Here is a Premier 751 Vibraphone in a bit of a state, sent in to me to be made usable. Whenever I get an instrument like any of the Premier 7 series vibes, I always ask how the instrument used. This is because I have invariably seen the same model instrument many times before and have a good knowledge how they break. For example, the resonators on the 751 (or 701) vibraphone are fixed in two points at the low end, but at the high end there is no mechanical fixing, they simply rest on a transom. Using gravity is fine on most instruments for holding resonators in place because of their mass, but to then expect gravity to be a structural component of an instrument’s design and resist the much larger forces of motion and mechanics is simply ridiculous. And yet I see it used all the time, by every manufacturer and even overlooked in most renovations, which is how I have come to the conclusion that either nobody knows what they are doing, or that they are making things to fail to generate future income.
So to get back to this vibraphone, what has resulted is that when viewed from above, the frame has become rhomboid and when viewed from the front it has become trapezoid. If this frame distortion is ignored, the instrument will eventually just die, but with a simple sub frame the problems can be rectified. The frames I make have a life time guarantee, that’s my lifetime, not the life time of a product (which is up to the moment it breaks), so essentially they are extremely strong, strong enough to be used to pull a frame back into alignment as opposed to just retaining it in a distorted shape. Alignment of an instrument is very important for longevity, especially when there are moving components like on a vibraphone.
Everyone has a method of working, I start at both ends; from the ground up and the top down. What I am doing is working from the known points and verifying that those datum lines are correct. By the ground up I mean the contact with the floor, and the top down is the players interaction. In order to get fit a subframe to Premier vibes it is necessary to remove the two lower transoms, this makes it easier to also fit new casters.
Another constantly recurring problem with most percussion instruments is the material used to make the frame out of. Aluminium is used because it is “light weight”, but it only saves weight if the component is designed properly to overcome its low strength, mostly manufacturers just use more of it to add strength which is expensive and heavier than steel. Premier have deviated from the norm and actually used an extrusion; all the little grooves massively increasing the components bending resistance. Where the casters are bolted on, Premier have even used the plastic end cap as an internal support to the tube to resist the tube crushing and wear on bolt holes. In fact on most of the Premier vibraphones I see, it is the steel note rails and not the aluminium that is visibly bent.
However, the problem I encounter when modifying an aluminium frame is holding the fixings in place. To simply drill a hole and put a steel bolt through is never going to last; the aluminium extrusion will compress introducing a gap, therefore movement, and therefore wear on the holes thus rendering the whole exercise a complete waste of time, effort and the customers money. This means that I have to make a whole range of subsidiary components to support the bolts which will affix the proposed frame modification, which takes careful thought, time and always some compromises to keep the ultimate cost down.
The final subframe looks very simple, but it is doing many jobs: It holds the four casters parallel to the ground, fixes the width of the instrument, pushes the back two casters outwards to remove the frame twist, pulls the frame back square so that the note bed is horizontal, and holds it there during use of the damper pedal, and finally it increases the structural strength of the whole vibraphone so that it can withstand being wheeled around the buildings where it lives and is played. Like all my solutions, I use the minimum number of wing nuts to reduce the players time when setting up or packing down; three nuts and the legs can be folded away. The only downside is that one has another component to carry, but only because I retained the original pedal bar to save money.
With the frame problems now rectified I turn my attention to the next area, and look at the damper bar. It is immediately apparent that there is a problem – one of the leaf springs has broken. They always break, the constant bending work hardens the steel making it increasingly brittle until it snaps. The thread in the plastic ball is stripped, and the ball is cracked. The felt is more like carpet than felt, and the bar itself is bent. Each of these problems can be repaired, but then you would still be left with an ineffectual damper system which has components that are prone to failure, and that is not what my customers want back as a completely refurbished instrument. Additionally my aim is always to return instruments that will give years if not decades of use.
Having made a new damper system recently on another vibraphone (1260: 701 vibe damper (pt 2)), it was a good opportunity to repeat the process. I am constantly reviewing how I do things and looking for improvements, or developing methods to make the process quicker and cheaper without compromising quality. This was no exception, I tweaked a few aspects of the design and the construction but essentially it is the same as before. By increasing the width of the bar I have increased the surface area of the note in contact with the felt which results in much better damping. On an operational level, because the bar is hinged, and because I have designed it, there is minimal horizontal travel as the bar travels through its arc. The original design, because of the leaf springs, shifts left to right as the bar is pulled down and up; this lateral movement not only drags the notes around, but from a musical perspective it creates woolliness in the damping.
The original Premier damper system, is an ugly, inelligent and inefficient design solution that I would never have been happy with, but that is essentially my gripe with most instruments and all of the brand manufactures; they put into production badly designed products which are then made cheaply and badly, and endorsed by high profile musicians. Even worse, a high profile musician “designs” and markets a new instrument. Whilst musicians know when they are playing on a nice instrument, they generally have very little idea as to what makes the instrument good besides the obvious. I have spent decades learning about materials, mechanical engineering, acoustics, etc, and I have more questions than ever. It’s like the drummer that wants to be a front man – the musician that wants to make instruments. Why don’t they start with something easier to understand and simpler to make like a violin or a guitar for their private enjoyment?
This repair continues in 1279: Premier 751 (pt 2)