Laiv uDAC Review & Measurements

 

Review

For the full review and my thoughts on the sound watch the video below!

Watch the video

Design and I/O

The uDAC is the little-brother to Laiv’s flagship Harmony R2R DAC, but despite its much smaller size, and much more appealing price-tag, it’s actually using the exact same R2R modules internally.

Externally, the uDAC shares the same design aesthetic as Laiv’s other products, with a nicely machined and finished black/gold or silver and gold chassis, and a crisp, clear dot-matrix style display. This is an area Laiv truly does do an excellent job and so I’m happy to see that the same level of polish is applied to this product even at the far lower price.

One change that was quite welcome in my opinion was the lack of spiked feet, instead opting for rubber-bottomed feet, which I much prefer as it makes it much easier to place and position the unit without any risk of scratching the surface you wish to put it on.

Internally, things are quite compact, but Laiv still managed to squeeze in galvanic isolation between the digital and analog sections, which effectively prevents noise from your digital source device getting through to and adversely affecting the performance of the DAC.

On top of that, or rather….underneath, Laiv also added a dedicated output buffer, something which was absent on the Harmony, causing it to have an extremely high output impedance of over 1000 Ohms on the balanced outputs. This output stage means the uDAC’s output impedance is substantially lower at 82 Ohms, allowing it to work with a broader range of amplifiers. This can often be a concern in the head-fi space as many amplifiers, in particular those with a focus on achieving high SINAD scores, often have a very low input impedance to help accomplish this.

So what is actually being cut down to get to this much smaller size? Well for starters, instead of the high end linear power supply found within the Harmony, the uDAC comes paired with an external wall-wart switching power supply, which helps to save on cost and size, but also leaves open the option for an upgrade such as an iFi iPower if the user desires.

Perhaps the most important aspect to note as having been cut down is the outputs, with the uDAC supporting only balanced XLR outs, and no single ended RCA outs.

Laiv does say that you can use a balanced to single ended adapter, but as you’ll see in the measurements below, performance can be inhibited by doing this, and as such it’s best to stick to fully balanced connections if possible, and users with single ended amplifiers may find the uDAC to be not the most ideal choice to pair with them.

So just how does it stack up to the Harmony? Well for my subjective take, head over to The Headphone Show and watch the full review, but for the measurements, read on, and take a peek at the measurements of the Harmony if you’d like to compare.

Measurements

Measurements Include:

• THD+N (SINAD)
• THD+N vs Output Level
• THD+N vs Frequency
• IMD vs Output Level
• Low Level Signal Output
• Reconstruction Filter/Upsampling
• Jitter
• Linearity
• Output Impedance
• Volume Matching
• Noise
• Intermodulation Distortion (IMD)
• Crosstalk
• Multitone

Additional measurements and test information available in the full report

Test Setup

• Audio Precision APx555 B-Series analyzer
• Measurement setup and device under test are running on an AudioQuest Niagara 3000 power conditioner.
• uDAC was connected via USB unless specified otherwise.
• uDAC was warmed up for 6 hours prior to testing
• OS Mode used unless otherwise noted.
• USB input, headphone output used unless otherwise specified
• Tests shown are with a 200kΩ input impedance configured on the analyzer.
• Exact analyzer/filter configurations for each measurement are detailed in the full reports
• CH1 (Blue) = Left, CH2 (Red) = Right

Full Measurement Reports

uDAC (OS Mode)

uDAC (NOS Mode)

Results

Dynamic Range (AES17): 110dB

SNR: 120dB

IMD SMPTE: -75dB

Noise Level RMS: 36uVrms (20hz-20khz)

DC Offset: 6.7mV active, 6.6mV idle

Susceptible to intersample overs: Immune to smaller +1dB intersample overs, +3dB overs will clip.

Output Impedance: 82Ω XLR

THD+N / SINAD

Disclaimer: SINAD should not be used as a figure to judge the overall performance of a product, it is a figure that combines several aspects of performance into one number whilst not including many others. It should be used as one factor among many when evaluating the overall objective performance of a device, and the type/structure of distortion can often be more important than the level of distortion/noise itself.

1khz 0dBfs Sine - XLR Output:

About 15 bit resolution at full scale, although as shown by the small signal tests further down, actual dynamic range is about 110dB/18 bits.

1khz 0dBfs Sine - Adapted RCA Output:

When using an RCA adapter, performance does drop a fair bit, it’s unclear how much of this is due to the lack of inherent harmonic-cancellation from XLR, and how much is due to additional stress on the output stage from the use of a shorting adapter. Regardless, if possible try to use this DAC balanced.

THD+N vs Output Level

THD+N vs Output level

THD+N vs Output level is fairly consistent. A challenge with many R2R designs is keeping things proportional as output level changes, but the Harmony does this quite well overall. Still a bit of a change around -40dB, but quite significantly less than what is found on some other R2R products such as the Rockna Wavedream for example.

