There was another trafo discussion started on another thread which led to more questions for me... this thread is perhaps more suited so I'll ask here, but here is the other thread for those who wish to read it:
http://www.groupdiy.com/index.php?topic=33970.20
Basically, what got me all confused is this post by MikeFatom:
actually mean, that the only configuration that worked perfectly for me is,
Input TX : CM75101APC wired for 150 ohm input.
RL = 17K.
This trafo, wired 150 Ohm (1:10) should have 150K as RL to "work properly," right? What am I missing here?
So, I started wondering about trafo loading and zobels... The EA2622 is a 1:7 trafo, yet the recommended RL (150K) is the same as for the Cinemag 75101, which is 1:10... This would give you an input impedance of 3K vs 1K5 with the Cinemag. Does this not make a difference in the sound? I'm assuming Ed (who knows much more than I do about trafos) was the one to suggest this value and I'm curious to know why/how.
Of course, I did not consider the zobel. I know you select zobels by passing a square wave through the trafo while the trafo is in the circuit, right? But how does the zobel resistor affect the overall load on the trafo? Meaning if you use the values Jeff suggests, (RL=150K, zobel = 10K + 220pF) what is the effective load on the EA2622 and what is the input impedance?
Thanks!