Top Audio Interfaces with SPDIF [2023 Reviewed]

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ThumbnailAudio Interfaces with SPDIFProRec ScorePrice
Antelope Audio Zen Go Synergy Core

Antelope Audio Zen Go Synergy Core

8.6
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Focusrite Scarlett 8i6 3rd Gen

Focusrite Scarlett 8i6 3rd Gen

8.2
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Native Instruments Komplete Audio 6 MkII

Native Instruments Komplete Audio 6 MkII

7.3
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Introduction

If you’ve looked at high-end audio interfaces then chances are you’ve seen RCA channels labeled as SPDIF IN/OUT. For the unfamiliar, SPDIF is a type of digital audio transmission, often confused with ADAT, that allows you to connect multiple sources together without losing audio quality. You can combine audio interfaces, external converters, and drum kits into a single digital device that you can control through your DAW.

Transmitting signals through SPDIF preserves the original audio data unlike what happens when relaying signals through converters. That’s why audio engineers prefer interfacing devices using SPDIF connectors instead of connecting them to an external DAC. On audio interfaces, the SPDIF connections utilize RCA channels that either carry 2 mono or a single stereo signal.

SPDIF connectors aren’t commonly found on most entry-level interfaces such as the ones offered by Focusrite. You’ll have to spend at least $200 for an interface with SPDIF functionality. If you’re only looking for SPDIF connectors to gain 2 extra input/output channels, then you’re better off buying an interface with a better I/O configuration. Paying the extra price for an SPDIF interface only makes sense if you’re planning to combine multiple units or if your main focus is the unit’s sound quality.

When choosing an audio interface with SPDIF, one of the most important specifications you should look out for is jitter. Jitter corresponds to the time delay that occurs when transmitting a signal between 2 audio components, think of it as how unsynchronized the devices are. For the average listener, the effect that jitter has on the audio quality isn’t discernable. However, a lot of professional audio engineers swear by the audio degrading effects of a high jitter.

Another important feature you should focus on is the unit’s DAC and ADC quality. In our opinion, you won’t notice any major difference in quality of converters between sub $500 audio interfaces. You could settle for an inexpensive unit with decent converters if it gets all the main aspects right. However, if you’re planning to record high-grade tracks with your unit, then it is worth investing in high-quality converters as well as other features such as an onboard DSP. In professional implementations, converters are arguably what makes or breaks a unit.

In the right situation, SPDIF can be extremely useful since it opens the room for a lot of different applications. However, a cheap audio interface with SPDIF won’t do you any good if it doesn’t produce good sound quality. The best approach would be to narrow down your options to only include the best sounding interfaces, then filter those according to SPDIF capability.

Top Audio interfaces with SPDIF Reviews

All text and image links lead to Amazon unless stated otherwise. All product scores are based on ProRec’s in-house scoring model

8.2Average Score
ProRec Score – Scarlett 8i6 3rd gen
Price to Performance
8.5
Input / Output
9
Sound Quality
8.5
Connectivity
7
Additional Features
8

The Scarlett 8i6 3rd gen is a robust audio interface that features 6 input and 4 output channels that can be expanded by 2 inputs and 2 outputs through SPDIF.

The back panel of the 8i6 contains the majority of the I/O sockets which include 4 line outputs, 4 line inputs, MIDI I/O sockets, and SPDIF I/O sockets. This panel also features a USB-C port, a kingston lock socket, a power switch, and a 12V external power jack.

On the front panel, you’ll find the 2 remaining input sockets which are TRS/XLR mic combo jacks. Each of them has separate INST, PAD, and AIR indicators (activatable through the Focusrite Control software) along with individual gain knobs. However, the 48V power button toggles phantom power for both mic inputs simultaneously. At the rightmost part of this panel, you’ll find a large monitor control knob and two ¼’’ headphone sockets which have their separate volume encoders.

Buildwise, the 8i6 is slightly larger than the average audio interface because of its additional number of I/O channels. The unit is also housed in aluminum which makes it sturdy but not so heavy.

