Last Updated on April 16, 2021.
It’s increasingly common to extend the I/O capability of small computer interfaces by connecting an external eight-channel preamp via an ADAT optical port, and some of these external preamps are just a multi-channel preamp and A-D converter, providing additional simultaneous recording inputs, while others can also provide D-A conversion and line outputs too, enabling the connection of analogue outboard send-return loops as well as more monitoring feeds, etc.
There are many popular ADAT preamp options out there, from the Behringer ADA8200 Ultragain at the budget end, to the Grace Design preamps, and everything in between.
In this article, I will be covering some of the 8-channel preamps in detail, from the very affordable ones up to the higher end devices.
Note: I wrote an article about what ADAT is and how it works, which you might want to check out in case you don’t exactly know what it is.
Let’s get started!
The Audient ASP800 is an 8-channel preamp that can be used stand-alone or as a cost-effective expander for the compact USB interfaces by Audient, such as the iD14, or any other interface with ADAT in capabilities, such as the Apollo Twin interfaces.
The first two Retro channels offer the HMX tube saturation emulator (used in some previous products) and a new “Iron” processor, which introduces transformer saturation, and these tone-shaping capabilities are an impressive set of features to have since not only do they allow sources to be enhanced during the recording process, but you can even use them to give your entire mixes an analog feel.
The Audient ASP800 costs substantially less than its older brother, the ASP880, and Audient managed this not by cutting corners and delivering a worse product, but rather by trimming the features in a balanced way.
Soundwise, the Audient ASP800 can’t be beat, which is why it holds the nr.1 spot on this list: It sounds clean, quiet, very accurate and transparent, and provides a lot of headroom, especially considering the price. As far as the retro channels go, they can certainly add some “dirt” when required, in a musical way, of course.
Find out more about the Audient ASP800 here:
Focusrite Clarett OctoPre
The Focusrite Clarett OctoPre is an eight-channel mic preamp and ADAT-format A-D/D-A converter that can be used either stand-alone or to expand the input/output capability of any audio interface.
It doesn’t come with MIDI, S/PDIF, or any other DAW-related facilities like its older brother, the Clarett 8Pre and 8PreX, and what you’re left with is an 8-channel preamp that features all the basic functionality at a much more affordable price without a compromise in quality.
Like all Focusrite equipment, the Clarett OctoPre is extremely well built with an all-metal chassis and the traditional Red Focursite look.
On the front, it’s got two combi XLR/TRS inputs while the other six are on the back, and you can engage phantom power separately for inputs 1-4 and 5-8, and the first two inputs can work as instrument inputs. It also features the Air circuit which when engaged will boost the higher end, giving it a more “airy” and open sound.
In addition to the six XLR/TRS combination connectors and eight TRS insert send/return loops, the rear panel features a Tascam audio-format 25-way D-sub connector, which carries the unit’s eight line outputs. There are also two ADAT-format input/output pairs that pass two I/O streams, containing channels 1-8 (44.1 and 48 kHz), channels 1-4 and 5-8 (88.2 and 96 kHz), or 1-2 and 3-4 (192kHz).
The OctoPre delivers exceptional audio quality and versatility for its price and is one of the most cost-efficient 8-channel preamps you can get.
Find out more about the Focusrite Clarett OctoPre here:
The Behringer ADA8200 is the ideal 8-channel pre for anyone on a tight budget that needs to expand their input count since it sells for about 1/4th of what the previously described Focusrite OctoPre does.
The ADA8200 doesn’t come with MIDI I/O or S/PDIF, and phantom power is supplied globally to all eight channels which, while not ideal, does get the job done, and it comes with the award-winning MIDAS preamps, which sound crystal clear and provide you with a lot of headroom.
Each of the eight input channels is equipped with an XLR and a quarter-inch TRS socket, receiving electronically balanced mic- and line-level inputs respectively. Both input formats are actually active and summed together; the line input is simply padded down and mixed with the mic input before being fed into the mic preamp.
In terms of sound quality, it cannot be compared to something like the Audient ASP800, but at close to 1/6th the price, I don’t think it should be compared but rather be looked at as an extremely affordable and reliable way of getting an additional 8 channels to work with.
Essentially, the ADA 8200 is a convenient, low-budget ADAT interface and eight-channel preamp that is extremely cost-efficient, and while it may not win any awards, any home recording enthusiast that needs 8 additional inputs will be glad to get their hands on it.
Find out more about the Behringer ADA8200 here:
The Midas XL48 is an 8-channel preamp that offers 8 XLR inputs on the back (not XLR/TRS combi), and each individual channel features a PAD, 48v phantom power control, a polarity flip switch, and both a High pass- and low pass filter.
This unit comes with two ADAT ports on the back and each one can carry 8 channels at 44.1kHz or 48kHz, whereas port one carries the signal of channels 1-4 and the second port the signals of channels 5-8 when recording at 96kHz.
Essentially, recording at 96kHz requires the use of two optical cables (TOSlink) and an interface with two ADAT inputs.
This unit also features AES3 (via DB-25) outputs for digital connectivity as well as 8 analog outputs via DB-25, word clock in and out, and it’s built like an absolute tank.
One huge drawback, however, which is why I wouldn’t recommend it to anyone recording in a small studio, is that it comes with a built-in fan for cooling that is quite loud. Recording with the Midas XL48 live is great, or if you have it set up in another room then you really shouldn’t have any issues.
Find out more about the Midas XL48 here:
TASCAM SERIES 8p Dyna
The Tascam Series 8p Dyna features two preamps which are accessed through front-panel in a combi-XLR format accepting mic, line or instrument inputs, as well as six additional ones on the back, along with two sets of balanced TRS analogue line outputs.
