here's some photos.

Got two D1's, both unmodified. PSU has the mod.
Not fooling myself. All of my DACs sound different, even the same model can do so, different production date, tolerances of those components; as you know? Revealing amp is essential.
Fosi BT20a Pro with OPA 2134, Van Damme blue driving Mission LX, nice and smooth in the bedroom.
Completely different experience to the lounge set up.

D1 powering devices with reverse current.
1. LEDs on disconnected USB C cable. The USB cable in it's entirety.
2. Successfully booting the Sanskrit MK3 (not MK4, wishful thinking).
3. Successfully booting the E50II.

Clearly sending power from the PC onwards through the Aux power input.

 

[_MAX_]

E50II, Sanskrit displays.

These DACs do not output power on Aux power input.

 

[antcollinet]

Hi Roland68,

Like it haha. You make me laugh (I should be decorating the lounge). Here's some photos.

Got two D1's, both unmodified. PSU has the mod.
Not fooling myself. All of my DACs sound different, even the same model can do so, different production date, tolerances of those components; as you know? Revealing amp is essential.
Fosi BT20a Pro with OPA 2134, Van Damme blue driving Mission LX, nice and smooth in the bedroom.
Completely different experience to the lounge set up.

D1 powering devices with reverse current.
1. LEDs on disconnected USB C cable.
2. Successfully booting the Sanskrit MK4.
3. Successfully booting the E30II.
4. The USB cable in it's entirety.

Clearly sending power from the PC onwards through the Aux power input.

This post (audible differences between DACs is off topic for this thread. You should create a separate dedicated thread where you can learn what you are not understanding.

 

[RandomEar]

[...]
Not fooling myself. All of my DACs sound different, even the same model can do so, different production date, tolerances of those components; as you know? Revealing amp is essential.
[...]

Nope. More fairytales. People fail to distinguish the vast majority of amplifiers in blind tests, DACs are more than an order of magnitude harder.

How can DAC's have a SOUND SIGNATURE if they measure as transparent?

I know there are people out there that think cables affect sound, which is much worse, but there really is no response to something like that, but just to smile and nod. But what about people who talk about DACS as if they were headphone drivers or speakers, and talk about the SOUNDSTAGE...

www.audiosciencereview.com

See if you can pass any of the ABX tests linked in this thread. Feel free to post your foobar2000 ABX results over there