Estey T-12: Bits And Bobs Part One

23 09 2009

1967 Estey T-12 Tube Amp Photo 10

As can be seen when the chassis is pulled, there ain’t a whole lot of circuitry to the Estey-T12.

1967 Estey T-12 Tube Amp Photo 11

The choke in the foreground looks shot to hell in person but the old guffer still does it’s job at 42 without a hitch.

1967 Estey T-12 Tube Amp Photo 12

This gets us a wee bit closer to things and as can be seen from the preamp and output tube assemblies, it’s true point to point wiring between the components.





The Estey T-12: Radio Tubes?

15 09 2009

1967 Estey T-12 Tube Amp Photo 9

For once, one of my amps has the schematic still attached! It’s a bit hard to see here but it’s all drawn up very nicely and also indicates that the amp design was approved for manufacture in December, 1964.

1967 Estey T-12 Tube Amp Photo 7

The tubes aren’t the average choices for most amps and that’s something I like; it sounds great while not featuring the same old 12ax7 and el84 lineup.

1967 Estey T-12 Tube Amp Photo 8

The preamp duties are performed by a 20ez7 with a 45b5 handling the output tube chores and a 36am3a serving as the rectifier.

Not sure if this is really the case, but I’ve read that a 20ez7 is a 12ax7 with a 20 volt heater. It’s definitely an uncommo valve and shows up in few tube radio applications in the early/mid 1960’s.

The 45b5 is known as a ul84 in Europe and was used in some mid 1950’s tube radio designs.

The 36am3a is a 7 pin vale developed in 1940 that was popular in the early and mid- 60’s for tube radio sets.





Strapless! Backside View Of The Estey

1 09 2009

1967 Estey T-12 Tube Amp Photo 4

The Estey T-12 is as humble around the back as she is up front.

1967 Estey T-12 Tube Amp Photo 5

And here’s a big reason why she sounds so sweet – Chicago’s finest – a blue label Jensen speaker.1967 Estey T-12 Tube Amp Photo 6

Date codes on the magnet cover peg this example from the 37th week of 1966, likely manufactured in September of that year.