... just be patient. Your tone will differ with the guitar, cabinet and speaker choice. It has taken me a while to find the tones I have been looking for. Remember this is not a spin-to-win amp. Each knob affects another and they are sensistive. I have found the best Metallica rhythms in Lead with more mids than you would think. The standard V in the eq doesn't work for me as well as when I adjust them to the song. I do like the 750 bottomed out though. 80,240,2200,6600 are all above the centerline and the next line up. If you use too much bass you mud out. If you use too much highs then the rest of your controls do little to nothing. I also tend to run a SD-1 into the amp though out of habit from prior amps (Marshalls). Again do not treat this like any other amp. It is a little different and requires patience and you will find what you want but you have to use your ears. Knob adjustment will be needed to get you close. Then you use the eq to fine tune it.
As far as giving you settings for Metallica goes, I would suggest you take the time to learn the amp with your setup. Your tone will change with your setup if you do not play in the same place (ie. if you gig) so you will need to be in control of your amp anyway. Try starting with the tone controls in the middle and slowly adjust them to your liking. This may take a little while but it is very effective. Make notes along the way if you find anything interesting. Do not get too frustrated that your clean and R2 can't both sound their best because they share their set of tone controls. Just choose which one is more important to you. I usually use the Lead channel for playing Metallica regardless of rhythm or leads. Keep your reverb low or off too if you are looking for that sound.
Don't forget that you will get different tones out of the Full Power/ Tweed power switch, Triode/ Pentode switch, Harmonics/ Mid-Gain switch, Class A/ Simulclass switch.
For home use I would suggest Tweed power, Harmonics, Triode, Class A. Though depending upon how loud you play at home and your taste in tone these settings could be different.
