Tweed and Brownface
58' Fender Bassman
The 58' - 60' 5F6a Fender Bassman is considered the "Holy Grail"of guitar amplifiers. The original design used a single 15" speaker. In 54' Fender went to 4-10" speakers and and larger output transformer to create 50 watts of power, it gained popularity as a guitar amp. Jim Marshall supposedly copied this amp circuitry to start his line of guitar amps. A friend of mine played this and expressed this was the best sounding amp he ever played.
63' Fender Deluxe
One of Fender's biggest changes was going from cloth, Tweed covering to Brown Vinyl in 1960. The circuit design changed as much as the covering although the Deluxe didn't change till 61'. The Deluxe is one of the most popular studio amps in history, This 6G3 is 18 watts with a Jensen 12" speaker and is another example of a great sounding Fender amp.
63' Fender Pro
Here is the next version of the Fender Pro, which like the Tweeds, has the same chassis as the Super and Bandmaster. This one has a Jensen P15N and sounds amazing. This is a early 63' version of the 6G5 Pro, later in 63' Fender released the Blackface series, also with single 15" speaker.
57' Fender Pro
The 57' 5E5a Fender Pro is 35 watts with a 15" speaker and can be used with various instruments. This one has a Jensen P15N and sounds wonderful. The Pro, Super, and Bandmaster were the same chassis. The differences were the speaker configuration, cabinet size, and output transformer. Fender used a 4 ohm tap on the Bandmaster even though it had 3-10" speakers with a 2.6 ohm load. This supposedly caused output transformers to blow at high volumes.
62' Fender Super
The 6G4a Super is also an early design with 2-10" speakers. In 64' they added reverb and 2 more speakers to make the 4-10" Super Reverb. This 40 watt great sounding amp that also became a studio favorite. Look at Wrecking Crew pics and you will see one of these in most pictures. This is also the amp the 1st Vibroverb was based on.
Here is a fairly rare Fender model. This amp was a fairly close replacement for the Tweed Bassman. This, along with the Vibrosonic, was released in late 59', both had a larger output transformer for more power.. This 6G12a Concert has 4 - 10" 10K5 Oxford speakers with plastic magnet covers. In 64' Fender released the blackface Concert that was soon replaced by the Super Reverb.