[andyr]

Gentlemen,

I came across this idea over in AA.  It seems to me to have good science behind it?

Any comments?  Anybody done this?  Can anyone think of a downside?

Regards,

Andy

[Lost81]

Heh heh...

I done this for various components in my system, but I never heard a difference. It helps me sleep better at night though


-Lost81

[andyr]

Heh heh...

I done this for various components in my system, but I never heard a difference. It helps me sleep better at night though


-Lost81

Maybe that's just coz your ears are full of wax?  

Regards,

Andy

[Carlman]

I use teflon-coated glass bolts, doesn't everyone?  

I can't imagine this would make any difference for the AKSA's torroids.  However, putting a little ERS around the torroids lowered the noise floor a little, tiny bit for me.

-C

[Seano]

Steel bolts really just sing along don't they. But in an annoying way - much like those damn Idols. Better to be rid of them.

The brass bolts just don't have the cachet and look you need in high end.  It's just too cheap.

I don't use the teflon coated glass bolt as the glass tends to resonate just that little bit. A bit like tinitus really. And I can never get them tight enough (to stop that toroid dancing) before the they shatter....very annoying.

So now I've gone for the ultimate.  A lovely piece of highly polished and lacquered 10mm beech dowel and a similarily presented beech disc washer 10mm thick and 100mm diameter. The dowel/chassis and dowel/disc connections are made by hammering (using a soft felt hammer) specially prepared Jarrah fillets into slots cut in either end of the dowel.  Beautiful result and the sound is magnificent. Only cost me US$350 for the kit to suit two toroids.

Although I'm beginning to think I could've used sticky tape.....

[AKSA]

Good one, Sean.......  I really enjoyed it!!  And you call this Shine Mock Toroid Anti-resonators?

A little irony for AKSAphiles!  

Cheers,

Hugh

[kyrill]

brass does have a much more pleasant resonance frequency than steel. That is why steel clocks are not that popular. however to hear the difference of the toroid bolts is very questionable. It is just such a small piece of the resonance building of the amplifier and the most mass locked one as well the toroïds being the heaviest part.. To hear the difference, make the whole enclosure of brass including the toroids shafts and bolts.

but to me, even that would be 2nd choice

[Malcolm Fear]

Is this thread serious?
If so, then what about using hot melt to hold the buggers in place?
If not, then you got me!!

[AKSA]

Mal,

Indeed, Sir, Sirius.......

Hot melt is good.  Stops vibrations, eliminates microphony.....

Hugh

[Levi]

Toroids should be quiet.  It should not hum...I am more concerned about stray magnetic fields that large toroids emit.  Here is a good article about Toroids vs EL.  If you insisted, I would use titanium rods and bolts, as it absorb vibrations, are lighter, stronger and it's exotic!

[kyrill]

hi Malcolm
Why are you so surprised?

An amplifier is a piece of theory never perfectly expressed. The design may be perfect and whole, the expression of the design never, but is hindered by many many things that negatively influence sound's purity. (components parts which measures the same, but do not sound the same)

Enclosures are NOT part of the electrical design, but do play their hindering role.
the big no no's are RFI and EMI and mechanical resonances, which indirectly will initiate extra EMI.
And last the pollution in the current from the wall

metal enclosures will have a sound of their own and this will be measurable with sensitive equipment.  C37 theory (which does make sense to me) can predict this.
But first of all the listener must  be sensitive too. My father didn't care about hifi and he could not even discern differences when swopping R an L  with channels with classical music!!

[Occam]

Just visit your local hardware emporium. If a smaller operation, not driven out of busisess by the national megolemarts, the plumbing secttion will contain long brass bolts and nuts sold for afixing your water closet. Just the ticket. If a megalomart, you'll find them in the 'hardware' section.  Similarly, you'll also find polyethelyte bolts and nuts for the same purpose. Those plastic, non-conductive, non-resonant bolts also have the advantage of when some dumbass (me), props the metaliic lid of an amp on the top of the amp to work on it, and you inevitably tip it so it makes contact with the affixing bolt, it doen't make that dreaded 'shorted turn' and blow everything to heck.....

Levi,

Thanks for the reference on EIs vs Toroids.... but the arlicle is simply a reflection of the issuers own commercial interests. Yes, toroids do have substatial benefits in cost, low emissions, etc.... But what the article fails to mention is that toroids can make rather a passable output transformer, i.e.  their bandwidth goes substantially beyound the 50-60hz required for rectification purposes, and do little to stop noise on the powerlines.  Which is why folks spend oodles on powerline conditioners. A properly implemented EI core with shielding between windings (aka 'rectifier' transformers), non-concentric EI core transformers (especially U core transformers and double Cs), or R-Core transformers (made of Unobtanium for the hobbyist or small manufacturer), all address these powerline issues far more effectively. And the latter two also have minimal emmissions.