When it comes to sound quality, the 8i6 contains fairly powerful converters and preamps. The converters provide a maximum sample rate of 192kHz and a 24 bit depth. They can capture audio down to the smallest details without imposing any notable latency. For a more comprehensive test, we recorded using all different sample rates starting from 44.1kHz up to 192kHz which the 8i6 handled perfectly well.

The preamps on the 8i6 produced crystal clear recordings throughout while generating almost zero noise. We noticed that the sound quality suffered a bit at max gain settings, however, this isn’t really an issue since you will rarely have to use the full 56dB range. We also used the 8i6 to record using a bass guitar and an electric guitar after activating the INST mode which yielded great results.

One thing that stands out with the 8i6 is the togglable AIR feature which applies a subtle dB boost to the high-end frequencies. When recording vocals, this feature adds an extremely pleasant effect which makes the tracks sound slightly warmer and fuller.

For a rather inexpensive price, we find it remarkable that the 8i6 features an SPDIF connection. We first tried running it in sync with a Tascam US-4×4 interface and noticed no jitter. We then used them to connect a drum kit which saved us 2 input sockets. We didn’t notice any sort of delay in both cases which is a huge benefit.

As far as drawbacks go, the 8i6 only has a few that don’t have a significant impact on  performance. For instance, while the XLR/TRS mic inputs work perfectly fine, the line inputs on the back panel have a much lower volume. The Focusrite control software is also a bit hard to navigate and certain features can only be accessed through it exclusively. Moreover, you can only activate phantom power for both inputs simultaneously. This might seem a bit trivial, but running a dynamic mic with active 48V can deteriorate the sound quality. As a result, you won’t be able to connect both a dynamic mic and a condenser mic at the same time unless you’re willing to sacrifice the dynamic mic’s sound quality.

The Scarlett 8i6 is a 3rd gen model that doesn’t have an immediate predecessor, however, the 2nd gen Scarlett 6i6 is the closest in terms of I/O and components. As the name suggests, the 8i6 has 2 additional line inputs on its back panel and features a USB-C port instead of the outdated USB-B port. The 8i6 als has the upper hand when it comes to sound quality. To be more specific, the 6i6’s preamps only offer a 50dB gain range and they have a higher THD+N. The 8i6 also contains better converters which provide an extra 5dB of dynamic range on both AD and DA conversions. Moreover, while both units have a similar design and build quality, the 8i6 looks a lot more polished.

Overall, the Scarlett 8i6 is one of the few decent mid-range audio interfaces that feature an SPDIF connection. The 8i6 can also produce amazing sound quality and has a lot of commendable features. Whether you value the 8i6’s SPDIF connection or not, we recommend the unit as an incredibly powerful and versatile audio interface.

Scarlett 8i6 Benefits

The 8i6 features the famous AIR emulators.

You can hook up an additional 2 inputs and 2 outputs through SPDIF.

The preamps are transparent and provide a high gain range.

The unit has 2 headphone sockets each with a dedicated volume encoder.

The 8i6 has a pleasant design.

Scarlett 8i6 Drawbacks

The TRS line inputs have a lower volume than the combo inputs.

You can only activate phantom power for both input channels simultaneously.

The Focusrite Control software isn’t very user-friendly.

All text and image links lead to Amazon unless stated otherwise. All product scores are based on ProRec’s in-house scoring model

8.6Average Score
ProRec Score – Antelope Zen GO Synergy Core
Price to Performance
8
Input / Output
7.5
Sound Quality
10
Connectivity
8
Additional Features
9.5

The Antelope Zen Go Synergy Core is a mid range audio interface that features 4 inputs and 8 outputs. The unit features the proprietary 64-bit AFC clocking technology which reduces jitter when connecting digital channels through the unit’s unbalanced RCA SPDIF I/O.

