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Thursday, April 18th, 2024 06:45 am

Synth Glossary

Analog Synthesis:
This term is normally used to refer to the tradional synthesis model used by analog synthesizers in the 1970s. It is also known as subtractive synthesis. It involves oscillators, the outputs of which are mixed together and fed into a filter (where certain frequencies are subtracted) after which they are fed through an amplifier. The amplifier and filter are normally also driven by envelope generators....


Novation BassStation Rack
Wisely, Novation resisted the temptation to just shoehorn the innards of a BassStation keyboard into a 19-inch-wide box. There have been some sonic improvements, there are more program memories, and the panel hardware seems of a higher quality. There are also several technical changes that improve upon the BassStation keyboard. The instrument is more comprehensive and yet easier to use. It just feels right.

The BassStation keyboard was a dedicated, monophonic synthesizer employing digitally controlled analog oscillators. It combined the sound-creation capabilities of classic mono synths such as the Minimoog and Sequential Pro-One with sounds and features of classic bass units, especially Roland's TB-303 Bassline. It did all this while remaining inexpensive.

Further motivation lies behind the creation of the BassStation Rack, namely expanding the instrument's range of applications. Sonically, you're given a lot more sizzle at the top end; half of the Rack's complement of 40 presets are now "lead line," as opposed to bass, patches. And this is not just a matter of tweaking octaves: oscillator sync--a function no lead synth would willingly forgo--is a brand new feature here.

Another major improvement is the addition of control voltage (CV) and gate inputs and outputs. These allow users who have pre-MIDI analog gear to connect devices to the Rack directly without the hassle and expense of a CV-to-MIDI interface. There are one or two MIDI improvements, too, which I'll get to in a minute.

The 1U rack-mount BassStation Rack measures a mere 4-inches deep. This "mini" concept extends to the front-panel hardware, which consists of some eighteen small, blue-topped control knobs; twelve switches; a keypad the size of a wristwatch calculator; a 2-digit screen; and a headphone jack. Clearly, if you have paws the size of heavyweight boxer, you're going to have problems. That said, the controls are well spaced and clearly labeled. The screen's writing is small, though, so when you mount the BassStation Rack, carve out a niche at eye level. Not surprisingly, with these dimensions an external power supply unit is requisite, but at least it's a "lump in the line" rather than a more obnoxious wall wart. Don't waste time looking for the power switch: there is none. As soon as you plug the unit in, it's on. Audio output is via one 1/4- inch jack, in glorious mono.

Oscillators And Modulation
The BassStation Rack is a 2-oscillator design. The balance between oscillators 1 and 2 is controlled from a single knob, which is not a perfect solution, but it's adequate and cost effective. Both oscillators can generate sawtooth or variable pulse waveforms and can be pitched independently. A lone 4-position switch on the oscillator 2 panel selects between octaves of 16', 8', 4', and 2'; oscillator 1 is fixed at 8'.

A rotary detune control progressively thickens a 2-oscillator sound by spreading the tuning as in a chorus effect, and a rotary control offsets one oscillator against the other by up to an octave, in semitone increments. Here's where you set up sounds that play in fourths or fifths, or, if you're King Crimson, major sevenths. The oscillator panel's relative dearth of controls limits you only in terms of programming speed; there's always a bit of flicking about between oscillator 1 and oscillator 2 positions in order to create your basic mix. But this is nothing drastic, and you quickly get used to it.

Even in the realm of bass, modulation is vital for colorful sounds. What have we here? If you're using the pulse waveform, the pulse width is fully variable, ranging from -5 (which yields a clarinet-like, 50% square wave) to +5 (where almost all you'll hear is high harmonics, with little or no fundamental). From clarinet to Clavinet, you could say. On the BassStation keyboard, I felt the "thinnest" pulse wave was not quite thin enough for really pinched, hard-edged nasal tones. On the Rack I had no such reservations.

With the PWM (Pulse Width Modulation) Source switch on manual, the pulse wave will remain static at your preset width. You can introduce some slow harmonic change within the sound by assigning envelope generator 2 to the pulse width. The shape (speed) of such changes is set up using the EG controls; the strength is governed by the Envelope Amount control. You can also control these changes in harmonic content with a fixed-speed LFO.

