Digital Converters
The prices shown exclude VAT
Buying a digital converter for the studio or home recording
Anyone looking to buy a digital converter already knows that they needs a way to translate audio signals from the analogue world into the digital one. This process is known as analogue‑to‑digital audio conversion. Digital audio converters are available in a wide variety of configurations, complexities, and of course prices.
Because of the different formats and requirements involved, it's not always easy to keep track of what's what, but this buyer's guide is intended to explain exactly what to look out for when purchasing a new digital converter. For even more information on a whole host of topics from the world of studios and recording, check out our range of in-depth guides.
Of course, you might have a question that only an expert can answer! That's why the the Thomann Studio department is on hand with advice and support at studio@thomann.de, via web chat, or by phone on +49 9546 9223‑30.
Sometimes, even with the best advice in the world, you order a device that's still not quite right. This is exactly why we offer our 30‑day money‑back guarantee, to allow even seasoned pros to test their new gear properly. Once you've found the right device, our 3‑year Thomann warranty ensures that you can enjoy it with complete peace of mind.
What's the difference between analogue and digital?
Analogue audio represents signals as a voltage curve. Put simply, the fluctuations in voltage correspond to fluctuations in the air – in other words, sound. Digital audio, by contrast, quantises these fluctuations, both in time and in value. Analogue‑to‑digital conversion is fundamentally the following procedure: At regular, very short intervals, a snapshot (sample) is taken of the voltage. This snapshot is then assigned a numerical value. Although the process involves rounding up and down, this is virtually irrelevant given that there are often several million possible values. The advantage of digital audio is that it can be stored, transmitted, and copied with very little loss. Computers rely entirely on this form of audio.
What is the resolution of a digital audio signal?
The two types of quantisation mentioned above determine the resolution of the signal. The resolution over time is referred to as the sample rate: Typical values are 44.1 kHz and 48 kHz, which correspond to 44,100 or 48,000 samples per second. There are also even higher sample rates, which can incrementally improve audio quality. More important is the resolution of the values themselves, which today is almost always 24 or 32 bit. At 24 bit, there are already 16.7 million possible values.
Direction of digital conversion
Converters work either as ADCs (also written A/D, A‑D, or AD converters), with an analogue input and a digital output – or the other way round, as DACs (D/A, D‑A, or DA converters). Devices that can handle both directions of audio conversion are also common, and are usually referred to as AD/DA converters.
)
What's the key factor when buying a digital converters? The number of channels!
Requirements for digital converters can vary widely, mainly depending on your chosen application. Anyone producing entirely in the box and simply wanting high‑quality monitoring only needs two channels of digital‑to‑analogue conversion. If you want to record drums, on the other hand, you'll usually need a relatively high number of A/D channels. In studios that use analogue outboard gear, it's common to work with a large number of both A/D and D/A channels.
Typical use cases: DA channels | AD channels
- Hi‑fi: 2 | 0
- In‑the‑box producer: 2 | 0
- In‑the‑box + vocals: 2 | 2
- Podcasting: 2 | 2
- Producer with external synths: 2 | 8
- Amateur studio: 16 | 16
- Professional studio: 32+ | 32+
Digital formats
A/D and D/A converters actually use different digital formats: After all, there are several ways of transmitting digital audio, each with its own connectors and characteristics. Most digital signals are sent via copper cables (electrical), but some are transmitted via fibre optics (optical).
In addition to standard PCM (pulse code modulation) signals, there's also DSD (direct stream digital), which is based on a different principle and is mainly used for playback in the high-end hi‑fi sector. Alongside converters that convert between analogue and digital (or vice versa), there are also devices that convert between different digital formats. These are known as format converters.
What sample rate do I need?
The impact of sample rate on sound quality is real, but often smaller than is commonly assumed. Most modern converters support up to 192 kHz. However, they also function perfectly well at 44.1 or 48 kHz.
What does word clock mean?
In digital audio, a precise timing reference determines exactly when audio samples are read and written. The term "word clock" refers to the signal that defines when each complete digital audio sample (or "word") occurs: When devices are connected to each other, their clocks mustn’t run independently – they need to be synchronised. Using a word clock is the best way to ensure that all devices are locked to the same clock. This transmission doesn't carry any audio signal, only the clock information.
