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Yamaha PLG150AN & PLG150PF

Analogue Modelling & Piano Daughterboards By Martin Walker
Published January 2000

Yamaha supply both Easy and Expert forms of their AN Editor for use in the XG Works environment.Yamaha supply both Easy and Expert forms of their AN Editor for use in the XG Works environment.

Yamaha's DB50XG daughterboard demonstrated to the world that a PC soundcard could offer high‑spec synthesis capabilities. Its latest descendents offer a digitally emulated Prophet V synth and a high‑quality piano. Martin Walker tries them out.

Yamaha must have thought long and hard about the possibilities of the daughterboard format after their phenomenally successful DB50XG. This set the standard by which most soundcard synths are still judged, and has since turned up in other products as well as computers, showing that as long as sound quality is high enough, a daughterboard can be sold to both synth and computer owners.

The PLG (PLuG‑ins) standard was launched to take advantage of this wider market, and uses a 15‑pin connector to connect daughterboards to the host device via a short ribbon cable. The range of host devices has been expanded to reach the widest possible market, and Yamaha currently provide a PLG connector in the MU100R and MU128 sound modules and the CS6x (see review starting on page 130), CS6R, and S80 synths, as well as the SW1000XG soundcard.

The advantage of a daughterboard synth card over a software synth is that it takes no processor power away from the computer or other host device. Compared to a hardware synthesizer, on the other hand, daughterboard synths largely eliminate the requirement for expensive extras such as a designer case, power supply, knobs, switches, plugs and sockets. This keeps the cost down, and the PLG products available to date range from £99 to £229 — a fraction of the cost of the equivalent synths in stand‑alone form.


Gary Gregson's An1xEdit is also available for free download, and is a compact stand‑alone utilityGary Gregson's An1xEdit is also available for free download, and is a compact stand‑alone utility

Yamaha have already used their advanced physical modelling technology (first seen in the VL wind synth range) to create extremely realistic models of analogue synths. These were first heard in their AN1x (reviewed in the August '97 SOS), on which the architecture of the PLG150AN is closely based. However, for the benefit of those unfamiliar with its virtues, let me elaborate.

In the simplest terms, the PLG150AN has a 2‑VCO, VCF, VCA structure, along with two LFOs, but this description hardly does justice to the huge number of routing and modulation options. For instance, both oscillators have extensive waveform selections beyond the usual sawtooth and pulse (such as Mix and Saw2, which combine the two in various ways). In addition, VCO2 has a Triangle option, while VCO1 has a wonderful Multi Saw option that fattens up the sound considerably by adding multiple saw waves together, complete with Detune and Mix controls (and all generated by one oscillator!). Both oscillators have width and depth controls for PWM (Pulse Width Modulation), and unusually, these affect not just the pulse waveforms, but the sawtooths as well. Sources for PWM include several envelope generators, the two LFOs, and the other VCO. Each VCO also has an 'Edge' control which can be used to model the waveshapes more closely on those of real analogue synths (the square or saw waves produced by real VCOs inevitably have slightly rounded corners). The effect of this is similar to a low‑pass filter: it rolls off the upper harmonics, and at extreme settings can reduce any oscillator wave shape to its fundamental sinewave.

The two oscillators can also interact in various ways, with a comprehensive range of sync options for those searing, tearing lead sounds, and X‑Mod (cross modulation), where the VCO2 Triangle or Sinewave output modulates VCO1 to create FM–like bells and pianos. There is even a simple AD pitch‑envelope generator for dramatic swoops at the start of each note.

The two oscillators can be mixed together in any proportion in the Mixer, along with their Ring Modulated product, Noise and Mix Feedback (where the output of the final VCA is fed back to earlier in the signal chain for somewhat unpredictable thickening and motor‑boating effects). The combined signal is then fed into the VCF. Here, once again, there is a host of options, from the classic Minimoog‑style 4‑pole (24dB/octave) LPF, through 3‑pole (18dB/octave) and 2‑pole (12dB/octave) LPF, BPF (Band Pass), BEF (Band Eliminate), and 12dB/octave HPF. The filter sounds wonderful, with a rich fruity resonance, and is stable enough to stay in tune when the resonance is turned up far enough for it to self‑oscillate. There is also a further HPF, which is useful for rolling off the overall low end so that sounds don't dominate the mix.

Both the VCF and VCA have full ADSR envelopes, as well as the normal options of keyboard tracking (for the filter), velocity sensitivity, and LFO1 modulation (for wah and tremolo). The two LFOs can also be pressed into service for PWM, FM, and Sync modulation, each having a huge choice of 21 waveforms comprising various permutations of sine, triangle, square, sawtooth, and sample & hold. The VCA output signal can also be passed through an amp simulator for the added dirt and bite of Stack, Combo, or Tube distortion, and finally through a 3‑band EQ.

And There's More!

Installing the PLG150AN board into Yamaha's CS6x synth.Installing the PLG150AN board into Yamaha's CS6x synth.

