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Two Notes Torpedo Captor X

Guitar Amp Dummy Load & Speaker Simulator By Dave Lockwood
Published August 2020

Two Notes Torpedo Captor X

Reactive load boxes that also offer top-quality speaker simulation have been seriously expensive — until now...

Dummy load and speaker simulator products allow guitarists to use tube amps at their 'sweet spot' level, either sending an attenuated signal on to a real speaker, or running silently and using a digital simulation of a miked-up speaker for recording. French company Two Notes were among the pioneers in this market sector, and their convolution-based, dynamic speaker-cabinet, microphone and room simulations are some of the most detailed and convincing available. They now offer a very comprehensive range of stage and studio products, from their top-of-the-range Torpedo Studio hardware box to their Wall Of Sound plug‑in.

Whilst the Torpedo Studio is the 'do everything' box, other products in Two Notes' portfolio fulfil more dedicated functions and cost less. Thus we have: the Torpedo Reload, offering a variable-impedance load box, attenuator, DI and optimised re-amping circuitry, conveniently gathered up in one hardware box; the Torpedo Captor, an attenuator with an analogue speaker simulation; and the CAB M ('Cabinets In A Box'), which has no dummy load/attenuator but hosts Two Notes' speaker and power-amp simulation, as well as user impulse responses, in a pedalboard-friendly, line-level box. The last can be remotely controlled from a smartphone or tablet using the elegant Torpedo Remote software.

The new Torpedo Captor X puts the dummy load/attenuator functions of the Captor and the sophisticated speaker and signal-chain software emulation of the CAB M into one compact — and surprisingly affordable — box. In fact, the software functions go beyond those of the CAB M, with variable output modes, a stereo reverb and the new Twin Tracker automatic double-tracking simulation.

Reactive Load

Starting at the loudspeaker signal input, the Captor X's reactive load has a fixed 8Ω nominal impedance, with a maximum power handling of 100W RMS. The housing's internal illumination will flash its red LEDs at you if things are getting too close to the limit, and thermal protection will kick in if you enter sustained overload — or, indeed, fire up your amp without switching the Captor X on. The impedance curve is the same 'averaged' one that Two Notes have used since 2010, which isn't derived from one specific loudspeaker or cabinet. There's been much discussion in 'forum world' over the last year or so about the 'accuracy' of impedance curves in dummy loads but it seems entirely logical to me that, when you want to emulate a range of different speakers in software, it's better to avoid starting from anything too specific. My own measure of how happy a load box is making an amp is to fire it up with an emulation of the same speaker and miking combo I might normally use it with, and see how much I instinctively start to tweak things on the amp — and for some of the Captor X's cabinets I found I wanted to change absolutely nothing. I'll say right up front that this is a great-sounding box and I'd think it a bargain even if it only had just one of the cabinets that I really liked.

The attenuator side of the Captor X is rather less sophisticated than its speaker emulation, offering three settings: Home (-38dB), Club (-20dB) and Stadium (0dB). When the last is selected, the amp isn't 'seeing' the dummy load at all — this contrasts with some other designs where the 'full-on' setting still actually has a degree of attenuation. That also means you don't have think about a parallel impedance having any effect on your sound. In the two attenuated modes, the amp is just seeing the 8Ω load of the Captor X. Although the Captor X only had an 8Ω version at launch, a 16Ω alternative is already in production. I shouldn't worry too much if you've already bought an 8Ω version and think you might have preferred a 16Ω unit — in my experience a 'single degree' of mismatch, such as four to eight, or 16 to eight, has always been safely operable with tube amps from mainstream manufacturers, unless specifically contra-indicated.

As for the attenuator settings, there really is no 'one size fits all'. The Universal Audio OX, for example, has six degrees and still everyone says they need the points in between! What everyone really wants is a continuously variable output level pot, but that's not an easy thing to achieve with speaker attenuation, and those products that do appear to have it — Torpedo Reload, Fryette, Boss TAE et al — do so using re-amplification after attenuation. I suspect that the Captor X's -20dB may be too quiet for many a stage setup, and -38dB not loud enough for some people's home 'noodling'. So if you're thinking of buying a Captor X primarily for use as an attenuator, just make sure that the available settings will give you what you need.

