I noticed this thread seemed to get side-tracked into the "latest and greatest" engineering answer (high tech cores are the answer to everything), and subsequently started to fade.
I think the kind of information CJ shared here is an indicator that very good sounding transformers (embedded in well-designed circuitry) don't require fancy-schmancy high-price-tag core materials. Non-grain aligned can sound VERY good.
I was hoping for a good discussion about what the other variables are. You can tell I think the saturation characteristics and the frequency rolloff as level increases is part of the "sound". I was hoping others would share their ideas.
And BTW, CJ, I have been told by a magnetic circuit designer (transformers are NOT his specialty, but he impressed me as knowing magnetic materials and magnetic circuits and generally what he was talking about in that area) that the purpose of holes in magnetic laminations are to round off the transfer curve as saturation is approached - it is sort of like adding air gaps in E-I cores, but it doesn't contribute to low-level hysteresis effects. The transfer function is a rounder "knee". Made sense to me.
And CJ, thanks for the remarks about different core material roll-offs frequency-wise. If you are inclined to share any more you know along that line I would love to hear it. Do you know of any places I could look for curves of the rolloff versus level? FWIW, I tend to think this is one of the pertinent variables that makes people prefer circuitry using good transformers to transformer-less designs.
Seems like your remark
Why would someone GIVE away something in mins what might have taken years of work to learn?
is a kinda sad comment on the human condition, Gus. Hope you come to a better place sometime soon. I don't think any discussion here would be a one-way street. Maybe people would share what they have learned - or think they have learned - in hopes of us all gaining a better understanding through sharing.
It's what the internet is all about IMHO. Sharing, cross-fertilization.
One thing I'd like to throw out here. Anyone else aware of the psychophysical research that indicates that the cochlea (the inner ear organ) generates lower order harmonics at moderate to high loudness levels?
Anyone else got a hunch this might be why some of those not-so-high-tech cored, but well-designed, transformers still tend to "sound better" than the transformerless-designs often described as "sterile", "clinical", or (the ultimate negative label) "un-musical". Or why there is a minimum listening level at which music sounds "live". I have experimented with various bass compensation schemes and it just ain't all about the ears' bass rolloff. Or reverb fields. IMHO.
Anyone here done any research on what happens to the higher frequency information in an audio signal in the presence of substantial, near-saturation-level lower frequencies (and not just < 100 hz bass frequencies)?
If nothing else, BUMP^ <grin>
