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Freqport Freqtube FT-1

Plug-in Valve Processor By Sam Inglis
Published February 2023

Freqport Freqtube FT-1

Freqport’s innovative desktop box makes adding valve warmth to your DAW mixes as easy as loading a plug‑in.

Ten years ago, it seemed only a matter of time before ‘the box’ swallowed everything. Computers were becoming ever more powerful and plug‑ins ever closer to the hardware they emulated. Even diehards like Michael Brauer and Andrew Scheps eventually gave up the fight and turned to mixing in software. If it didn’t sound identical, it sounded good enough, and the advantages of portability and perfect recall were becoming too tempting to overlook.

As it turned out, though, there’s since been a resurgence of all things analogue. This has been a big deal in electronic music production, where DAWless is now a word. It’s been a bit more low‑key in the mixing world, but there are quite a few people out there exploring innovative ways to integrated analogue circuitry into a computer‑based setup without losing recallability. Notable examples so far include McDSP’s neat Analog Processing Box, Elektron’s Analog Heat, analogue processors with plug‑in‑based digital control from the likes of Wes Audio, and the fiendishly clever Access Analog remote processing system.

The latest attempt to place analogue tools in the hands of digital mix engineers comes from Freqport, a new company that is part Australian, part Danish. Of the systems described above, the Freqtube FT‑1 somewhat resembles the McDSP APB, in that it is an all‑in‑one ‘black box’ processor which handles A‑D and D‑A conversion internally. However, what it does to the audio once in the analogue domain is quite different!

Black Box

The FT‑1 is a modestly sized desktop device with a robust black metal shell. It is powered by an external DC power supply, and connects to a host Mac or PC using a single Type‑C USB cable. There’s no analogue or digital audio I/O at all. If you want to pipe audio through the FT‑1, you must do so using the dedicated Freqtube plug‑in. At the time of writing, VST and Audio Units versions had been available for a while, and the AAX plug‑in was in beta. The list of officially supported DAWs is not exhaustive at present, but I did my VST/AU testing in Studio One v6, which is not on the list, and encountered no serious issues.

What the FT‑1 lacks in socketry, it makes up for in hands‑on control, and the lower half of its top panel is given over to two rows of four rotary knobs. The top half houses a colour screen that is used to convey information about what the encoders are doing. In the middle is a slotted ventilation grille revealing the secret processing weapons within: pairs of E83CC (a modern ECC83/12AX7 variant) and ECC81/12AT7 valves emit a moody orange glow. Unsurprisingly, these are not operated at their rated 330V plate voltage, but neither are they being run in ‘starved plate’ mode; Freqport told me that after a lot of experiment, they’d settled on 65V as a good compromise.

The FT‑1 is a compact unit designed for the desktop, though a rackmounting kit is available.The FT‑1 is a compact unit designed for the desktop, though a rackmounting kit is available.

The plug‑in installation is accompanied by another program called Freqport Hub, which runs in the background whenever a Freqtube plug‑in is loaded. This has a small user interface that can be inspected to confirm everything’s working correctly, and also set the buffer size. Three options are available — 128, 256 or 512 samples — plus a ‘Lower Latency’ tick box. The FT‑1 always operates at the same sample rate as the host DAW.

The FT‑1 provides four channels of plug‑in processing, one for each valve, and it’s possible to use both E83CC or both ECC81 channels in linked mode for stereo operation. Apart from the valve type, the signal path is the same for each channel, and can be overlaid on the plug‑in user interface by clicking the helpful eye icon. First of all, the input encounters a split point, where a dry signal is tapped. This is routed through an optional single‑band filter and a polarity control, before a wet/dry Mix control recombines it with the other half of the split, just prior to the internal A‑D conversion.

The wet half of the signal passes through an identical single‑band filter, and then encounters a Drive control. An additional +18dB boost button effectively gives this two ranges, acting not unlike the Punish button in Soundtoys’ Decapitator. Suitably boosted or attenuated, the signal then hits the valve, with the saturation behaviour determined by a Harmonics control, before a joyful reunion with the dry signal. Last of all, a level slider allows you to compensate for the gain changes introduced by all this processing, which can of course be fairly extreme.

The Freqport Hub runs in the background whenever a Freqport plug‑in is active.The Freqport Hub runs in the background whenever a Freqport plug‑in is active.

Path Finding

The filters used in the FT‑1 are implemented in hardware, but they are digital rather than analogue. Consequently, although there’s only one filter band each in the wet and dry path, these are pretty flexible. They can be set to low‑pass, high‑pass, band‑pass and parametric modes, with adjustable slope, Q and gain. What you can’t do, though, is change their position in the signal chain: the filter in the wet path is always the first item in the chain, processing audio before it reaches the valve.