On the back panel, you’ll find 2 Line/XLR combo input jacks, two ¼’’ balanced monitor outputs, two unbalanced RCA outputs, and SPDIF I/O sockets. Thepanel also features a Kingston lock socket, the main USB-C socket, and an extra USB-C socket which can be used for reverse charging.

The main panel of the Zen GO features a single large controller knob which sits next to 3 buttons. These buttons can be used to dictate what functionality the dial performs such as altering gain levels, sample rate, and monitor volume. You can monitor these levels through a full-color LED screen that provides detailed information about the system settings and the onboard inputs. You can also use it to monitor the 2 headphone outputs which can be found on the unit’s front panel.

Physically speaking, the Zen GO is relatively lightweight and compact even though it is made of robust metal. The unit also has a slick and simplistic design which looks great but can be somewhat limiting since it can’t be placed in the middle of an equipment stack. Additionally, we would’ve preferred if the mic inputs were on the front panel.

For the price, the Antelope Zen GO has remarkable features. For starters, the unit’s ultra-linear and transparent preamps offer a high (65 dB) gain range. In simple terms, you can amplify any mic’s signal regardless of how low it is. We tried recording using some old gain-hungry mics we have and didn’t even have to use the max settings. The Zen GO also seems to add a pleasant yet subtle warmth to our recordings.

One thing we can attest to is that the unit’s converters are a cut above anything we’ve tested in a sub $1000 interface. They provide an incredible 127 dB dynamic range which translates to high-fidelity and high resolution audio. Matched with the unit’s remarkably low latency, you can use the Zen GO to capture the room with impeccable detail while monitoring in real-time.

When it comes to extra features, the plugins library which Antelope Audio offers contains super useful analog-emulated effects such as EQs, compressors, guitar amps, etc. 37 of those plugins are free to use which prompted us to spend some time testing them out. At one point, we had around 7 plugins running simultaneously with no notable latency because of the unit’s powerful built-in DSP.

As far as downsides go, we don’t have any major complaints about the unit’s sound quality. We do however have qualms about the unit’s drivers. The Antelope Zen GO has some noticeable issues and glitches. While we didn’t face any major driver issues that rendered our tracks inaudible, we were frequently presented with random pops, screeching noise, and connection errors. Additionally, the control software seems a bit rough around the edges and can be hard to navigate. Even though Antelope Audio kept on frequently dropping new software updates after the Zen GO’s initial release, the software still has a lot of bugs.

The Antelope Zen GO Synergy Core is part of the Zen models which include the Zen Q and the Zen Tour. Both of those models are superior to the Zen GO even though they’re much more expensive. The 14×10 Zen Q which is very similar to the Zen GO contains the same preamps and DA converters. However, the Zen Q’s AD converters offer slightly more dynamic range and have a much lower THD+N. On the other hand, the Zen tour has a ton of I/O channels (18×26) compared to the Zen GO. The Zen tour also has far more FPGA and DSP chips, better AD and DA converters, and features a touch screen.


Overall, the Antelope Zen GO is a very powerful audio interface considering its price. We do believe that the unit requires slight tweaks, but it is by no means an impractical product. From the extremely powerful converters and preamps to the amazing plugin library, the Antelope Zen GO has all the tools you need to record professional-grade tracks. For music production purposes, we recommend the Zen GO as an incredibly productive unit that can drastically improve the quality of your recordings.

Antelope Zen GO Benefits

The preamps offer an incredible 65dB gain range.

The unit contains high-fidelity converters that can produce crisp and detailed audio.

You can run more than 8 plugins with no notable delay.

The Zen GO features 2 headphone sockets.

The unit’s 64-bit AFC technology guarantees zero jitter when connecting inputs through SPDIF.

Antelope Zen GO Drawbacks

The unit has a lot of driver issues.

The software is very buggy.

