Posted by jmpsmash (A) on November 10, 2020 at 13:38:47

Hi all,

I am trying to figure out which Lundahl transformer to use for I/V stage for a AD1865NK. I have a Audio Note Kit DAC2.1 currently. I have replaced the factory transformer with a Stevens Billington TX103 in 1:5 stepup, loaded with 1k at the secondary. This is what I had lying around and it sounds incredible. However, I want to move that back to MC stepup duty and need to replace it.

I have been googling and seems like many ppl uses LL1674, some have LL9226, and going through the Lundahl datasheets, but there are also a few others that can be configured to 1:4 or 1:5. I would like to use amorphous core for the detailed sound.

LL1674/LL1676 (just ratio difference?)
LL9226
LL1931
LL1684

or should I use something with 1:1 ratio?

The question is, what're the criteria other than the ratio. What else should I look for in order to maximize sound quality? the LL9226 is smaller in size but has lower primary/secondary DC resistance. Does that mean lower loss? but why is it smaller with smaller physical size?

Also, does K&K keep all these in stock? are there lead time to ordering?

Sorry for all the question and appreciate any help.