The onboard cooling fan isn't massively noisy and won't be noticeable on stage, but you'll want to be a little more careful about placement when using it in a recording studio.The onboard cooling fan isn't massively noisy and won't be noticeable on stage, but you'll want to be a little more careful about placement when using it in a recording studio.Line outputs appear on a pair of balanced, earth-lift enabled, 600Ω XLRs, which the software allows you to configure as a stereo pair or as a 'wet/dry/clean-feed' separation. Selecting the Dual Mono mode gives you an individual Right channel output in the software, with its own EQ and the ability to bypass all speaker and mic simulation. The latter would allow the recording of an 'amp-only' signal in order to defer having to commit to a particular speaker and mic choice, whilst the player is still able to record hearing a proper speaker and mic sound via the other channel. You can then decide on a cabinet and mic setting using the included Wall Of Sound plug‑in in your DAW, whilst now hearing the guitar part in the context. The separate EQ on the Right channel might be useful where the two outputs are split between front-of-house PA and stage monitor feeds.

Alongside the Output Level is a Voicing control that gives you a 'more' or 'less' mid-range control when moved from its centre detent, and a Space control, which is configurable in software to govern ambience and stereo-width related parameters. The Voicing knob works across all presets, and is perhaps most useful for adapting your overall sound to the environment in live performance, although I also found it ideal for just temporarily 'scooping' clean sounds a fraction, or pushing mid-range on single-note lines when recording, without then having to change anything in the presets I had set up.

The Space control can be either a wet/dry mix, or a width control for the ambience. This proves particularly immersive on headphones, which are connected via a quarter-inch jack and governed by the main output level control. A six-way rotary switch allows the selection of one of six presets directly from the front panel. The Captor X will store 32 on-board, but only the first six are accessible from the hardware. Changing which ones are accessible from the front panel just requires dragging them into a different order in the Preset Manager part of the software. Although the Captor X will only hold 32 cabinets at a time, there are 128 preset slots available. If you want to add a cabinet, you have to temporarily bin one of the existing ones, although you can always get it back again if you need it.

The Captor X can be controlled via a smartphone or desktop app.The Captor X can be controlled via a smartphone or desktop app.

Wireless & Wired

The Captor X's software control app can be wireless via Bluetooth (Torpedo Wireless Remote for iOS and Android) or wired via USB (Torpedo Remote for Mac OS and Windows). A wired connection on a big screen reveals it at its best, but a wireless phone and tablet option will certainly be invaluable under some circumstances.

In the mobile app, the two halves of the screen are paged, but the desktop view lets you see and adjust everything at the same time, making for a very efficient and intuitive interface. The warm neutrality of the very balanced Two Notes Studio A environment makes this slightly idiosyncratic miking sound great!In the mobile app, the two halves of the screen are paged, but the desktop view lets you see and adjust everything at the same time, making for a very efficient and intuitive interface. The warm neutrality of the very balanced Two Notes Studio A environment makes this slightly idiosyncratic miking sound great!The display centres around Two Notes' now-familiar photo-realistic-ish display of a dual-miked speaker cabinet in a studio or stage environment. Channel controls for mics A and B sit below, and to the right, or on the next page if you are in mobile view, are the effects and output controls. By default you have 26 guitar cabs and six bass cabs to choose from, to be partnered with any pairing of the eight mics available. In the mini-channel strips, you can set distance and off-axis angle individually for both mics, invert polarity ('flip phase'), and decide if one or more of the mics is placed at the back of the speaker. These micro-adjustments are made possible by Two Notes' dynamic IR Synthesis process — normally, using IRs, if you don't like the mic distance used, you have to swap out the IR for a different one, and clearly it would be impractical to have an IR library that covered every possible position, mic and speaker combination.

