Best year for Ampeg B15

[bobyoung53]

The silver dust cap isn’t in and of itself an indication of a issue with the voicecoil. I’ve seen examples of D-140 ‘s with either dust cap.

I know, it sounds very good but like the speaker I took out will occasionally bottom out, I don't think those things are baffled for the low notes though and they may be unloaded down there or relatively unloaded.

 

[Ric Vice]

I know, it sounds very good but like the speaker I took out will occasionally bottom out, I don't think those things are baffled for the low notes though and they may be unloaded down there or relatively unloaded.

Could be, I played a B-15S that sat in band room of one local high schools.
As I recall it was a Thiel box with insulation batting fixed to cover the back rear wall on the inside of the cabinet.
I wonder if there’s something stuck down inside the port, you mighy check to see if there is.

 

[-Adrien-]

I would include a cathode follower at the end of the preamp. This allows the amp to drive a DI without loading the power amp and decreasing the volume. Later revisions had this, it works better. Also better if you want to drive another power amp with the B-15’s pre.

Do you know when it was introduced? I’m not sure how to identify it on the schematics.