The Hohner Electra Piano

The sound of early 70s Euro fusion used by bands such Nucleus and pianists such as Keith Tippett and Gordon Beck, as well as in the background on Stairway to Heaven and Come Together.

Do not be put off by the mid century home piano appearance of the console model: the Electra is a serious piece of kit on a par with all the better known electromechanicals. There is also a stage model, the Electra T, completely redesigned for portability.

A console Electra I serviced October 2020 for Klassic Keys.

Below are some photos taken during the service of this Electra with a brief service guide. Any questions let me know. I've worked on quite a few now so have a good knowledge of how to get them sounding and playing good! There are also a couple of patents for the console Electra as well as the Electra T so I will aim to translate these and provide a review here.

A few classic Electra tracks to get you in the mood before you delve into the info below. The definitive exponent of the Electra Piano in my view is Gordon Beck, and the definitive track is Ariadne. Thanks to Greg Foat, student of Gordon, for making me aware of this and other great Electra tracks. Next is Bora Rakovic Soft Hands Had the Rain from his album Ultra Native, which has plenty of great Electra. And also let's not forget Keith Tippett A Stately Dance for Miss Primm. I'll add more when I find Greg's compilation he made for me, 'An Hour with the Electra'!

The Electra keybed is an extended version of that found in the Clavinet and Pianet T. As most are around 50 years old now the grommets will need changing. The action is slightly more forgiving than a Clavinet as the extra weight of the hammers mitigates key sticking, but still important to make sure each key is moving freely. Below are photos of the keybed before and after repainting.

keybed before.jpg keybed after.jpg

The keys are standard Hohner keys with an extend keyshaft and a damper arm screwed to the middle. The Electra damps the front of the reed so simply depressing a key disengages the damper for that note. Damping on the free end of the reed does lead to a lot of damper wear however, a weak point in the design compared with a Rhodes or Wurlitzer. But if properly maintained and regulated there should be plenty of stopping power. Another weak point is the tongues that attach the sustain bar to each individual damper arm. These are literally made of cardboard and a prone to breaking. Here is a photo of the keys removed for cleaning and grommet replacement. I've numbered them as from experience it seems that even though Hohner keys are uniformly manufactured they seem to develop a relationship with their position, either over time or through factory bending to account for manufacturing inconsistencies. So if you're working on one of these, a Clavinet or Pianet T please take note! Otherwise you take all the keys out, mix them up and on refitting the keybed will be full of uneven gaps and sticky keys with inconsistent heights all over.

keys out.jpg

It looks as though Hohner analysed the Rhodes action and its various problems. The solution they came up with was to implement a similar basic cam and follower action, even though the hammers are much smaller and the head is connected to the cam with a thick piece of wire. The main difference is the regulating screw in the rear of the cam. This sets escapement. When the key is fully depressed the screw head contacts the key pedestal felt, stopping the movement of the cam with the hammer tip short of the reed. This screw can be adjusted through a slot in the back of the piano case so that the action doesn't need to be removed from the case thereby avoiding a lot of work. The Electra action is not easily accessible for servicing.

The critical question though is if the regulating screw stops the hammer tip short of the reed how does the hammer tip strike the reed? I can expand on this more once I have translated the patent, but in reality even after the hammer is stopped by the regulating screw there is still a small amount of travel and this enables the note to be sounded. But it also means that the escapement distance must be carefully maintained as striking power rapidly diminishes as the key pedestal felt compresses and the escapement increases.

Here are some pictures of the action.

hammers.jpg hammers2.jpg hammer cams.jpg

As a cost saving measure it seems that the same type of felt as used for the key pedestal, pretty high density stuff, is also used on the midrange and bass hammers. The damper felt is the same density, though 3mm rather than 4mm thick, and appears to have also been used on the midrange felts. The top 2 octaves use bushing cloth and buckskin respectively.

action.jpg action2.jpg

As you can see the hammers rest on foam. The original disintegrates, much like the foam in the sticky pads on early Pianets, and must be replaced otherwise as on note release sound of the hammer returning to rest position is pretty loud.

The tone generator in the Electra draws heavily on the Rhodes tine and tonebar relationship. Though the Electra appears to use mostly generic hardware to achieve this. The tonebars are a straight metal rod, counterweighted in the bass by what appear to be large lumps of lead. The reeds are similar blued steel to what is found in the Pianet T, though some are triangular in shape. Remember the Electra came first so these would have been adapted for use in the Pianet T. What is unique is the pickup system. The pickups are mounted on the side of the tonebar. They are simply a thin metal strip wound with wire. They measure very low compared to a Rhodes, around 3 ohms depending on register. The metal can be bent towards of away from the pickup to vary volume and timbre. This setup needs care where tuning reeds or adjusting dampers as is it very easy to catch the thin pickup wire with a file. Fortunately it is possible to rewind the pickups by hand. So even though I have never seen any spare parts available for sale, the Electra can still be kept running. The tone generator assemblies are mounted on rubber and attached to the harp, which is just a heavy steel angle supported by wooden blocks at each end. With the weight of the lead on the lower notes is extremely heavy. The rubber mounts are unfortunately glued to the generator assembly and not easily removeable, I suspect they harden with age and reduce sustain in the top end.

treble generator.jpg bass generator.jpg harp upside down.jpg

The pickup wires are soldered each side of small square piece of pcb, 1 for each note. The signals are combined in series, but each register of the Electra is grouped and then sent to a passive mixer. The mixer board features one of the same high end Beyerdynamic high end mic transformers (far end of the board behind capacitor) found in the Clavinet to boost the output. The switch for the soft pedal is also on this board, along with a master volume control.

mixer.jpg

It's possible to remove the whole piano assembly from the case, just desolder the audio cable and add an output socket. Here it is being tested through a Rhodes suitcase.

<testing through rhodes suitcase.jpg