??? Output Transformer - Silicon Steel or Amorphous

[planet10]

Originally Posted by BudP

I will never know how this OPT really performs objectively, as George passed away recently and there are no amplifiers available to investigate.

Chris & i know where there is a captive example

dave

[BudP]

Dave,

Will your test gear pull loaded data from those hidden treasures? Other than the rather noticeable distortion fatigue from them, what do you like and dislike about those amps?

Bud

[planet10]

Chris is the one living with the amps. Daniel could rn ome tests on them... you'd need to query him about what we can do. The HP network analyser we have is pretty capable.

dave

[chrisb]

Dave - you're certainly welcome to test them, and Bud, some of the modifications you suggested (along with a few minor others) have been performed on these.

Yes, it's a great shame that George never embraced the use of higher sonic value components, or at least allowed space in his chassis for those who do.

[LinuksGuru]

Hi, BudP,

What model/mark/brand of material you would recommend for amorphous core PP transformer? This is very large group of alloys, different manufacturers use very different designations, for example Finement (Japan) = FeCubNbSiB (China), FeSiB (China) = 2605-S2 (USA), etc.

[TV Man]

Really interesting thread.

I'm curious which of the material types mentioned will lend more weight or body to an instrument's sound/tone? I'd like a bit more weight in the sound of my system and am willing to try getting it and possibly other gains by upgrading output transformers. Any ideas?

Thanks,

[agent.5]

Shall we add nickle to the discussion?

[BudP]

TV Man,

I would need to know a bit more about your system and what you mean by weight and tone, before offering my opinion.

In a general sense, a properly designed and built commercial core OPT, using M3 and treating differential dielectrics within the coil structure as an E Field lens, as opposed to amorphous core construction, which will have slightly better distortion performance but be somewhat lacking in gradient information, for the internal structure of notes and transients, might be a better choice for you. However, a lot depends upon your speakers and your definition of weight. The two types will be roughly comparable in cost, at about $1000 per pair.

At the next level down, they will again be roughly comparable in cost but the above differences will be more noticeable and the cost around $500 per pair.

The last, but not least level will have very few amorphous core contenders and the commercial core has a noticeable advantage in information retention, with a wider gap relation in distortion. Cost here will be around $300 per pair.

Below this point the commercial core transformers reign, but their construction details begin to erase the level of gradient detail the above transformers attain.and though smooth and melodious, they are not going to allow you to hear what it sounds like you are after. Costs here run from $120 per pair up to $200 per pair.


Bud

[BudP]

Agent 5,

Nickle core is limited in the sizes available in E/I core construction. Tape / cut core nickle can be very good, but there are still some niggles with what level of coupling can be allowed in the coil structure, before Q sets in and you have both rising phase and frequency response, to a peak, at about 30 Khz. E/I M3, used in interstages, is also under this threat.

Bud

[BudP]

Links Guru,

Sorry, I missed your post. I no longer know what the various nomenclature refers to in performance with amorphous core. You might ask Dave Slagle at Intact Audio on hid forum. He is a current advocate of all types of C Core construction and may be current with what is being offered in the market place. Alloys do seem to come and go in that material as it's usage changes. It is also possible Per Lundahl at Lundahl would respond. They have their cores wound for them and I am sure have only a couple of materials they have settled on.

Bud