Input impedance (resistor value changes)

[Ivan303]

Planning on installing built-in step-ups from Cinemag.  Currently having very good luck with the step-up box built using  a pair of 3440AH with a toggle for 150 Ohm/37.5 Ohm even though the cartridge I'm currently using seems to prefer (if the reviewers are correct) to see about 100 Ohms.

Cinemag will do costume winds and those are likely done by David Geren himself?  Also a few more $$$.

And they answer questions via email!

So the question would be, dare I lower the input impedance of the Eros 2 to about 33K as opposed to the 47k as currently built to get to about 100 Ohms  using the 1:20 winding?  Would not worry much about going higher but....

With all of the gain available in the Eros 2, gain is not a problem and the 1:20.

Maybe just go with the 1:20 winding and be happy?

[Paul Joppa]

Here is a really good reference on step-ups:

http://www.rothwellaudioproducts.co.uk/html/mc_step-up_transformers_explai.html

From  the viewpoint of the preamp itself, there is no reason not to change the input load resistor from the 47K stock value , as long as it's less than 1 Megohm. 

[Ivan303]

Thanks Paul,

What I suspected and likely I'll just stay with the 1:20 step-up.