Hohner Pianet T

 

Hohner Pianet T
Hohner Pianet T

The Hohner Pianet T is a lesser-known electromechanical piano that was made in the late 1970s.  It is completely passive without even a volume control, with little Wurlitzer-like reeds and the tiniest pickups I have ever seen.  The sound is like a cross between a Rhodes and a Wurlitzer. The amazing thing about it is how small it is.  It probably weighs around 30 pounds.  If I was gong to give all the electromechanical pianos I have known (Rhodes, Wurlitzer, Clavinet, this one) each a score that was the ratio of how good it sounds to how much it weighs, this one would get the highest score. Why even bother with a 140-pound Rhodes when this little thing sounds almost as good?

Hohner Pianet T tiny pickups
Pianet’s tiny pickups

There isn’t a lot of information about this instrument online.  The mechanism is very unusual.  The arm of each key has a sticky plastic pad on it that, when the key is at rest, sticks to the reed just via its adhesive.  When you press the key and the back of the key comes up, the pad simply pops off the reed, causing the reed to vibrate and sound. With no-longer-sticky pads as this one had, it basically just doesn’t make sound.  It needed a full set of new sticky pads.  Before putting the new pads on, all of the very-rusty reeds had to be sanded and cleaned so that they would vibrate properly, and after sanding, they had to be retuned which is done by filing the little solder blocks that are attached to them, much like on a Wurlitzer.  There was one dead reed that had to be replaced.

Repair Tips:

Since there’s so little info on these I’m going to go a bit more in-depth than usual on what we figured out/learned “the hard way” while working on this.

Don’t try to unscrew the reed screws unless you are replacing a reed! That is not how you tune or voice this instrument and the screw will almost definitely break. The machine screws for this are M3 x 10 that you can get at any hardware store, but you need to use a special spacer. Sticky pads were sourced from Clavinet.com, replacement reed from Vintage Vibe; the reed we bought came with the spacer, but if you need the spacer, Aaron at Clavinet.com has them too. Neither of these places had both of the things we needed, and no other place on the internet seemed to have any Pianet parts at all.

The keyboard design is similar to a Pratt-Reed with the same kind of keystops, brackets and bushings, but the keys are not on the same kind of springs and you can’t remove the plastic key tops (the white or black parts).  We had slow keys to deal with because of bad bushings. To remove a key, you have to push the translucent plastic bracket that holds the back of the key arm DOWN until the key pops out.  It doesn’t seem like it will work but it does.  Then you can replace the bushings with Pratt-Reed type bushings.  Sand a little of the sides of each bushing and lubricate them with something like Dow Corning 7 before you slide them onto the keystop.

Work done: sanded rust off and re-tuned all reeds, replaced sticky pads, straightened key shafts as needed. Replaced one bad reed and bad hardware on one other. Replaced some bad key bushings.  Lined up pickups across the board to normalize volume and tone.

12 thoughts on “Hohner Pianet T”

  1. Hi Alison. Did you refinish the reeds with the blue coating after sanding off the rust?

    I’m working on a Pianet T with rusty reeds. I’ve been able to clean them back to the original, smooth metal, but I hope to get them close to their original state. Or maybe that blue finish doesn’t matter too much?

    I tested Nu-Blu gun finishing liquid, but I haven’t gotten it to work the way I want.
    Thanks!
    Zack

    1. Hi Zack My thought on this is: the blue coating sure didn’t do a very good job of protecting the reeds from getting rusty in the first place, so I wouldn’t worry too much about trying to reapply it. We have seen a Pianet come in whose reeds had very little rust and one that was very very rusty (the one we were working on when I made this post), and I’m guessing the biggest factor in rustiness is the environment that the instrument is stored in. My advice regarding this and every other electronic musical instrument is just to not store it in a humid place.

      1. old accordion trick is staple in a silica gel pack or two as a desiccant.
        Except for the sticky pads, Pianet IS a modified accordion

  2. Brilliant!
    Thanks for sharing alison. I bought a Pianet T a little while ago and I’m only now getting round to attempting a similar restoration. It will be my first project of any keys instrument. On my model the metal arms attached to the keys have rust as well as the reeds. You would definitely recommend sanding away rust from the reeds? I’m worried about detuning and never being able to bring it back. Also I noticed on clavinet.com as well as fresh sticky pads they sell an electrical contact brush/rust remover… any thoughts. Kind regards. L

    1. Generally, we try to remove as much rust as we can from the reeds without going so far as to sand them, because you are correct, sanding can put you way further behind with respect to getting them in tune. Try rubbing them with a rag with WD-40 sprayed on it. You don’t have to get them so clean that they have no rusty color, just so that they no longer feel gritty to the touch.
      I hadn’t seen the rust remover brush for sale on Clavinet.com so I’m not sure what it is or how well it works. However, whatever substance you use to clean the reeds, you really have to make sure you get it all cleaned away when you’re done, or the sticky pads then will not stick! 98% isopropyl or denatured alcohol should work for that final cleaning step.

  3. In your repair tips You say not to unscrew the reed screws, how else do you get the rust off the reeds? Just picked up a pianet, it’s awesome! Trying to dive in and learn more about it.

    1. Hi Jack,
      In Pianets with reeds that were not rusty, we have succeeded in unscrewing the reed screws without breaking them. If they’re very rusty, it’s quite risky. I’d say just do your best to try to clean off the rust with the reeds still installed. We’ve done it with decent success before.

  4. Hi Alison,
    I have successfully cleaned sticky pads and removed most of the rust off the reeds of my Pianet T using rubbing alcohol and by buffing with cotton swabs. Also, I find it is helpful to align the key shafts so that they are centered over the reeds. These techniques help in voicing the notes.
    I enjoy your site-thanks!
    Stephen

      1. Hi Stephan,
        Regarding the sticky pads, I first washed them with soap and water, allowing time to dry, then taking care to replace each pad to the individual key shaft in the same position from where it was removed. Many pads had a black stain on the bottom. Subsequently, after buffing/cleaning an individual metal reed (top and bottom) with cotton swabs and alcohol, I would remove the pad and wipe the bottom with rubbing alcohol, to assure the pad was clean.
        It is noteworthy, that I had difficulty getting volume out of one of the reeds in the high end. I had success with this reed by following the demagnetizing process prescribed by support@clavinet.com. Good luck.
        Stephen

  5. Good tips stephan, thanks. I used soap and water for the sticky pads too and found that there was some alignment that made a difference, I didn’t know about the demagnetizing, nice one

  6. I wanted to share my experience regarding a maintenance issue for the Pianet T which is also relevant to some other Hohner keyboards as well. The grommets or bushings under the individual keys dampen the action when played, such that there is no clicking noise when the keys are depressed. Sometimes, with age or exposure to heat or chemicals, the grommets swell slightly such that the keys do not spring back into place when they are depressed. Using my experience tinkering with old British automobiles long ago, I found that the Pianet grommets can be conditioned by swabbing them with automotive brake fluid. It is important to use a brake fluid that is compatible with natural rubber. The keyboard assembly must be removed by unscrewing the six machine screws on the bottom side of the case. Using a cotton swab, I applied brake the brake fluid to the grommets for the keys that were problematic. The keys immediately responded to the treatment. It is noteworthy, that when reinstalling the key assembly, it is necessary to gently torque the six machine screws until they are snug. Then check the keys for playability. If say, the base keys are not producing a sound, then torque the machine screws at that end of the keyboard until the keys play as they should.

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