That being said, torroids will continue to increasingly dominate the market for their size and cost advantages.

[Lost81]

... you'll also find polyethelyte bolts and nuts for the same purpose. Those plastic, non-conductive, non-resonant bolts also have the advantage of when some dumbass (me), props the metaliic lid of an amp on  ...

I put a 2nd Nylon / plastic nut on top of the brass nut so that the shorted turn situation described above can never happen.


-Lost81

[SamL]

Why stop at the Toroids? I am using copper screw, nuts and washer for the  transistors on the amp pcb. Not sure if it make any different since I've been using it on day 1.
The good thing about copper - they don't rust, they are none magnetic and they have good heat transfer.

Have fun,
Sam

[Gordy]

Lost 81 -  If your nylon nut is truely nylon, you'll want to replace it sometime soon with a polyethylene or polypropylene nut, as per O.  Having spent 30ish yrs. in polymer/textile research, I'd be wary of nylon's brittleness and tendency to self distruct, which will only get worse over a relatively short period of time.  The poly's are 'soft' and will last a coupla centuries

[Seano]

After concepts involving brass, copper, titanium, timber, gaffa tape, hot melt and even some fancy plastic nuts and bolts I've just realised the perfect low tech/high art solution to toroid fixing.

Some nice cotton string with an artfully made knot.

Knots are pretty.........

[AKSA]

Ribbon, Sean, s'il vous plait, pink ribbon........

Hugh

[jules]

SEAN:. A lovely piece of highly polished and lacquered 10mm beech dowel and a similarily presented beech disc washer 10mm thick and 100mm diameter. The dowel/chassis and dowel/disc connections are made by hammering (using a soft felt hammer) specially prepared Jarrah fillets into slots cut in either end of the dowel. Beautiful result and the sound is magnificent.

Maybe there should be a prize for the ultimate high-end irony amp. Sean's fasteners are a must but clearly every single component should be either gold, wood, a recently discovered rare element or some combination of the three.

Almost everything about amp evaluation is delightfully subjective but surely in this case (torroid bolts/torroids) the test is simple. If the amp is on with a source connected but nothing playing we should hear ... silence![presuming the signal is "on"]. Of course there may be different qualities of silence as in "What is the sound of one hand clapping?" and I can hardly wait for the debate on this.  

Jules

[Lost81]

Lost 81 -  If your nylon nut is truely nylon, you'll want to replace it sometime soon with a polyethylene or polypropylene nut, as per O.  Having spent 30ish yrs. in polymer/textile research, I'd be wary of nylon's brittleness and tendency to self distruct, which will only get worse over a relatively short period of time.  The poly's are 'soft' and will last a coupla centuries

Ah,

Thanks for the tip about the short life of nylon fixtures., Gordy.

A point I should have clarified, the Nylon nut  performs no structural / binding duty. All it does in my case is cosmetic (or maybe psychological reassurance for the truly paranoid). I replaced the steel mounting bolt, nut and washer with brass equivalents, and then a single Nylon nut sits on top of the brass nut. The chassis lid measures about 5 inches above the top of the toroid bolt. The U-chassis and the lid, rear cover are made from 12 gauge steel; the face plate is made of 3/8" thick aluminium. The entire structure is strong enough for me to sit / stand on top without it flexing--so the chance of the lid coming into contact with the brass bolt of the transformer is rather low...  

Drilling holes in the chassis is a major pain though

Actually, I also replaced ALL semiconductor-to-heat-sink mounting hardware with brass (e.g. mounting bolts for most of the transistors, apart from the NPN, PNP pair). If an improvement is desired by the substitution of ferrous hardware with non-ferrous equivalents, I would hazard to guess--in my unschooled-in-EE opinion--that an improvement is more likely to be found in that tangent.

For what it is worth, I compared the older Harman Kardon Signature Series amplifiers (made in USA / Japan) vs the current made-in-China models and noticed that the former employ copper screws / nuts near the signal paths / electronics. The current, much cheaper, HK models use generic galvanized steel hardware everywhere.


-Lost81

[jules]

Lost 81:, I also replaced ALL semiconductor-to-heat-sink mounting hardware with brass

Brass, did you say BRASS Benny! Putting aside other debate about the properties of this substance,  there can be an unfortunate electrochemical reaction between brass and aluminium that leads to poor electrical connection over time. A white oxide deposit forms ...  not sure if it's Zinc oxide from the brass or Aluminium oxide.  There are some auto fuses available in aluminium that gradually become non-conductors when used between brass connectors. Copper sounds safe though.

Jules