I'm replacing all my pots with ...

You jest but that's how the Bridgewater Hall was built. To ensure that the Hall's carefully designed acoustic remains cocooned from all outside noise and vibration, the entire structure floats free of the ground on almost three hundred, earthquake proof isolation bearings. These sets of mighty steel springs ensure that there is no rigid connection between the 22,500 ton building and its foundations. In the Hall's undercroft, a forest of foundation columns, each capped with a cluster of spring units, create a mysterious silent world as compelling and dramatic as any of The Bridgewater Hall's more public spaces. Apparently it is so well isolated that when the IRA bomb went off no one inside heard or felt it.

Er so do we all have to rebuild our houses as well?

 

one of my previous bosses decided to have a house built with an observatory on top. in order to do this the supports for the observatory had to be seperated from the main house and isolated spereately as someone walking upstairs could cause the view through the telescope to blur.

pete,
no i've not ordered one and i won;t as they are far too expensive for what they are and i don;t have one of the pots mentioned in my kit.
i wasn't being facetious. i was just trying to make the point that it's a question of magnitude. my real point was don't knock it 'till you've tried it.
cheers


julian

 

... And this is your new place in Scotland you say? I thought you were a Hutter man.

 

Sorry, wasn't paying attention, I don't look here as often as I should

I used a spectrum analyser and this wonderful magic chamber I have at work that's good for warming mice pies, cooling drinks and has the biggest vibrator you've ever seen along with a power amp that makes a Krell look like a kids toy and has a PSU that makes Naim's look like the efforts of a girl

My view is that often things I can hear are at ridiculously low levels in normal useage and whilst many can be resolved given enough effort, sometimes upping the magnitude of the problem a little is easier than lowering the measurement noise floor, within limits.

So far there's been a good correlation between audible effects at normal levels and measured ones at elevated levels all else being equal. One has to be sensible, there are very real physical changes if you stick in silly vibration levels!

All this has done is added to my resolve to try and remove any potential source of problems wherever possible. Things like warm up can also be dealt with similalry through the use of better components, that change less with time. Not eliminated, but significantly reduced.

I now try to avoid certain types of components wherever practical, for a number of reasons, some mechanical, some electrical.

Andy.

 

Tasty are they? :lol:

The tests you've described though, we're talking high amplitude, lowish frequency vibrations then right? I guess it's perhaps not too surprising that this will have and effect, since there clearly will come a point where the friction of the volume pot will be overcome and you'll get a fluctuating volume setting.

 

I'd imagine you'd have to have your amp attached to the top of a pneumatic drill or something though

 

Not if yuo're attaching the source of vibration directly to the volume knob, as I assume was done here?

 

But aren't we more likely talking about the microphony/feedback effects of the knob/cabinet rather than micro-movements of the potentiometer?

 

Re: Mice pies

LOL - can't believe I typed that!

Not really.

It's simply a way of getting the actual vibration input to the system in a far more controlled fashion, it's still relatively low level.

If you put a hand on top of my power amp, whilst the system is cranked up, you can easily feel the vibration being introduced. But since testing at high levels in a domestic environment isn't such a practical thing to do, the chamber is a rather more elegant and easier on the neighbours, method. The levels I'm introducing are no higher than potential domestic ones.

The shaker is limited to about 15kHz, but this is more than adequate, in a domestic situation treble levels have far less energy than LF stuff, and are attenuated more by the house structure.

The effects are measurable in a number of components, some capacitors being probably one of the worst.

 

OK, in my defence I'm feeling pretty hung over at the moment, but here's a chance for you to all have a good laugh at me :NADowner: . When I read this:

I thought you meant a female toy... :duck:


Hmmm... any point even trying to make a sensible comment after that? Probably not, but here's a shot...

We're talking about sitting an entire unit on a vibrating platform, or in a vibrating chamber then are we? So, Andrew, you're talking about having heard/measured sonic differences to vibration in general, rather than specifically of the volume pot, as I'd understood from your first post?

Go on, humour someone having a bad morning and explain it to me .

 

I'll go easy on you Martin, in your delicate condition

In answer to your question I've tested individual components, as this is the only way to isolate the effects of different items.

Testing is only done on a final item as a means of seeing the benefits of the changes made to the unit as a whole.

Andy.

P.S. My boss has taken the digital camera, as I would have posted a pic of the vibrator for you.

It's about 1m wide and has a pneumatic suspension that needs to be pumped up - tee hee!

 

It sounds like you've done some really interesting tests there. If you do get the chance to post any photos or more details I for one would be very interested.

 

Well I just wanted to say Ive replaced all my knobs with these.

Its cost me just over two grand. The girlfriend says Im mad - I could have had a foreign holiday and 100 new albums, but what does she know.

Theres a certain ''wooden'' sound now that there wasnt before. Its sort of ''organic''. Beechy even.

When you press your nose very lightly against the wooden knobs you can tell they vibrate with a resonance frequency that actually CANCELS the existing resonant frequency of the product.

Its amazing how mother nature had this ability in trees all the time and only now audiophiles have realised how to cancel these damaging vibrations.

Ancient greeks used to call this ''byzantyflartyburst theory'' and its only just been picked up in recent months in quantum mechanics.

Ive contacted the supplier to see if I can get extra knobs to put on the bottom of the sofa. That way if I fart all of a sudden the resonances will be cancelled before they damagingly reach the floor and thus my hifi.

Its a complex world this hifi business, and Im glad of all the things I can do to make it sound so much better.

So stop knocking things you havent tried right, cos thats just daft.

 

Chris,
I discovered that after a good sprout session my flatuence was exciteing a room node in conjunction with the speakers (in particular Frank Zappa's Your an Asshole). After months of DBT with various anal isolation devices i settled on the RA oak cones, i can highly recomend these. The beuty is that you dont put them under the sofa (spoiling the aesthetics of your furniture) but instead insert them in the offending orrifice.
Also of note, but not quite to my taste was the RS232 remote controlled inflatable butt-plug, i believe this had a similar effect to a pneumatic isolation device. I didnt fully conclude the testing of the RS232 butt-plug as i found the jumbo oak cones to be a much more fulfilling solution.