• Synth Lite [JPG]
  • Synth Lite Rear Panel [JPG]
  • Synth Lite Bottom [JPG]
  • Synth Lite PCB [JPG]
  • Synth Lite PCB Bottom [JPG]
  • Synth Lite PCB w/ Component Labels [JPG] 434KB
  • Synth Lite Case Interior [JPG]

    MFB Synth Lite Review posted to Analogue Heaven

    I know this is an incredibly lengthy review but if you are even thinking about purchasing an MFB synth you owe it to yourself read further.

    After seeing MFB products on ebay and the web I finally got a chance to audition the MFB Synth and Synth Lite at NAMM last month. I had oodles of fun with the Synth Lite and purchased one a few weeks ago. I chose it over the MFB Synth because the Synth Lite featured ring mod, oscillator sync, and a dedicated LFO, but you lose the sequencer and third oscillator. The only comparable synth (both size and price wise) is the Technosaurus Microcon, so I'll be making some comparisons here and there.

    The MFB Synth Lite is housed in a small 5"x7" plastic project case and is powered by a small external DC adapter. The front panel graphics are screened onto a separate inset panel. The unit features:

  • two oscillators with range, tuning, and saw or square waveforms
  • oscillator sync
  • ring mod
  • LFO with three waveforms and oscillators or filter as a destination
  • glide with three settings
  • four pole moog style filter with contour
  • two ADS(R) envelope generators with selectable release (release time = decay time)
  • MIDI in with velocity and mod wheel modulation routings
  • external audio input

    So how does it sound? The filter sounds great, and as long as the oscillators are set to square wave you can get some amazing moogish bass sounds out of the unit. It also does well for soaring leads. The LFO can drive the filter and oscillators in the audible range for great FM fun. MIDI velocity modulates the filter just enough to give it some kick and the mod wheel can modulate filter cutoff across the full range. With the ring mod setting and some audio frequency FM of the filter I was able to get some great sci-fi sounds.

    Now the bad part. The really bad part. The unbelievably bogus bad part.

    At home in the studio where the noise floor is _significantly_ lower than the NAMM show floor, I could hear all kinds of harmonics when the oscillators were set to sawtooth. At first I thought maybe the waveshaper circuit just wasn't up to snuff, but the more I played with the unit the more I knew something was amiss. What really opened my eyes were some horrible anomalies with the oscillator sync and ring mod settings. When set to oscillator sync there is a horrible clicking/beating sound at about 1/4 the beat frequency of the two oscillators. The ring mod also has some "steppiness" right around the null point that I couldn't put my finger on.

    So how do I determine the source of my woe? Time to crack the unit open and take a look. Immediately upon extracting the PCB from the case I notice something is amiss. There is no analogue circuitry in the oscillator sections. Over by the filter I only find enough trannies and OTAs to support the filter and VCA. So where are the oscillators? At the bottom left of the board is Fujitsu microcontroller of some sort so lets go look that up on the net. Turns out it's a fairly powerful Fujitsu F2MC 16 bit MB90F497G microcontroller with 128kB of ROM and 4kB of RAM, as well as a nice complement of built in A/D. (datasheet available at http://www.fma.fujitsu.com/pdf/e713713.pdf) It only took a minute to trace out the circuit path of the tuning controls in the oscillator section to see they're feeding the microcontroller. After studying things a little more and putting an oscope on the micro-p it's obvious what's going on. Despite what MFB's own website, marketing literature, user manual, and unit itself says, this unit has

    *** 100% DIGITAL OSCILLATORS ***

    What a crock of #@$*in' @#$@!!!! No wonder the sawtooth oscillators have harmonics - the unit uses a 3 bit psuedo-DAC to make the sawtooth. Even worse is that the "ring mod" is digital. Don't even get me started on the pulse wave shape being positive DC. Or the bug in the last note priority code. Or that the LFO sawtooth waveform modulates the oscillators inversely.

    So what's this all mean? If you want a small synth with the Oberheim detune sawtooth sound you best look elsewhere. In fact, unless you filter the sawtooth waveforms heavily with the filter plan on only using square waves and forget oscillator sync or ring mod unless you can live with rhythmic audible glitching. I'm really disappointed because up until I noticed the sawtooth waveform and ring mod/sync glitches I really thought this was on par with a non-patched Oberheim SEM. It would be so awesome to have a sub-$500 MIDI analogue synth with the features of the OB SEM. And the MFB almost delivered. *** ALMOST ***

    I'll probably hang on to my MFB Synth Lite. It's a nice little box and will be a fun addition to rig at work. I will be following up with MFB and Geoff Farr (US distributor) so that their website and all documentation is corrected and that they do not misrepresent this unit as having analog oscillators. For those interested I have a high resolution picture with key components labeled on my site at http://www.retrosynth.com/gear/synthlite/synthlite_pcb_labeled.jpg.

    PS: I'm hoping someone at EM and/or Keyboard mag plagerizes this article when they do a review of this synth.