Yamaha PSS-680 Retro Review - Malcolm Ramage

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Yamaha PSS-680 Retro Review - Malcolm Ramage

Post by exxos » Fri Jan 12, 2018 9:41 pm

PSS-680-1.jpg (54.66 KiB) Viewed 27 times
It seems such a long time ago now, but back in 1988 Yamaha and Casio ruled the U.K. home keyboard market with a series of decidedly average keyboards. Ok, there were a few exceptions to the rule, such as the Casio CZ-230S, but on the whole the sound quality was, well compared to keyboards of today, pitiful.

Which was odd really, as the two companies had a war going on between them in the professional synthesizer market, with the Casio CZ series taking on the Yamaha DX series, both pretty realistic (For the time) sounding synthesizers, which between them had decimated the analogue synthesizer market and left many of the other competitors scrambling for their very survival.

Many didn't make it, but that's another story.

Yamaha had brought their top of the range Frequency Modulation (F.M.) synthesis to the masses in the PSS series, though they could hardly be called realistic. The top of the range had sound editing with sliders for various parameters, but there was no MIDI and to be honest very little else to say. The higher end PSR range was not much better, but did have full sized keys instead of the mini keys of the PSS series.

Then in 1988, all that changed with an almost complete revamp of the PSS series from the middle of the range through to the top with the PSS-X80 series, but it was the top 2 keyboards that drew the most attention, and deservedly so. These were the PSS-480 and the PSS-680 music station, and they could do a lot more in terms of sound creation than the front panel led you to believe.

They also had the coolest demo song of any home keyboard on the market at that time.

The sound was almost like the arcade game of the time, Outrun. You could almost imagine the high speed drive in the open top Ferrari with the blonde girl in the passenger seat. The other thing was, there were enough notes left in the synthesis engine for you to play along with whatever sound you wanted, including sounds you had edited.

The differences between the PSS-480 and PSS-680 are in reality quite small, the 480 has a 4 octave mini keyboard and 8 sampled drum sounds, while the 680 has a 5 octave mini keyboard, 32 sampled drum sounds, a set of drum pads below the keyboard with 3 fill pads, a sync/intro/outro pad and start/stop pad. There is also a pitch bend wheel and a MIDI Thru port in addition to the MIDI In and MIDI Out ports, more on that later. Other than those differences, the 2 keyboards are identical in every other way, which is handy if your looking for a synthesizer with hidden depth.

The synthesizer section can play up to 12 voices at once, which also translates into 12 part multi-timbral plus drums. It has 5 memories for custom synthesized sounds, 5 recordable tracks for song sequences and 5 memories for chord progressions, if your into using these for making songs. There are 100 pre-set voices, 100 drum track styles, digital effects (Of a sort), a synthesizer editing section, keyboard tuning, transpose and some MIDI function buttons. Up to these new additions to the PSS range, many of these functions could only be found on more expensive synthesizers, but now they were available to purchase for the home.

The synthesizer can be set to respond over all 16 MIDI channels, or a selection of channels if you want it to co-exist with another device. Drums are always on MIDI channel 16, something to remember if you want to use the drum section. The keyboard and the drum pads (On the PSS-680) do not transmit velocity information, however both the drum section and the synthesis section will respond to velocity information over MIDI, something that some more expensive professional synthesizers didn't do in 1988 (Korg's DW series being a good example).

Sound wise there are a few gems, including the tubular bell sound (Sound 62 from the front panel, program 61 over MIDI) and musical saw (Sound 98 from the front panel, 97 over MIDI), though many of the sounds are average, though way better than the generation of keyboards that came before. This in part was due to a better implementation of Yamaha's F.M. synthesis which gave the owner access to more of the controls and better still, gave you them on both of the F.M. Operators.

PSS-680-Synth.jpg (49.77 KiB) Viewed 27 times

I think a brief explanation of F.M. synthesis is needed here. An operator is what was called an oscillator in analogue synthesizers. It provides the waveforms that make up the sound and a minimum of 2 operators are required, 1 carrier and one modulator. Still with me? Good, here's the techie bit. The carrier generates a waveform which is modulated my the modulator, sounds simple. The resulting waveform is a mathematical combination of the 2, dependent on both the waveform and the differing frequencies, this becomes the sound you hear. There are other things involved, but a more in-depth explanation can be found here.

