I put this advice to share the information I gathered on this amp.
Defective bought for next to nothing in a flea market. it is only opening I discovered that there is much beautiful people in there: four 12AX7 and EL84 5 1 5AR4! He was down? Not really just change a 12AX7 to get more than 40 years!
It's heavy! As the solid actually more! All welded point by point by hand! I intend to use it with bass guitar and keyboards! with a booster I'm sure it'll rock!
If you have a chance, Go ahead close your eyes! It's not that I knew previously Realistic! (We are far from useless stuff and plastics usual brand!)
Stereo Amplifier Tube Made In Handwired States.
22.5W per channel for a total of 45W RMS tube.
5 12AX7 ....
4 EL84 ....
1 .... 5AR4
Bass and Treble controls for each channel
Control Balance L / R
Switch Mono / Stereo
Input selector: Phono TN / Tuner / Aux
Output selector: L Stereo Norm. / Rev Stereo / Left Channel / Right Channel
Ability to patch the output impedance of the back: 4,8,16 ohm
Output Stereo Recorder
Manufacturing: Technical Apparatus Co., Inc., Boston 17. Mass (Massachusetts, United States)
I put here the data sheet as that of 40b Stereo Stereo 40 / A is found. However, there is very little difference between the two amplifiers.
The Stereo 40 / A does not have:
The remaining specifications are the same.
date of manufacture: less than 1963 (Stereo Model 40b for the Radio Shack catalog 1963)
40 / A stereo amplifier at radio shack famous Savings!
Most Advanced Technics Quality-All Features
New Super-Power Transformers-
-14-Tube-Top Operation Stability
Full-controls; Case included
The 40b marks a giant step forward in better production of audio equipment. LATEST engineering techniques and superb craftmanship created this superior instrument. Priced Lower Than competitive amplifiers, the 40b Delivers a full 45 watts (90 watts peak) of stereo power combined with the Necessary controls for full Enjoyment of Both monaural and stereo material. It Is Ideally suited for use with low efficiency speakers. Now Improved by a full octave is lower frequencies, it employed new, massive output transformers to Provide extra wide frequency response at Both ENDS of audio spectrum. Dual stereo controls allow Adjustment of Each speaker Individually. Obtain IS perfect stereo balance with the single knob control balance ... No Need for fussy speaker placement! 9 Tubes (5 dual) more correct Provide ultra stable 14-tube performance. center channel output (derived) Eliminate Need for a supplementary channel stereo amplifier for Three. Special adjust stereo switch Loudness compensation. Improved Styling panel includes stereo headphone jack
-Output: 22.5W Each channel (Monaural peak).
-Frequency Response: ± 1 dB from 20 to 20.000 cps (Hz)
-Distortion: 0.9% RMS at full output.
-Hum: (At full output) Mag Phono-59dB-59dB Tape Hd Tuner 79dB-79dB Aux-
-Sensitivity: (At full output) Mag-Phono 3mV at 100cps (Hz) Tape Hd-2.2mv at 500cps (Hz) at 1000cps Tuner-180mV (Hz) In-180mV at 1000cps (Hz)
Tone Control: ± 10dB at 50cps (Hz) ± 10 dB at 10.000 cps (Hz)
-Loudness Control: ± 14dB at 50cps (Hz) ± 3 dB at 10.000 cps (Hz)