One thought it may be best to print these mod's and get together with a techy type and have a mod tasting session. It is much better to play the same guitar with the speakers in the same spot and have someone else install and remove the mod's. Just focus and listen for the changes. Once you hear the changes re-adjust the amp to hear what changed at the extremes.
Another tip is to record amp via pro tools or a small mixer , then A/B changes with headphones on. This will make the changes very apparent and easier to notice with less fatigue.
Tip #1 - For MAZ 38 and MAZ 18 Reverb amps ONLY.
Solder a feedback cap to V1's socket across pins 6 and 8 ( plate to cathode ). The cap values should vary from 250pF/500pF/ 1000pF or .001 uF.
Each will take a slightly higher degree of Brightness away and will warm up the amp some, remove any harshness, and smooth out the overall distortion. This is a trick used by Dumble in various stages of his amps. They are credited with the creamy smooth distortion his high gain amps are famous for.
I use a parallel wired 12ax7 in V1, so this cap choose the one you like best will connect pins 1 & 6 one one end of the cap and 3 & 8 on the other end. Parallel plates to parallel cathodes.
If this is confusing to you DON"T TRY IT YOURSELF get a someone with a bit of tech savvy to install it. OK so much for parametric shelving now onto Tip #2.
But remember the MAZ is a combination of the HOLY GRAIL VOX, MARSHALL, and FENDER we just dealt with the Marshall Frequency/Gain of the 1st and 2 nd stage removing some of the Marshall's bite and Mid range bulge. Now TIP #2 deals with the Fender Tone Stack. We will adjust the EQ's smiley face by varying
the slope resistor. The slope Res. is the horizontal mounted resistor mid board between the 250 uF Treble cap and the .1 uF Bass cap. You will need values of 33K,47K,56K, and 82K. Your amp will have a 56K stock. 33K will give the MAX Bass and lower Mids, 82K will give the most Treble and upper mids. Also if you feel Froggy try a 25 K Audio taper pot in the Mid control instead of the 10 K that is stock. The 25 K will broaden the mids, remove some scoop, and lessen the Bass controls contribution. As you can see you are lessening the FENDER like tone stack.
Now TIP #3 - This will deal with the VOX vibe. The CUT control cap, only used on MAZ Juniors and MAZ Seniors. It is located at the end of the Phase Inverter connecting on one end to the EL-84's grids and the CUT knob. Varying this from .0022 uF, .0033 uF,
.0047 uF and .0068 uF , your amp has .0047 uF now. Changing this cap will increase and decrease the amount of Presence your amp has. Remember Presence is there to make your amp sound closer to you without it being louder. Adjust the CUT pot and see what works best for you. OK that works on the VOX side of the MAZ we hit all three .