Fender Tweed Deluxe Amplifier

One of the most popular tweed Fender amplifiers ever made was the Tweed Deluxe. The chronological order, from beginning to end, is: 5B3, 5C3, 5D3, 5E3, 5F3, with each being different from the others.
The 5B3 and 5C3 are nearly identical, with both having a wide top panel on the front and three inputs. Two inputs were for the musical instrument channel and one input is for the microphone.
Typical of both amps were the metal 6SC7 preamp tubes and 6V6 output tubes. 6SC7 tubes have lower gain than a 12AX7 and use a socket that is the size of the output tube. While the 6SC7 is twin triode like the 12AX7, the tube has only one cathode.
The 5B3/5C3 amps have an unique grid leak bias first gain stage. This is one way to bias a preamp tube in which there is no cathode resistor, but instead a capacitor and large value resistor (5 meg) are in series with the grid signal circuit. Grid current leaks out through the input circuit causing a negative voltage to appear on the grid, thus biasing the tube.
Of course this arrangement has its disadvantages, the main one being that it cannot handle a very large input signal. Grid leak bias circuits are pretty much obsolete and have not been used since the mid 1950s. Be careful using a tube driver or any other high-gain device on these amps.
The5D3 Deluxe was introduced in 1955. This was nearly identical to the earlier models except that it used a self-balancing paraphase inverter, whereas the earlier models used a conventional style. Some of the 5D3 Deluxes have 6SC7 preamp tubes, but others had the chassis punched for the large octal size socket with an adapter covering the chassis hole and a 12AY7 and a 12AX& pin place of the two 6SC7s.
From 1958 to 1960, the 5F3 Deluxes were produced. This circuit was almost identical to the 5E3. Voltages were somewhat higher, giving more gain. Cosmetically, it looked the same. Both the 5E3 and 5F3 had more gain than all the previous model Deluxes.
All tweed Deluxes had solid pine cabinets with Jensen speakers. Some of them came stock with P12R Jensen and some had the P12Q, which sounded better. When buying an old Deluxe don't assume that the speaker is original just because it happens to be a Jensen. Jensen made many models of 12" speakers, some of which were no good. For instance, both the P12S and the P12T are Jensen but are non-original with hardly any power. The P12N is worth major dollars, if you can find one.
Triad made the transformers for all tweed Deluxes. If the output transformer has end-bells, it is non-original. Original transformers were wound with papger and had no end-bells.

From Desktop Reference of Hip Vintage Guitar Amps