Toroids better or cheaper?

[bleeding ears]

Hi guys and gals,

After some discussion at Club Rotel I thought it would be good to get some more opinions on the above subject.

Do toroidal transformers really contribute to a better sound quality or are they just cheaper to produce.

From what I have read, apparently they are very efficient compared to the traditional styled amp (called Op amps I think) and they can produce a lot of power for their size, however is the toroid amp used due to the lower cost per watt? or does it really sound better?

Anyone????

[Karma]

HI Ears,

to·roid ( P ) Pronunciation Key (tôroid, tr-)
n.
Mathematics.
A surface generated by a closed curve rotating about, but not intersecting or containing, an axis in its own plane.
A solid having such a surface.
A body having the shape of a toroid.

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[tor(us) + -oid.]
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to·roidal (tô-roidl) adj.

Source: The American Heritage® Dictionary of the English Language, Fourth Edition
Copyright © 2000 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.

toroid

n 1: the doughnut-shaped object enclosed by a torus 2: a ring-shaped surface generated by rotating a circle around an axis that does not intersect the circle [syn: torus]


A toroid is the mathematical name given to the geometrical shape we commonly know as a doughnut. Its use in amplifiers is generally confined to power transformers. A toroidal transformer has a doughnut shape. It is formed by the way the primary and secondary windings are curled around a central, circular iron core. They are magnetically efficient and therefore are smaller than a transformer of conventional design rated at equal power capability. Thus, they are cheaper to build and require less real estate on the chassis.

But those are not the only advantages they have when used in hi fi amps. They are also very quiet. Conventional power transformers often emit a 120Hz buzzing sound even if very high quality due to the iron core plates vibrating against one another. Toroidal transformers are essentially silent.

Taken by itself, a toroidal transformer in an amplifier is not a mark of quality though it is promoted as such. However, the world is heading quickly to toroidal transformers due to cost and space savings. I do not consider them to be a significant sales factor unless the equipment is placed close to the listening position where the slight buzzing of a conventional tranformer might be noticed.

Sparky

[bleeding ears]

Karma, from what you have said, it appears there are advantages of a toroid over an Operational amp or Op amp.(if that is the correct term)

Just to clear up any confusion for others,

I am definitely talking about transformers used in Hi Fi gear (eg Rotel) and not donuts, although I do like donuts a lot!

Pete

[Karma]

HI Ears,
You are comparing apples and oranges. A "Op Amp" is a class or type of amplifier. The operational amplifier is an amplifier topology that has a specific technical definition. It has nothing to do with with power supplies. A power supply that uses a toroidal transformer implies nothing else. It's just a transformer, period. And, the power supply in an amplifier is considered a sub-system that is essentially separate from the amplifier itself. This is not totally true because there are interactions and the amplifier cannot be designed without considering the power supply, But, functionally, the power is supply is separate.

A power supply which uses either toroidal or conventional transformers can be used with any amplifier topology. By itself, a toroidal transformer carries no additional implications that influences other aspects of the amplifier design.

Thus, to say that such and such amplifier is a toroidal amp is a non sequituer. It's accurate to say, for example, that an amp is a Class A design which also uses a toroidal transformer in its power supply.

To use the term "Op Amp" to describe an amplifier can make some sense though it is not usual. Many modern amps do use the Op Amp concept to implement portions of the amp especially the global feedback loop. However, no amp uses the Op Amp in a pure form from the front to the back. No tube amps use Op Amp design elements.

I can't take this explanation much further without you understanding exactly what an Op Amp is. If you are interested, google Op Amp and you should find conceptual and technical information that will add to my explanation. Op Amps are definitely interesting beasts.

I hope I'm making this clear.

Sparky

[bleeding ears]

Sparky, thanks for the info, your knowledge of this stuff is obviously way beyond mine.


The main reason that I wanted to know if toroidal transformers are better is that from what i have noticed, there seems to be a trend towards the toroidal type transformers eg in the Rotel pre amps Rsp 1066 (not toroidal)
V's Rsp1068 (toroidal) and I wasn't sure that this equates to better sound quality at the speakers.

Apparently there is a sound difference with these two above mentioned pre amps and it makes me wonder if this sound difference has been brought about by the use of the different transformers.

Aparently the 1066 pre with the non toroidal transformer has a warmer sound comared to the 1068 which has been described as sounding a little different to the 1066.

This difference in sound may or may not be due to the different transformers used in each unit, however I am not aware of anything else that is different within these units.