Another thing worth noting about the fixed wet signal path is that the Drive control affects the gain at the D‑A converter. If you push it too hard, you’ll hear audible clipping on peaks, and you’ll see the clip LED light (unless you have the filter active, as this disables the clip LED). This clipping is taking place prior to the valve stage, and the position of the wet/dry Mix control and the level slider at the end makes no difference. The effect of this is to limit how hard you can hit the valve processing: it’s not possible to massively overdrive the valve and then use a downstream level control to rein things back in. (After this review went to press, Freqport told me that they are planning a firmware update which will increase the headroom substantially before clipping occurs.)

The Harmonics control varies the bias voltage applied to the valve, and is accompanied by two graphics showing visual representations of its effect on a hypothetical sine wave. Values above zero see the top half of the waveform flattened, while negative values cause the lower half to bottom out. The other graph shows the relative levels of the first few harmonics.

Turning Up

The FT‑1 isn’t only a processor. It’s also a controller, courtesy of the eight knobs on its top panel. These do not have an additional press‑button action, and they are not endless encoders, but rather have a fixed travel with a start and end point. Whatever control data they generate is not exposed to the host DAW, so they can’t be used for controlling other things besides Freqtube plug‑in parameters. Assigning a knob to a plug‑in parameter is easy: you simply click one of eight buttons within the plug‑in interface and then use the mouse to move the plug‑in parameter you want to assign. Once you move the physical knob through the position of the parameter, it will then take over controlling that parameter.

The display at the top of the FT‑1 shows all of this quite neatly. A control that has ‘caught up’ with its assigned parameter appears as a solid circle with one position indicator in it, whereas one that is not yet active shows up as a hollow ring with both the plug‑in parameter position and that of the physical knob visible. A paint bucket icon within each plug‑in instance allows you to select one of seven colours, so in situations where you have knobs controlling the same parameter on different instances of the plug‑in, it’s easy to tell which is which. Text fields below the circles display the parameter assignment and, in theory, the track name, though this is dependent on DAW support — you can’t enter a name manually in the current version.

One thing that impressed me from the off was how quiet the FT‑1 is. At normal monitoring levels, there’s very little noise audible even when you crank up the Drive.

Gently Does It

The titles of the factory presets give you a pretty good idea of the strengths of the Freqtube FT‑1 and of its intended applications. Words like ‘crush’, ‘obliterate’ and ‘destroy’ are noticeably absent, and instead we get settings designed for mastering, drum fattening, enhancement and other relatively subtle use cases. Many of these make good use of the filtering and the parallel processing option.

One thing that impressed me from the off was how quiet the FT‑1 is. At normal monitoring levels, there’s very little noise audible even when you crank up the Drive, and such as there is is relatively dark and unobtrusive. It’s noticeably less noisy than, for example, Soundtoys’ Radiator and similar ‘analogue warmth’ plug‑ins, and as such, is eminently usable for applications like mastering. And, although I left the review unit switched on all the time I was in the studio, it never once produced any other untoward noises.

As I’ve already mentioned, the fixed signal path and gain structure do limit what you can do with the FT‑1. There’s only one filter per path, and it’s not possible, for example, to switch an unused filter from the parallel path back into the wet signal path, or to place the filter after rather than before the valve. The way the Drive operates also means that you’ll often run into clipping at the D‑A converter before you push the valve into filth mode, so don’t expect to use it as a distorted guitar amp. Yet despite this, it’s a surprisingly versatile unit. Simply running any source through it set to 100% wet at a conservative Drive level provides an excellent alternative to recording through a valve preamp in the first place. Filtering out all the low end and blending a small amount of valve signal in with the dry sound turns the FT‑1 into a rather lovely and very controllable harmonic exciter. Do the same with the filter set to low‑pass and you can add serious weight and thump to drums and bass, or use it in band‑pass mode and add midrange thickness and girth to an anaemic vocal. In most applications, there isn’t a radical difference in sound between the E83CC channels and the 12AT7 channels, but the latter tend to be more subtle and less abrasive.

The hands‑on control can be very useful. As you’d expect, adjusting the Drive control makes a big difference to the output level, so at the bare minimum, having this and the output gain on adjacent knobs makes it easy to keep the perceived loudness constant while you look for the right Drive setting. However, you can also put the knobs to more creative use by assigning them to the Harmonics control and the filter parameters. In their low‑, high‑ and band‑pass modes, the filters are resonant, so there are plenty of interesting wah‑like effects to be had by sweeping the corner frequency up and down. And the plug‑in controls generate automation data, so these performances can be recorded for posterity.

