Will preamp manufacturers tell you if the model is phase inverse?

You can't just invert a single ended cable. :)

You can't just swap the leads, because the outer conductor is almost always ground. You'll just end up with ground on the center, and ground on the ring.

This would work for truly balanced inputs, which are very rare in RCA inputs.

Best,

E

I think the idea of having a phase inverter makes the most sense, given the possibility of a recording being inverted or not, however...

I should also point out that the simplest designs invert phase, since they use a single tube stage per channel. That's the simplest possible design. To get phase accurate, you have to add at least one more stage.

Best,

E

For the record, multi-way speakers often invert one or more drivers relative to the others to achieve correct phase matching through the crossover regions. You can see this in the Stereophile step response measurements.

In general (but not legally enforced) the woofer’s are positively aligned, and other drivers are chosen to invert or not based on phase matching to the driver below. Of course, some designer may think that mid-range phase is most important, so this is a general rule.

To test the polarity of your woofer, take a 1.5 - 9V battery and attach positive to positive. If your woofer moved outwards, then it is in positive polarity. You may even be able to tell the midrange as well.

1.5V cells are safe to use on tweets too.

Best,

E