PSR-6700 (1991)
The coming on age of Yamaha's arrangers. Now you can call me a Pro!
Release Date: 1991
Introduction – It’s Time for the Pros
Towards the end of the 80s decade, Yamaha started to say goodbye to FM synthesis and moved to newer technologies, in which PCM samples played a central role. Yamaha called its own version of PCM synthesis as “AWM” (Advanced Wave Memory), but in fact, during a certain period of time, the technology used was a combination of AWM and FM synthesis.
The PSR-4500 and PSR-4600 (which are actually the same keyboard, released in 1989 and 1990, respectively) were the first flagship arranger models to use this new technology, labelled as “DASSystem” (Dual Architectural Synthesis System), and based in the new (back then) GEW-5 chip. Nevertheless, the PSR-4500/4600 weren’t as good nor as powerful as one might expect from a flagship model, and they didn’t really take full advantage of the potential of the new synthesis technology.
The PSR-6700 was released short after, in 1991, as the new flagship arranger from Yamaha. While in terms of technology the new model wasn’t really a significative innovation (just like the previous PSR-4500/4600, it’s based on the same GEW-5 hybrid AWM/FM synthesis architecture), it was a HUGE leap in terms of quality, power and capacity, and brought up the potential of the new synthesis almost to the max. It is, in my opinion, the very first arranger model released by Yamaha that can be considered as truly “professional”, and a plausible alternative to a synthesizer in the studio or live.
The reasons for the above statement will be developed in the following sections, but as an appetizer, these are some of the most salient features:
· Very well built and sturdy, made in steel and rugged plastic, heavy as hell (24 kgs., that’s over 52 lbs.), and with internal PSU
· 76-key semi weighted keyboard, with an excellent touch and feeling
· Backlit LCD screen, bigger than many of the synthesizers of that time, and 3.5” floppy drive
· 40-voice polyphony
· 2 DSP effects units
· A highly improved accompaniment system
· Full synthesizer functions, comparable to “real” synthesizers, with capacity for 100 custom voices
· An advanced and fully featured 8-track sequencer
· Velocity-sensitive percussion pads (the only Yamaha arranger with this feature, AFAIK)
· (This might be minor, but also very significative) For the first time in an arranger from Yamaha, the model number appears in the back panel
It's pride time!
Looks and Design
Despite being launched just one year after the PSR-4600, the differences between the PSR-6700 and its predecessor are quite radical. While PSR-4500/4600’s aesthetical design was boldly vanguardist and “futuristic”, the PSR-6700 opts for a much more conservative/traditional/sober (or, ultimately, “serious”) appearance. Clean and straight lines are predominant, without edgy or curvy elements. In fact, its design is very similar to Yamaha’s synthesizer line of that time (SY series). Despite its size and weight, it’s quite slim, with only 12 centimeters in height, considering that it has 16 cm (6,5”) woofer speakers and a 3,5” floppy drive under the keys. The top panel design has a series of horizontal lines that contribute to dissimulate the presence of the speakers, and hence helping to provide a more “professional” appearance and less of that of a home keyboard.
Other elements also contribute to provide this feeling of a high quality, pro-level product. The bottom panel is made of steel, being to my knowledge the only Yamaha arranger to date, besides the 9000 Pro, with this feature. Maybe this decision was taken with the idea of using the keyboard in live concerts or shows, just like synthesizers. Anyway, this fact contributes to make this keyboard very heavy (24 kilograms, not much less than my Montage 8, with its 88-keys weighted keyboard mechanism).
Another relevant point is the keybed. Not only the PSR-6700 is the first (and one of the very few) arranger models from Yamaha to have more than 61 keys, but the quality is excellent. It seems to use the same FS semi weighted keyboard mechanism as the DX7 and many other top-level synthesizers such as the SY99, the W5 or the EX5. In any case, the feeling and response is delightful, noticeably better than any previous model (and better than most of its successors). The only drawback, if it could be considered this like this, is that it hasn’t aftertouch. In a surprising move, the 8 percussion pads above the keyboard (BTW made of plastic, not rubber) are velocity-sensitive (wow!), and to my knowledge this is the only arranger ever from the company to have this feature, including the recent ones such as the Tyros and the Genos.
