Why do some keys sound "plunky"

[camaro guy]

I have '79 Stage piano that works pretty well, but some of the lower keys have a plunky, metallic tone underneath the correct sound.  That's the closest I can describe it in words.  The piano itself was in beautiful condition and shows no evidence of abuse or being stored outside.  No evidence of case warping and all the keys line up nicely.  The problem area starts with the C below middle C and continues most of the way down that octave.  The rest of the piano sounds very nice.  Here's what I've tried so far without success:

1.  Replaced all grommets and screws with the Vintage Vibe kit.
2.  Replaced all hammer tips with the Vintage Vibe kit.
3.  Unscrewed the harp and tried moving it forward and backward to adjust the strikeline as well as up and down with different shims (no help).
4.  Adjusted the escapement of the affected keys with the screws.
5.  Removed and re-tightened the tines to the tone bars with a long-handled socket wrench.

What I found is that if I play the key once and push with some force, it sounds good, but if I play quarter or eighth notes, the later notes have the plunk.  Also, if I don't hit the key with much force, I get the plunk, even on a single note.

If I've missed something or if anyone here has come across a similar problem, I'd be very grateful to hear how you fixed your problem.

[pianotuner steveo]

Is the key dip too shallow?

[camaro guy]

Is the key dip too shallow?

I'll give it a shot.  This is increased by removing shims from the front pin?

[Ben Bove]

It would be great if you could have a video or audio example.  There are a few different problems that could result in some clunky-ness.

It sounds initially like a possible double-strike problem.  Can't say exactly without a listen but would like to help

[pianotuner steveo]

If you have paper punchings (you called them shims) under the felts at the fronts of the keys, and the keys are bottoming out, then yes, remove some of the paper shims. That would likely mean that someone altered the piano at some point and made the dip too shallow. The keys are not supposed to touch the felts in a Rhodes as they do in a Wurli or an acoustic piano.

Measure the dip first befre doing anything else. It should be 3/8" - 7/16". Press one white key down and measure the distance it drops compared to a neighboring white key.

Refer to the service manual for the Rhodes method of setting the key height and dip. It s done differently than conventional pianos.

I prefer the traditional method, but most people want it done the way it was originally.

[Max Brink]

I agree that double strike is likely. Otherwise it may also be an issue with the strike line for the particular note or a loose hammer tip that isn't firmly attached to the pedestal. All of those can cause thump-like sounds.

For the strike line sometimes raising or lowering the particular tone bar can sometimes create much better tone. If you can isolate it with a hammer tip (try swapping an adjacent hammer arm with a good sounding strike) then swap out the hammer tip.

[camaro guy]

I went back and pushed the escapement down on the affected notes and got rid of most of the plunkiness.  Changing the strikeline didn't help, though.  I also think that part of it is my playing - I think I've been too weak in pushing the keys.  No need to abuse it, but playing with a bit more authority also helped a lot.  I've been used to changing volume on an acoustic piano by my touch.  I have to remember that on a Rhodes, that's what the volume knob is for.  :-)

[camaro guy]

I stumbled into a "fix" for this problem today.  If I run through an eq with everything above 2K zero'ed out, all the plunkiness is gone and the tone doesn't suffer (at least to my ears).  While this fixes the immediate problem, I'm really curious as to whether something might be messed up in my tone control.  Should the Rhodes normally filter out frequencies > 2K or so?

[eki70]

Out of interest, what kind of amplification/speaker combination are you using? If running through a mixer/PA, could one explanation be that a full-range system makes the plunks more audible than for example a tube guitar amp?

[camaro guy]

I've tried a range of amps.  I've used a couple of guitar amps (Fender Princeton Chorus and Vox ADVT50) and a bass amp (Crate BX-100).  The bass amp sounded much better overall, but still plunky without the eq.  Interestingly, the plunky keys are from 1 - 23, which corresponds to the first hammer tip type.  I don't know if that has anything to do with it, but it's an odd coincidence.

[bourniplus]

A video might help to troubleshoot your problem.

Are you sure you put on the right kind of hammer tips for notes 1-23?

[Max Brink]

Are you reaching a firm stop-lock position when the key is depressed? I was looking back over this thread and it night be worth revisiting the key dip question.

Also, is there a firm connection between the bass hammers and the pedestal locked into the right angle where it should? Every once and a while I'll find plunking when the hammer tips are not firmly glued to both surfaces.

EQ should be a last resort.

[camaro guy]

Thanks to everyone for their replies.  I've never tried shooting a video, but an audio recording would be no problem.  Is there a YouTube-like place to upload just audio? 

I'm afraid that I'm not exactly sure what "firm stop-lock position" means.  In terms of hammer tips, I had the plunkiness problem with the hammer tips that were on the piano when I bought it, and installing a new set of VV tips didn't change anything; the sound was exactly the same (THAT was a disappointing discovery).