All text and image links lead to Amazon unless stated otherwise. All product scores are based on ProRec’s in-house scoring model

7.3Average Score
ProRec Score – Komplete Audio MKII
Price to Performance
7
Input / Output
8
Sound Quality
7
Connectivity
7
Additional Features
7.5

The Komplete Audio 6 MKII is the cheapest audio interface on this list that features an SPDIF connection. With a 6×6 USB-B configuration, the unit  features a maximum sample rate of 192kHz and a 24-bit depth.

As far as build quality goes, the Audio 6 MkII is made of plastic but doesn’t feel flimsy or cheap at all. The knobs are also buttery which helps with the fine-tuning process. We did however notice that our Mic channels were slightly wobbly, but we don’t think that it’s something to be concerned about.

The back panel of the Audio 6 MKII contains 4 line outputs, 2 line inputs, and MIDI I/O sockets. You can also find the USB-B port and the SPDIF I/Os on this same section.

On the other side, the front panel features the 2 main mic XLR/TRS input jacks and their corresponding gain and INST controls. This panel also contains a 48V button which activates phantom power on both mic inputs and a Mono/Stereo switch. To its right you’ll find a channel switcher which sits above a direct monitoring knob.

The main panel of the Audio 6 MKII contains a slick segmented LED meter which provides detailed info on the gain and output levels. You can alter the latter using the huge knob which controls the channels indicated by the switch. On the other hand, the 2 headphone sockets which can be found on the front panel have their separate volume dials.

To test the unit’s sound quality, we connected a Shure SM7B to one mic input and an electric guitar to the other channel with active INST mode. The output from both inputs was extremely crisp and granular and had a ton of detail. They also synced really well together so neither were overbearing or dominant. We did however need to crank the gain settings all the way up for the dynamic mic since the unit’s preamp doesn’t offer a lot of gain. However, they still provided a crystal clear output with incredible transparency.

Meanwhile, we were referencing through a pair of DT 700 headphones while monitoring through Presonus e5 studio monitors. The Audio 6 handled both outputs exceptionally well and  managed to minimize any output noise. However, we refrained from connecting high-impedance pairs since the Audio 6 doesn’t have enough power to drive them.

In fact, we noticed that the Audio 6 has an incredibly flat frequency response in the 5Hz-20kHz range that we even used the Audio 6 to measure the response curve of different studio monitors.

The Komplete Audio 6 MKII (2019 release)  is the immediate successor of the original audio 6 which was released back in 2011. In such a large time period, NI completely revamped the audio 6 into a slicker unit that is indistinguishable from the first gen model. They also put a lot of effort towards improving the unit’s sound quality and performance. For instance, the MkII provides an extra 9dB of dynamic range on headphone outputs and offers half as much THD+N. The MKII also has a much flatter frequency response curve (around ±0.1 dB deviation) compared to the Original ±0.5 dB. Most importantly, the MKII offers a maximum sample rate of 192kHz while the first gen only offers up to 96kHz rate. Nonetheless, we should give some praise to the original Audio 6 which has better crosstalk specifications (less signal bleed).

Despite being an overall well-rounded unit, the NI Komplete Audio 6 MKII has a few flaws. For instance, even though having 2 headphone sockets gives the Audio 6 MKII an edge over its competitors, they don’t really provide enough amplification. We had to crank the level knob all the way up just to get a decent output. Moreover, after some hours of use, the headphone output will even start producing annoying hissing noise and occasionally some random pops which persists until the unit gets reset.

Everything else works perfectly fine; the unit’s flaws only come from its poorly designed headphone outputs. We expected a much flimsier unit because of its plastic build, but the Audio 6 doesn’t feel cheap at all.

Overall, the NI Komplete Audio 6 MKII is an extremely powerful mid-range audio interface that has an abundance of I/O channels. From its incredibly low latency to its remarkably detailed converters, the Audio 6 MKII gets all the basic features right. If you’re on a tight budget the Audio 6 is the way to go.

NI Komplete Audio 6 MKII Benefits

The Audio 6 has 2 headphone sockets.

You get great sound quality for the price.

The unit boasts a very low latency.