It's also remarkable that this is the first Yamaha’s arranger with a backlit LCD screen (24 characters x 2 lines), combined with a 3-digit segment LED screen. Although it’s not a very big LCD screen, is bigger than, for instance, the one of the SY22 or the SY35, the synthesizer models which are closer to the PSR-6700 in terms of technology and sound. It’s also the first arranger to include a 3,5” floppy drive, of which many synthesizers lacked then, and which is much more flexible and versatile than the previous cartridge system.
In a very sensible decision, Yamaha abandoned the weird control bars of the previous PSR-4500/4600 in favour of standard pitch bend and modulation wheels, which this time are the thicker ones from the SY series, and not the thinner ones from the DX line.
A classy touch is that there is a lid made of steel in the upper part of the panel that can be opened or closed. If opened, you can see a printed list of the preset voices and styles, and also access the buttons for advanced functions such as the sequencer and the custom accompaniment programming, the synthesizer or the advanced configuration functions.
Last but not least, there is a little detail which IMHO has a great symbolic significance. For the first time, an arranger from Yamaha has the model number printed on the back panel of the keyboard, like synthesizers. The “PSR-6700” logo is big and clearly visible at the right side of the back (from the spectator’s point of view). In home or lower end products, usually there is only a generic “Yamaha” logo. Not only Yamaha, but also the rest of manufacturers, tend to put the model name/number at the back only in high-end products, or those that in some sense the manufacturer is “proud of”. This detail sends the message that this keyboard is a “serious” machine, and that Yamaha wants the people to know which model it is.
Hardware and Synthesis Technology
Despite being a great improvement in quality and functionality, the PSR-6700, quite surprisingly, it’s not a relevant technological advance with respect to the previous PSR-4500/4600. Indeed, it’s basically the same technology, although taken to the max.
The responsible for the sound generation is the already known GEW-5 chip, used in previous Yamaha models, including the PSR-4500/4600 and the SY-22 synthesizer. As already pointed out, this chip combines PCM-based synthesis (AWM) with 2-Operator Frequency Modulation (FM). Voices can have either 2 elements (one AWM and one FM) or 4 elements (two of each). The synthesis engine is rather basic, as it doesn’t have any filters. Basically, all you can control is the pitch and the amplitude of the waveforms, but not the tone colour (harmonics). Each GEW-5 provides 8 voices of polyphony and is 8-part multitimbral, and can access to a total of 2 Megabytes (16 Mbits) of 8-bit or 12-bit samples. But a great feature of the GEW-5 is that several instances of the chip can be combined to provide more polyphony, while accessing the same waveform ROM memory. For example, the SY-22 and the PSR-4500/4600 have two chips to provide 16-voice poly. And here comes the good news: The PSR-6700 not only has 2 Megabytes of sample ROM (the maximum amount), but mounts a total of five GEW-5 chips to provide a grand total of 40-voice polyphony. This is not only the greatest polyphony in a Yamaha’s arranger to that time, but it’s a really great figure for a keyboard in 1991. Even the most advanced professional synthesizer workstations of that time, such as the Korg T-series or Yamaha’s own SY-99, were limited to 32 voices of polyphony.
Taking a detailed look at the manuals, the similarities between the PSR-6700 and the SY-22 and its siblings become evident. The wave list (the basic building blocks of the voices) is very similar. Many of the AWM waveforms seem to be the same, ant the FM wave list is identical, in fact. Very likely, the PSR-6700 is capable to reproduce any sound that can be created in a SY-22. It’s true that the PSR does not implement the “vector synthesis” feature, but this “synthesis” just controls the relative amplitude of the different elements of the voice, or their detune (pitch), and in principle this could also be done in the PSR-6700 via midi data. In sum, the PSR-6700 could be considered as a SY-22/SY-35 without the vector synthesis and the aftertouch, but with a larger and better keyboard, more polyphony, a bigger LCD screen, a comprehensive sequencer, built-in accompaniments, drum pads, a floppy drive and speakers in exchange 😉
The DSP effects department also receives a serious boost since the previous PSR-4500/4600. Although the chip is the same one, the YM3413 (also known as LDSP), the algorithms are much better this time and there are two effects blocks, which can be independently activated or deactivated, and allow for some degree of control (just the intensity or level of the effect and the target: orchestra voices, accompaniment and/or drums).
The first effects block provides different variations of reverb, delay and other specific effects such as distortion or localizer. The second effects block provides different versions of tremolo, chorus, flanger and symphony (a kind of chorus). This second effects block cannot be applied to drums, but only to orchestral voices and/or the accompaniment. The quality of the DSP effects, as usual in the late 80s and early 90s, is certainly not very good, but better than nothing and light-years ahead of the PSR-4500/4600.