This unit comes with two ADAT ports on the back and each one can carry 8 channels at 44.1kHz, whereas port one carries the signal of channels 1-4 and the second port the signals of channels 5-8 at 96kHz, and only two channels per port at 192kHz.
It’s worth noting that this unit doesn’t come with ADAT Inputs since it’s designed only to provide additional recording channels, so if you want an expander to connect analogue line-level gear you’ll have to look elsewhere.
In terms of controls, it’s fairly straight forward; You get a Gain control for each channel as well as a one-knob compressor. Channels 1-2 have a three-way switch that allows you to select between mic/line, instrument, and mic with phantom power.
Channels 3-8 have red buttons to engage phantom power on a per-channel basis.
The Tascam Series 8p Dyna sounds clean, quiet and transparent, with plenty of headroom in normal use and the compressors are a nice bonus to have, especially for those who like to keep their recording levels high.
Find out more about the Tascam Series 8p Dyna here:
ART TubeOpto 8
If you’re looking for a preamp with a more vintage vibe to it, then the TubeOpto 8 might be for you. It gives you eight channels of discrete Class A tube mic preamps each with XLR and quarter-inch jack inputs and up to 64dB of gain.
Additionally, a PAD, Phase, and a low frequency roll-off (set at 80Hz) switches are all available for each channel individually.
Instrument inputs are only available on the first two channels which are on the front, contrary to the XLR inputs which are all in the back, which allow you to connect instruments such as Guitars and Basses.
Every individual channel comes with two knobs, one for the Gain and one for the output level, and these feel quite sturdy and don’t wiggle at all. However, they do rub against the front panel, and even though this doesn’t affect their functionality, it is a bit of a drawback.
Another slight drawback is that this unit can get quite hot after running for long periods of time, and that phantom power cannot be supplied to each channel individually, but rather to channels 1-4 and 5-8 via two different switches on the far left of the device.
On the back, in addition to the XLR/TRS inputs, it comes with 8 TRS balanced outputs, word clock in and out, as well as ADAT in (some preamps only feature ADAT out) and it can handle eight channels of 24-bit audio input and output at either 44.1 or 48 kHz sample rates.
Lastly, to the right are the power switch and the sample rate/sync selector, which enables you to switch between 44.1kHz and 48kHz from its internal clock or to select external ADAT or word clock sync sources.
Find out more about the ART TubeOpto 8 here:
RME OctaMic XTC
What differentiates RME OctaMic XTC from all other preamps on this list is that it’s a digitally controlled mic pre, which means that it can be remotely controlled via MADI, USB, or MIDI using the RME MIDI remote app, and it can even be daisy chained up to 8 units, giving you a total of 64 additional channels to work with.
The first four of the unit’s eight high-quality, digitally controlled mic preamps are also usable as line inputs, and the last four as instrument inputs for connecting guitars and basses.
It also features 8 channels of AES/EBU and 3 ADAT ports, two outputs and one input.
One additional feature of this device is that it comes with two headphone jacks, and you can create two completely different mixes for each one, add effects (if you’re using their TotalMix FX software), and control those mixes remotely from a PC or iPad.
TheRME OctaMix XTC even works as an 8-channel standalone audio interface, which means that you can connect it to any computer, or any other class compliant device, like an iPad, and record those eight inputs separately to your DAW.
It’s worth noting, however, that this unit doesn’t come with any analogue outputs, only digital. So, keep that in mind before buying.
Lastly, an internal routing matrix allows any preamp output or digital input to be auditioned, as well as patched freely to any other digital output, providing extremely flexible signal routing and format conversion.
RME have come up with an extremely versatile preamp/interface, and being able to daisy chain multiple of these units together to get up to 64 additional inputs is interesting, to say the least.
Find out more about the RME OctaMic XTC here.
And last but not least, we have the Grace Design m108, which I would by no means consider a budget 8-channel preamp, but it’s a great-sounding and very versatile 8-channel preamp.
Grace Design m108
The Grace Design m108 can be remotely controlled in a variety of ways, and the m108 is also an eight-channel A-D converter, with AES and ADAT outputs, and includes a reference-grade headphone amplifier with a built-in stereo monitor mixer.
Additionally, it boasts a class-compliant USB 2.0 interface, allowing it to serve as a basic computer audio interface that you can use to record audio straight through it, and an expansion slot for additional I/O is also included.
It only features 8 XLR inputs on the back (not XLR/TRS), and two instrument inputs on the front for connecting guitars and basses, and two headphone outputs with fully independent source selection, allowing you to create completely different mixes for each one.
Two ADAT lightpipe sockets are also available on the unit, and these deliver all eight channels in duplicate at the base sample rates, reducing to four channels on each at double sample rates. However, the 176.4 and 192 kHz sample rates are not supported over ADAT, they are, however, by the AES3 outputs.
A pair of BNC sockets for word-clock in and out can also be found on the back, as well as MIDI I/O and an Ethernet port for network connectivity, which allows you to control it remotely and works flawlessly on the Chrome Browser, however, the functionality is a bit limited and using Grace Designs’ dedicated Windows/OS X App might be a better choice.
As far as sound goes, it’s very clean and neutral-sounding and gives you a ton of headroom to work with. The only con I see with this unit is that it doesn’t provide any balanced analogue outputs or TRS inputs.
Find out more about the Grace Design m108 here.
In most cases, I’d recommend that you stick to either the Audient ASP800 because of its great audio quality, the Focusrite OctoPre because it’s more affordable yet just as good as the Audient preamp, or the Behringer Ultragain ADA8200 simply because it costs less than $200, which is a steal.
I hope this information was useful!
Have a great day!