speaker replacement for ampeg sb-12?

[southpaw802]

any suggestions or links?
not 100% sure it needs to be replaced, going to have it checked out.
not sure of the year. mid 60's?
tubes 5ar4, 7868, 12ax7.
the plastic housing covering the magnet is bent and touching the frame a little. maybe it can be fixed. looks to be jensen.
thanks.

 

[JimmyM]

SB-12's came stock with a Jensen C12N, or you could get a Jensen EM1202, JBL D120F, or Altec 417B as an upgrade at different times during its production. The JBL is considered most desirable for 60's SB-12's, though many swear by the Jensens. You could also try an Eminence Beta or Delta 12, as they are the new speaker that Welcome to Fliptops -- Parts for Ampeg and other Vintage Amp Lovers recommends. Or you could get the Jensen reconed.

Or maybe there's nothing wrong and it just needs tightened.

 

[southpaw802]

thanks for the info. and link. looks like it might be the em1202. played last night and it sounded pretty good. couldn't hear the slight buzz with distorted guitar next to it. got in there with a light and mirror.
there is only a number on the cone. the tag says jensen concert.

 

[JimmyM]

Sounds more like a C12N then, as I believe C stands for "Concert." Could be wrong, but there are a lot more C12N loaded SB-12's out there than any.

As for the distortion, I wonder if you have an air leak somewhere. That sounds pretty typical of an air leak to create some distortion that you probably wouldn't notice in a mix but drives you crazy at home. Very hard to tell without looking since there could be several causes, but just spitballing here with ideas based on our own experiences with rattle chasing.

 

[southpaw802]

air leak? in the speaker or cab?there are a couple holes drilled in the cab. ext speaker? or tie down? not sure.

 

[JimmyM]

Not tie downs, but would have to see to know. But yes, holes drilled in the cab are notorious for that sound if they're not sealed.

 

[southpaw802]

the holes are right up by the lid on the cab. one in the top middle straight down and two on the back at an angle. great. thanks. i'll put a little silicone in those holes.
at one time it belonged to the "N.Y. Bass Amp Club". its painted stencil on top.

 

[JimmyM]

I wonder if that was the lock they would install on them to keep non-club members from using them. Dude, pictures are a must!

 

[southpaw802]

filled those holes and it worked great. now i think it needs a cap job, and a new cord. not sure how to post photos.?

 

[savakus]

the holes are right up by the lid on the cab. one in the top middle straight down and two on the back at an angle. great. thanks. i'll put a little silicone in those holes.
at one time it belonged to the "N.Y. Bass Amp Club". its painted stencil on top.

Little tidbit...


Russ Savakus started and ran the NY Bass Amp Club. This was back in the 1970s. Each member would join and add one amp to the club, then they would lock amps up at each of the studios/locations. Any member could show up, unlock the am and have at it.

As I recall he drilled some holes and fitted screw eyes into the holes- a Sesame Lock and chain would secure them. I actually still remember a few of the combinations...

As I recall it was started on Feb 1 1971.

 

[JimmyM]

It was actually in the early 60's. Not sure of the year but B-15's were available in 61 so it very well could have been 61.