Roger’s Guitar Amplifier projects

Designed by Roger Knopp, M.Sc.E.E
knopp.electronics@iname.com
phone/fax: +46 31 252345

The Universal Guitar Amplifier KEW/UA-92C seen in this page is my third attempt in building a cheap but good guitar amplifier for musicians or "poor" tube-loving enthusiasts. My chosen Williamson Power Amplifier KEW88-91DN is actually integrated into this Universal Guitar Amplifier. Output tube voltage clipping has been chosen as an optional dirstortion feature. The tone control rolls off at the standard RIAA frequency of 2.1kHz. The amplifier might even be used as a "travelling mate" to amplify for instance a CD-freestyle. Not to mention a guitar or RIAA correction for (MM) pick-ups. My next version will even include a DC/DC-converter for optional portable "beach" usage!

	Main Data: Power Consumption: 100W@230/115V 50-60Hz Maximum Output Power: 40Wsqr@6R/1kHz Mic/MM Sensitivity: 7mV/47k//150pF Overall OL-gain: 84dB@Mic/1kHz Miscellanous I/O: 1) Line-in: 150mV@100k (inverted) 2) Pre-in: 1.5V@1M 3) Rec/Pre-out: 230mV@400R 4) External Speaker: 4-8R (DF0=16dB@6R, BF=OL/17dB)
KEW/UA-92C, The Knoppson Universal Guitar-Amplifier Mk III.

KEW/UA-92C, The chosen Knoppson Universal Guitar Amplifier circuit diagram
KEW/UA-92B, The second generation Knoppson Universal Guitar Amplifier circuit diagram
KEW/UA-92A, The original Knoppson Guitar Amplifier (photo & data)
KEW/UA-92A, Circuit Diagram
KUC-00A, Simple PWM DC to AC/DC Converter

(The original Roger’s Guitar Amplifier projects is unfortunately not longer online)