Instruction and explanation Vox Echo Short Tom MKII CO2 (1963-1968 ) en Long Tom MKII CO2 (1965-1966), CO3 en CO4 (1966-1968).

The tube assignment V1 to V6 is as follows for all Tom types : V1 input preamp 1 + 2 ECC83 / 12AX7 V2 input preamp 3 + mixer ECC83 / 12AX7 V3 recording amplifier ECC82 / 12AU7 V4 feedback and playback amplifier ECC83 / 12AX7 V5 rectifier EZ80 V6 erase oscillator EL 84 at CO2 and ECC82 / 12AU7 at the later CO3 and CO4

Trimpots  between the tubes to set with all front potentiometers at 12 o'clock, with clean heads and new tape .   - Unity Gain – middle front : to balance direct signal with the echo signal. What the guitar in the echo brings to your liking come true. Adjust the trimpot  from zero clockwise the  softly slow far away signal to a hard direct  signal. - Intensity – left back: to set the Feedback level. Adjust the trimpot from zero clockwise from tam to over the neck.

The 49.8 cm long tape is driven directly at the Short Tom by the spindle of the motor and a pinch roller. At the Long Tom by a brass flywheel with 5 inch capstan and pinch roller . This gives the LT a speed of about 300 RPM, the tape speed is about 7.5 inches = over 19 cm / sec with a tape length of 68-68.5 cm.

Connection transformer-motor module is done at Long Tom CO2 by means of an Octal plug and socket , at CO3 and CO4 by means of 9 pin connector strip with 3 fuses under a metal cover.

The CO2 models have Marriott Brown bakelite heads attached with flanges the later CO3 and 4 models Marriott Brass heads attached with saddles .

All models have a R(ecording) head, 6 P(lay)B(ack) heads and 1 E(rase) head. The different echoes are set with the 4 push buttons and an "Echo- Repeat " ( rapid-slow ) switch that only works if the "Hallo" button is also pressed on. (Recording heads 1 to 4 on this picture are unfortunately no longer original, but replacement Vikron heads )The push-button " Echo" brings the echo with a delay of 7/10 sec, the buttons " Repeat and Hallo" of 3/10 sec. The " Reverb ." button adds reverberation and feedback.The " Echo" button switch on head 6 , head 5 with the " Repeat " button. The " Rapid " stand + " Hallo " switches head 1 to 4 in, " Slow " + " Hallo " only head 1 and 3.

The front panel shows next to the 4 pushbuttons, 3 individually controlled inputs ("Input / Vol 1 to 3 " ) , switchable by pulling out. A  Normal-Echo (amount) control which, by pulling out the motor , thegreen "motor" lamp and the  taperun start . The off / on switches the power and the red " Mains " indicator on and off . The output " Amplif ."   goes to the (power) amplifier and the " R emote " switches the echo off by a footswitch.  

Below the prints of two original Instruction Manuals from JMI. What can be confusing is that they mention a " Microphone " input, while the display only indicates "Input 1 to 3" for connection of instrument or microphone (high impedance ) . Note: In the case of a microphone with low impedance , the transformer should be tuned to it .