Information about Mckenzie F800 transformer (passive summing box)

[creature.of.habit]

I was wondering if anyone knows anything about these transformers, as Google isn't showing anything useful.

I recently bought a small (likely home brewed) box with a Mckenzie F800 transformer. It's supposedly summing 2 inputs to 1 output, I've bought it to sum the outputs of my 4 track to mono, and it's working and sounding fine, although, admittedly I've no idea if it sounds any different than just going out of the 4 track with either of the outputs, haven't really done any serious testing yet. But it does sound OK.

Visually, I had never seen anything like this, as the transformer looks "hollowed out".
No idea of impedances or anything, really, other than the fact it sums 2 outputs to 1.
It's also quite light, much lighter than any transformer coupled small thingy I own or owned before.

 

[lukas]

What's happends with core?

 

[CJ]

air core inductor with heavy wire = crossover network, that would mean the square thing is probably a capacitor,

 

[creature.of.habit]

air core inductor with heavy wire = crossover network, that would mean the square thing is probably a capacitor,

Thanks, CJ. So, not actually a transformer, is that it?

 

[Ike Zimbel]

Thanks, CJ. So, not actually a transformer, is that it?

I think what CJ is saying is that this may not be a 2:1 direct box, but actually a 2-Way passive crossover, with the input being the single jack, and the two jacks being LF and HF outs. The "square blue thing" appears to be a large film cap.
I think it needs further testing to determine what it is. Can't say I recall ever seeing a passive crossover built into a box like that, but maybe it was a kluge for a Leslie cabinet or something.