Anyone who has ever double-miked a speaker cab will know that there are some positions that will sound a bit weird and 'hollow', requiring you to go back and move one of the mics an inch or so and then probably again, when you find it still sounds weird and hollow, just in a subtly different way! No such problem here: the Two Notes programmers have very sensibly done the phase optimisation for us, so there are no 'wrong' mic positions, letting you get on with simply tweaking positions until you have the tonality that you want. Of course, there is no such thing as fully 'in-phase' across the whole frequency range because of all the different wavelengths involved, so this is always a slightly subjective choice, but Two Notes' algorithm does automatically what engineers have always done by ear in the real world — you simply line it up to the point where it sounds most 'full' and tonally 'in focus'.

Effects & Processing

Post-mic processing includes a five-band fixed or semi-parametric EQ stage, Reverb/room simulation, and an Enhancer stage. The latter's controls, Body, Thickness and Brilliance, are all additive and sound most like a very wide-bandwidth additional EQ stage set at frequencies that are somehow 'just right', combined with subtle compression. A Dry/Wet mix control and Guitar and Bass optimisations, further add to the Enhancer stage's usefulness in arriving at precisely the sound you want. Overcoming an initial scepticism, I soon found myself using the Enhancer stage in preference to the EQ. It just works, provided you don't over-cook it. A 15dB pad allows you to optimise the level entering the 24-bit, 96kHz sampling digital circuitry — I found myself keeping the pad activated for everything except a little Princeton, as it just seemed easier to keep both internal and downstream levels optimised. A 30Hz to 19kHz frequency response, and 95dB signal-to-noise ratio exceeds anything required by the context of normal usage.

Other functions include a very stable, large tuner display, and a flexible gate that will do both relatively subtle noise reduction, with a Learn mode, and modern-metal 'cliff-edge' gating. And finally, there's Two Notes' new Twin Tracker automatic double-tracking simulation. A Tightness control allows you to vary the degree of random variation from "is it on?" to the verge of too much. I'm not sure it could ever pass for the real thing, but it could certainly be a time-saver doing lots of crunch-chord layering, or perhaps give you a 'larger' on-stage guitar sound that would just fill more 'sonic space' using a stereo rig in a limited line-up like a three-piece.

There's a decent collection of bass cabs in the Captor X, too, and some mics that make sense of recording them or using a virtual-miked PA feed. Miking a bass cab gives a 'formant tone' element to the sound that means that the 'bassiness' of notes varies less with pitch than compared with a DI signal. I've never felt that it is quite as much of a challenge as a guitar cabinet, but then I've never had to code it! It is certainly nice to hear it done well, as it is here.

The Two Notes programmers have very sensibly done the phase optimisation for us, so there are no 'wrong' mic positions.

Roll Your Own?

You can upload your own impulse responses or third-party ones to the Captor X's 512 memory locations, in WAV or AIFF format, and use the IR Loader function of Torpedo Remote to create IR-based presets, using up to two IRs simultaneously. Obviously, you'll no longer have the ability to 'move' virtual mics around, as their contribution is 'baked in' to the IR. But all other 'post mic' effects — EQ, Enhancer, Reverb, Twin Tracker — remain accessible. Having two IR slots lets you balance a close-mic IR against a more ambient, 'roomy' one, thereby giving you a little of the adjustability of a full-on Two Notes cab. For some people who have IRs that they love, I am sure that will be an invaluable facility, but I have to say, even using some very nice IRs from my Celestion collection, I didn't manage to make anything as 'real' and playable as the best of the Two Notes factory collection, and given the range of included cabinet options, I'm not sure why I'd be trying!

The lively stage and hall environments are almost too convincing, but dialling back the 'wet' a bit makes them very usable if you are looking for a less controlled, exciting recorded sound.The lively stage and hall environments are almost too convincing, but dialling back the 'wet' a bit makes them very usable if you are looking for a less controlled, exciting recorded sound.The software's Setup Manager dialogue allows you to tweak the Captor X's end-to-end latency (converters and internal processing). The default is 3.5ms, with the option to go down to 2.2 or up to 4.8. Why would you want to go up? Well, accepting greater latency allows you to use longer impulse responses, which in theory are more detailed and accurately representative of the real thing. This works for both third-party IRs and Two Notes cabs. I know the theory, but even in my own collection I've got 'short' IRs that I prefer to longer ones, and vice versa, so I don't think IR duration should be viewed as any inherent indicator of subjective usefulness. It is good to have the flexibility, though, as I know other people have stronger views than I do on how long a speaker and mic IR needs to be.

