The real story is more or less this:
After Acoustic Control Corp. folded, engineer Russ Allee went off to found Amplified Music Products. I forget his partner's name right now. They hired Steve Rabe (also ex-Acoustic) to do a preamp design and the first products out were the Rabe designed SL-1 Premap, an 800 watt stereo power amp and the XB-15 speaker cabinet.
Steve Rabe went off to start SWR shortly thereafter.
Russ Allee redesigned the SL-1 preamp slightly and used it in two integrated heads, the BH-420 and BH-220. A combo version of the 220 was also introduced (CX-220) which used a cab design similar to the XB-15.
The 220 amps were upgraded slightly to create the BH-260 and CX-260 amps. A.M.P. introduced at least two more cabinets (both 1-15", one had a horn), a 30 watt solid state guitar combo and a keyboard head based on the BH-420.
They went out of business around 1989.
Russ Allee then revamped the BH-420 design for Gibson as the GB-440 amp head. Gibson sold both 4-10 and 1-15 cabinets to go along with the head.
Russ Allee did some consulting with Eden on the World Traveler amps although it is unclear exactly how much he was responsible for.
A few years ago Thunderfunk bought up the remaining parts stocks from Gibson and built up "new" GB440 heads which were all sold on eBay. The last few built had Thunderfunk logos (still Gibson parts inside but Thunderfunk had run out of the Gibson made enclosures). Sales were good enough that Thunderfunk did some redesign on the amp and went into production.
Amplified Music Product's main failing (in my opinion) was a complete lack of promotion. They ran ONE ad in Guitar Player over the life of the company. What amps they did sell were totally through word of mouth. They did have some very famous users including Jaco (in his last days), Jack Bruce, Darryl Jones, Tommy Shannon. Although they sold their own cabinets these were never as successful as the heads and are quite rare; at the same time they partnered with Hartke, who recommended the BH-420 for use with their cabs (like ALL of the above famous users). After A.M.P. went under Hartke decided to start making their own amps.