The five GEW-5 chips (code XF987A0) in all their glory
The Voices and the Synthesizer
In the sounds department, IMHO the PSR-6700 goes as far as its technology allows. We have to consider that the waveform ROM size is limited to 2 Mb (not bad in 1991, but neither cutting edge, as other synthesizers already had 4 or even 8 Mb at that time), that samples are limited to 12 bit @ 22Khz, and that the synthesis engine is rather limited, without filters of any kind.
That said, the keyboard sounds pretty good (always considering the context of that time), and much better than the previous PSR-4500/4600. There are 100 preset voices and it’s possible to create 100 more custom ones. Just when turning it on, the piano voice (which is the same one as the SY-22, BTW) sounds noticeably better than the one in the PSR-4500/4600 (which, honestly, is rather bad). It’s not, of course, an excellent piano, and I wouldn’t consider it even as ‘good’, but it’s quite decent and does its job in the mix. The electric pianos, on the other hand, are somewhat deceiving, including the FM, DX-like. But in general terms all the ‘acoustic’ patches are more than decent and sound much better than in the previous model. There are not many ‘synthy’ voices, although thanks to the fully featured synthesizer (read about this below), it’s possible to create your own and sound as good (?) as a SY-22/35 synth.
On the drums/percussion department, this time there is a total of 74 sounds, including sound effects (there are exactly 14 sound effects and 60 drum/percussion sounds). The quality is comparable to the SY-22/35 and although not particularly good, they are the best percussion sounds to date in a Yamaha’s arranger.
A very good thing of the PSR-6700 is that, for the first time, Yamaha includes in an arranger keyboard similar synthesizer’s capabilities than in a dedicated synth. In previous models such as the DSR-2000 and the PSR-4500/4600, synthesizer functions were limited to a few parameters and didn’t allow for the control the whole synthesis engine. The engine of the PSR-6700 (and the SY-22/35) is not very sophisticated but it’s possible to tweak it in a similar way than in the SY series. This means that you can select the waveforms, edit the envelope generator (attack, decay, sustain and release), set the relative volume and octave of each element wave, detune them, or edit how the pitch and modulation wheels affects the voice, among other things. As the synthesis engine has no filters, you cannot do miracles or drastically affect the tone and character of the voice, though. On the other hand, in contrast to the SY-22/35, it’s not possible to adjust the level and the feedback of the modulator operator in the FM elements. But in sum, the PSR-6700 could be considered as a synthesizer in its own right.
Some examples of the preset voices of the PSR-6700:
And here's one of the built-in demos:
A partial view of the panel, with the preset voices printed in the lid
The PSR-6700's AWM wave list...
... and the SY-22's AWM wave list are very similar
While the FM waveform lists are identical!
Stylish Accompaniments
Obviously, a keyboard couldn’t be considered as an arranger if it hadn’t built-in auto-accompaniments. If in the previous PSR-4500/4600 the focus was placed on quantity rather than on quality, this time it’s the opposite way, as the PSR-6700 has only 36 preset styles, but with a high level of complexity and quality. Each style consists in a drum/percussion track, a bass track and two “chord” tracks. Nevertheless, it happens a bit quite the same as in the PSR-4500/4600: the styles are quite too “busy”, with rather complex melodic lines and harmonies, which are not always adequate for the performance that the player wants to make.
In all the older models we’ve seen so far, accompaniments had a “normal” and a “variation” version at most. In the PSR-6700 there is a qualitative leap, as each style has five different sections (without counting intros, endings and fill-in patterns), labelled as “verse 1”, “verse 2”, “chorus 1”, “chorus 2” and “solo”. These labels are quite self-explanatory. In general terms, the “chorus” sections are more musically complex than the “verse” ones, and so are the “2” variations compared to the “1”. Instead of having separate fill-in buttons for every pattern, there are only two, one for a fill-in without changing the accompaniment section, and the other for changing the section after the fill-in (from “verse” to “chorus” and vice-versa). The most curious addition is the “solo” section. As one might think, this section activates a solo part of the song, including the melody and the changes in the chords. Literally, the keyboard plays a full arrangement by itself. These arrangements are quite long, and in general terms are musically nice and well programmed, but raise an obvious question: what’s really the point of this? It’s in a certain way just like listening to a demo. The aim of the accompaniment styles of an arranger is to provide a backing for what the player is performing, so this seems to be quite a bit out of place.
