Thanks Eric, I was just about to place an order with Chris, now there is more to add to it. Sounds like last time I ordered stuff. I've now looked though 3 pages of repair parts and done a couple of searches, but I still can't find the OPV fix it area on his site. Any part numbers I could use?

Mark

Just thinking about ideas..

Vibration is caused by mis-balance thus we can (a) reduce the initial vibration, (b) lessen the contact points or (c) convert the energy of the vibration to another form of energy (such as heat)
Noise can also be due to resonance - standing waves that reinforce or cause other non-connected bits to vibrate in sympathy.

Couple of thoughts:
a) balance the rotor shaft of the pump - just like garages do for your wheels when you have new tires. Downside is that this involves taking it to pieces..

b) reduce the contact points - audiophiles (like us but instead of taste they go nuts over hearing) use points (like pin points) to separate loudspeakers from the floor to reduce vibration.
This works for vibration which isn't going to cause physical movement as there's little to prevent sideways movement.

c) use of specialist damping rubber converts the vibration to heat. Engine mounts are a good example - the key is to get the right material. When the material is designed for heavier things (such as engine mounts) the material will be too stiff and the vibration will just be transferred. Materials for too lighter purpose mean that device would move too much with vibration possibly hitting the endstops (knocking).
For DIY this is trial and error.. for the scientific we're looking at the vibrations - taking FFT analysis and selecting the right materials to dampen the most powerful frequencies.

You could use steel beams to flex in sympathy but 180degrees out of phase.. thus cancelling out the more powerful frequencies too. This could be done with active electronics too.. although the less electronics close to water,steam and my coffee the better..

d) It could be possible to suspend the noisy bits too.. with dampening springs or oil cylinders too..

e) not having square 90 degree flat inside panels will help prevent the creation of standing waves in the internal space. Additionally FFT analysis would help identify the lengths between panels to avoid.
Adding acoustic dampening (such as suggested car engine bay damping material) will help too.

f) lastly - proper structural bracing will prevent panels vibrating in sympathy to vibration frequencies. Just how loudspeakers are braced to prevent the walls from creating unwanted frequencies.

It's also important to ensure there's no openings that would act as a 'port' for waveforms set up - just like the ports on loudspeakers.


*pats his Yew Harlech Castle speakers, Musical Fidelity A220 and Myryad MC100 CD player.. *

erics wrote:Mark -

http://www.chriscoffee.com/produc...expansionvalveseat

Be sure to ask them for an O-ring for the adjustment "screw" and lubricant.

I actually order one back in March when I ordered some other stuff. I'll get the O-ring on this order.

I've two tubes of lubrication (low temp and high temp) that should last until my kids inherit my tools.

Mark

Nickk1066 wrote:b) reduce the contact points - audiophiles (like us but instead of taste they go nuts over hearing) use points (like pin points) to separate loudspeakers from the floor to reduce vibration.

I believe, though I might be wrong, that the point of the "points" is to couple the speakers to the floor, not decouple them. In that world, the tighter the speakers are attached to the floor the more stable they are and the more stable the imaging is.

Ira

That's probably right.. I'm not a loudspeaker guru. Although that does question why the same is used for equipment stand and equipment shelves.

Same reason, you want all the equipment rigidly attached to something so it's less likely to be moved by the music and effect the sound. It's obvious why it might be a problem with Turntables, speakers and tube equipment, less obvious with other items.

This was sure simple, I should have done it a while ago. Replacement parts, lube, a chop stick with and a small crescent wrench and you're set. The old seat had a fair indentation in it. Cleanup nicely in citric acid and went back together rather smoothly. Adjusted with a blind filter (and while it had unheated water) to 9 bar, re-seat the silicon hose so it has no kinks and done. Probably took longer to take the case off and back on.



Edit: Added the after descaling picture.


The harsh braaaakkkkkk sound is now more muted. The new owner will be pleased.

Mark