Category Archives: Anything

How to measure real output power of audio amplifier. Sometimes on some cheap audio devices you can see magical numbers like 1000W or something, and device is handheld. It is not real power, it is bullshit. Attach dummy load to … Continue reading →

I removed few Optrex DMC50264N LCD modules with few buttons from some old laser printers. These modules are controlled by Mitsubishi M50530-026FP and M50521FP chipset. It is 4 lines 16 symbol special LCD module controlled by master CPU only by … Continue reading →

In older post I wrote that long time ago I built my first tube amp. Today, in old magazine, I found the schematics. As I remember, the output stage was working, but I made some mistakes in pre-amp. I left … Continue reading →

For my audio amps I needed some small generator just for testing. And I also had MAX038 chip sample. Here is the abstract from datasheet: The MAX038 is a high-frequency, precision function generator producing accurate, high-frequency triangle, sawtooth, sine, square, … Continue reading →

In German (sprut.de) pages I found small schematics for caps meter. This schematic is designed for electrolytic capacitor metering. According to author, device range is from ~10µF to ~65 500 µF. This is not very accurate meter, but it is … Continue reading →

In elektronika.lt and in original pages at sprut.de there is placed simple frequency counter schematics. It consists only from Microchip PIC 16F84 cpu and LCD text module. Author states that this counter is capable metering frequencies from 400Hz to 50MHz. … Continue reading →

At my workplace there is old big copying machine- Minolta Dialta. Recently we bought second hand printer module for it. It is called Minolta Pi 1800, GDI printer module. I decided to make it work in intranet. It was possible … Continue reading →

One day I had small attack of shopping and I bought small pellet of gallium. It is quite strange, non toxic metal. It’s melting point is only 30°C. To be exact- 29.7646°C. And boiling point is very high- 2204°C! It … Continue reading →

Older post tube amp schematics looks something like this: Big circuit diagram for printing This schematics and tube amplifier is not designed for tube maniacs. It is designed to test tubes. Resistor’s and capacitor’s values may differ, because I build … Continue reading →

I have lots of 12AX7 and 12AU7 pull-outs. And I need to test them. While building some testing gear, I decided to add one more tube and transform it to tube amplifier. Why it is “second tube amp”? Because, about … Continue reading →