THD+N vs Frequency

(96khz bandwidth used on the analyzer. Don’t compare this directly to standalone audible band THD+N measurements as the measurement setup is not the same.)

20khz Bandwidth

96khz Bandwidth

NOTE: Ignore the random spike on the 96khz graph, this was due to a momentary USB buffer issue.

THD+N vs frequency is overall quite flat, in fact with the 20khz band-limit we see a drop toward higher frequencies, whereas with the 96khz bandwidth it’s flat out to 20khz with a slight but sharp increase at the very top end (likely just due to filter cutoff).

Frequency Response

Frequency response is as would be expected flat besides the differences in filter rolloff. NOS mode causes a roughly -3dB attenuation by 20khz. Whereas OS mode is flat up to just over 19khz and then begins a steep rolloff. Use of external oversampling with something like Roon or HQPlayer can allow the DAC to extend flat past 20khz.

IMD vs Output Level

IMD does change a fair bit depending on output level, as is typical with most R2R DACs.

Low Level Signal Output (96khz bandwidth)

This test plays a very low level signal through the device to check for any unusual behaviour.

-90.31dBfs 24 bit dithered sine

-90.31dBfs 16 bit undithered sine

-90.31dBfs 16 bit dithered sine

For extremely small signals, we can observe a slight difference in behaviour on the positive side of the signal vs the negative, very similar to what was seen on the Harmony. We are right on the limit of the DAC’s dynamic range here, so at this point we are starting to more clearly see the limitations of the ladder’s accuracy. Though being an R2R DAC, it does not apply any dithering or noise shaping of its own unless you are running it in OS mode. This means that we can quite clearly see the difference at 16 bit between the dithered and undithered signal. The ability to run NOS and lack of any applied dithering when doing so does also mean you may be able to get measurably better performance and linearity by using external oversampling & noise shaping tools like Signalyst HQPlayer or PGGB in ways that aren’t always possible on delta-sigma converters.

Reconstruction Filter (Nyquist/Oversampling Filter)

OS mode

There is only one filter option in OS mode, which does roll off ever so slightly before 20khz, but with decent attenuation at the Nyquist frequency, and fully attenuating shortly after.

NOS mode does not filter out any ultrasonic/imaged products as there is no oversampling filter in place.

Jitter

Jitter performance is not the best, and is the main area where I saw significant differences between the uDAC and the Harmony. I did also try using the uDDC in combination with the uDAC but performance was best with direct USB input. Additionally, performance seemed to be somewhat variable, and I did occasionally see poorer performance than what is pictured here, though this could also be due to lack of warmup in those tests.

Linearity

This test plays a 1khz tone through the device, and steps down the level in small increments. Linearity measures how accurately the actual output of the device reflects the intended output. For example, if the level was stepped down by 20dB, but the output of the device was 19.7dB quieter, there is a 0.3dB nonlinearity, which would show as a 0.3dB rise on the graph.

Bandpass filtered, this is measuring only the accuracy of the 1khz tone itself

No bandpass filter, this factors in noise into the result

Noise

Noise levels are overall very low, but with higher levels of ultrasonic noise than the Harmony..

The spike visible towards the right of the graph swaps between 705.6khz and 768khz depending on the base rate of the content you are feeding the device. This is because the DAC itself even in ‘NOS’ mode is running at 16x rates. It could therefore be argued that this isn’t ‘really’ NOS, as it is technically oversampling, but just doing zero-order-hold interpolation which provides an output functionally identical to NOS. But the important factor is the lack of dithering in NOS which allows you to fully benefit from high performance external noise shapers. High performance external oversampling will still have the same effect on any DAC regardless of whether the DAC itself is oversampling or not.

Crosstalk

Crosstalk performance is quite good, remaining below -96dB for the full bandwidth, and going down towards -140dB the lower in frequency you go.

Multitone

The multitone test shows us what the THD+N vs frequency and 1khz FFT already showed us, which is that distortion vs frequency is overall very flat, and the ‘floor’ here is not due to actual noise, but rather the harmonic distortion products themselves.

Conclusion

The Laiv uDAC performs in most areas extremely similar to its big brother the Harmony, with a fairly consistent slight step down in performance. This isn’t a Harmony in a smaller box, but gets you very similar behaviour and sound for a fraction of the price. It performs reasonably well for an R2R DAC, though it faces stiff competition from the likes of the Holo Cyan 2 which outperform it quite comfortably for similar money. The main deciding factor there for most will be that the Cyan 2 is NOS only, whereas the uDAC does have internal oversampling available.

I’m happy to recommend the Laiv uDAC for those wanting a warmer presentation to their music, but for those looking for more of a reference/neutral presentation, other options like the SMSL Raw DAC or Eversolo DAC-Z8 may be better options.