"1985 - The AC30 undergoes a redesign in order to reduce it's production costs. This cost cutting assures that it is not dropped from the catalogue. The design uses one PCB (printed circuit board). A reduced gain stage is employed to overcome problems with the lack of availability of good quality valves, as well as the hum associated with the single PCB design. The contractor Audio Factor, who also made the Venue range, made these AC30s."
Excerpted from the "History of Vox" as published in the official Vox web site at www.voxamps.com.
The AC30TBR and
AC30TB amps were
produced for Vox, under sub contract, by a
UK electronics firm
named Audio Factors
from 1985 thorough 1988.
In 1983, Rose Morris was
facing several problems
that nearly resulted in the
death of the Vox AC-30.
Here is the story.
Rose Morris purchased Vox from Dallas Arbiter in 1979. Dallas Arbiter operated a manufacturing plant for Vox products in Shoeburyness, Southend-on-Sea, Essex England. After their purchase of Vox in 1979, Rose Morris continued to purchase Vox amps made under contract by Dallas Industries in that facility until late 1982.
Rose Morris grew dissatisfied about quality and dependability issues at the Shoeburyness facility and decided to terminate the relationship. They wished to find a new electronics subcontractor to build Vox amps.
Rose Morris also was facing a shortage of quality tubes (valves) for use in guitar amplifiers. The supply of good quality British and US made tubes had pretty much dried up by 1982. By that time, most new tubes were produced in eastern Europe, Russia, and China. These tubes did not perform to the standards of tubes produced in the UK in the 1960's and 70's.
Many of the 12AX7 (ECC83) tubes produced after 1980 were highly microphonic. Combining these tubes with the high gain circuitry of the AC-30 preamp often started an oscillation between the speakers and the preamp tubes. This oscillation resulted in a high pitched squeal coming from the speakers, similar to the sound heard when holding a microphone in front of a PA cabinet. This problem still affects AC-30 amps of any era that employ certain brands of modern tubes.
Many at Rose Morris wished to discontinue the AC-30. It was difficult to manufacture and the high gain structure of the AC-30 preamp section was incompatible with the low quality preamp tubes available in the early 80's.
Rose Morris contacted former Marshall engineer Ken Flegg to investigate the possibility of a redesign the AC-30 onto a single printed circuit board to simplify the amp and reduce manufacturing costs. Flegg designed and developed a new single PC board AC-30 that would be simpler, faster and less expensive to build. Flegg also trimmed back the gain in the preamp to accommodate the lower quality tubes that were commonly available in this period.
Initially, Rose Morris hoped that Ken Flegg would build the new AC-30 in his own facility, but that idea was scrapped when it was determined that Flegg might not have enough cacacity to satisfy demand. Rose Morris next turned to Audio Factors, a large electronics subcontractor in the UK, to manufacture the AC-30TB and AC-30TBR.
Rose Morris produced several different versions of the AC-30 amp that they called the AC-30TBR. It was first introduced as the 1985 limited edition "Silver Jubilee" edition. The model carried on, less the limited edition badging, for two additional years. This series of amps can be identified by the words "The Original AC-30 Topboost" on the control panel (see control panel above).
The AC-30TBR had four ECC83, two ECC82, one ECC81, and four EL-84 tubes. The amp did not have a tube rectifier. It had three channels, Top Boost circuitry in the "Brilliant" channel, Vib-Trem, reverb, and two 16 ohm 12" Celestion Greenbacks.
The cabinet was constructed of particle board and covered in an "elephant" grained vinyl similar to that used by Marshall in this period.
In 1988, Rose Morris replaced the the Audio Factors produced AC-30 featured on this page with the "AC-30 Top Boost Reverb - Catalog No. 1007" produced by Precision Electronics, another UK based amp manufacturer.
My thanks to Les Haynie of Blue Moon Music in Fayetteville AR for allowing me to photograph this AC30TBR from his inventory to present in the Vox Showroom. Blue Moon Music is one of the coolest vintage amp and guitar stores I have ever visited, and I encourage you to stop in if you are ever in Fayetteville, Arkansas.
||27.56" x 10" x 20.9"