So based on you hypothesis , one big un, better than 2 small un's , I'm assuming Torods ..?
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Yep, go for the single big 'un. But toroids have maybe 10X the capacitance to mains of the other types, at equal VA ratings. So if the bigger amp requires a toroid, that could be part of the reason the bigger amp doesn't sound so good.
Very, very few amplifiers are non-toroids today , even the expensive shiney ones, is this xtra capacitance really an issue...
Pros vs cons, how does it affect the sound ............. ?
Pros vs cons, how does it affect the sound ............. ?
Hi,
Leakage is unavoidable, however magnetic coupling at high (RF) frequencies is minimal due to eddy current losses in the core, so what remains is capacitive coupling. And that is something that can be readily addressed using traditional transformer design techniques.
No, it has a spec for leakage current however, that forces certain design approaches that as a side-effect minimise RF leakage.
It is however possible to improve on this too.
One may also employ additional RF filtering, though this is usually only operates above a few 100KHz, leaving a wide open door for some of the most pernicious stuff.
R-Core, LL-Core and Double-C Core transformers allow for example a much more thorough optimisation than EI, M or Torroid transformers.
As for using two transformers, while high HF frequency gunk is not amenable to improvement using two generic transformers, Low RF gunk can be fairly successfully cancelled using suitable arrangements.
Ciao T
Leakage is unavoidable, however magnetic coupling at high (RF) frequencies is minimal due to eddy current losses in the core, so what remains is capacitive coupling. And that is something that can be readily addressed using traditional transformer design techniques.
No, it has a spec for leakage current however, that forces certain design approaches that as a side-effect minimise RF leakage.
It is however possible to improve on this too.
One may also employ additional RF filtering, though this is usually only operates above a few 100KHz, leaving a wide open door for some of the most pernicious stuff.
R-Core, LL-Core and Double-C Core transformers allow for example a much more thorough optimisation than EI, M or Torroid transformers.
As for using two transformers, while high HF frequency gunk is not amenable to improvement using two generic transformers, Low RF gunk can be fairly successfully cancelled using suitable arrangements.
Ciao T
Well I reckon balanced inputs are largely immune to common-mode induced sound quality issues, provided pin1 is properly terminated on the XLRs. Unbalanced inputs? - don't touch them - on big, toroidal-fuelled poweramps would be my advice. If you only have unbalanced ins, wide-band mains filtering would be the mitigating option. Problem is - with the heavy current demands of a beefy amp it becomes increasingly difficult to filter effectively.
Hi,
Most if not all that you find in the catalogs of Digiykey, Newark, Farnell, RS-Components etc.
As a counter-example, Plitron makes transformers (not all, but some specific ranges) that are distinctly non-generic.
Ciao T
Most if not all that you find in the catalogs of Digiykey, Newark, Farnell, RS-Components etc.
As a counter-example, Plitron makes transformers (not all, but some specific ranges) that are distinctly non-generic.
Ciao T
Hi,
This is only true for generic transformers. Ones correctly optimised for audio use may have much lower RF coupling than generic EI or related designs.
Ciao T
This is only true for generic transformers. Ones correctly optimised for audio use may have much lower RF coupling than generic EI or related designs.
Ciao T
actaully one "high end" amp I know of has EI mains xfmr in a cylindrical drawn metal case - because for a while toroids were precieved as "hi tech"
nowdays toriods are often cheaper than EI due to the material efficiency, lower shipping weight
nowdays toriods are often cheaper than EI due to the material efficiency, lower shipping weight
Hello T,
So 2 in parallel is better than one big un ..? 😕 what is plitron doing differently , bifilar wound ..?
Then you need to tell those guys with the trafo GB.....!!!😛
SMPS ... S.team M.y P.ower S.upply ..? 😕...........................😛
Oh the F5X guys? A quick look shows their spec has only the two secondaries bifilar wound. No problem with that - I was thinking you were talking about primary and secondary being wound that way. But I see they are specifying electrostatic screens - which are just dandy so long as your earth is clean 😉 I know mine isn't..... 😛
Hi,
Why? They probably are looking for the most efficient way to couple noise into their circuits, so they can hear maximum differences between interconnects and mains cables (note, minimising noise coupling does not eliminate differences, but it makes them a lot harder to hear... 🙄).
Switched mode power supply.
The way most (or as RAW would say Mosbunall) are implemented they are to audio circuits and audio devices what Fed-Ex is to packages... A trial not only of design and implementation, but also of faith.
Ciao T
Why? They probably are looking for the most efficient way to couple noise into their circuits, so they can hear maximum differences between interconnects and mains cables (note, minimising noise coupling does not eliminate differences, but it makes them a lot harder to hear... 🙄).
Switched mode power supply.
The way most (or as RAW would say Mosbunall) are implemented they are to audio circuits and audio devices what Fed-Ex is to packages... A trial not only of design and implementation, but also of faith.
Ciao T
Hi,
No, not as such. But two sufficiently identical transformers may be configured mechanically and electrically to cancel both some of the stray fiields and most of the stray capacitance (the more precise the match the better the cancellation, so generic transformers from really big industrial winders in the US and EU are better then eastern european and far eastern ones.
They have a website at Plitron, why not peruse it?
Thanks heaven, no...
That is a very good way to make a transformer with exceptional coupling up into the MHz range, which may make some sense (at least for bragging rights - my balanced output transformer goes to 15MHz - Hey mine goes to 22!) in audio, but zip in mains transformers.
Ciao T
No, not as such. But two sufficiently identical transformers may be configured mechanically and electrically to cancel both some of the stray fiields and most of the stray capacitance (the more precise the match the better the cancellation, so generic transformers from really big industrial winders in the US and EU are better then eastern european and far eastern ones.
They have a website at Plitron, why not peruse it?
Thanks heaven, no...
That is a very good way to make a transformer with exceptional coupling up into the MHz range, which may make some sense (at least for bragging rights - my balanced output transformer goes to 15MHz - Hey mine goes to 22!) in audio, but zip in mains transformers.
Ciao T
Because SMPS is the same steam engine rotating with thousand times higher RPM. In addition to low frequency ripples we need to filter as well high frequency ripples created by SMPS itself. I.e. in attempt to reduce weight ans size we create more problems that affect sound quality, unlike weight and size.
Like, in modern power plants nuclear reaction produces still the same steam from the same water. As the result, such power plants create more problems than simple steam engines.
By smaller I meant 25 or 50W vs 200W, of similar reasonable design.
I notice Self and Cordel don't exactly agree, so it was a very good tip to get both.
I notice Self and Cordel don't exactly agree, so it was a very good tip to get both.
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