Back In The Real World

There are interesting and usable sounds to be got by moving the Harmonics control away from the centre position, particularly on drums and percussive sources. This often seems to affect the dynamic envelope of the sound as well as its tonal content. Freqport say that the extremes of its range should be considered experimental, and I found that the negative end of the dial in particular produced blips and splats that were quite odd, though not obviously usable in a musical context. Again, though, automating a slow turn of the Harmonics control in conjunction with the filter settings could generate a wealth of interesting breakdowns and sweeps for dance tracks.

Sweeping the Harmonics knob on a stereo track also tends to expose one of the key differences between the Freqport and plug‑ins that fake analogue warmth. As you get towards the end of its travel, you’ll likely hear the stereo image pull noticeably to one side. It’s a reminder that these are real valves and they have tolerances! Provided you keep the Harmonics control centred, stereo material stays subjectively balanced, but if you really wanted to process left and right channels exactly the same, you’d need to bounce them separately through the same setting on the same FT‑1 path. Duplicating a mono track and routing both copies simultaneously through the same preset using the same valve type won’t usually achieve anything approaching cancellation when one is polarity‑inverted.

To my mind, this inconsistency is probably part of the appeal of the FT‑1. It’s like a more extreme version of those console emulation plug‑ins that model the variation from channel to channel — except that there’s no modelling going on! At any rate, I compared the FT‑1 with various valve emulation plug‑ins, and I never really managed to make any of them sound the same. I wouldn’t say it always sounded better, and it’s certainly less controllable and versatile than something like FabFilter’s Saturn 2, but what it does have is an immediate, ear‑catching quality that I didn’t find elsewhere. In full‑range or enhancement contexts, it can brighten up the signal in ways that are subtle or brash, but without sounding harsh or strained. And if you use the filter to focus its action on the low end or midrange, you can warm and thicken things up without drowning everything in mud.

As you can probably tell, I’m impressed by the FT‑1. Its status as a brand‑new product is still apparent in one or two areas, such as the limited official DAW support and a rather thin user manual, but it’s clear that Freqport have solved the big technical hurdles inherent in the concept. It works fine alongside a conventional audio interface, and never once dropped out or glitched during the review period. It’s easy to set up and use, and fully recallable. It’s both quiet and good‑sounding. And, as far as I’m aware, it’s unique. Both McDSP’s APB and Elektron’s Analog Heat can apply analogue saturation as a DAW insert, but neither is a valve device. If you want to add real valve warmth to your tracks whilst remaining entirely in the box, the Freqport FT‑1 is currently the only game in town.  

Watch the SOS Superbooth 2022 video to learn more about Freqtube.

Preset Management

The Freqtube plug‑in. The two E83CC valves are in use by this instance; the first 12AT7 valve is not shown, meaning that it’s allocated to another plug‑in instance.The Freqtube plug‑in. The two E83CC valves are in use by this instance; the first 12AT7 valve is not shown, meaning that it’s allocated to another plug‑in instance.The Freqtube plug‑in has its own preset saving and loading system, and presets can include control assignments. The version I tested included only 10 factory presets, and these store nearly all Freqtube parameters but not the valve type; so, by default, they all load with the E83CC selected, but if you manually switch to the 12AT7, factory presets will thereafter load with that option. User presets, by contrast, seem to store a choice of valve type and slot as well. One consequence of this is that if you save a preset on a mono instance of Freqtube, that preset will load in a stereo instance, but will default to using a single valve and having a mono output.

Given that there is a limited quota of knobs and valves to be shared across up to four instances of the plug‑in, it’s easy to end up in a situation where loading a preset in a new instance tries to claim resources that are already in use. In general, this is handled very sensibly; preset control assignments are automatically remapped to the next unused control, and if both E83CC valves are tied up, only the 12AT7s can be used, and so on. If you do a lot of instantiating and then removing different instances on different mixer channels, confusion can arise in DAWs such as Studio One that aren’t yet officially supported, but for the most part I found it stable and well‑behaved. Freqport recommend using the plug‑in’s internal bypass button rather than bypassing within the DAW, and indeed the latter option is actually disabled in the AAX plug‑in. And, like any analogue processor being used as a plug‑in, the Freqport FT‑1 only supports real‑time bouncing at mixdown.


  • Real valve processing in plug‑in form, with no audio cabling or routing required.
  • Offers four channels and two different types of valve.
  • Good and varied range of sonic possibilities including enhancement, warmth, grit and more.
  • Useful and creative hands‑on control options.
  • Quiet and reliable.


  • Inconsistency between channels becomes obvious as you crank the Harmonics control.
  • Fixed signal path with only one band of filtering per path.


An impressive technical achievement and a versatile mixing tool, the Freqtube FT‑1 offers real valve processing at the click of a mouse button.