So, it's my understanding that if i pull 2 power tubes, the outer ones, it reduces the power from 120 to 60 watts. and if i'm running the head at 8 ohms into the cab at 8 ohms, i have to switch the head to 4 ohms.

1.will this make it a little more tolerable for my family when i play with them at home? 2.is it safe to do without any damage to the amp? and 3. can i put the tubes back in and switch back to 8 ohms any time i want to play at 120 watts, and is there a certain procedure i must follow when doing so?
1997 Ibanez RG550 w/ EMG 81 bridge - C standard
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Looks like you've done your research!

1. It will make basically no difference. The 6505 is designed to run the power tubes very clean, so you gain no real advantage by lowering the headroom of the power section by a small amount. I won't say that it does nothing, but most people are surprised at how little difference this makes to the volume.

2. It's perfectly safe for the amp.

3. Yes, just drop them back in, no changes needed beyond the impedance.
Remember the first rule of guitar amps - Wattage is a measure of headroom, not volume. A 5W amp can piss off your neighbors just as easily as a 300W amp.
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Yeah you have it right. Pull the 2 outer tubes or the 2 inner ones and set the ohm's on the amp to 1/2 of your cabs impedance.

I have some recordings I did of mine running at 60 watts I'll see if I can dig up later. I was able to turn up the post gain higher with only two tubes. However, I didn't really notice a significant difference in tone other than when I dimed it and placed the cab in a separate room with the door closed.

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