The default 3.5ms latency makes for a very comfortable playing experience, especially as I have no other digital process in my monitoring chain when recording. Latency is cumulative, however, so it always pays to be aware of other digital processes downstream, and also to check your DAW latency default if using software monitoring.

MIDI & More

Integrating a Captor X into a more complex system, perhaps with a foot controller for stage use, is aided by the presence of a comprehensive MIDI 2.0 spec interface. The connector is a mini-jack (eighth-inch TRS), but Two Notes include the necessary adaptor to get you connected straight away. Whilst changing cabinet and mic presets mid-note is no more seamless than you'd expect, you can certainly punch EQ, Reverb, Enhancer and the Twin Tracker in and out without a glitch.

The Captor X is obviously designed for free-standing use: in a live situation it would sit neatly on top of most tube amps, with controls to the front and connectors to the rear. One of those connectors would be the 2.1mm plug for the external 12V DC 1A power supply. I'm in two minds about that: on the one hand I always worry about a 'mission-critical' component having a non-locking connector in a stage environment, especially for something that might be your sole source of audio if you are only going direct to the PA. On the other hand, the fact that it is a standard DC supply, rather than a unique PSU, means that it is easy to carry another as a spare. Maybe a little cable safety hook wouldn't have gone amiss? You know, the sort that nobody ever actually uses!

In the studio, it might seem tempting to place the Captor X somewhere close at hand, as I did. It didn't stay long. The Captor X's fan is small, as dictated by the compact enclosure, and needs to run quite fast to move enough air, which make it audible at my kind of — I'd say fairly average —monitoring levels when recording guitars. Its speed, and therefore noise, is also related to input level, which manages to make it slightly more irritating. Ultimately, it is the price to pay for the compact dimensions. Placing it initially under the desk rather than on it, and later just six feet away, took care of the issue. It's just something to be aware of. In a live context you simply won't know it's there.


The Captor X has some very high-quality virtual cabinets and 'rooms' that sound great, even in mono — they just become a significant, supportive part of the sound without ever making you feel they are over-ambient. Two obvious points of sonic comparison are Universal Audio's OX and the Boss Tube Amp Expander. Being able to listen to all three side-by-side, there is something I like in each of them — but I have to say the Captor X scores a big win on the sheer convenience of its portability and, of course, its price. That price may have been achieved with compromises in certain areas: the limited choice of attenuation settings, the fan, the external PSU, the headphone level and the line out level not being independently controllable, and the absence of a line input for a backing track feeding straight to the headphones — many people's favourite mode of private practice. But neither the OX nor Tube Amp Expander has the last of those.

I didn't find any amps, from a selection of vintage and modern Fender, Marshall and Mesa Mark series models, that felt at all uncomfortable with the Captor X's load, but, interestingly, amp and speaker combinations that tend to work best in the real world seemed to be at their best in the Two Notes environment, too. Call me unadventurous, but I like that. It suggests a degree of accuracy that allows me confidently to make use of my years of familiarity with the real versions.

I think the Captor X is one of those 'right thing, right time, right price' products and, despite a slight delay in coming to market, by the time you read this I think it may already be making a lot of users very happy.


Universal Audio's OX and the Boss Tube Amp Expander fulfil a similar role, albeit at a significantly higher price point. To get similar reactive loading and high-quality speaker and mic simulation at this price, you'd probably have to look at separating the two functions and using an attenuator/load with Two Notes' Wall Of Sound plug‑in for full 'adjustability', or one of the many stand-alone IR loaders now available.


  • Great-sounding virtual cabinets and miking.
  • Great-sounding virtual spaces.
  • Very usable Enhancer stage.
  • Compact and portable.
  • Good wired and wireless remote options.
  • More affordable than the competition.


  • Limited choice of attenuation settings.
  • Small, slightly noisy fan.
  • Non-locking external PSU.


A top-quality speaker sim and dummy load to compete with the best of them, in a compact package, and at a very attractive price. What's not to like?


£469 including VAT