The Guild 99-U "piggy back" Ultra amp was described as follows in the 1963 Guild catalog
Because speaker cabinet can be separated from amplifier unit and moved about for most effective sound projection, this "piggy-back" model overcomes many of the professional's acoustical problems. Separation also eliminates tube noises arising from speaker vibrations. It removes tubes as source of heat and thus minimizes drying out of speaker cone. Speaker is totally enclosed in specially designed high fidelity sound box of 3/4 inch plywood having back panel insulated with acoustic material so that full tone range is directed out front. Highest standards of tone quality are combined with exceptional convenience of operation.
Has 6 tubes (3 dual purpose) for 9-tube performance; heavy duty 12-inch super-power concert speaker; 30-watt output; 4 inputs; separate volume controls for each channel input of High and Low; special Brilliant input jack; ultra-sensitive tremolo with individual speed and strength controls; tremolo foot switch jack; 8-ohm speaker jack, external speaker jack, both in rear with polarity line switch; fuse holder on control panel; combination stand by and on-off power switch. Washable, scuff-proof Blue-Grey vinyl on lock joint plywood cabinet.
Amplifier case (not sold separately) is available with choice of 12-inch or 15-inch heavy duty speaker. With 12-inch speaker, complete unit is 22 1/2 inches high, 10 inches deep, 21 inches wide and weighs 43 lbs. With 15-inch speaker, complete unit is 25 1/2 inches high, 10 inches deep, 21 inches wide and weighs 48 lbs.
Amplifier advertisements originally published from 1962 onwards. Click on the images for larger copies. Check out other vintage Guild advertisements
Guild 99-U - Be good to yourself with a Guild (1962)
This advert from a Summer 1962 issue of Downbeat magazine shows a number of Guild instruments representing different areas of Guild guitar production. "How to succeed in music without really trying...
Guild 99-U - Guild showcase for talent (1963)
Early 1963 Guild advertisement showcasing a number of instruments, each representing a segment of Guild's 1963 product line. The single cutaway Starfire III, archtop acoustic Stuart A-500, Mark II ...