behringer v-amp

Last update: Thu Jun 5 22:25:40 2025

Some random stuffs about my Behringer V-Amp!

Presentation

Principle

A guitar virtual amplifier, very nice, small and cheap.

Power supply

Why

In second hand auctions, I managed to score a V-amp 2 and later a V-amp 3 but in the end I have only one power supply. So I hoped to make one for cheap and sell the "improved" V-Amp 2 therefore, maybe with an USB cord instead! Might not be that easy though...

Details

Unusual thing for this puppy is the power supply:

4 pins + casing type of connector (old mouse/keyboard style for the boomers)

11V AC and 20V AC : not DC!

After probing :

Connector case is ground,

Left/Right pair of pins are a AC (1 AC and 1 GND)

Opening the beast, the investigation continues:

One AC signal (the 20v) after regulation by diodes goes to 2 15v regulators : 7815 to make 15v and 7915 to make -15v

One other AC signal (the 11v ?) after regulation by diodes and caps stays as is

Part of the above signal goes to an old faithful 7805 to become 5v (with a big fat heat sink)

... half a year later ...

I bought this below venerable transformer, sirca 1978 edition (Showa 53 as we say here in Japan). It has the voltages I need with sufficient amps. Details are listed below.

入力は、(input voltage)
　①0V-100V-110V-120V
　②0V-100V-110V-120V

出力は、(output voltage)
　①20V　0.5A
　②17V　0.1A
　③17V　0.1A
　④11V　1.5A
　⑤10V　1A
 
Size 約90ｍｍ×65ｍｍ×50ｍｍ

About 1kg of antique goody

Links

Helpful sources

Inspiration

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