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SMSL DL100 DAC and Headphone Amp Review

Rate this DAC & HP Amp

  • 1. Poor (headless panther)

    Votes: 3 1.4%
  • 2. Not terrible (postman panther)

    Votes: 4 1.8%
  • 3. Fine (happy panther)

    Votes: 46 21.2%
  • 4. Great (golfing panther)

    Votes: 164 75.6%

  • Total voters
    217

amirm

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This is a review, listening tests and detailed measurements of the SMSL DL100 balanced stereo DAC and headphone amplifier. It was sent to me by the company and costs US $179.
SMSL DL100 Stereo RCA USB DAC Headphone Output Review.jpg

The DL100 is a fair departure from standard SMSL offering in that it uses a stamped steel enclosure instead of machined aluminum. Despite that, the unit maintains its high quality feel and you only notice otherwise when you look from behind and see the seams in the lid:
SMSL DL100 Stereo RCA USB DAC Headphone Output back panel remote control Review.jpg

The slanted back and bright display make it easier to see the settings at the desk. Alas, I wish that it would show the volume by default than sample rate. A remote control is provided (not shown).

I love that despite the budget pricing, and slim case, the power supply is in the case. And support for HDMI ARC (which I cannot test at the moment).

Navigation of the settings was surprisingly easy display the limited display type.

We expect superb measured performance from SMSL so let's test to see if there are any surprised.

SMSL DL100 Measurements
As usual we start with our dashboard:
SMSL DL100 Stereo Balanced USB DAC Headphone Output Measurement.png

This nicely lands the DL100 in our excellent category:
best budget stereo dac headphone amp.png

Output can go higher, delivering even better performance:
SMSL DL100 Stereo Balanced USB DAC Headphone Output THD vs Level Measurement.png


Here is RCA output:
SMSL DL100 Stereo RCA USB DAC Headphone Output Measurement.png


Here is the dynamic range:
SMSL DL100 Stereo Balanced USB DAC Headphone Output Dynamic Range Measurement.png


IMD tests shows slightly earlier distortion rise (curve starting to flatten) but it is still impressively low:
SMSL DL100 Stereo Balanced USB DAC Headphone Output IMD Measurement.png


Multitone performance is superb in mid and higher frequencies where it matters:
SMSL DL100 Stereo Balanced USB DAC Headphone Output Multitone Measurement.png


As is measurement of 50 Hz tone into 600 ohm load per stereophile test:
SMSL DL100 Stereo Balanced USB DAC Headphone Output 50 Hz distortion Measurement.png


Linearity is perfect but shows a very slight offset at both ends of the spectrum:
SMSL DL100 Stereo Balanced USB DAC Headphone Output Linearity Measurement.png


Jitter is excellent sans harmless couple of sidebands:
SMSL DL100 Stereo Balanced USB DAC Headphone Output Jitter Measurement.png


I did not mess with filters so here is the default behavior (filter 1):
SMSL DL100 Stereo Balanced USB DAC Headphone Output Filter Measurement.png

SMSL DL100 Stereo Balanced USB DAC Headphone Output frequency response Measurement.png


At first blush, wideband distortion+noise vs frequency looks quite high:
SMSL DL100 Stereo Balanced USB DAC Headphone Output THD vs frequency Measurement.png


But that is an artifact of measuring all the way to 90 kHz and pulling in "noise shaping" behavior:
SMSL DL100 Stereo Balanced USB DAC Headphone Output 1 kHz FFT Measurement.png


Actual distortion spikes are down a whopping -135 dB so no audible issue at all.

My minimum standard for headphone output with 300 ohm is 100mwatts and DL100 easily passes that mark:
SMSL DL100 Stereo Balanced USB DAC Headphone Output 300 ohm Measurement.png


Notice the incredibly low distortion before it clips. Story gets even better with 32 ohm load:
SMSL DL100 Stereo Balanced USB DAC Headphone Output 32 ohm Measurement.png

Good current delivery ability means that it is able to keep increasing power all the way down to 16 ohm!
SMSL DL100 Stereo Balanced USB DAC Headphone Output vs impedance Measurement.png


Most headphone amps in this class start to droop the voltage at 32 ohm and below.

Sorry forgot to save the 50mv test results last night. :(

SMSL DL100 Listening Tests
I went right to the stress test of using my everyday Dan Clark E3 headphone to pair with the DL100. This is a rather difficult headphone to drive but the DL100 had no trouble producing superb fidelity with it and no hint of any distortion even at max volume. Speaking of that, comfortable listening was at -10 dB on the display. Pushing to 0 dB allowed just enough headroom to shorten your hearing lifetime by a bit while producing excellent dynamics! :) Someone had complained about switching track glitches with SMSL DACs but I heard nothing here with my Roon player.

Conclusions
DL100 provides some form factor changes and inclusion of HDMI ARC. Performance is more than excellent in every area, making for a compelling package despite its attractive price. I especially like its high current drive for headphones that have low impedance.

I am happy to recommend the SMSL DL100 dac and headphone amplifier.
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As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
 
Here is the dynamic range:
SMSL DL100 Stereo Balanced USB DAC Headphone Output Dynamic Range Measurement.png
It should be noted that this is not the DL100's true Dynamic Range.

