The Boomstar range of desktop analog monosynths from Studio Electronics came out last year and have been growing ever since. There are now six in the range - though not all are shipping yet. Each of the two oscillator monosynths has a common voice architecture, but with a different analog filter in each model. The current line up goes like this:
5089 - Moog ladder filter
3003 - TB 303 style
SEM - Oberheim SEM
SE80 - Yamaha CS80
4075 - Arp 2600
700 - Korg 700 (as yet unavailable)
We've got the 5089 and the SE80 here.
First up, the solid metal case feels weighty, like it's got a lot going on inside it, there's an unusual external power supply, so I guess there must be.
Top surface has bolted on knob caps to what appears to be surface mount plastic spigots, there is wobble but not concerning. switches are all metal case bolted. Top edge has analog connectors - CV/GATE, Frequency CV, Amplitude CV inputs on Eurorack style minijacks, plus a single combined Osc out - pre filter and VCA. There's also an Ext input too.
Rear panel connections:
Mains in, MIDI In/Out (learn button for MIDI ch assign), single audio output. And in the case of the SE80 - a mini din input for the Traveller connection.
Along the bottom edge of the Boomstar are additional parameters on small Korg Monotron style knobs:
Master Tune, Bend range, Glide, Dynamics -velocity to Env 1 depth, Env1 to PW1, then a mixer section for VCO1, 2, Ring Mod, Noise (white) and Feedback - a screaming output to input type loop - very effective.
Common Voice Structure:
2 VCOs - both with Lo (LFO range) and 32-2' pitch range, VCO 2 has +/- 7 semitones tuning. VCO 1 offers Saw/Tri switchable, SQ/Sine switchable, plus a square Sub - gain (half/off/full). So it's possible to combine multiple waves on VCO one plus a sub, theres a Pulse Width knob which can be modulated via LFO or ENV1, VCO 2 has SQ/Tri/Saw only but can have it's pitch tracking disabled for use as another modulator. Pitch mod for VCO 2 can be routed via Env1 or 2. Pulsewidth mod can be dialled in from the LFO for VCO 1 too. VCO 1+2 can be synced and yes, it does scream.
Which brings us to the two envelopes, both ADSR types capable of nice snappy performance, but yet have quite different features:
ENV 1 routed to VCF - can be switched to inverse and also looping mode - that neat feature allowing it to be used like another LFO,
ENV 2 - routed to VCA Inverse and LFO trig modes, single and multiple trigger switchable, plus a Drone (always on) and MASTER mode - this routes the VCF to ENV 2 instead so you can create a single envelope for both and free up the ENV 1 to deal with PWM or pitch.
XMOD + LFO
Single LFO with continuously variable waveform so you can travel through Sine/Tri/Saw Up/Saw Dwn/SQ/PW1/PW2/Random/S&H, MIDI syncable. It doesn't go right up high, but you can use VCO 1 for that if you need audio rate mod. There's then a two slot mod matrix which lets you mod VCO 1 PW/VCO Frq and VCO 2 PW/VCO 2 Frq.
Additionally the XMod takes VCO 2 and applies it to either VCO1 PW or Frq.
Finally, the VCA has a little overdrive toggle switch for breaking up the sound in a most musical way, between this and the feedback knob you can go from polite, twinkly electronic sounds to seriously messed up and warm distorted tones - it doesnt get really mad until the last 1/4 turn of the feedback knob which allows for more subtlety.
First up, the VCOs sound really good. Deep, charismatic with a good range and pitch stability a great starting point for pouring into the filter of your choice. Certainly there's a quality to these oscillators that make you sit up and take notice.
So between the two filter types I had to test, there are major differences, the 5089 really does sound very Moog-y with that warm smudge and hard corner to the resonance. Combined with the VCOs and it can sound absolutely massive, or not...
The SE80 however has a very different quality, a very brassy sound (on saw) with a more polite resonance - indeed this filter does not go into self oscillation like the 5089, but the resonance gives you a beautiful sing-song harmonic shift. But when you dial in the HPF and resonance the subharmonics are monster low down. I think I like this one better just for flexibility, and the Traveller input will soon allow for modulation of the HPF parameters too - currently they are on the little plastic knobs - which is a shame - but it's a darned close run thing. Thank goodness I didn't have more to play with.
Some synths you turn on and have to work at to get an impressive sound out of, some it just pours out of. The Boomstar fits the latter category, it's hard to review this kind of instrument as you just keep getting sidetracked into riffing and tweaking. In fact the neighbours complained, due to room rattling - a first here.
I have to say I really liked these synths and although I know they are on the pricey side for a mono (£769/$899) they do sound worth it to my ears. You also have to remember that Studio Electronics are also a small manufacturer without the benefits of large scale overseas factories so there is premium to pay. But if you get the chance to try one or more, do so - and turn them up loud!