More Edcor XSM10K/10K Specs

[valveitude]

I had asked for some more detailed specs on this transformer a while back, and Larry Weston sent me this today...

Casey, Some of the info you wanted. These units are wound bifilar. DCR primary & secondary 620 ohms.Inductance primary & secondary @ 1000 Hz 36 H. Leakage inductance with secondary shorted 5 mH.Capacitance primary to secondary 41 nF. All measurements at 1000 Hz and no loads. These are nominal(average of 25 units, minor variation with samples +/- 5 %.



Larry Weston

Perhaps the more savvy transformer folk could comment on these specs.

-Casey

[Geek]

With that inductance and leakage capacitance, I'd use them as no higher than 4.5K/4.5K impedance, if you want HiFi performance.

But, I've underestimated Edcor's before... they have yet to not surprise me in the performance-for-price department.

Hey Tubelab, whaddya know of these ones?

[valveitude]

Hey Geek,

With that inductance and leakage capacitance, I'd use them as no higher than 4.5K/4.5K

Yay, the capacitance looks pretty high, but like you said, loading them down might just do the trick.

I'm thinking about using them for a phase-splitter, maybe driving it with a 6S45PE, or some paralled 6922's.

-Casey

[Geek]

Hi Valveitude,

They should do the trick nicely.

If it's a true bifilar wind, the capacitance for the most part cancel itself out in a balanced circuit.

[Ryssen]

I'm thinking about using them for a phase-splitter, maybe driving it with a 6S45PE, or some paralled 6922's.

Better use a 6S45PE,they sound better,oh,but thats just me..
Show us the result then.

[tubelab.com]

Hey Tubelab, whaddya know of these ones?

I have not tried them. I have tested the small Edcor SE OPT's (XSE15-8-5K) and the large SE OPT's (CXSE25-8-5K). I have a pair of the lowest cost PP OPT's (XPP10-8-8K) but have not tried them yet. Too many projects, not enough time!

[jrdmedford]

36H should tell you enough to proceed conservatively.... Most PP
transformers have Lpri around 300 H. Case in point being the
Lundahl 1660/PP which is designed for PP 6SN7 (at worst) and 20-30kHz (at best).

Let empiricism rule... I have... Keep the source impedance low and
keep DC off the primaries and they work well.

Dont forget, the work really nicely as input transformers and are an
inexpensive way to do a phase splitter. The circuit to try is this:

XSM600/10K -> 6SN7 differential pair -> KT66/6V6/whatnot -> 6.6K/8

Drop a cheap CCS on the differential pair.... Drive the XSM600 input
from a decent PC sound card with 600 ohm XLR out. Golden.
Immaculate.

-- Jim

[Dave Cigna]

The capacitance is not shunt, but between primary and secondary. This is typical of bifilar wound transformers. You can think of it as a 'hidden' coupling cap. Provided it's connected properly (you don't try to use it to invert phase) the capacitive coupling actually improves hf response where the inductive couple becomes less effective.

-- Dave

[Wavebourn]

41 nF for 10K is toooo much. It improves "performance" of asymmetrical leakage.