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Q's about tonebar 'front' and 'back' springs and spring tightness

Started by kevinplaystheblues, September 19, 2024, 07:49:06 PM

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kevinplaystheblues

I am in the process of replacing the screws and grommets of my MK1 73. I have some questions:

  • I ordered a number of the stronger bass springs from vintage vibe - these are referred to as 'back springs' by VV. I assume this means the spring furthest from the pickups - is this correct?
  • I had been carefully keeping the springs in the same positions/on the same bars as they were originally, but last night there was a small accident and about ¬30 tonebars went out of order and some lost their springs. This has caused me to pay a bit more attention to the tightness of the existing springs (when referencing the keys that weren't jumbled up!). I am noticing that my treble keys have two different springs - a light spring at the 'back' and a heavier spring 'at the front'. This heavier spring seems to be the similar to the mid range springs, if not the same. I've never seen any reference to differential springs before, and based on the above, where the heavier bass spring goes at the 'back' the orientation of the light and heavier spring seems at least 'backwards'. Any advice here?
  • Is there any guidance on general tonebar spring tightness? It seems pickup alignment can be achieved across quite a range of turns, ie: I can achieve alignment, then tighten each screw a half turn, and have that alignment back, and another half turn and so on. I realised that I had tightened my new bass springs to the point they were completely compressed, which doesn't seem like a good idea to me, but I imagine too loose would be a problem, too. I've attached a photo of current state, noting I have not done fine adjustments top to bottom yet.

Jenzz

Hi :-)

The drawings are right, this is the way its supposed to be.

You should have 3 different sort of springs:
Stiff (mostly marked with yellow spray paint) on both tonebar screws for the bass range
Medium (plain) on both tonebars in the midrange up to the right harp bracket and 'pickup-side' of the treble tonebars
soft (mostly marked with blue spraypaint) for the 'Keyboard-side' of the treble tonebars.

In some cases, the first 4 tonebars right from the right harp bracked will have medium springs on BOTH screws. The intend seems to be because these 4 tones use the somewhat softer white hammertips.

The average distance between the bottom of the tonebar and the wood of the harp should be 9,5mm (= thickness of the square tine bolt). Looking at the pic, most of them seem to be too low.

Jenzz
Rhodes tech in Germany
www.tasteundtechnik.de
www.spontaneousstorytelling.net

VintageVibe 64 ACL + Type 120 (DIY MXR MX-120 clone) Env. Filter, EHX SmallStone, EHX NeoClone

Adams Solist 3.1 Vibraphone

In the Past:
Stage 73 Mk1 (1977)
Stage 88 Mk1 (1975)
Stage 73 Mk2 (1980)
Stage 73 Mk2 (1981 - plastic)
Suitcase 73 Mk1 (1973)
Suitcase 73 Mk1 (1978)

kevinplaystheblues

Quote from: Jenzz on September 20, 2024, 12:45:30 AMThe average distance between the bottom of the tonebar and the wood of the harp should be 9,5mm (= thickness of the square tine bolt). Looking at the pic, most of them seem to be too low.

Jenzz

Thanks mate, that's a very helpful rule of thumb....but how will I align my list tonebar when I have used up all my tine blocks?! ....jokes, I have *almost* the right thing for the job.


kevinplaystheblues

Quote from: Jenzz on September 20, 2024, 12:45:30 AMIn some cases, the first 4 tonebars right from the right harp bracked will have medium springs on BOTH screws. The intend seems to be because these 4 tones use the somewhat softer white hammertips.


This probably saves me getting on my hands and knees looking for light springs...as I get to the last ten or so tonebars I was thinking I was missing a few!