Eventide bills its MixingLink as a "Mic Pre with FX Loop." It is so much more than that! I tried to sum it up technically:
It's a mic/line preamp. It's an instrument preamp/DI. It's a headphone amp. It has a balanced effects loop. It has a smartphone/tablet loop via 1/8'' TRRS (4-conductor). It has an output to drive an instrument amp. The main output is switchable (via a recessed switch on the bottom) between line and mic-level. It's in the shape of a guitar pedal. The effects loop is engaged with a foot-switch.
But I gave up on writing a list. The practical applications are endless!
The MixingLink's mic preamp is excellent in terms of transparency, and it's worth the asking price on its own. A hi-fi channel strip that costs me three times more beat it slightly — for noise floor and extended frequency response. Admirably, the MixingLink's frequency response is less than 0.5 dB down at 20 Hz and about 0.6 dB down at 20 kHz — and only about 2.5 dB down at 10 Hz and 40 kHz (the latter being about 0.2 dB down from my measuring interface). It has phantom power if plugged into the wall with the included mini-wart, but if you don't need phantom, it can run from a 9V battery. There is no separate battery door though; you have to remove four screws and the bottom plate to access the battery compartment. The lack of a battery door is a shame, because the MixingLink would make a great field preamp, but screws are easy to lose in the field. I did not try battery operation for the review, because I installed the included rubber feet over the screw holes as soon as unboxed the unit, before realizing I'd need to undo the screws — a tip for the bottom-label designers.
The instrument input is equally good and did not affect the tone of passive-pickup instruments. If anything, a guitar plugged into the MixingLink with pedals in the effects loop seemed to sound a little better than the guitar straight into the pedal board, but I did not do any empirical testing in this regard. In general, if you are not relying on current-starving for the tone, then current-buffering is usually a good thing. The unit does not soft saturate but sounds pretty good when completely overdriven. One obvious bonus to using the MixingLink's effects loop is you can enable many processors at once by leaving them on and using the foot-switch on the MixingLink.
The MixingLink will connect to recording and/or live-processing software in any device equipped with an 1/8'' TRRS jack (stereo out and mono mic/line in) using a single cable. In theory, a quality smartphone/tablet audio interface that connects to the smart device digitally would sound better than using the built-in I/O of the device, but in practice, I was impressed and did not hesitate to use the MixingLink this way. The sound I got from a tablet was at least as good as the pedals I compared it to, probably better. The simplicity of the one-cable analog hookup was a welcome trade-off too. The number of sound manipulation apps that you can get for a few dollars each is staggering, and if you check the reviews, a lot of them are well liked. I had to search a bit online before I found a male-to-male 1/8'' TRRS cable worth buying. The cable cost me $11, but assembling one myself would have cost more, and I gave up on finding the appropriate raw cable. Since these cables are not common (and the feature is so cool), including one in the box would have been a nice touch.
The mic and instrument amp are live at the same time, but there's only one level setting. A clean-boost pedal for instruments is a good workaround. Tricks like singing along with guitar lines through an amp were loads of fun. The effects loop and smart-device loop are also simultaneously active, with a similar limitation in setting levels. Speaking of levels, the MixingLink handled +4 dBu outboard processors as well as basic guitar pedals quite well. The effects send level results from the input gain, and I always had some kind output gain control on the processors in the loop, so in practice, this scheme worked fine. There are three modes for the effects loop, controlled by a toggle: fixed dry signal with effects gain setting, wet/dry ratio control, and effects only. The only issue I ran into was when using the MixingLink with a line- level signal from a DAW interface; with the input gain at minimum, and the Hi/Lo gain button on Lo, I was still clipping the inputs of guitar pedals which had no input gain control. I was forced to digitally attenuate the DAC a few decibels, which my OCD would prefer me to never do, but it sounded fine anyway.
My only complaints are with the labeling. Much of the text is black-on-grey or white-on-grey. This is exactly mediocre contrast. My bedroom studio is brighter than every commercial studio I've been in, but I was using a flashlight to read most of the labels until locations of everything were imprinted in my memory. The pots are detented throughout the whole turn, but there are no markings around them, so to repeat settings, you'd have to count clicks. Maybe the designers only meant for the knobs to be harder to knock out of a setting, since it is a pedal, but I found the knobs easy to turn with my feet anyway, and why not throw in some hash marks at least?
Regardless, this is the ultimate audio signal interface. It never failed to hook up anything to anything else, always sounding clean and good. The headphone amp is even stereo, and music piped in through the smart-device loop is stereo. So, with proper cabling, you really could use this as another headphone amp channel too. As if it didn't do enough already! I'd love to see a dual-mono rackmount version with separate control of all I/O levels, especially effects send/return, as well as separate levels for mic/line and instrument inputs, but I think the compromises in the current design are well thought out (other than the minor gripes I pointed out). I was ready to buy this when I heard that it could be used for sending line-level signals safely to guitar amps, and it had a mic preamp. For the price, that combination already seemed like a good deal. Why has this box not come along sooner? There's no reason these features couldn't be on mixing consoles and DAW interfaces. Why didn't I think of that?!?! Absolutely anyone that records could use this box, but new recordists especially should look at this for their first preamp upgrade. You start with the MixingLink's great preamp, and then you can go hunting for cheap, used pedals — and you end up with an inexpensive creative palette for anything you record. Or use a smartphone or tablet, or both, at once, and... and... and. The various individual things this unit does are each worth the asking price, but it integrates many such things in the space of a pedal. I love it so much, I wrote it a haiku:
little metal box
creative recording now
Tape Op bunny sketch