The unit is compact, has a good design and build quality

NI Komplete Audio 6 MKII Drawbacks

The headphone amps can’t provide high volumes and can’t drive high impedance pairs.

You might start getting random pops and static noise with your headphones after some time.

Verdict

audio interface with SPDIF scoring model comparison

According to our scoring model, you’ll see that there is a 1.3 point variance between the highest and lowest scoring unit. You’ll find that the highest variance is in the Additional features and Sound quality categories. In both categories, the Antelope Zen GO scores very high beating both the Scarlett 8i6 and the Audio 6 MKII by at least 1.5 points of variance. You’ll also see that the Audio 6 scores the lowest in those same categories while the Scarlett 8i6 performs fairly well scoring 8 and 8.5 in the additional features and sound quality categories respectively.

In addition to scoring the highest in the sound quality and additional features categories, the Zen GO outperforms the other 2 units when it comes to connectivity. Unlike the other 2 units, the Zen GO has 2 USB-C sockets one of which allows for reverse charging. It also offers a built-in DSP, a huge plugin library, and a ton of onboard controls which is why it almost aces the additional features category. Moreover, none of the 2 other units come close to the Zen GO in terms of sound quality because of its superior converters and preamps which are comparable to interfaces twice the price.

We should mention that the Scarlett 8i6 which is the runner-up for the Zen GO remains stable throughout as it doesn’t score below 7 in any given category. It even scores the highest in both the Price to performance and input/output categories which prove that the 8i6 is the most price-efficient unit of the bunch. The only category that the Scarlett 8i6 scores relatively low in is the connectivity category, but its only because the Zen GO offers an extra USB-C port which is by no means a necessity.

However, the composite of small well-implemented details is what makes any product stand out from the competition. In fact, the Antelope Zen GO perfectly embodies this statement which is why it emerges as the top SPDIF audio interface. Leading with an overall score of 8.6, the Zen GO displays excellent performance in all categories especially in the sound quality category which is exactly what you should look for. We did mention that the Zen GO can be unstable at times, but that doesn’t take away from its prowess and versatility. With its powerful converters, remarkable preamps, and additional features, the Zen GO is nothing short of a professional audio interface. We recommend the Zen GO as an extremely powerful audio interface that you can’t go wrong with.

Frequently Asked Questions

What is the most important aspect of choosing an Audio Interface with SPDIF?

Your main focus should be getting an audio interface with powerful preamps and converters while making sure that it doesn’t impose any notable jitter. That way you won’t lose on sound quality when transmitting data through SPDIF and your audio interface can produce impeccable audio.

Is there an alternative to SPDIF on Audio Interfaces?

SImilar to SPDIF, Optical channels (which operate on ADAT protocol) can also be used to combine multiple interfaces. However, unlike SPDIF channels which can only carry 2 channels, optical channels can carry up to 8 channels at 48 kHz/44.1kHz or 4 channels at 96kHz/88.2kHz. ADAT also utilizes Toslink or fiber optics unlike SPDIF which is transmitted over coaxial cables or Toslink.

How do I use the SPDIF functionality on my Audio Interface?

In order to interface your different devices using SPDIF, you will need to use a coaxial RCA cable to connect the SPDIF OUT channel of the first device to the other device’s SPDIF IN channel. That way, the device receiving the SPDIF Input will act as the clock slave while the other device acts as the clock master. After you establish this connection, you then change the clock source of the clock slave unit to be the SPDIF channel. You could easily do this through the audio interface’s control panel on the computer.

How much should I spend on a good SPDIF Audio Interface?

It really depends on what you hope to achieve and how much money you’re willing to spare. The cheapest SPDIF interface costs around $200 and almost all interfaces beyond that price tag have SPDIF channels. You won't notice major differences in sound quality between sub $500 interfaces but you could still find a lot of well-rounded units. On the other hand, If you’re planning to record professional grade tracks then you should expect to shell out at least $700 for a decent unit.