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Page 2: Hammond SKX Pro

Dual-manual Keyboard By Gordon Reid
Published August 2022

The Monosynth

You might think that a dual‑oscillator virtual analogue monosynth built into a Hammond organ is going to be little more than a bit of a bonus; adequate, perhaps, but nothing to get too excited about... and you would be wrong. For example, it offers six oscillator models. Duo mode allows you to select sawtooth, saw+square and square waves for each oscillator, while Unison mode offers up to seven instances with programmable detune. Pulse mode offers a single pulse wave with PWM that can be driven by the LFO, the pitch contour and the note number, while Sync mode offers detune and three sources of modulation. Then there’s a simple 2‑op FM mode (don’t discount 2‑op FM — it was the underlying engine for the mighty Yamaha GS1) and, finally, there’s a multi‑colour noise generator that can create sounds ranging from 1950s sci‑fi to the expected wind and rain effects. Whichever you choose, the output from the oscillators is passed to the resonant and overdriveable multi‑mode filter (high‑pass or low‑pass, each with 12dB/oct and 24dB/oct modes) before passing to the audio amplifier and then the monosynth’s dedicated MFX1/overdrive/MFX2 effects sections.

It has three modulation sources. The first is a multi‑waveform LFO with its own contour generator for delayed modulation effects, and you can direct this to the oscillators, filter and amplifier with independent depths for each. The second is a shared pitch/filter cutoff frequency contour, and the third is a dedicated loudness contour with ‘return to zero’ and ‘pick up from where you left off’ options. The contour generators are velocity sensitive (which is great) but I found them to be rather linear, sometimes resulting in cusps at the transition points (which is not).

With its four key‑priority modes, dual portamento modes, and pitch‑bend and modulation wheels, I found it to be an expressive soloing instrument capable of generating an impressive range of lead synths, orchestral imitations, and bass sounds. Sure, it’s not an all‑singing, all‑dancing instrument designed for off‑the‑wall experimentation by Eurorack fanatics but, during the course of this review, I needed to recreate a Minimoog sound and play a solo in a Floyd Effect rehearsal, so I decided to see whether I could use the SKX Pro for this. After a single run‑through, I had a room full of grizzled musos demanding that I buy one!

It’s not often that I end up with a silly grin plastered across my face when I’m reviewing a keyboard, but that’s what happened here.

In Use

There’s much more to the SKX Pro than I’ve had room to describe here: couplers, polyphonic pedal facilities, a ‘shallow’ keyboard option to make it feel more authentic when playing it as a vintage Hammond, the ability to connect two pedals to a single input using a TRS cable, ‘reverb spring shock’ for Keith Emerson impersonations, shortcuts to speed editing, and more. I hadn’t expected it to be so flexible but, once I had discovered its capabilities, I wanted to push it to its boundaries to see whether it could transcend its obvious role as an organ and emulate various twin‑keyboard setups that I play on stage. I started by allocating an organ to the upper manual and a piano to the lower. That was too simple, so I decided to split both manuals, with an organ and a lead synth on the upper, and strings and piano on the lower. With appropriate octave shifts, I was able to use all of these comfortably. So I then tried allocating various Components in the piano and ensemble sections to different ranges. This placed up to 12 distinct sounds — many with their own effects — at my disposal. I could even have multiple, simultaneous monosynths because each Component can be programmed to be monophonic, even selecting from five key priorities and two modes of portamento. With careful programming of sounds, volumes, responses and effects, the SKX Pro could be the only stage keyboard that some players ever need. That was not at all what I had expected!

Of course, there are shortcomings. I’ve already mentioned the lack of aftertouch and the acoustic grand pianos, so I won’t discuss them further here. Perhaps seasoned organists are more likely to be distracted by the smooth (rather than quantised) response of the drawbars and by their wobbly heads. To be honest, the former didn’t bother me at all but, at this price, I would have expected the drawbars to feel more robust. Operationally, a numeric keypad would save a lot of scrolling through parameter values, but the lack of this could be ameliorated by an editor/librarian; the SKX Pro’s extensive NRPN/SysEx structure appears to be able to support this and I think that it deserves one. Finally, I think that Hammond should consider adding an L100 model to MTW1. This was an important instrument used on countless recordings and, with its different character from the B3 and its siblings, it would be a valuable addition.


The SKX Pro’s transistor and pipe organ emulations, piano and ensemble sections and VA monosynth are all surprisingly flexible, and (the acoustic pianos notwithstanding) sound better than you might imagine. But what you really want to know is whether Hammond have succeeded in recreating the sound and feel of their iconic console organs. In my view they have. Recent offerings from elsewhere might convince your audience that you’re playing a 50‑year‑old bucket of rotating thruppenny bits, but I suspect that the SKX Pro might even convince you, the player, that you’re playing a 50‑year‑old bucket of rotating thruppenny bits. It’s not often that I end up with a silly grin plastered across my face when I’m reviewing a keyboard, but that’s what happened here. The SKX Pro isn’t cheap, and it hasn’t been designed for casual players who need a bit of organ now and again. It’s an instrument for those who can tell the difference and are willing to pay for it.  

The Rear Panel

Hammond SKX Pro rear panel connections.Hammond SKX Pro rear panel connections.