The CS43131 DAC chip used here employs a feature similar to ESS Sabre's Dynamic Range Enhancement (DRE), where the DAC will reduce the output noise once signal level drops below a certain threshold.

DR's signature -60dBFS stimulus signal is low enough to trigger this so in a way, Cirrus are "gaming the system".

True Dynamic Range should be closer to 120dB.
 
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DR's signature -60dBFS stimulus signal is low enough to trigger this so in a way, Cirrus are "gaming the system".
It is muting any signal below -60 dB??? That makes no sense to do as that will mute then on real content as well.
 
Thanks Amirm! Always informative. God we live in the best times for audio ever! Too bad music and mastering mostly suck nowadays but there's still great people doing great work out there and we always have the past. Great to see so many companies paying such close attention to perfection, my RME-ADI2 still sounds fantastic at -113dB S/N, and it is clear enough to hear the difference of cd (-96) compared to SACD (capable of -120) thru a breakout box for input thru Toslink.

Pic not related
 

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Thank you for the review, as always @amirm,
Sub-$200 for such a DAC offsets the price of groceries.
Last week, I purchased the DO100Pro for $204 and I am trying to figure out the differences to this DL100... (besides the ES9039Q2M v. CS43131).
I have no buyer's remorse, though!:)
 
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No.

Given a low enough signal amplitude, the DAC will go into Low gain and boost the digital input signal to compensate.

This is totally seamless and invisible to end users, though does result in artificially inflated DR numbers.
This is the same technique HDCD used. I don't see an issue with it.
 
This is the same technique HDCD used. I don't see an issue with it.
AES17 Dynamic Range was designed specifically to counteract mechanisms where DACs would modulate their noise floor depending on the content.

Cirrus OTOH just adapted their noise modulation to work with the new measurement stimulus, side-stepping the entire point of it.

And unlike ESS who, on DAC chips with the DRE feature, clearly state the chip's true DR with it turned off and explain how and when DRE engages, Cirrus don't mention the existence of such a feature in their chips anywhere and still claim 130dB DR as though the DAC could actually play a signal 130dB above the nose floor (it can't).

Within the industry, it would be considered a dick move.

Imagine there was a camera brand that releases a new camera with claimed 20 stops of dynamic range and nowhere does it say that that was measured using HDR exposure bracketing.

Canon and Nikon would suddenly look pretty stupid with their 13-15 stops of (actual) dynamic range.
 
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AES17 Dynamic Range was designed specifically to counteract mechanisms where DACs would modulate their noise floor depending on the content.
Not so. This was to get around DACs muting with no signal. That is not what is happening here.

Cirrus OTOH just adapted their noise modulation to work with the new measurement stimulus, side-stepping the entire point of it.
Nope. That would be the case if they detected the test and cheated. Them trading digital headroom for analog is a valid method to increase dynamic range. As I explained, HDCD did that also to get to 20 bits of dynamic range in a 16 bit format.
 
Imagine there was a camera brand that releases a new camera with claimed 20 stops of dynamic range and nowhere does it say that that was measured using HDR exposure bracketing.
That's already done in cameras with intermediate ISOs being digital gain. And if they did what you said, as long as it has zero side effects (HDR method you mentioned gets messed up with motion), then it would be valid as well.
 
Thank you for this review, really interesting unit.
Sorry forgot to save the 50mv test results last night. :(
Don't even remember the result? As a prevalent iem user it's one of the measure I'm looking for the most.

Anyway they still sticks to the damn sample rate display instead of volume, what a shame.
 
how would the HDMI arc be used?

You can get PCM audio from a TV.

Some Samsung’s actually let you use a USB dac!

What I don’t know is if the ARC also allows you to control the volume via HDMI CEC. I presume not…
 
The photograph of the back panel of the SMSL RAW-MDA 1 suggests that this is also stamped steel, rather than cast aluminium. Side by side the display of the RAW-MDA1 is more appealing, there is the added attraction of dual ESS 9039Q2M chips and the additional optical and coaxial input - although it is for a few dollars more. From the information available the component hardware used in the RAW-MDA 1 is impressive, at that price band. On the other hand the DL100 employs 4 x CS43131 chips.

The measured performance is reasonably similar so it is the same question that has been asked many times before: - why do manufacturers like SMSL and Topping market devices that essentially compete against their own products with similar performance and similar price and very little else to distinguish the products?
 
I think I'll buy one of these, use my machining skills to put it in a really fancy case, put some fake WBT connectors on the back, and market it for $12,000.00

How much you want to bet that people would buy it, and then claim that it "sounds way better than that cheap Chinese junk" ???
 
You can get PCM audio from a TV.

Some Samsung’s actually let you use a USB dac!

What I don’t know is if the ARC also allows you to control the volume via HDMI CEC. I presume not…

Why wasn't this tested, when 99% eyeing at this DAC is for this input so they can hopefully use volume control from their TV?

Also insert mini-rant about TVs still sucking so hard at Toslink out.
 
Thank you, Amir.

This is starting to become ridiculous! A complete Dac/Amp with an HDMI/Arc input no less, and balanced outputs able to competently drive most headphones and with inaudible levels of noise and distortion for only $179, and I don't give a rip that the case is stamped steel. Just don't sit on it!

How much longer before the $150 barrier is broken? Best of times, yada, yada, yada!

Now let's do this with speakers!
 
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