Hughes & Kettner Vortex Guitar Amp Head, 80 Watts

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Vortex Front: Hughes & Kettner VortexVortex Front: Hughes & Kettner Vortex Made in Germany, but so what? Pretty cheap bare bones construction: particle board cabinet that was cracked, needed glue and clamping, dowels that held the joints together had come apart due to lack of glue. The Korean spring reverb inside had fallen off due to cheap springs that held it to the chassis. The chassis itself was just a piece of rolled metal, not a box like the nice Fender chassis. Anyway, the amp came to me non functional and blowing fuses. I tried powering the amp up slowly on a variac and it would blow a fuse when brought up over 20 VAC. Which reminds me, it had the small european fuses. Anyway, I figure out that there was a ton of current in the output stage. I checked the voltages on the output transistors and viola, there was no base to emitter voltage to support that current. This indicates a bad transistor and sure enough, it was shorted. I replaced it and the amp worked. It was a TIP142 and TIP147 in there. Pretty common audio output transistors, you'll find them in a Fender Deluxe 85 also.

All that being said, gotta give them credit for building the audio amplifier section out of discrete transistors as opposed to most of today's amps which just use an IC. This probably had something to do with the sound of the amp, which was actually pretty good. Nice metal tones with smooth distortion.

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