With only the functions so far described you could create a huge range of sounds, but things don't stop there. You also get a comprehensive arpeggiator with 30 preset patterns and Swing, Gate, and Velocity control, or a step sequencer with up to 16 steps and various loop modes. One of the most interesting features is the so‑called Free Envelope Generator. The Free EG function lets you automatically alter parameter values over time by drawing the changes into a graphic window, and then mapping the resulting 'graphs' to one of a huge selection of parameters such as Filter Cutoff, LFO Speed, or Ring Mod level. Up to four such Free EG tracks can be created per voice, each mapped to a single parameter, but with a common length ranging from half a bar to 16 seconds.

Various drawing tools for creating Free EG graphs are provided in both the AN Expert Editor and AN1xEdit, such as a pencil tool for freeform drawing and draggable LFO‑style waveforms for quick ramps and steps. Any selected portion of a Free EG track can be Smoothed, Randomised (allowing it to be used to create analogue‑style random oscillator detuning), Scaled, or Moved.

Even more exciting is the Morph function, which lets you allocate any MIDI controller to morph every single control setting for the current voice to those of another voice. This lets you create totally unique real‑time performances!

From rich synth brass to luscious strings, from pseudo‑voices to fat pads, from fruity basses to clangourous mayhem, the PLG150AN does them all with panache. And that filter!

The PLG150AN is monotimbral, and thus uses a single MIDI channel. It has five‑note polyphony in Single mode, and also offers a Unison mode where all 10 virtual oscillators are layered and detuned for extremely fat monophonic voices. Both modes feature variable‑speed portamento.

Of course, to do justice to a synth like this you would really benefit from real‑time control knobs, and while the original AN1x had plenty of these, you need to do a little more work to manage similar feats with the PLG150AN. If you install the card in a free‑standing synth such as the CS6x, a subset of its parameters can be directly controlled from the front‑panel controls of the host instrument. Otherwise, the supplied editing software is the easiest way to get full access.

Using the Control Matrix page of the editing software you can assign up to 16 different MIDI controllers to control separate PLG150AN parameters in real time — an ideal task for a Kenton Control Freak or Keyfax Phat Boy hardware controller box.

Prophet Of Mood

PF Easy Editor makes light work of choosing and tweaking voices, but doesn't provide full access to all aspects of the PLG150PF board.PF Easy Editor makes light work of choosing and tweaking voices, but doesn't provide full access to all aspects of the PLG150PF board.

Finally, then, to the sounds themselves. While Yamaha can't actually label the PLG150AN a 'Prophet 5 simulation', it's an open secret that the original AN1x has been re‑voiced and re‑tweaked in this new incarnation to make it sound as close as possible to this famous Sequential Circuits synth. So close, in fact, that many P5 owners allegedly haven't been able to tell the difference. It's been some time since I last played a Prophet, but I've little doubt that Yamaha have got it right. This emulation sounds wonderful, and it makes most soft synths sound bland by comparison. It's a long time since any synth made the hairs on the back of my neck stand up, but the PLG150AN managed it (just listen to the supplied X_Solo.mid file if you need convincing!). With the other supplied MIDI files it's instantly obvious which part is being played by the AN synth, which just goes to prove how distinctive the sounds can be.

The PLG150AN, moreover, goes beyond the P5 by adding a whole range of extra FM possibilities. From rich synth brass to luscious strings, from pseudo‑voices to fat pads, from fruity basses to clangourous mayhem, the PLG150AN does them all with panache. And that filter!

There are several differences between this card and the AN1x: the PLG150AN has only one 5‑note polyphonic 'Scene' to the AN1x's two, but boasts additional oscillator cross‑modulation (X‑mod). The other main difference is that the AN1x has far more built‑in effects (14 variations, plus dedicated Delay and Reverb) — but of course the AN has access to the effects of whatever PLG host it is installed in, which largely make up for this. At its current street price of around £400, the AN1x is already something of a bargain, and while this board may not have every single feature of its stand‑alone sibling, it comes pretty damn close in most departments, surpasses it in a few others, and for £199 is also great value for money. If one of your Yamaha synths has a spare PLG socket, get your order in now before the queue gets too long!

New Turbo SW1000XG Cards

One of the by‑products of providing significantly more circuitry on the new PLG150‑series daughterboards is that they take significantly more current, with the result that in the case of the SW1000XG soundcard, additional heatsinking is needed to prevent overheating. The latest P‑series SW1000XGs are already fitted with this modification, and are clearly marked as SW1000XG/P on the backplate. Those of you (like me) who have earlier cards can get a free 'turbo' upgrade, which must be done before any PLG150‑series board is installed, otherwise you will fry your card. Each of the PLG150 daughterboards reviewed here came with an A4 sheet containing details on how to get the upgrade.


