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

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

So much for plug and play. Lots to consider when purchasing a preamp

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

So I’ve owned gear that inverted phase and the owner’s manual instructed that wiring to the speakers should be flipped. What i never understood is if the circuit inverts polarity why doesn’t a manufacturer simply reverse the leads heading to the component’s output so that once leaving the component polarity isn’t reversed any longer. 

Thats a good question