This video is the first part in a deep-dive into Electro-Harmonix Linear Power Booster pedal, the EHX LPB-1. We get slightly more technical with a basic AC Analysis and some experiments to measure our calculated values.
The circuit is a simple Common Emitter Amplifier with Voltage Divider Bias and Emitter Degeneration Resistor.
00:00 Introduction
00:31 Converting the Circuit to AC Equivalent
01:47 Simplifying AC Circuit
04:27 Exploring an AC Transistor Model
15:00 Recalculating Voltage Gain
17:03 Measuring the Voltage Gain
17:42 Measuring Input Impedance
22:28 Calculating Output Impedance
26:21 Measuring Output Impedance
30:10 Calculating Frequency Response
33:05 Measuring the Frequency Response
34:27 Summary
35:27 Coming up in Part 3
My notes can be found here:
www.dropbox.com/scl/fo/z4hlxd...
Coming up in Part 3 - Modern additions to the pedal and the pedals based on this one such as the Screaming Bird and Mole.
I am no expert in electronics, I remain a curious hobbyist. However, I have always been fascinated by learning how audio electronics works and, as I make these videos my knowledge increases massively, I hope yours does too. If you're unsure about the more technical side of things, my best advice is just to get started, mistakes and corrections (and the occasionally popped component) are how we learn.
If you found this video useful, want to correct my knowledge, or just want to know more about my DIY pedals and test gear leave a comment below.
If you'd like to support my channel and get some cool stickers, you can find my Etsy Store here (I'll be adding some electronics kits in the future): www.etsy.com/uk/shop/MusicTec...