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Transformer input and resonance

Mike, are you referring to the sharpness of the LF rolloff formed from the output cap of the source and the transformer primary?

I don't have Spice, but someone who does could figure it out pretty quickly for a few likely values of C. There's no primary inductance spec on the Jensens I used in the Heretical (nor the Cinemags I used in the ImPasse), but I'd guess it to be in the range of several hundred Henries. That inductance is in series with 1k5 DCR of the winding and shunted by 10k of the reflected load. The Q is not likely to be very high.:D
Yes, you guys understood me. Not having any specs (it is amazing how little information even mainstream manufacturers provide) on a tranny I am planning on using I just ran my spice simulation with 25H on pri and each secondary. In simulation driven by a CF with one or two uF coupling cap I got a 3-5dB peak followed by what looked like a 2nd order roll off. Spice indicated that it could be managed by a resistance across the primary (or less effectively in series with it). My concern was that even with the transformer specs in hand one would not know what capacitance and series resistance any particular source would have. What I am hearing is the the inductance and series resistance in an actual transformer typically swamps that out.

I have the transformer in hand now so getting primary resistance will be easy enough. Measuring the inductance will be a bit tougher but just building the circuit and measuring the response may be good enough.

Thanks for the input guys (no pun intended).