If you're just connecting two devices, this isn't ever necessary, and many other setups work perfectly well without it too. Equally, there are also dedicated clock generators, whose sole purpose is to provide a highly stable master clock with minimal jitter.
Digital audio formats: Connectors, sockets | Max. channel count | Max. sample rate | Max. cable length (m)
- S/PDIF electrical: RCA | 2* | 96 kHz | 10
- AES/EBU: XLR, BNC or 25‑pin Sub‑D | 2 | 192 kHz | 100 (XLR), 1000 (BNC)
- S/PDIF optical: TOSLINK | 2* | 96 kHz | 5
- ADAT optical: TOSLINK | 8 | 44.1 kHz* | 5
- TDIF: 25‑pin Sub‑D | 8 | 192 kHz | 7.3
- MADI electrical: BNC | 64 | 192 kHz | 100
- MADI optical: Fibre optic (SC or LC) | 64 | 192 kHz | 2000
- Exceptions possible
Note: Multichannel formats usually only support higher sample rates if the number of channels is reduced.
Audio‑over‑IP systems such as Ravenna, Dante and AVB are not, technically speaking, digital audio formats. Similarly, USB, Thunderbolt and similar connections are computer interfaces that transmit data packets rather than audio signals directly.
)
Buying digital converters: Which analogue connections do you need?
The analogue standard for inputs and outputs on digital audio converters is line level, usually provided on balanced TRS jack sockets (the large, 1/4" jack) that can be used to connect effects units, synths, keyboards, drum machines, mixing desks, and many other devices. Some converters also have built‑in microphone preamps, in which case they're fitted with XLR sockets. On the output side, alongside line connections, you’ll sometimes find built‑in headphone amplifiers with the appropriate sockets (3.5 mm or 6.3 mm stereo jacks).
Is an external digital converter worth it?
Digital audio technology is now more the rule than the exception, and even many consumer products include digital converters. Often, external converters are a necessity simply because of the number of channels a project or setup requires. That said, investing in high‑quality A/D or D/A converters is also worthwhile in terms of audio quality.
Form factors of digital converters
19-inch units designed for installation in studio racks are the industry standard for many audio tools. They're operated from the front, with connections on the rear – and digital converters are no exception here. However, some digital converters are available in much smaller formats. In particular, AD/DA or D/A units offering only a few channels are often housed in compact enclosures to save space. In some cases, modern stereo D/A converters are barely larger than the cable jack itself. For live use, converters with very rugged housings are especially popular.
How do I hook up a digital converter – and to what?
If you want to connect digital devices to each other, you'll need to create a digital connection: Otherwise, the additional and unnecessary steps of D/A and subsequent A/D conversion can lead to a loss of quality. Digital mixing desks, digital effects units, and digital sources such as CD players can all be connected in this way.
Often, though, analogue signals need to be passed on, for example for making recordings: If the device that's going to handle this task is a standard desktop or laptop computer, simply buying a basic A/D converter won't do the job! One option is to use a digital converter that's also equipped with computer connections such as USB. Alternatively, the digital signal can be passed to an audio interface – and this is by far the most common setup. Many audio interfaces include digital inputs specifically expand the channel count.
What alternatives are there to digital converters?
Instead of buying a dedicated digital converter, there are a number of other devices that may suited to the task. At the top of the list are audio interfaces. In most cases they perform conversion anyway, but also provide additional infrastructure: For example, many include microphone preamps, outputs for monitoring and headphones, and other extras.
Some multichannel microphone preamps also offer converter options. Whether these devices are really converters with preamps or a preamp with converters is a matter of some debate. Also widespread are combinations of high‑quality D/A converters with equally high‑quality headphone amplifiers. Some monitor controllers, in turn, likewise include digital inputs.
Which companies make digital converters?
There are many manufacturers who specialise in producing digital converters. These include Mutec, Lynx, Benchmark, and Burl, as well as RME, Antelope, Focusrite, and MOTU. Very affordable devices are available from brands such as Swissonic, Klark Teknik, and Behringer.