Difference betweeen Aragon 4004 Mark I and Mark II

Thanks for the response. I am thinking of getting a used original 4004. Based on your response, I should be looking for the Mark II version then. I can live with a lower performance amp but I don't want to worry about resistors damage.

If the emitter resistors are "flaming", the amp has a LOT more problems to worry about than just a few smoked resistors. That's because those resistors will only "flame" when the transistors are damaged / on their last leg. As such, you can replace the resistors if / when you have to replace the transistors. Granted, this is a problem that should have been addressed with the original design, but at the same time, it will only happen under specific "high stress" situations. Sean
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What effect does it have on the sound if any and why can you not do the replacement yourself if it's only a few resistors before the output?

Just thinking?

Another difference is the use of a bias system that adjusts itself to changes in line voltage in the Mk II.

This is the first I've heard of flaming resistors!

I had a 2004 Mark I for over 10 years and never had a single problem with the unit. It now serves duty in my brother's system, continuing to function flawlessly. You can check with aragon about the difference. They have very good customer service.