RFI can be super-imposed or "ride on top of" other AC frequencies and also DC. Better designs make use of "bypass caps" in the power supply, which should drastically reduce the effects of RF on the AC lines. Some designs, such as Bryston's, are supposedly insensitive to power cord changes.
If you study the design of Bryston products, they make use of the aforementioned "bypass caps" across the rectifiers. This serves two purposes. First of all, it helps to reduce the amount of RFI that finds its' way into the circuitry and it also helps to smooth out some of the ripples and harmonics generated from within the AC to DC rectification devices themselves. As such, this is a beneficial approach that is desirable. Sean
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PS... I am not suggesting that Bryston products are the best available. I am simply commenting on a single aspect of their design. I chose this brand as others here have commented on their lack of sensitivity to power cord changes and i was able to verify the design of their power supply via schematics that are published on the net.
As i've mentioned before, there isn't anything that one can build into a power cord that shouldn't already be built into the component that you're connecting it to. The bigger the difference a power cord makes, the more under-designed that component is. In this respect, i would say that Bryston is at least as good and probably better than most products out there. |
Sean, this is onother information, I need to know,
It make sense, nice to see you back. |
So basically, the benefits of a garden hose stuck in yer amplifier will depend on the internal architechure of the amplifier?
In essnce, some gear benefits highly from high grade PC's and some might not? |
Slappy, you're catching up! |
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Sean:
It certainly is refreshing to hear a voice that listens
first to theory and engineering, and sometime FAR later
listens to the marketing rhetoric.
Good to see you back on AG. |
Dats right,
Had ta kickit low style in tha hizzie cause some haters were tryin ta get my chedder cause they be spottin my dope kicks and be frontin like they are down with tha thug love in da west si-ee-dah.
So my peeps hollared out a niz-ine and spotted up dat follio's ride while droppin da capshells.
In da end tho hatas be gettin dissed, i be gettin missed, homegirl is already pissed, cause some hoochie thought she could play a playa by mackin my dogs chuggy.
So im back in the swing of things now and look forwared to working on my stereo system.
Peace :) |
Sean,
Thanks for your post. For some reason, however, my Bryston 7 BSST sounded a bit more "dynamic" and "fuller" (best I could come up with, sorry) when I replaced the stock chords with the more substantial JP Cables Maximum Gold models.
I don't think it was purely emotional because I switched back-and-forth over a period of a month. (Maybe it's that voodoo business that's going around.)
I have enjoyed your posts on this subject (and others) and learned a great deal. |
Thanks for the kind words. Believe me, i had a helluva time "staying away" from Agon. I still don't like the way that some things are being handled, but as i myself mentioned before, it is their site to do with as they please. Love it or leave it and evidently, i love it more than i want to leave. Besides that, i'm tired of arguing with people at AA and would rather just share ideas : )
As to Vvrinc's comments, i don't know if Bryston uses the same exact design / lay-out for all of their various models / power supplies or not. On top of that, it is possible that you were experiencing voltage sag with the stock cord that you weren't with the heavier aftermarket cord. I do not know the specifics of the stock Bryston cord and the aftermarket cord that you used, but this could account for a few things. Since the sags would primarily take place on transient bursts or long duration, high current demand passages, the dynamic contrasts of the amp would be the most likely to demonstrate such a problem.
Having said that, bare in mind that wire gauge is not all there is to building a "good" power cord. Obviously, voltage sag is one aspect that is measureable but my personal thoughts are that there are a lot of other factors at play here. Starting off with a heavy gauge cord that is of a low inductance design will get you most of what you are looking for in a power cord. If you can find those attributes at a reasonable price, go for it. Chances are, you won't be sorry and it will be a step up from a stock cord. Sean
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Hi Sean. I too find AA difficult...as well unnavigable at best. Just wanted to chime in with my firmly-held belief that very-low dielectric involvement insulation (DISCLAIMER: like the Teflons used in my DIY PC Kits) is in most instances more important than huge amonts of copper, except of course in kilowatt monos.
Indeed power supply design is always the overriding factor. Yet even in (supposedly) highly-sophisticated supplies one can hear improvements in upper octaves transparency and staging depth when changing to a PC with superior insulation. Air and/or Teflon are simply better than cheap plastics/rubber/cotton, etc. By this statement I do NOT mean to condone the current over-spending for PCs, as you probably know, as PCs of the best materials should still be VERY affordable, after all. |
FWIW, I too am of the belief that after a certain point, the gauge of the wire has little influence. I also agree with the 'guru that even with the best power supply designs, anything that the cord can pitch in with respect to shielding or superior insulation materials. I also share his opinion that good PC's can be affordable (I made my own as well).
However, one thing that nobody has mentioned yet is the importance of good connectors on either end of the cord. Loose electrical connections are noisy, and don't transfer energy efficiently. Over time, these loose connections can get pitted and coroded, further degrading the transfer of electrical energy, and therefor the performance of the equipment being powered.
On a side note, ditto the sentiments regarding AA, especially the navigation part. I have always found A'gon more user-friendly, at least as informative, and certainly more civilized (except when somebody starts bashing tubes, then the fangs come out).
Mike |
Yes, connectIONS are important, but connector cost is often NOT correllated with performance! I use an affordable all-black Leviton AC male, for example, that outperforms its, and other, 5266's simply by the ABSENCE of the unnecessary cheap-dielectric wire guides that as well only use ONE SIDE of each T-shaped screw-clamp. In a multiwire/conductor cable (like star-quad or more), being able to evenly distribute the mechanical load symmetrically across the two sides of a T-shaped screw-clamp is a great advantage. And of course air is a better insulator than the $$ plug's nylon "guide". Since the brass contacts are identical, it's a winner. Similarly some folks spend too much on fancier-sounding IECs than necessary. The fairly-new affordable Schurter with all-brass screw-clamp terminal "beds" is a clear winner...especially if you slightly bend its readily-accessible spade-leaves toward parallel for more surface area of contact. (Don't do this to the ground, though, as you'll lose too much stiction with a loose component IEC female.) Nothing like hardwiring, guys.... |
