Transformers - less expensive equivalent/replacement for Lundhl LL7903

[newvoodoo]

Ive got a PCB im excited about building/populating, but it requires a Lundahl LL7903 and where I can find them at ALL..they're running $150-200!!
Im hoping someone here has an idea about what/where/if there are any equivalents or transformers that are close enough for government work (the specs are within a not-too-large range of the 7903)?
Ive built a good many things since I started this hobby about a year ago but I have little/no knowledge about transformers. Ive basically bought and installed..I dont really know enough to tell if one is like enough to another to use as a substitute.  Im hping someone here can/does?

Thanks for any help you can provide!
or, alternately, Thanks for taking the time to read this post!

[R.G.]

It is unlikely that you'll find anything with even close to the performance. A glance at the specs indicates that the LL is a fairly high performance device. Transformers are very much not like resistors in interchangeability. Unless there is one designed as a direct replacement, chances are very bad you'll find one that fits the same holes and is close enough but cheap. If it's designed as a replacement, it will not be much cheaper, if at all.

If we knew the PCB/circuit, it might be possible to suggest some alternatives. It is possible there is something that could be kludged into the circuit that would be a transformer that was not horrible. But it probably won't be a good physical fit.

[moosapotamus]

I recall Edcor transformers having a pretty good bang for buck. Don't know if they have an exact replacement for that Lundahl, but you could try browsing their website - edcorusa.com. They've got a pretty wide selection.

~ Charlie

[PRR]

> Ive got a PCB im excited

To do what??

If this is a Mike Preamp, how good a preamp do you need?

The LL7903 is an exceptionally great transformer. $150 is cheap for what it is.

Do you really need +28dBu input?? (20 Volts!!)

Do you know if the PCB uses the LL7903 as 1:1, 2:1, 4:1, 8:1?

If you want a "starter" transformer, go to RadioShack and get the heavier XLR(f)-to-1/4" mike adaptor. In there is a 1:7 transformer which does not suck. Signals over 0.1V at 50hz will overload it. I worked for years in live-sound and recording and this was rarely a problem. The $20 mike-adaptor is not shielded near as much as the obsessive LL7903, so you have to keep it away from power wires and transformers.

OTOH, a "PCB" which is designed for the slick LL7903 probably has many other slick design details. Maybe 990 amp-modules? ($50-$200 each) Unicorn-hide capacitors? Platinum resistors?