Montarbo Echo Unit 115 patented magnetic memory echo unit - from: 1978 to: 1980

Link: kristiankriesel.blogspot

Summing Up, I think the main theme of all these old echo devices is repair, So while their fun be able to fix them or know someone who can. checkkhk out his video to see how much fun repairs are https://youtu.be/Hhdyf04vAhk

Controls:

• Level: Input Level (Microphone) & Input Level (Instrument).
• Tone: controls the tone (bass/treble).
• Repeats: controls the amount of Repeats.
• Volume: controls the Master Volume.

Knob:

• Selecting The Delay: 1/2/3
• Echo On/Off

Connectors:

• Audio IN (Microphone *1 & Instruments *2) on standard 1/4' Jack.
• Audio OUT (20dB & 0dB) on standard 1/4' Jack.
• Foot Switch

Power Type and Voltage:

• Alternating Current supply (AC) / 220 Volt.

http://www.montarbo.eu [PDF]
http://www.radiomuseum.org