The variable-speed LFO (yes, these are two separate LFOs) governs classic vibratos and trills. The LFO rotary control on the modulation panel governs the amount of modulation. On the named LFO panel, you'll find a choice of three waveshapes--random, triangle, and sawtooth-- plus rotary controls for speed and delay. Delay is an essential LFO parameter, especially on bass sounds, as many parts would be unlistenable if constantly "vibratoed." (A constantly wobbling voice would probably send you screaming to the gun cabinet.) Delay allows you to program a period of calm before the storm of modulation occurs. All well and good, except that the delay control here is somewhat arbitrarily calibrated. From seven o'clock to twelve o'clock, it does almost nothing. Only from two o'clock does any appreciable delay occur. The maximum delay (five o'clock) is around five seconds. The final control on the modulation panel is Sync. This feature forces oscillator 2 to start its cycle "in sync" with oscillator 1, even if differences in cycle and pitch would (thanks to how you have set the oscillators) have occurred. The result is a forced-sounding, dramatic timbral change. Sync is instant power. Instant "lead synth." Instant Emerson. It's a matter of taste, of course, but this is not a device I'd use on bass. For lead sounds, as mentioned, it is indispensable.

Filters And Envelopes
Perhaps the BassStation's killer punch is its filter section. Over the past couple of years in the UK, the new generation of retro-synth enthusiasts has fallen totally under the spell of Roland's ancient TB-303 Bassline. Mindful of this, Novation has not only given the Rack a 2-position filter with 12 dB/octave and 24 dB/octave settings, but has also configured the 12 dB setting so as to re-create the range of options available on a TB-303.

When you are in 12 dB mode, in other words, the three filter controls of frequency, resonance, and mod depth behave very much as the equivalent parameters do on a TB-303. In this mode, then, there is no negative modulation option (which there is in the 24 dB mode). Also, you still get a chink of resonance showing through even when the resonance is off. Finally, the range of movement is quite broad, providing what could be called a high "tweakability" factor. Both envelope generators conform to standard ADSR types. The addition of Velocity control allows you to determine the strength of the EG depending on how hard you strike the keys. As with the oscillators, the two EGs share a single set of physical controls: a 3-position switch allows you to select between EG 1, EG 2, or both. The maximum specified attack speed of 500 Ás is certainly fast enough. At their slowest attack setting, the EGs appear to delay the start of a note for up to ten seconds, even though a figure of only five seconds is listed in the manual. Decay and release both operate over a range of three milliseconds to ten seconds. A multiposition switch governs the envelope triggering modes. When the Autoglide position is set (mimicking Slide on a TB-303), moving from one note to another while keeping the first note held down only affects the pitch and does not retrigger the envelope cycle. In the Single position, the envelope is set in motion only by the first, held note. Multi is the normal, multiple- triggering mode whereby the envelope is retriggered with each note played. A volume pot and a portamento-amount control round out the Rack's sound generating and tweaking parameters.

Driving Force
So what's it like to play the BassStation Rack? Broadly, pretty much of a dream. The original BassStation keyboard has but seven memory locations, selected via a click-stopped rotary control and only responds to a handful of Program Changes over MIDI. By comparison, the Rack has 100 program memories (40 presets, 60 user) and a display screen. It responds to MIDI Volume and Modulation (and a lot more besides), and simply fits in well with the rest of your equipment. It has character, still, to be sure, but not character as in "operates completely differently from everything else I own," which is how the BassStation keyboard tends to function. Because there are 40 presets--editable, but not overwritable--I'll run through some so you can see how applicable they are to you. Moog Bass (Preset 00) is an excellent, firm, all-purpose bass with just a hint of resonance. The Bee Gees "Jive Talkin'" about sums it up. Wow Bass (01) is quite a nice wet bass tone; it's gruffer, with rasp as well as wow.

Jacko Bass (02) is round, smooth, but with plenty of punch. Electric Bass (04) is very direct and substantive; quite "guitary," in other words. I'd call Percussive Bass (06) "organ bass." Preset 07 is called EOW bass. That's a good description. Paul McCartney used exactly this sound on a single a decade or so ago, but I can't put a name to it.

Power Bass (08) is raspy and growly, while Preset 10 is the classic TB-303 autoglide bass: electronic, wowy, squelchy. Novation aptly describes Spit Sine Bass (11) this way: "Spit, blown speaker, heavy attack." Preset 13 is another TB-303 type, this time heavy on the portamento. Trance 1 (16) is one of those nasal, whistly types. If you're into the rave scene I suspect you'll recognize and love it, but it's just not me, sorry. Novation lists Preset 20 as Yazoo Lead. Vince Clarke may take issue with this, and I thought it worked far better as a Taurus bass sound. Of course, many of the (programmed as) lead sounds also work as basses. Judged strictly as lead-line sounds, though, don't go looking for a Minimoog in full flight. The patches are good but work better as obbligato, arpeggio, or gate-effect sounds, rather than as rip-snorting solo sounds.

