Dmance said Apparently tapping on the circuit board can be heard . . .This never occurred to me. Have you tried this and heard anything? (as opposed to shaking the entire DAC)
You can easily see the current produced by a MLCC (surface mount cap) on a scope when you tap it. They are piezoelectric. Any capacitor whose geometry isnāt very well constrained can also act as a mic (condenser mic?): most probably electrolytic caps (or non-surface mount caps on legs.) This is also true of inductors, but they can be built to flex less without messing with their inductance (much.)
On the other hand I donāt use any MLCCs in the audio path (mostly for digital bypass, etc.) And I donāt use aluminum electrolytic caps except in power supplies that which arenāt powering analog circuits (there I use solid polymer caps which are much more stable and non-piezoelectric.) One of the advantages of surface mount boards compared to thru hole boards is that the components are much more mechanically stable and hence will be less microphonic.
That doesnāt mean that isolation canāt make a difference in the DS, but itās less likely to be needed for the DS than by most other components of audio systems.
Ted, if I had a Power Base under my DS, and another under my P10 - would your gut feeling perhaps be theyād be better utilized under my BHK 300ās? [which are currently sitting directly on a tiled floor].
All of these things are empirical and personal preference. Iād check the weight limits on the Power Base and Iād try it both ways. The BHKās are heavy enough Iāve got to wonder how much vibrations in the room might affect them.
Great thread guys, some good info.
Thanks.
Ted, ignoring the two aspects you mentioned:
- the effect that better ss equipment is possibly resonance optimized regarding their semi conductors anyway as you did and therefore less sensible
- the weight effect of most chassis of better components which makes them less sensible to acoustically caused resonances
In theory assumed now resonance would come from its own transformerā¦
- imo then decoupling would be contraproductive as resonances then stay in the chassis
- coupling would be helpful, as resonance from transformer through board would be hard connected by the board screws to the chassis and from there deducted to the base
- imo then it must be avoided that the vibration of the chassis would reach the semi conductors. This could be done best if the cirquit board itself would be decoupled from the chassis and resonance from chassis would be coupled/deducted to the base, but it possibly also works more or less even if the board is hard conected to the chassis, even if then resonace would still reach the board
- imo then the whole component must be decoupled from the floor
- by no means it should be coupled to the floor
If all this would be true then an owner of such components, who knows where potential resonances come from, would have a simple rule:
- especially lightweight source equipment (no matter if external or internal resonance is the problem) should be coupled to the base (hard)
- power amps on the floor (assumed they have a quite solid chassis) should be decoupled/isolated (soft or hard) from the floor
- If someone has a resonance optimized and heavy enough source component as the DS, which is less sensible to pure acoustic waves, it can make sense to decouple it from the rack to avoid picking up remaining resonances coming from the floor through the rack into the component.
- people having a non solid or floor resonace picking or glass rack should probably better decouple source components generally
Of course all variations (even coupling a component to a resonating base) can make their own sound of preference, no matter whatās optimal in theory.
Ted Smith said You can easily see the current produced by a MLCC (surface mount cap) on a scope when you tap it. They are piezoelectric.That's wild.
This is a great topic and one Iāve explored a lot in the past, from mundane to wacky. From high end bling to a huge range of simple materials. Iāve come to the conclusion there are simple, cheap and effective dampeners so why not use them.
I now use small oak pyramids that I cut myself, after a friend made me a few to try. Iāve used them under all my electronics and even speakers. Itās surprising how well they work and even sound different when pointing up instead of down. The DS sounds better with them pointing down. I donāt know why and Iām not pulling your legs 
I particularly like the idea of Teds marble shelves. I use marble slabs under the rack and speakers on suspended wooden floors and also on top of components (with a soft liner to avoid scratches). Put a heavy paperback on top of a component - voila, the case just stopped ringing. I often think we ignore the engineering principles involved and go straight for the most expensive option. The main criteria here is to achieve a well-damped platform for our hifi components. I donāt want them to tune the sound, just to do their job and get out of the way. Like a good cable does.
I hate glass shelves and used to own some expensive ones. If you want to hear how a shelf will tune your overall sound through microphony, then just tap it. I sold all my expensive shelving and now use flexy shelving with laminated MDF. A friend prefers hardwood, others plywood, then thereās carbon fibre reinforced aerospace aluminium honeycomb. My point is there are many effective materials to fit your pocket or bias.
billg said I now use small oak tripods that I cut myself . . .Do you mean a pyramid, or something more exotic than this? If something other than a pyramid, can you post a picture? I am having trouble imagining what you might mean if it is not a pyramid.