For anyone like me who once owned a Fender Rhodes Stage 73, or a more obscure model like the Hohner Pianet, most sampled electric pianos are sadly lacking in expression and feel. Another problem for MIDI pianists is that it's easy to use up dozens of notes of polyphony, and nothing sounds more obvious than a piano part with note‑robbing. So, for any pianist with a spare PLG connector the PLG150PF could be manna from heaven, as it provides 64‑voice polyphony and a veritable cornucopia of acoustic and electric piano sounds crammed into 16Mb of ROM. These are created using Yamaha's AWM2 sample‑based synthesis, and the 128 presets are grouped into four main categories: Acoustic Piano, Electric Piano, Harpsichord, and Clavinet.

There are a number of grand piano sounds, so there should be one to suit most tastes, along with electric grands, honky‑tonk, added effects such as flanging and chorus, and songwriters' favourites such as piano plus strings and piano plus choir. The electric pianos contain some wonderful Fender Rhodes sounds (with much more responsive touch‑sensitivity and timbre changes than similarly named XG sounds), along with Wurlitzer, Pianet, DX and FM pianos. TremWurl had me instantly playing old Supertramp riffs, while those with added effects such as Phase 70 sounded exactly like playing through a stomp box, as we used to in the old days before multi‑effects were available. The timbre of the harpsichords certainly sounded realistic, with the correct plucked attack of a real instrument, but the illusion was slightly spoilt for me by the lack of a muted release. However, the clavinets more than made up for this, and it was very easy to forget that you weren't actually playing a D6.

The PF Easy Editor software lets you audition voices easily from a PC, and has two main editing pages. The PF page is basically a 2‑band EQ with frequency and gain sliders for both bass and treble, while the XG page lets you get at the familiar XG draggable envelopes for Envelope Generator (Attack, Decay and Release time), Pitch EG (attack time and initial pitch, release time and final pitch), Filter (cutoff frequency and resonance), and Vibrato (rate, depth, and delay). However, it doesn't let you get easily at other parameters mentioned in the manual, such as the relative levels of the individual elements in a sound, and velocity scaling, although you can apparently access these using assignable controllers on the CS6x. The PLG150AF also offers four built‑in effect busses (reverb, chorus, insertion, and EQ) in addition to those available on the host synth, but again you don't seem to be able to get at these using the PF Easy Editor.

Overall, the basic sound quality was far better than similar standard XG voices, and although the PLG150PF voices are only monotimbral, I doubt that many people would find this much of a limitation. Those with multiple PLG slots can even add several boards for more polyphony (two boards can be fitted in the CS6x for 128 notes, and three boards on the MU128 for 192 notes). However, while auditioning the sounds on the review board I noticed a great difference in sound quality between different patches. Many were extremely clean and crisp, but many others (such as TremDyno) had what sounded like aliasing distortion and low‑frequency rumble — one patch made my speaker cones jump whenever I released a note. With some patches (like the otherwise excellent Fender Rhodes 'Tea') some notes played perfectly, while there was obvious distortion when playing others. I find it hard to believe that Yamaha have missed such obvious anomalies in their ROM data, but I don't know what else could be causing this: it would be worth double‑checking before you buy one. Overall the PLG150PF should prove ideal for pianists, but as always, piano sounds are very subjective, and what may be the perfect instrument for one player might not suit another. Try before buying.

AN1x and PLG150AN — The Main Differences

Polyphony: 510
Multitimbrality: 1 part2 parts (5+5 notes)
Hardware Control: None61‑note keyboard, eight assignable rotary knobs, ribbon controller, pitch and mod wheels
Arpeggiator & Step Sequencer:YesYes
Free EG: 4 tracks per voice4 tracks per voice
X‑Mod: YesNo
Built‑in Effects:3‑band EQ, Amp Simulator (but can access effects of host synth or card) 3‑band EQ, 14 variation effects, Delay, Reverb

Giving It The Works

In order to use the Windows 95/98 editors for both the AN and PF daughterboards you need to have Yamaha's XGworks version 3.0 (or higher) or XGworks Lite already installed on your PC, though the supplied MIDI songs and Voice data can be sent to the daughterboards using any software or hardware MIDI sequencer capable of transferring bulk data. XGworks Lite is included on the CD‑ROM with the CS6x, MU128, and so on, and XGworks is also supplied with the SW1000XG. I used XGworks 3.0, but installing 36Mb of entry‑level sequencer package just to edit your new daughterboard does seem total overkill.

However, another solution for PLG150AN owners is to download the free AN1xEdit editor written by Gary Gregson. This has a more elegant interface, works with both Windows 95/NT and MacOS, and takes under 4Mb of hard disk space. It also provides useful Randomise facilities for voice generation, as well as intelligently converting voices from AN1x to PLG150AN format and vice versa. You can download it from Gary Gregson's web site ( The Yamaha web site also maintains extensive information and free voice banks for the AN1x.


  • Excellent, distinctive sounds.
  • Under £200!
  • Largely compatible with existing AN1x voice data, so loads of free patches are already available.


  • At this price no‑one could grumble about anything.


At under £200, this new card is arguably even better value than Yamaha's AN1x.