So this all comes back again to what I was wondering.

Are toroidal transformers used because of their sonic qualities or is it because they are power efficient and possibly cheaper watt for watt compared to the other transformers used?

Pete

[brac]

The transformer in a pre-amp is used to reduce the voltage from 120 to ... whatever they are running on thr circuit boards. Since there is no audio signal going through it. I can't see how it could effect the sound. All things being equal voltage wise. Now the use in a power amp could be very different....
I think...

[Karma]

HI Ear and brac,
Do not misunderstand. A great power supply desgn is essential to good sound. It makes no difference whether we are talking about pre or power amps. Obviously, there are major differences between the power requirements of a pre or power amp. But within their performance envelopes, both are crucial. The type of power transformer is irrevalent, quality wise. I think I already said this.

Sonically, the type of transformer is not important. The capacity of the transformer is. I doubt very much that the differences in a preamps signature is due specifically to the power transformers. But it is possible if one power supply provides power better suited to the amps needs. This just means that one power supply is designed better than the other. It has nothing to do with the type of transformer.

BTW, have you personally verified these differences in careful, controlled listening tests or are discussing heresay? And. how do you know ther are no differences? Have you studied the schematic diagrams? Have you opened up the units and examined the components used? Do you understand enough to make informed judgments about the design and components? Without doing this you should not assume there are no technical differences. If you verify there are sonic differences, I'll bet there are technical differences beyond transformer types.

I need to clear up a point. The power supplies basic job is to convert the AC voltage from the wall supply to DC voltages that are useful to the amplifier circuits.

Sparky

[NonSense]

Pete

There are difference between the 1066 and 1068 beyond the transformers. For one, the 1068 has an analog bypass option which suggests an improvment in the playback of analog source material. I also believe it contains the next generation of DSP/DAC chips.

The big difference between the two types of transformers is the winding architecture. A standard transformer is essentially a solenoid. Linear windings which form a tube. The turns ratio of the primary winding to the secondary winding offer a step up or step down in voltage. The electromagnetic energy is coupled from the primary winding to the secondary winding. To increase the efficientcy and the amount of coupled energy, ferrite material is placed in the core. If you are familiar with the "right hand rule" you can predict that a significant amount of energy field extends out the ends of the cylinder. To capture additional energy in the field, the ferrites were extend and then made into capped E shape to help increase the efficientcy. Also, features like laminated ferrite material were adopted to again increase the efficientcy.

Now, if you could connect one end of the cylinder to the other, you wouldn't lose all that energy extending out the ends. Thus, the toroid. Wait a minute, these are not very easy to build, especially if you need multitaps on the secondary winding.


A would suggest that a toroid as an individual component should be better, but I would agree with Sparky, that it is only one component. If the power supply is designed properly for the requirement of the system, there should little difference, as other system parameters may have a greater influence.

[bleeding ears]

thanks guys, I understand a lot better now that the transformer is most likely not responsible for the differing sound from each pre amp.

However, I am now wondering if the High end amplifiers use toroidal transformers or if brands such as Krell or Halcro or bryston stick with the traditional or older block style transformers.

If they do not use toroidal transformers it would be interesting to know why?

Pete

[ThomasW]

Tororidal can be made somewhat smaller and if properly designed will have a smaller radiated field.

Some high-end amps use toroidal, other use the 'standard' designs.

It's a function of the designers choice and the price point. So not much to debate.

[whoaru99]

thanks guys, I understand a lot better now that the transformer is most likely not responsible for the differing sound from each pre amp.

However, I am now wondering if the High end amplifiers use toroidal transformers or if brands such as Krell or Halcro or bryston stick with the traditional or older block style transformers.

If they do not use toroidal transformers it would be interesting to know why?

Pete

I would tend to say that most do use toroidal. There are probably good reasons other than marketing hype, but hype likely plays some role greater or lesser.

After all, something got you thinking about it and or put the idea in your head that tended you to think toroidal may be better, yes?

[bleeding ears]

Yes the marketing hype did originally have me thinking toroidal transformers were better for some reason, but as with everything cost, or rather cost reduction is what I think brings about most changes.

Thats why nearly everyones manufacturing in China these days.

Unfortunately cost reduction may not also bring about the best in sound quality or reliability.

Thats not to say that decent products dont come from China or that toroidal transformers are any worse than other types. In fact they may actually be better in many respects.

It just makes me wonder why the change?