Presets or user programs can be called up either remotely via MIDI Program Changes, or from the front-panel keypad. Alongside the display is a 5-LED strip of mode lights, running you through Program (to select presets, etc.), MIDI Receive Channel, MIDI Transmit Channel, Utility, and Save modes.

All parameters under the Utility heading can be seen (just barely), are marked, and can now be accessed on the tiny keypad. This is well presented, though, as it means there's no stabbing through endless edit pages to alter Pitch Bend range (parameter 1), or tweak Aftertouch/Breath pitch-modulation depth (parameter 4). (In the latter case, the unit responds identically to Aftertouch or Breath Control messages.) Additional items include pitch-modulation depth, filter- modulation depth, Aftertouch/Breath filter-mod depth, Aftertouch/Breath EG bias, LFO rate to MIDI Clock, CV/Gate MIDI channel/type, tuning, and Polyphonic mode. Once in Utility mode, you simply prod the relevant button and scroll to a new value with the increment and decrement keys. It's simple.

Midi Control
One of the best things about the Novation keyboard is its ability to transmit and receive certain parameter information over MIDI. You can record your bass line, then overdub, say, some filter- cutoff tweaking on a second pass; on playback, there is your bass line with "real-time altered" filter-cutoff. To say this makes your playing spring to life is putting it mildly. Of course, the Rack has the same capability, only more so. I quickly spotted the feature that syncs the LFO to MIDI Clock--and was immediately deflated to find that there was a bug on my unit that prevented such a switch of control from taking place. However, you will be able to drive the speed of LFO modulation from your sequencer, and for tight, dance-oriented bassline bubbling and burbling, this will be (boo-hoo!) a rare treat. Various different "values" are offered so the LFO will fire off at different multiples of the external clock rate. Another aspect of the BassStation Rack I was sadly unable to investigate--this time through no fault other than not owning a CV/gate-equipped piece of old analog equipment--is the instrument's CV and gate potential. In case you're wondering why you would want these ancient interfaces, they allow you to perform tricks such as driving an unMIDI-ed Minimoog via the BassStation Rack's MIDI and CV/Gate connections.

Novation deserves full praise for not just drilling a couple of extra holes in the casing and wiring them up, but really thinking about how--and under what circumstances--these connections would be made. For instance, there are three CV/Gate types to choose from: Roland/ARP/Sequential (volts per octave, positive gate pulse); Yamaha/Korg (Hertz per octave, negative S/Trig); and Moog (volts per octave, positive S/Trig). In addition, you can assign a separate MIDI channel for your CV/gate-driven devices, which lets you drive the Rack from, say, MIDI channel 1 and a Minimoog connected to the CV/Gate jacks on MIDI channel 2. The Rack's invitation to the outside world is not over yet. You can even process an external audio signal through the Rack's filter and envelopes via a rear-panel audio input. In fact, the setup is quite complex here--it also involves driving the unit via MIDI--but for the serious studio hound constantly looking for new ways to process sounds, this will be a popular feature. Perhaps the ultimate external Rack application is to hook up lots and lots of them, something you are encouraged to do via the Polyphonic option in Utility mode. Someone is bound to link up a half-dozen Racks for a 6-voice polyphonic instrument, but this is going to be an expensive proposition. (I suspect, though, that a single polyphonic instrument lurks somewhere within the bowels of Novation HQ in England.)

Think Of Everything
With its well-implemented MIDI-controller capabilities; full set of program memories; advanced interfacing ability; and strong, rich set of internal sounds, the BassStation Rack is pretty hard to fault. It's a shame that here in America the price tag is not quite as mind-blowingly low as it is in England, but that's the price English buyers have been paying for years on Ensoniq, E-mu, Peavey, Alesis, and Oberheim instruments.

I'm reminded of the story of the gas-station employee who, upon spying a golf tee on the passenger seat of a Rolls Royce and inquiring what it was for, was told by the whiskery Brit behind the wheel, "Why, it's to put your balls on before you drive off." "My goodness, Sir," replies the startled gas-station employee. "Rolls Royce certainly does think of everything!" Novation really does seem to have thought of everything on the BassStation Rack. If you have been hanging about on the sidelines as several such dedicated bass synths have appeared over the past couple of years, now is definitely the time to jump in.

Hosted by Jesse Mullan