Brownface, brown Tolex-the 1963 Vibroverb
The original (6G16 circuit) Vibroverb was introduced in February 1963, the speaker lineup and the output transformer were based on the Fender Super amp of the time, the circuit based on the Fender Vibrolux of the time, with no presence control and only one 12AX7 tube for the tremolo effect. It sported typical "brownface" cosmetics, with brown "Tolex" covering (introduced by Fender in 1959), and wheat-colored speaker cloth. The 40-watt amplifier boasted two channels (NORMAL and BRIGHT). Both channels had VOLUME, TREBLE and BASS controls; the single-control REVERB affected only the BRIGHT channel.
The tremolo effect (labeled VIBRATO by Fender had two controls, SPEED and INTENSITY, affected both channels. To make room for the reverb circuitry (not found on the Super amp) the company used the direct-coupled oscillator vibrato circuitry found on Fender's previous generation tweed amplifiers (which used two tubes fewer than the Super's brownface vibrato circuit). The TREBLE control was the same as found in many Fender amplifiers of the time (i.e. Pro Amp -6G5A-, the Super -6G4A-, the Showman -6G14-, the Vibrolux -6G11-). It was fitted with a "tapped" treble circuit, meaning that the treble control is "flat" at setting "5"; cutting or boosting the treble was possible by turning the knob down (below "5") or up (above "5"), respectively.
'63 Re-issue Vibroverb (1990-1995)
Fender made great efforts to reproduce the tone and look of the original unit. A "direct-coupled" oscillator circuit was used for generating the vibrato (albeit with different components). The noticeably "warmer" reverb sound of a vintage brownface Vibroverb (due to the original reverb send and recovery circuit unique to the Vibroverb) was also present. The cosmetics incorporated the brown "Tolex" and wheat-colored "Ecru" grill cloth used in 1963, as well as the "flat" Fender logo plate found only on the brownface amps. Although cosmetically and-more importantly-tonally accurate, there were several notable differences to be found (solid-state rectifier, printed circuit boards, ¼" reverb/vibrato footswitch jack, 3-prong power cord). Fender did use the original templates, molds and blueprints from the Oxford company archives to manufacture Oxford-style loudspeakers. The Fender '63 Reissue Vibroverb was released in 1990.
So what's up ? Are these amps different ?
Yes they are. They are different amps. But the sound characteristics are very much the same. They are both very-very musically sounding amps. Fantastic dynamics, but no harshness. Plug in a guitar and you have a great tone. No hassle, ready to go. I have the ability to compare them thoroughly and I notice only subtle differences in sound behaviour. But I also notice slight differences between different Re-Issues ! In general the vintage amp is a little "smoother" and sounds somehow more "glassy". The amp tends to start distorting at a lower volume / at a certain level of string attack. The reverb and tremolo are slighly smoother from the vintage amp. The vintage amp reacts to pedals with more forgiveness. Pedals sound a little more smooth. The vintage amp has a very little additional noise at high sound levels in combination with the vibrato.
From my point of view there is no reason at all to long for the original Vibroverb 63, unless you are a vintage collector !
For collectors it is a possession to be proud of, but it has no relevant functional or sound advantages.