Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: norstroms on March 18, 2015, 04:06:32 pm

Title: Immortal amp mod vs Trainwreck - MOV parallel to 1N4007s?
Post by: norstroms on March 18, 2015, 04:06:32 pm

I've been thinking about R.G.Keen's Immortal Amp Mod suggestions lately. I've used the Output Spike Protection suggestion from the Trainwreck Pages (RIP Mr. Fischer) for years, three 1N4007 diodes in series from plate to ground. Mr. Keen suggests that an MOV would be a better choice. Since these components work in different ways but in this instance are employed for the same-ish purpose, I was wondering would it be unwise to place an MOV across the series of diodes? I'm merely curious, this is not a stunt I would actually try without learning more.

For reference to those who may not be familiar with these:
Trainwreck Pages: www.blueguitar.org/new/schem/ (http://www.blueguitar.org/new/schem/)trainwreck/the_trainwreck_pages.pdf
Immortal Amp Mods: http://www.premierguitar.com/articles/the-immortal-amplifier-mod-1 (http://www.premierguitar.com/articles/the-immortal-amplifier-mod-1) [follow links below the article for mods 2-4]

Title: Re: Immortal amp mod vs Trainwreck - MOV parallel to 1N4007s?
Post by: trobbins on March 18, 2015, 06:35:34 pm

Understanding the reason why the diodes or the MOVs are there is a good place to start.

http://dalmura.com.au/projects/Output%20transformer%20protection.pdf (http://dalmura.com.au/projects/Output%20transformer%20protection.pdf)