Hey Zach,
I’ve got an Ampeg B-15, serial number0137XX, and I suspect it is from the mid1960s. Can you tell me a little about myB-15 and what it is worth today? Also, doyou know of where I could get a replacementLucite plate?
Thanks!
Art
Pittsburgh, Pennsylvania
Hey Art,
Ampeg’s B-15 is one of my all-time favoriteamps, not only because of its fantastic toneand universal application, but also because ofits unique design and versatility. While Ampegfounder Everett Hull didn’t reach the successthat Leo Fender achieved, they were two ofthe most innovative men in the guitar industrybetween the 1940s and 1960s. Hull created anupright bass pickup by mounting a transduceron an extended peg that was inserted into thebody of the bass. Hull received a patent for hisamplified peg (Ampeg) design in November1947 and began manufacturing them in NewJersey with his new partner, Stanley Michael.
Shortly thereafter, Hull and Michael wenttheir separate ways and Hull moved Ampegto Manhattan where he slowly began buildingamplifiers and developing the Ampegname. Ampeg introduced a variety of guitar,bass, and accordion amplifiers throughout the1950s, and in mid-1956, he hired Jess Oliver,who became Hull’s right-hand man throughmost of the 1960s and is mainly responsiblefor designing the Portaflex. Ampeg was alwaystrying to perfect the tone of their amplifiersand Oliver began experimenting with designssuch as a double-baffle porting system anda closed-back reflex cabinet. Oliver also borroweda design from an old sewing machinewhere the unit would flip out of the cabinet.
The first Portaflex amp was formally introducedin 1960 as the B-15. The double-baffle portingsystem gave the amp what Hull describedas “the creamiest tone.” At the time, comboamps were the norm, with all componentshoused in a single cabinet, but heat from theelectronics often caused the amp to overheatand made the speaker fail. Separate head andspeaker cabinet systems, often referred to aspiggybacks, became a solution in the early1960s, but it also negated the portability of thecombo. The Portaflex addressed both of theseissues, as the electronics were mounted on thetop panel that could be flipped over. In transit,the electronic components were flipped downand housed inside the cabinet. For playing, thehead was flipped up and exposed. Four latchessecured the top to the cabinet and the topwas entirely covered so it matched the cabinetregardless of which position it was in. WithAmpeg’s Portaflex design, users didn’t have toworry about their amp overheating while theywere still able to transport it relatively easily. Infact, Ampeg offered a heavy-duty four-wheeldolly for these amps that became standardequipment on later models.
Much like all of Ampeg’s amps, the B-15underwent constant change, and the B-15was replaced by the B-15N in 1961. In 1962,Ampeg updated the B-15N with a solid-staterectifier called the B-15NB and introduced theirfamous “blue check” vinyl covering to theirentire amp line. Ampeg went back to a tuberectifier and changed to a printed circuit boardin 1964 (B-15NC). This model lasted until mid1965, when they introduced the B-15NF withfixed bias tubes and a single-baffle cabinet.
According to the serial number 0137XX, youramp was built in 1965, which would make iteither a B-15NC or B-15NF. Your B-15N haseither a 25-watt (B-15NC) or 30-watt output(B-15NF), one 15' speaker, a six-tube chassiswith two 6L6 power tubes, and two channelswith three inputs and Volume, Treble, andBass controls for each channel. One of thecoolest features of the B-15N was the LuciteAmpeg panel that illuminated when the ampwas turned on. This panel sat in the middle ofthe head and it could be custom ordered withthe user’s name engraved on it.
There are a few things to note about Ampegproduction from this time. Hull was not a fanof rock ’n’ roll music and never designed anamp for this genre. Therefore, power ratingswere very conservative and Ampeg discouragedusers from increasing volume to thepoint where they distorted. In fact, mostamplifiers had accordion inputs throughoutthe 1960s, and Ampeg amps were neverreally marketed to rock players until Hull leftthe company in 1968. Ampeg went throughnumerous ownership changes over the nexttwo decades with Unimusic taking over in1967, Magnavox in 1971, and MTI in 1980.
St. Louis Music bought Ampeg in 1985 andfinally returned some stability and respect to thebrand. The company also reissued the B-15NPortaflex with blue check covering in 1995.Ampeg was purchased by LOUD Technologiesin 2005, and in 2010, they introduced the newHeritage Series that is produced in the US.
The B-15N has held relatively steady in theused market and is currently worth between$1200 and $1500 in working condition.Gregg Hopkins of Vintage-Amp Restorationreproduces these Lucite plates for the B-15and can even personalize it with your name.Given its cool features and history, theAmpeg B-15 is definitely treasure.

Source: Ampeg—The Story Behind the Soundby Gregg Hopkins and Bill Moore.
Zachary R. Fjestad
Zachary is the author of the Blue Book of AcousticGuitars, Blue Book of Electric Guitars, and the BlueBook of Guitar Amplifiers.
Questions can be submitted to:
Blue Book Publications
Attn: Guitar Trash or Treasure
8009 34th Ave. S. Ste #175
Minneapolis, MN 55425
bluebookinc.com
guitars@bluebookinc.com