Rongge

This is Stereo Amplifier On this schematic amplifier circuit  use the ic AN7145L , but can use the following IC : AN7145M AN7145H AN7146M AN7146H You can use of all ic above. anthis circuit need suply voltage with dual voltage . Minimum voltage 6 Volt and maximum voltage 20 volt . Voltage just (-) and (+), but (-) can also ground. Maximum power output 2 X 20 watt with minimum impedance 4 ohm. Click image to view enlarge. You can operate this circuit with  plugging input to , PC or other media can give signal audio.

The circuit above is a dummy load capable of handling up to 10 watts of RF power for a few minutes, and its impedance is 50 ohms. It is constructed with 10 parallel resistors 560 ohms per 1 watt, R1 to R10, a voltage divider R11-R12 and a rectifier D1-C1. Its output voltage in a voltmeter which can be connected to measure the RF power.

Just like everything else on this vintage Hofner Colorama II, the electronics have been treated badly and need some attention. By “badly” I mean that they have been left in a damp or wet environment and the pots are scratchy or cut out completely. The output jack also needs to make better contact. This can hopefully all be fixed with the help of some electrical contact cleaner, but first I’m going to remove all the parts from the pickguard. This isn’t strictly necessary, but since I’m restoring the whole guitar, and the pickguard also needs attention, this is the route I’m going to take. Firstly, here’s the whole pickguard/electronics assembly. As mentioned in another post, the beauty of the Colorama is how the entire electronics circuit is attached to the pickguard and can be lifted out in one go: Here's how it looks from behind: The knobs are removed, revealing some rather disturbing evidence of damp. Check out that rust! Rather that turn the whole pot by accident when I’m unscre...

This post is under consruction