Another novelty introduced in this model is the “Interactive Accompaniment” function, which seems to be a kind of artificial intelligence that scans what the player does (such as the strength or the velocity at which the keys are played) in order to select and change the corresponding section of the accompaniment. If no keys are played, after a few bars the “solo” section is activated. Sincerely, it’s better to keep this function deactivated.
A couple of examples of “Interactive Accompaniment” (no melody is played in the keyboard):
And a couple of styles with melody and no Interactive Accompaniment:
Besides the preset styles, it’s possible to program and store another 6 new styles in the internal memory, and more interestingly, new styles can be loaded from the floppy drive.
A partial view of the panel with the style list and style controls
Did I Mention the Sequencer?
All the previous flagship arrangers we’ve seen so far have some kind of multi-track recording, but the PSR-6700 is the first one which includes a proper sequencer, one that really deserves that name. It has 8 different tracks (the manual doesn’t specify the memory capacity, though), and all the features and functions that could be found in the sequencers of the workstations of that time. For example, whereas in the older models there was only one recording method (what you played replaced what there was there before), in the PSR-6700 you can select between “Replace” (erases the previous content and replaces it with the new data), “Overdub” (adds information to what was already there), and “Punch-in” (allows to replace a specified range of measures with new data without affecting what it is before and after the punch-in range).
There are also tools for editing the recorded data, so you can, for instance, mix two tracks into a third one, quantize data (with 7 timing options), delete a specific measure or range of measures, insert a measure or a range of measures in a specific point, erase notes or individual events (such as pitch bend, modulation, sustain, etc.), change the note velocity, or transpose (shift) notes. There’s only memory for one song, but of course you can save it to disk when needed.
Amplification, other functions, connections and MIDI
Following the same principle of a big increase in quality, this also affects the built-in amplification system. All the previous models used single-way, 12 cm speakers, with an amplification of 5 or 8 watts per channel. The PSR-6700 not only increases the amplification power to 10 watts per channel, but also implements two-way speakers with 16 cm (6,5”) woofers, wood cabinets and bass reflex ports. With these specs, one might think that the keyboard sounds good through its speakers, but the truth it that it still doesn’t sound very well, or to put it in other words, it should sound much better considering the specs. It’s not until the next generation (PSR-5700) when an arranger from Yamaha will have an internal amplification that a flagship model deserves.
Another relevant improvement comes in the form of the panel registrations, which increase their number from the previous 5 (PSR-6300) or 4 (DSR-2000 and PSR-4500/4600) to 16 (two banks of 8).
In the connections department, the PSR-6700 has the usual MIDI ports (including MIDI Thru), headphones, and stereo inputs (RCA connectors) and outputs (jack). This time, though, there are 3 pedal connectors: the usual ones for sustain (jack) and expression (RCA) pedals, and another jack one (switch type, not continuous) for other selectable functions, from accompaniment start/stop to fill-in patterns, glide, or even for playing individual percussion sounds, among other things.
Staring form the previous PSR-4500/4600, the default MIDI mode is 3 (omni off, poly), so the keyboard can be easily used as a multitimbral sound source in a DAW. The synthesis engine provides 8 different parts, and thanks to the extended polyphony of 40 voices, it’s possible to program more complex arrangements. The MIDI implementation, though, is still quite limited (for instance, it’s not possible to control some quite basic parameters such as expression, portamento or reverb send).
Some examples of MIDI arrangements:
This one uses custom voices programmed by me:
Verdict
At last, Yamaha releases an arranger which can be considered as a professional quality product and a real alternative to a synthesizer in the studio or on stage.
Pros:
· High-quality product, very well built and serious-looking design
· Excellent keyboard mechanism with an extended range of 76 keys
· Pretty good sound, comparable to the synthesizers of that time (not the flagship ones, though)
· Fully featured synthesizer and plenty of user memory (100 user patches)
· A real sequencer
· Backlit LCD screen, floppy disk drive
· Very good polyphony at its time
Cons:
· Heavy as hell, not very “portable”
· A keyboard of this quality should have aftertouch
· A limited number of accompaniments, with pretty “busy” arrangements and dubiously useful “solo” and “interactive accompaniment” functions
· Amplification system not as good as expected
· Pitch bend is limited to 2 semitones max. and no portamento function