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-   -   Supermalloy for the Power transformer? (http://www.diyaudio.com/forums/tubes-valves/219898-supermalloy-power-transformer.html)

rhythmsandy 17th September 2012 04:09 PM

Supermalloy for the Power transformer?
 
I got a very good source for Supermalloy and since I am looking for the best for the trafo. Im getting that for 40USD for 1KG and its all supergrade.

Since I havent seen anybody who is using supermalloy in the amplifiers so thought to ask that how is the sound quality if we use supermalloy when compared with silicon steel..

Im expecting that the transients will be breath taking and mid could be more smooth and what about bass? or I am wrong...

If anybody have used this trafo as Main Psu trafo please tell me your opinions...

kevinkr 17th September 2012 04:14 PM

Never heard of this alloy is it a subset of permalloy? Provide link.. No audible benefit at all in a power transformer and a lot of added cost IMHO.

Found link, it is essentially 80% nickel (20%) iron alloy : http://www.mag-inc.com/products/tape...es/supermalloy, it is apparently a replacement for ultraperm which I have heard of.

Again this would be good in a properly designed output transformer, but would provide no useful benefit in a power transformer.

Cores would probably have to be upsized significantly to avoid saturation issues as compared to M6.

rhythmsandy 17th September 2012 04:59 PM

yes its from mac-inc and its said by few people that the high frequency transients are very aswesome and even mid will be very vivid and distinct when it comes to the deail in the mid. I do agree that the difference could be identified by the top of the tweeters like revelators or ribbons but according to mathematics does it makes difference?

Audio note specifically says that using these have improved like from an Artificial light to natural light difference. So thought there could be a difference like said by the one of the most regarded audio equip manufacturer.

Please let me decide on this but even if some body have used 48% Nickel alloy did u find the difference when compared with silicon steel?
If there is difference with 48% nickel alloy there could be difference in supermalloy..

kevinkr 17th September 2012 05:13 PM

The benefit can be very significant in an output transformer - I use amorphous core and permalloy audio transformers in my system, but in a properly designed power supply the only things that really matter are a sufficiently low winding resistance and adequate capacity to handle the load current - there should be no significant audio current present on the transformer windings. (Mechanical quiet is important as well, I hate noisy, buzzing power transformers.)

If you've got money to burn or are building these yourself go for it, otherwise.. :D

Hopefully Bud P will weigh in, he's one of the local transformer experts, I'm not.

wrenchone 17th September 2012 05:20 PM

Well, supermalloy has a lot lower saturation flux density than silicon steel, so you'd have to use a larger core or more turns than a power transformer of similar capability in silicon steel. I'd say not to bother and save the good stuff for the output transformer.

rhythmsandy 17th September 2012 05:42 PM

what if the psu is used in solid state will it make difference there?

no problem we can go ahead even its a bit expensive so we can get bigger core and more turns aswell..

Like for example I want to get best out of a 500VA trafo or 1.2kva trafo what is the core size which is best like for

cross section area, inner diameter , outer diameter and height...

wrenchone 17th September 2012 05:47 PM

What benefit do you expect to acrue for all the expense and bother? Volt- seconds are volt-seconds, whether the supply is solid state or vacuum state.

rhythmsandy 17th September 2012 05:53 PM

im looking at the transients... the psu should be able to handle those transients...

rhythmsandy 17th September 2012 06:11 PM

this is the text from Audionote design principles...

The Cores

The core of the transformer is vital for it’s operation. In our standard transformers we use good quality silicon steels but in our finest specialist transformers we make no compromises and use the very best and very expensive nickel irons such as Radiometal. 3% silicon steel is widely used around the world and is produced in vast quantities China, America, Japan, Russia and the UK are amongst the countries where this material is manufactured. For our economy transformers we use a material known as M6, in laminations of 0.35mm thickness. The material is first cold rolled, to align the grain structure, into a tape then it is punched into laminations. The problem with this is that the flux runs anti-parallel to the preferred direction at the back of the "E". This means that at that point the materials full potential is not realised at that point increasing losses and decreasing effective permeability. M6 steel has reasonably low hysteresis, good permeability (approximately 10,000) and high saturation flux density (approximately 2T or 20,000 Gauss). The problem of poor grain orientation is alleviated if we move from I-E laminations to a C-Core. Here the metal tape, after being cold rolled, is wound into a loop and then cut, now the magnetic flux always travels in the preferred direction in the steel, this alone gives a significant increase in performance. When we move up to a C-Core we change the material’s specifications to M0 or HiB silicon steel a material that has slightly lower losses and higher permeability than M6, the permeability of HiB can be 40,000 or more. HiB is processed in a different way to M6 giving it a different grain structure this special material is manufactured in Japan and America only. Our finest transformers use two versions of Radiometal core in the form of a C-Core. Radiometal is a 36% Nickel iron and Superradiomatel a 48% Nickel iron alloy of excellent magnetic properties the permeability is similar to that of HiB but it’s saturation flux density is lower at 1.6T or 16000 Gauss. Radiometal has a much lower hysteresis loss than silicon steel and is far more sensitive to small signals. If one is to firstly listen to a transformer with the best silicon steel core and then change to one with the Radiometal core, one experiences more colour and texture in the performance and more low level details are present. The high frequencies are so much clearer. It is like the difference between an artificial light and sunlight.

wrenchone 18th September 2012 04:55 AM

What does this stuff have to do with the role of the power supply transformer?

Do you understand how a power supply works?

If a power supply transformer must directly handle the transients from an amplifier load, the power supply is not doing its job at all.

Keep in mind that for a capacitor input filter, the transformer is only in the circuit for a short fraction of the AC cycle. For a choke input filter, the filter inductor is in between the transformer and the load.

Read up about power supplies before you try to apply propaganda about output transformers to a power supply transformer, a totally different situation. I'm bowing out of this thread as you seem to be absolutely determined to spend your money where it will do the least good, but I will leave a few hints before I go. What is between the output transformer and the load that may have some bearing on the power supply output impedance? What can you do to a power transformer to improve its isolation with respect to the (woefully dirty) AC line, as well as its isolation to adjacent components (both magnetic and electrostatic coupling count). How can you clean up the power supply output to reduce the need for the amplifier to cope with garbage (both in-band and out-of-band)?


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