Valco — best known for the Supro line of amps — also manufactured Gretsch's amps through the 1950s and '60s. Therefore, Gretsch amps are usually carbon copies of Valco-made amps sold under other labels.
In addition to Gretsch and Supro, Valco also made amps for National, Oahu, Airline and other brands, and the same amp design would be sold under the different brands, sometimes with small alterations for each particular brand. For example, the same amp chassis might be connected to a different brand or size speakers when sold under different brand names. However, control panels layout and design usually remained consistent and offer one of the better ways to ID a Valco-made amp.
Gretsch amps were offered in at least five basic styles, with the earliest ones usually covered in a tweed material. Beginning sometime around 1954 or '55, tweed was phased out in favor of a charcoal gray cloth with silver streaks in it. These late '50s "Electromatic" amps have a very distinctive appearance, especially with the wrap-around speaker grill many models adopted. It should be noted that "Electromatic" does not refer to any particular amp, but instead refers to the range of amps, just as Synchromatic or Electromatic do not refer to a particular guitar. During this period the amps were also offered in "Chet Atkins" trim, covered in white with brown leather decoration These are often referred to as Western or Cowboy amps.
There were actually two styles of wrap-around grill. Up until about 1958, the grills were relatively square. Later Electromatics feature an angled grill (as shown to the right).
Sometime around 1962 Gretsch switched to a simpler cabinet and full speaker grill, reflected in the 6161 DualTwin, (also known as the Twin Reverb) which is essentially the same amp as the earlier 6161 Electromatic. Wattage appears to have increased with the changeover, and some models received different speakers.
Beginning in 1966, the bigger models switched to a piggyback configuration, and the cabinets on the midsize models changed, too, mounting the controls on the front instead of on top or in back. Jensen speakers were no longer standard. It is believed Baldwin gradually phased out amp sales after the purchase of Gretsch in 1967, but some solid state amps soldiered on for awhile, most notably the Rogue and Tornado models.
Certainly any amps made after '68 or '69 (when Valco went out of business) were made by another manufacturer, probably Premier/Multivox. Reverbs were built by a Madison, Wisc., company called OC Electronics or another company called GSM. It's also possible some Kustom amps were sold as Gretsches, since Kustom was also a Baldwin company, although this is very uncertain.
When identifying amps, please remember this information is not complete, and specifications often changed from year to year.
Also note that model numbers and even names were sometimes used for very different models, just as Gretsch offered a '50s Corvette hollowbody and a '60s Corvette solidbody.