The first socket you’ll encounter on the right of the rear panel is for a single‑ or three‑channel 11‑pin Leslie speaker, and connecting to this disables the internal emulation. Next come sockets for stereo headphones, stereo line outputs, and dedicated outputs for the rotary channel and pedal generator of the organ section. Alongside these, two individual outs allow you to send a stereo piano, ensemble or monosynth, or monophonic versions of any two of these, to the outside world, bypassing the internal reverb, master EQ and master volume. There’s also a 3.5mm stereo audio input with an associated gain control that lets you mix external audio with that generated within the instrument.

There are four controller inputs. The first two are assignable switch inputs, the first of which can accept a Leslie half‑moon controller. The third input accepts a continuous expression pedal, and the fourth is for a damper/sustain pedal.

For MIDI in and out, 5‑pin DIN sockets are provided, and you can of course use the former to connect a pedal board. MIDI (but not audio) is also carried via the class‑compliant ‘To Host’ USB port and, in addition to using a computer for storage, a flash drive socket also allows you to save sounds as well as update the SKX Pro should you ever need to do so. An IEC socket for the internal power supply completes the panel.

The Effects

Each of the four sound generators in the SKX Pro includes four dedicated effect sections in series. The first is a multi‑effects section offering a tremolo, wah‑wah, ring modulation and a compressor. This is followed by an overdrive, a second multi‑effects section with auto‑pan, a phaser, a flanger, a chorus and a delay, and finally a dedicated EQ. The effects are more sophisticated than I had expected. For example, the tremolo offers five modulation waveforms, the wah has its own multi‑waveform LFO and numerous modulation inputs, the ring modulator has an audio‑frequency oscillator with multiple modulation sources, the overdrive offers multiple models, the phaser offers five options for the number of stages, the flanger and chorus have high‑pass filters to allow you to retain the body of the sound... and so it goes.

At the end of the signal path, there’s a three‑band master EQ, and you can select two master reverbs simultaneously — one for the organ section and the other for the mixed ensemble, piano and monosynth sections. So if you want to play your organ through a spring reverb while your choirs sound like they’re in a cathedral, that’s no problem at all.


Eschewing arpeggiators, conventional auto‑accompaniments and sequencers, the SKX Pro offers a system called ProChord within the piano/ensemble engine. This allows you to add additional harmonies (determined from chords played on the lower manual) when playing a melody line on the upper. This idea has been around for a long time, but it can still create some unexpected and interesting results. I particularly enjoyed distributing the Components in the ensemble section across the upper manual, programming each to generate a different sound, and then allowing ProChord to create some unusual orchestral‑style arrangements.


Each of the sound generation sections offers a range of factory presets that cover many of the uses to which you might want to put the SKX Pro. These include 100 organs divided into 13 broad categories such as rock, jazz, gospel, classic pipes, Vox and Farfisa; 300 piano/ensemble patches including some very usable e‑pianos and clavs alongside a range of strings, brass, pads, other polysynth patches, plus some unexpected Mellotrons and monosynths; and 100 virtual analogue monosynth patches. In addition to these, there are 100, 300 and 100 user memories respectively. You can also save organ+monosynth patches in a thing called a Bundle, and there are 100 memories for these. The top level is called a Combination and, in addition to the 100 factory Combination presets, there are yet another 100 slots for your own creations. Ten banks of 10 favourites then allow you to build sets for live use.

If you choose to design your own Hammonds, Leslies or pipe organs, four additional types of memory slots are provided. There are 12 preset tonewheel setups and space for 12 user setups, three preset pedal registrations and space for three user registrations, eight preset cabinets and space for eight user cabinets, and finally three pipe organ setups and space for three user setups. And remember, these are memories for the underlying organ models; any sounds that you create using them can be saved in the 100 patch memories mentioned above.

MIDI & External Zones

The SKX Pro has a weird MIDI specification that favours the upper manual in preference to the lower and any connected pedals. Beyond the obvious things that can transmit MIDI performance messages and the commonly used CCs, every physical control and many of the menu parameters can also send a stream of data entry and NRPN values that you can record and then replay as part of a sequence. This means that automation can be far more detailed than simply selecting patches and tweaking a few top‑panel controls.

In addition, the SKX Pro provides three External Zones that you can allocate to any manual and program on a patch‑by‑patch basis. These offer independent MIDI channels, key ranges, velocity curves, volumes, octaves and transpositions, pedal and modulation wheel responses, and so on. This means that the SKX Pro can transmit on up to six MIDI channels simultaneously and, because the manuals themselves can send and receive on different channels, receive on three others. All of this makes the SKX Pro a surprisingly flexible MIDI controller.


  • Two manuals are always better than one.
  • The Hammond emulation is state‑of‑the‑art.
  • The transistor and pipe organs are very useful.
  • The piano and ensemble are far more flexible and useful than I had expected.
  • The virtual analogue monosynth is much better than it has any right to be.
  • It’s much more convenient than a collection of separate organs, pianos and synthesizers.


  • It neither generates nor recognises aftertouch.
  • There’s room for improvement in the pianos.
  • The ensemble/piano library isn’t expandable.
  • It’s not cheap.


I believe that the SKX Pro is the best Hammond B3/C3/A100 emulator yet developed for stage use. But more than that, it’s a powerful and flexible combination of various organs, two PCM‑based polysynths, and a surprisingly good virtual analogue monosynth. An all‑in‑one solution? For some players, I suspect that it could be.