Description: For sale is a 1965 Fender® Princeton® blackface amp, rebuilt by Alexander Howard Dumble in September, 1972 in his Santa Cruz, CA workshop. The Princeton® combo amp was converted to a head, most similar in construction to a Fender® Showman® amplifier. Historically this amp was completed at the same time the first Dumble Overdrive Special was finished. The prototype overdrive special was shown to the original owner of this particular amp, on the day he was called to pick up this conversion. The original owner was a Santa Cruz graphic artist, responsible for introducing Mr. Dumble to using silk screening for the lettering that was from then on to appear on Dumble amplifiers. In the fall of 1994, Dumble borrowed this amplifier from the owner and showed it to Jackson Browne. Browne was rehearsing at the time at an MGM sound stage in Hollywood for the "Late For the Sky" tour. He liked the sound of the amp so much that he insisted on using it for the remainder of the rehearsal. Browne then ordered his first Dumble amp after the rehearsal, and it is well known that he has been a Dumble fan for many years, along with David Lindley who was also at the same rehearsal, and was a member of the band. The control knobs from left to right are volume, treble, bass, middle and pre-amp volume (overdrive). The original vibrato circuit was removed, and the vibrato pedal jack on the rear of the chassis is now a line-out jack. There are also 2 speaker output jacks on the rear. The amp produces lush clean tones with both volume knobs set evenly. Turn the 2 volume controls past 8 and you will get the overdrive sound that you would expect from a Dumble rebuild. Also included with the amplifier are two Fender® Bassman® cabinets converted by Mr. Dumble. One cabinet houses two Altec 417-8 12" speakers. The second cabinet has two 12" JBL-D120F speakers. The rear panel of each cabinet has the Dumble oval opening most often seen on later Dumble cabinets. Modification consists of a Showman® power amp and power supply conversion. Diode rectifier feeds the existing filter cap only doubled up on one section. This provides the B+ to the 4 6L6 power tubes driven by a Showman® phase inverter circuit. Plate resistors are slightly different values on PI (V2). There is also an adjustable bias control. The preamp is the stock 2 stage Fender® circuit (V1). There is a master control between the preamp and phase inverter. A middle tone control added and the tremolo was removed. there is a line out at V1b. The amp has a lot of clean power and the gain is moderate. With a medium pickup and the master turned down there is only slight preamp overdrive. COMPONENTS: The Showman® transformers used are the following: Output 0022897 manu. code 606-2-49 85 ohm output Power 022756 606 2273 Choke 022699 606-3-48 Tubes are (4) 6L6 and (2) 12Ax7
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Last edited by boldaslove6789 on Wed Jun 13, 2012 8:27 pm, edited 2 times in total.
