Kawai EP-705M

This is a strung electric piano. It has 3 tonal variants (accessed by 3 control panel buttons). Very easy to use. The chorus button is also a simple "on-off" button. Unlike the Yamaha CP series, there is no Tremolo (or vibrato) & thus neither a "depth" nor a "rate" adjustment on this.
The midi control surface section - though quite simple in terms of what it actually does, is fairly poorly explained in the manual. One is not sure whether the buttons 1-4 are midi channels, or setup bank slots. (I believe they are the latter). The LED midi channel selector goes up to 99, but, I think the instrument only sends on 1-16. This selector may also be for GM patch numbers on outboard gear, but this is not yet clear. I rate the ease of use 7 - instead of 10 - because of confusing terminology for midi in the manual.

This piano is the next model after the EP-608. It was made in 1990, and was discontinued shortly thereafter.
The piano is a three-quarter width upright. It features 75 light wooden keys with round lead weights. The scale compass is from low F (roughly 45 Hz) to high G. Unlike its grand sibling - the Kawai EP308M - which has 88 keys and unison (dual) strings above second G (approx 100 Hz) to the top, this piano features all single strings per note. Although easier to tune or pitch raise, this is still a design flaw, as the single strung top half of the piano is acoustically weaker than the heavy single wound strings in the bass. By comparison, the Yamaha CP-60 has unison (dual)strings per note in the upper registers which would make the high end keep up with the low end in volume.

Polyphony is full (or more than full 75 - if you mash down the sustain pedal and play everything at once in rapid succession). This is real strings and hammers. The effect - chorus button mentioned above - is suitable for a medium slow chorusing that makes the sound more spacious and "Rhodes"-like.

It does not have "expansion" capabilities - unless you count slaved external midi devices.

The midi is touch-sensitive and the sustain pedal messages are also sent. There is just one midi out (no in nor thru). The midi contacts are the rubber hood type, over a black compound on a printed circuit board.

In addition to Left-Right analogue out quarter inch jacks at the back, there is a pair of quarter inch jacks for hooking up after-market effects boxes.

There is no sequencer.

There is just one pedal - sustain. Its linkage is hidden in the base. The pedal itself is chromed and generously wide - size of a pocket book.

The action is a compressed upright piano type. It is very short, so, there are no stickers. The key speed is light and fast for an upright, and the jacks re-seat quickly. Thus, the "stuck-jack" problem on soft trills in upright actions is largely not a problem.
The action rail is aluminum, and most of the action parts (back-checks, hammer butts, whippens) are Kawai's proprietary styrene plastic that lasts for centuries. I haven't had to do much regulation, except to minutely adjust (bring closer to string) the dampers for 4 notes around E below middle C. I also put a felt washer between the frame and the action where the action's left side screws on. This helped the dampers in the bass seat better.

The hammers are covered with a soft, fairly thin, beige synthetic suede. Mine - because it was a 13 year old used piano - arrived fairly grooved from the impact with single strings. I purchased about 7 dollars worth of real suede - rough on one side smooth on the other, and about a sixteenth of an inch thick - and re-covered all 75 hammers with this (rough side up). I first cut out 75, 1 cm wide strips around 3 inches long and then glued (carpenters glue is fine) these right over the old suede. DON'T PUT GLUE UNDER THE HAMMER TIP AREA - THIS WILL MAKE THE THING TOO HARD & ALTER THE TONALITY. You pull the suede tight around the hammer and clamp with clothes-pins along the back of the hammer-shaft where the glue can go. I first experimented (no glue - just elastics to hold) various hammer covers - felts, hard leather, combinations etc. - but, the single new layer of suede over the old worked best. After 2 days of light playing, there was a new slight impact groove and the sound stablized to a balanced soft-hard just like the original. Hammer densities (and their organization in layers) is apparently a real science. The slightest changes radically affect tone.

The dampers are the normal felt type, and, thankfully are overbuilt for strings this short.

The overall acoustic output is quite low, so, you can use it in apartments late at night, and listen via pickups, amp & headphones.

The pickups are the piezo ribbon type. This is 2 ribbons covering the lower 45% and upper 55% of th

The sounds are partly discussed above.

I would mention here, that despite no soundboard, there is still significant string-to-string interaction (slightly through air -despite impedance transfer drop) and probably along the frame. This sympathetic resonance makes it a joy to compose on. If you can find a symp-res. module to layer (like Oberheim midi grand or GEM module), this combination would keep your ears inspired for hours.

If you remove the upper and lower front panels and play it unplugged (no piezos) and it is properly tuned, it sounds remarkably real and pleasant. Decaying chords (with sustain pedal), beat together nicely in ensemble. (Unlike the deathly separated, non-interacting, non-musical, no-ensemble "strings" of static digital pianos). This string-to-string "choral singing" will help you compose some nice music. You still hear the inharmonicity in the bottom double-wounds, but at least with the piezo shut off, it's one less source of un-musical artefacts.

To enhance my experience of the direct strings, I am building an electro-magnetic pickup. Three zones. Left, Right, and bottom half octave. The latter's sub-mix volume will be turned down, and then LF content only, boosted back via 50Hz recovery circuit on Behringer T1954. Further, I will boost layered midi-triggered samples down low to cover & balance this area. I am also planning to thicken the lower back of the box (where is is thin sheet metal), the front panels, and partially damp the inside with strategically placed fiberglass.

