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Peter · 07-21-2008, 08:58 AM

Quite right, Amplifier: the way the tube works in the AVT50 is on both channels. The pre-amp feeds into the tube. On channel 1, the tube is fed a clean signal, which overdrives the tube's input when the gain is up. With my mods, channel 1 gets some serious tube crunch on full gain. Channel 2 is like having a built-in distortion pedal in the preamp before the tube.

CapNCrunch, finding the right tube for you is pure trial and error. I tried over 15 tubes, and most sounded average, and some sounded flat. I am lucky for my old made-in-holland Rogers tube, which crunches, but still sounds sweet. I found I do like the Sovtek 12ax7wb tube, which is not expensive.

Thanks for your input, Arcarix. You are right about the parts; I get some of them from surplus. A complete kit, as well as a web-site are on the horizon. Thanks very much for your interest.
Cheers!

07-21-2008, 08:58 AM	#21 (permalink)
Peter Member Join Date: Mar 2008 Posts: 45	Re: Marshall AVT50 Mods Quite right, Amplifier: the way the tube works in the AVT50 is on both channels. The pre-amp feeds into the tube. On channel 1, the tube is fed a clean signal, which overdrives the tube's input when the gain is up. With my mods, channel 1 gets some serious tube crunch on full gain. Channel 2 is like having a built-in distortion pedal in the preamp before the tube. CapNCrunch, finding the right tube for you is pure trial and error. I tried over 15 tubes, and most sounded average, and some sounded flat. I am lucky for my old made-in-holland Rogers tube, which crunches, but still sounds sweet. I found I do like the Sovtek 12ax7wb tube, which is not expensive. Thanks for your input, Arcarix. You are right about the parts; I get some of them from surplus. A complete kit, as well as a web-site are on the horizon. Thanks very much for your interest. Cheers!