While the front panel gives you a reasonably good selection of controls, a look in the back of the manual (Available online here)

at the MIDI specification shows that there is an awful lot more editing potential. Both the PSS-480 and PSS-680 will respond to system exclusive messages for voice editing, though you need an external MIDI editor for your computer to access these sounds. As it happens, an editor for the Atari ST series is available here.

Using this software brings these humble keyboards to a sonic capability just short of Yamaha's own DX100, as 8 different waveforms are available for each of the PSS series operators, so a single operator can generate the output of 2 operators on the DX100. Of course the PSS does not have the flexibility on how it's operators are arranged, so it still falls short of the more professional DX100, but it is surprisingly close and at about half the price.

The built in speakers are pretty good for the time, though there is noticeable noise at higher volumes. This is cleaner from the line output jacks so putting these through a mixer or an external amplifier is a must if you want a cleaner sound. As the digital to analogue converters are a lower resolution than the converters in the higher end DX series, some aliasing noise can be heard on the fading of some sounds and can make some of the sounds a little cold. However there are a few tricks on these systems you can use to make it sound a little more 'analogue'.

If you have a bass line playing along, layer it with the same bass sound. The slight phasing will sound a little like the randomness of an analogue synthesizer playing the same pattern as you will introduce a random phasing into the sound, and in effect, adding a little more frequency modulation into the mix. This also works with string pads, although in some cases it makes the sound a little more thin and tinny. All I can recommend is experiment and play around with the sounds.

One last thing to cover is the MIDI ports. I've mentioned how the system will respond to velocity information, provide you with more editing parameters and make this sound like a more professional machine as a result, but there is an oddity with this machine that you should be aware of...

The PSS-480 does not have a MIDI Thru port, only the PSS-680 has this, however to help musicians who may need the function of a Thru port, Yamaha made the MIDI Out port behave as a Thru port in that it passes all the information received at the MIDI In port. This can be confusing for MIDI sequencers and they may need some settings disabled, such as a MIDI Thru function. Confused yet? Well on the PSS-680, there is a Thru port, so the MIDI out must just be a MIDI out and not have a thru function as well, right? Wrong... Both the MIDI Out AND the MIDI Thru will pass the information received at the MIDI In port. IF you set it up on your sequencer, press a key and end up with a note that continually repeats forever, you need to find the MIDI Thru function in your sequencer and turn it off, unless your into experimentalism.

There is another issue. In 1989 Yamaha released the successors to these keyboards, the PSS-580 and PSS-780, essentially the same but with playtime colouring on the cases and drum pads, an inferior demo song, and the sounds on the front panel grouped together in sound 'families' and in a different order to the keyboards that had gone before. However when selecting sounds over MIDI, the sounds were in the same order as the old PSS-480 and PSS-680, just to confuse you. Also the PSR series from 1989 onwards also used the same sound mapping over MIDI, so it is a good idea to get a listing of the PSS-480 or PSS-680 voices so you have some idea what voices you need to select when using MIDI.

And here they are...
PSS-680-Voices.jpg (83.58 KiB) Viewed 27 times
Apart from a few oddities with MIDI, and not allowing you to access all editing parameters from the front panel, these F.M. MIDI keyboards are pretty good systems. Put them through a decent mixer and use an external editor edit the sounds and you have a very competent synthesizer for very little money. In the U.K. I've seen the PSS-680 for around £49 but if you don't need the drums and can live without pitch bend on the keyboard, the PSS-480 can be had for as little as £15 if you look carefully. Similar prices for the PSS-580 and PSS-780, though to be honest, the first generation would be better, if only for the sake of sanity when trying to use it over MIDI and selecting sounds.

Would I recommend it? Well I've had one as a constant companion in my collection since 1988, and for the money, you can't really go too far wrong. If you don't like it, sell it again, chances are you will get most if not all of your money back.
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