For those not familiar with inharmonicity of this type. First, the low F string in a concert grand would be around 60 inches in length, and have very light, single windings on it and sound very musical.
A huge 56-inch upright would still be about 48 inches or so at low F, and be largely still very high-fidelity. It would likely still be single wound. The EP-705m is about 26 inches long at low F! This means, it is roughly half length. Thus the mass has to be seriously amped-up in the double windings. The resulting stiff string contains some low-F fundamental but, loads of high unrelated unmusical harmonics reminiscent of smashing a metal trash bin with a bat.

The EM pickup will have no colouration. I will (possibly) explain in a further review how this worked out. They will go into a modern low-noise sub-mixer with tons of gain possibility, so that I can get lots of dynamic range and low noise floor.

I rate it 6 overall for sound. It would be 10 as a longer strings, unisons, 80-note, and EM pickup design. It still gets at least a 6, as it is a joy to compose on, and makes a heck of a weighted 75 key controller.

Also interesting, is that if you don't like to set temperment with listening for beats, and then tune all other strings, you can - via midi - tune it to your favorite PC or module piano. (These have temperment already set in them in the pianos they were sampled from). I tuned the 705M to the Q-up Holygrail Kawai. It's some type of slightly stretched tuning, but it works well. (Just tune for all beatless bewteen your EP and the outboard one. The proper beats in 4ths and 5ths will already be there).

I had the wall-wart glass fuse (1A) blow twice on me, so, I replaced it with a 2A type. I also had a technician tighten loose parts in the wart, as it arrived rattling and not working.

Overall, the piano is stable in tuning (no swelling soundboard) and has mostly inert action parts. The wound strings are probably at their half-life for "growl" after 14 years. The preamp is a tad noisy but reliable. Well cared for, this piano should last 25 or 30 years.

For some reason (and I believe this is an anomaly or, someone once ran the wrong wart (& voltage into it), the midi died. As it turns out, the following was done by a local service technician:

"Modification to EP705M to make MIDI out compatible with a PC MIDI IN:

The IC was a blown "MIDI buffer" 74LS05
A buffering resistor was also blown ( 22 ohm 1 watt)
The centre pin of the MIDI cable (pin 3) is supposed to be earth ground (on a PC), but on the EP705M , it is a floating ground (because the piano uses an AC wall adaptor). The ground pin wire on pin 3 (inside the EP705M) needs to be either "cut" or regrounded to the
"digital ground" on the printed circuit board which supplies power to the MIDI circuit ( 5 volts).

If the EP705M is being used to drive a MIDI module of some kind (that doesn't use earth ground) - this modification doesn't need to be done".

I should mention, that after the above procedure, the piano - with midi direct to PC via a cable & gamer harness that went to a mainboard gaming port (mpu-401) & C-Media drivers - the EP705M, with PC running, wouldn't come on. I finally got rid of that midi hookup and instead, now run the Kawai midi first into a Yamaha YME8 active midi-through box, then onto the PC via a Steinberg USB midi hub. The YME8 seems to protect the Kawai from whatever was causing it to stay dead when the power was turned on. Also, I now run its wart into a switched surge bar. I always shut this off when not in use - thus the wart isn't humming and cooking for days when the piano isn't in use.

I also personally cleaned all midi contacts with alchohol & Q-tips. Pull out all wood keys and gently remove grey rubber hoods. The worst were the ring contacts inside the rubber hoods. The contact board surface also took a few soft-cloth & alch. wipes to get rid of brown haze.

I also adjusted every key for velocity. It's a simple procedure: Turn the little brass screw in the centre of each wood key all the way upwards (out), until there is no sound. Then turn in a bit until there is sound. This is the full-on instant 127 vol position. Then, continue turning in & down about two-thirds of a turn. This will be the properly ranged 0-127 clear midi velocity setting. If you turn it in too far, you get a limited vol. poor range, and strangled phased sound. (Please clean your contacts first as above).

Hopefully all of the above may be of interest to other EP & CP owners. These are museum instruments now. With a little TLC, you can coax some
muse-inspiring sound out of these little pianos. The big thing now, is to finish the EM pickups. I may also try running the piezos through an acoustic processor (Boss AD-5 perhaps), to scrub some of the artefacts out of the piezos, so they can be used in parallel with my planned EM pickups.

Because these units are normally very reliable, and some mis-handling of voltages etc. may have caused the above, I still rate this high for reliability. It wasn't gigged though, and I don't plan on using it "out" very much. I give it a 9.

I think, given all that I know now, that next time, I'd likely get the EP-308M instead (funds permitting). The 88 keys would be nice, and the balanced sound from upper unisons. I'd still build EM pickups for it too though, and protect the midi area with the YME8. An owner of a 308 sent me some photos, and due to the way it folds up in one piece, it would go on my elevator too.

It's hard sometimes to find knowledgeable service for older instruments. I was lucky - my local tech. guy was fantastic - and, he saved me some coin by showing me how to maintain her from here on, as he knew I was handy with tools etc. It was not under warranty, nor, was the instrument bought new.

Paid $500 plus $80 delivery, then, $20 wart repair, $7 suede, $3 fuses and $300 Kawai service call. Overall, not bad for $910 CDN. Further mods (custom EM pickup parts from electronics surplus store & used sub-mix) should be under $200 CDN). I figure entire project at $1100 to be better than original spec. and a great late-night composition tool, with real strings, midi, and weighted keys.