Tube Amp Archive

I picked up a used Mersa Thiele Cabinet for my 1x12 EV 12L Speaker. Turns out it was the wrong type speaker mouint, so I redrilled and put T-nuts in and mounted my 1x12 EV.
Since it came with no grill, I put a frame, and am going to have cut a metal grill. I also insulated the cabinet
Also ordered new feet and handle.

I am stuck on something. It has a mono cliff jack to connect the 12" EV 12-L speaker. Its already wired wiht both wires on the same side lugs, with a white wire to the tip of the jack that I put to black ground speaker, and a black wire closer to the input that I put on the red/hot speaker lead.
Is this correct?

It's this jack. Which lug is positive polarity?;

[img:400:400]http://grangeramp.com/shop/images/cliff_jack.gif[/img]

It is wired backwards. The conventional wisdom is that the speaker should be wired so that a positive signal at the tip terminal causes the cone to be driven outward, away from the magnet. It's easy to check using a 9V battery.

It will work either way!

Like Martin said it's wired backwards.

If you view the Jack from the front so you are looking at the bezel, the lug on the left front is the sleeve/ground and the left back is the tip/positive. Don't worry about the lugs on the other side

The polarity would only matter if another speaker was wired in as well.

You would want both in phase.

John

Although there are some people who say there is a difference in sound one way vs. the other when one amp is driving one speaker, particularly in the case of a combo amp, it is best to wire all speakers and extension cabs the same way, in case they are run in parallel with another speaker or cab.

I for one could not possibly relax if i had a speaker cab wired out of phase...

Hah

Years ago, I bought a 2-15 Bassman cabinet that just sounded terrible. I didn't pay much for it, and let a bass player friend have it at cost. He had me replace the speakers with 2 EVM15-B. When I opened it up, there were 2 EV SRO15's wired out of phase. I fixed it and had him listen, sounded great! He still had me install the EVM's so I did get some nice SRO's out of it.