Akai Professional AX60 by criminallysmooth
It's tough to rate the AX60's sound quality on a 1-10 scale. On one hand, it's a VCO-based polysynth, and can produce ultra low and high tones with no aliasing, silky smooth pitch bends, screaming analog filter resonance, and so on. On the other hand, it has a basic tone which is somewhat harsh and metallic, and maybe not immediately "musical" in the sense of what's expected in pop music. It also has issues with noise floor when using the sampler input or the onboard Chorus effect (see: features). In its' sweet spot(s), the AX60 is capable of very organic VCO string sounds and deep, smooth sub basses, but it probably won't be mistaken for a Moog or a Juno in terms of raw musicality.
Ease of use:
The AX60 couldn't be any easier to use. Patches are edited with a series of sliders that are basically 1-per-parameter aside from the VCF/VCA Envelope Generator, the controls of which are shared via a toggle button. The voice architecture is straightforward and all editable parameters are laid out and clearly labeled.
-6 Voice Polyphony and Unison/Mono Mode, stacking the 6 VCOs. Tends to exaggerate the fundamentally harsh tones of the oscillators and produce a dramatic phasing effect as the oscillators drift.
- Filter FM uses the oscillator frequency to affect filter cutoff. This is a key feature of the AX60s otherwise basic synth engine, because it can surprise you with timbres that are more complex than you'd expect from a 1 OSC synth.
- Speaking of timbres, the AX60 is Bitimbral. The keyboard can be split at an arbitrary key point and play two different patches at once. Each side of the split responds to a unique MIDI channel, so with external control it is possible to use two patches simultaneously across the entire key range.
- Arpeggiator, in conjunction with bitimbral splits, is a great asset for performance and quite fun when set to "hold."
- Certain vintage Akai samplers can be routed through the AX60 filter and VCA, with the proper cable. Audio In mods are also possible, with DIY cables.
- Modulation and pitch bend/filter cutoff can be automated via MIDI
-Analog Stereo Chorus with fast/slow modes. Sounds nice, especially in stereo, but introduces some slight noise to the output.
Bang for buck:
AX60s are selling in the $300 to $600 range in 2011. This is, AFAIK, the most affordable VCO-based synthesizer in existence. However, on the lower end of that price range, you can expect to put some money into repair, as the front panel buttons (such as the 16 patch selection buttons) and LCD screens are prone to failure or damage. Ultimately, the AX60 must be considered a bargain buy at any reasonable price, given the prices of any other synth with comparable architecture, but with the caveat that with that lower price comes somewhat questionable build quality and a fundamental tonal quality to the oscillators and filter that isn't to everyone's taste.