Step Up Transformer Question

@elliottbnewcombjr the Bellari SUT I have now to play with has 1:30 as well and when I switch to that the hum does not go away. I really think it's cable related but can't prove that until I get more cables. 

@pindac you did mention the sculpture A prior. What turns ratio did you use for a 0.2mv cart?

@terry9 I've looked at that option a little bit. There are even some premade boxes to put SUTs in online. You can buy kits from lundahl's US importer and I've thought about that as well vs getting a Rothwell from the UK with decent lundahl units in it. 

Again, thanks everyone for all the input. Super helpful. 

@rmdmoore I would have to get it confirmed by the individual who loaned the SUT's for the Demo's but do believe the Sculpture A with a Copper Winding was 1:26 Ratio.

The nano crystalline core is not too commonly seen on audio, and it is this material, that certainly seems responsible for a proportion of the standout impression made.

Lundhal are offering this Core Type on some of their designs for a Tranx. 

@pindac I'm chatting with an eBay builder about building one with lundahl 1941s. The core is listed as amorphous. Is that what you're talking about? 

Not to make an already very confusing thread even more confusing, but Jensen make great  step up transformers, too, at a reasonable price.  And their staff of engineers are very knowledgeable and helpful to DIYers. Go for their top of the line, and you won't be sorry.

Amorphous is not Crystalline.

The following is a bit of other forum talk on the subject.

"According to Per Lundahl, writing by email, "Choice of core material is a question of taste. Our top-of-the-line MC transformers are available with either our uncut amorphous strip core (like the LL1931) or with a conventional mu-metal lamination core (like the LL1933). As it has turned out, the amorphous-core transformer is most popular, but the mu-metal lamination transformer is still preferred by some audiophiles. In THD ... and linearity measurements, the mu-metal lamination version outperforms the amorphous core version, but in listening tests, the amorphous core usually wins."

"I asked Per to explain the metallurgical differences between mu-metal, amorphous cobalt, and nanocrystalline transformer cores."

"In true amorphous material, there should not be any crystal structure. Atoms are randomly oriented, and there is no repeated structure such as you find in most solid metals. To achieve this, the melted metal is cooled so rapidly that atoms get stuck in their random positions. ... This very rapid cooling requirement is the reason why amorphous metal is only available as thin film, about 1 mil (0.025 mm) thick.

"To achieve nanocrystalline material, special amorphous iron is carefully heat treated at very controlled temperatures. In this process, very small [nano]crystals are formed."