The old guard of the D*A*M's were all born from the same primordial swamp. Tone Bender's and Fuzz Face's were king, they roamed the land devouring all in site. No other viciously saturated beast even came close. The life force and magic contained within could not be matched. The Dragonfly, the 1966 and the Deluxe (MHX) were all intended to operate in this old school way, there is no stun control just kill.
To begin - set it full and inch it back. Don't start at noon. Start at full bore. There is no stun remember, though there is more going on here than you think. The idea is about cutting what you have. If you are only interested in high gain tones you only need to think about the small rotation from 3 - 5 O'clock, 5 being maximum. The upper most top end of the gain will cut and fast. You may only need to move the control a wee tiny bit to find that balance from all out war to simmering on the front line.
If you are rolling before noon you'll find the tone darkens a fair bit and the use of the Treble control will become more open. There is a lighter and more dynamic side to the MHX if you give it time and explore this lower setting. It helps to have the Level control set high and to be playing your amp at a good volume. This was a pedal designed to handle and to really shine at very high volume so it will sound more alive when used as such. Remember this. MHX likes it loud.
If you are concerned about slamming the shit out of your lovely little vintage amp do the following:
1) Plug everything in, your instrument to the 'IN' socket, amplifier to the 'OUT'.
2) Set all the controls to zero, all full left, and then activate.
3) Bring up the level control until you reach unity with your clean bypassed tone. Between 10 and 2 O' clock depending on your pick-ups and guitar type.
4) You can now roll up the Attack. Like I say, these controls are best used in attenuation. Set at full and roll it back to taste.
If the tone is too dense turn your attention to the Treble control. Notice how the low bass frequencies drop out as you roll towards the right. Around 11 O' clock is good if you desire clarity and like to chug (palm mute) and around 3 O' clock and upwards if you desire and fast choppy dynamics. If your desires are only for mucho sludginess shut that fucker down and roll if all off.
The Treble is what it is. It will not vastly shape your tone like a Big Muff's tone control would though it will sculpt the signal flow offering intensity and pronounced dynamics as you see fit. The tone overall will remain the same though as you remove treble and add more bass the circuit will clip a little harder. The crudity of this is intentional. As dominating as the MHX can be its only an ingredient in your signal chain. Its the spice in your Curry.
Lastly, a little noise as you turn the Fuzz control is normal. I didn't break it.