Yes, I do mean pyramids, sorry for the confusion (I edited the previous post to reflect this). This one is 35x35x35 mm. I use larger ones for heavier components.
Very nice!
Thanks for further explaining.
Have you compared them to the many cones available made of other materials (brass, carbon fiber, etc.)?
Not in that exact shape but have tried points and blocks, of various metals: steel, brass, aluminium. I once had some of the carbon/aluminium honeycomb - it was used to replace the arm boards and sub-chassis on LP12s. Also carbon fibre pads, ball bearings, marbles, stones, various woods and ply, laminates, plastics, rubber, foams, bluetack, crystals, sand boxes, springs. And vibrapods, stillpoints, Iāve forgotten a lot of them.
IMO getting the system anchored to the ground is important. Next is dampening the cases. I use a weight (block of marble, wood, or book) on top and 3 wooden pyramids underneath to dampen the bottom of the case and avoid any tiny wobbles.
One thing I might experiment with more is placing screens around the rack to avoid inducing resonances in the components.
You certainly have covered the gamut. Interesting final choice.
billg, if you aim for perfection and have some spare money, try those:
http://www.thixar.com/files/datasheets/thixar_info__active_platform__silencer__en.pdf
I once had two of them and made various tests with different equipment. If you have those, youāre set, I think thereās nothing better, they were developed for electron microscopes initially. You can see by LEDās when they work, triggered by acoustic waves etc.
What I learnt from those tests was, that a lot of what we try makes different effects but is often not correct in terms of really killing/avoiding the resonances. This perfect solution is mostly less spectacular in its resulting sound, but after one got used to it and removes them again, it was obvious, that theyāve done it right. What I also learnt was that a lot of electronics (especially the better built) is not really sensible unless one listenes at insane levels.
I ended up, finding a cheaper sophisticated solution for my turntable that sounded very close to those platforms (which were great as reference) and very cost effective solutions for the electronics.
So if you want to know how āno resonanceā from the base and perfect resonance killing in the base sounds, try to rent one of them.
Cool, I used to work with electron microscopes. In NZ we had to locate the things away from fault lines.
It pays to start with the best platform you can (probably not) afford. The local supplier lists the Silencer as POA! Isolating goes against my principle of grounding, even though Iām sure each approach is effective in its own way.
In recent years Iāve become much more consciously seeking big bangs per buck. That supports some of my choices - like a P10
The thing is, this platform does not only isolate from downstairs, it also kills the resonances deducted from upstairs.
The opposite of isolation (deduction to the base/ground) only works if the ground kills those resonances and introduces no own. Exactly this does the platform. So you can couple hard to that platform if transformer vibration or acoustic wave caused vibration of light chassis is your problem.
Elk saidOne might guess this to be true, but SS benefits at least as much from high quality, effective vibration control as does tube equipment. Tubes are more influenced by large thumps/gross vibrations than is SS, but small vibrations impact both similarly.
</blockquote>I certainly have found this to be true with my tube AND solid state gear and have not skimped on, or underestimated the importance of, decoupling any of it.
One inexpensive tweak Iāve used to control resonance on MDF shelves with good results is sheets of Dynamat applied to the bottom of the shelves. Because it is the bottom of the shelf, you canāt see it from your seat. The resulting improvement in vibration control for your shelf is very significant and audible with whatever equipment you place on it. Iāve also treated the inside and bottom of audio component cases (amps, preamps, transports etc.) with Dynamat with very noteworthy improvements. Vibration in almost all electronic audio components has a very negative and audible impact on sound quality. Dynamat (strategically placed to not mar aesthetics) is a relatively cheap tweak you can add to your arsenal that provides outsized improvements for its cost.
-Jeff
Karl Salnoske saidHow did the Isopods work out?Ionson, thanks for the recommendation on the IsoPods. I ordered a set from The Cable Co, as I do have space in my rack for these, so Iāll let you know how it sounds.
According to UPS, they will arrive on Monday. They shipped from CA today and I assume they are coming ground, since I ordered 3 sets to take advantage of the discount.