Fender Twin Reverb Silverface 1969

Fender Silverface Twin Reverb
1969
Serial No. A20769

The Fender Twin Reverb is one of the most popular and desirable amp in the Fender tube amp line. It is re-issued by Fender and remains a current product in the Fender amp product line-up, attesting to its popularity. It has an awesome clean sound that is well-complimented by its built-in reverb and tremolo effects. It is pedal friendly and it is easy to get desired sounds using outboard effects.

I did a very rough comparison noodling through my '69 Twin Reverb and my '73 Fender Vibrolux Reverb (rated at 40 watts) using the same set of speakers. They both sound sweet and inspiring. I'd give that round to the Fender Twin though I think it is mostly because I liked the quality of the reverb of this particular Fender Twin better than the Vibrolux's. It maybe just a quirk in my particular amps and/or the "reverb tanks" used and may not hold true for other examples of these amps.

My '69 Twin Reverb has all original transformers. It has an original multi-voltage power transformer (selectable power voltage). I got this amp in a home-made head cabinet. I imagine that it would be cool to have a custom pine combo cab made for this amp. Hmmm...

According to the Fender code system, this amp was manufactured on the 25th week of 1969 (or June 1969). Just a month or two ahead of Woodstock that was held in mid-August 1969.

Teisco Model #62 Tube Amp

Teisco Model No. 62 Tube Amp
Made in Japan
Year circa '60s(?)





This is a one channel, Class-A (Single-Ended) all-tube guitar amp that puts out about 4W of power to one 6" speaker. There are four (7-pin) vacuum tubes specifically 2 x 6AV6 as preamp tubes, one 6AR5 power tube and one 6X4 rectifier tube.

This amp was marketed internationally under Teisco, Beltone, Northland, Takt and other brand names. There is a similar model with an additional 6AV6 tube and corresponding circuitry and controls for 'tremolo' effect. These 'tremolo' equipped models usually has 2 speakers.





It has 2 inputs, one volume and one tone control knobs, on-off switch and pilot lamp. I like the quality look and feel of the panel and its components.



The power transformer has a 110 and 220 Volt tap and a vintage knife-type SPST voltage selector switch.



There is very little information about teisco amps on the internet, I have not found any schematic so far.

I expect that the circuit would be very similar to vintage Gibson Kalamazoo Model One and Fender Champ 600 amps. The two 6AV6 preamp tubes in the Teisco would be equivalent to the two triodes (V1a and V1b) of the 12AX7 in the Kalamazoo Model One, shown below.


Schematic author is Miles O'neal of Austin, Texas and is originally from http://www.rru.com/~meo/Guitar/Amps/Kalamazoo/M1/schem.html

I added a phono plug and jack so that an external speaker can be conveniently plugged-in instead of the internal 6" speaker. I will fix the jack in a bracket to make it more secure and elegant looking.