YJM Rig:
Its as simple as this:
Fender Strat [pref Vintage White] scalloped and dimarzio'd up.
Dod250 Overdrive Preamp [this baby does give you that Malmsteen tight low end]
Dunlop Wah [optional]
Marshall 50watt NON master head c.72-73 or the Marshall 1987x re-issue, an exact replica of the 72 metal panel Marshall which is what YJM uses - he is not a plexi man.
Marshall 4x12" [x2] pref loaded with Celestion 30watt speakers [70's vintage] not V30's.
In an optional rack then put in:
2x Korg DL8000R [delays]
1x TC Electronics G Force
Boss NS-2
Noise Suppressor
Boss Flanger
Boss Octave.
This is all run after a line out signal has been taken from the Marshall heads then run through the rack into Marshall 400watt poweramps back into the multitude of Cabs.
For older YJM then just bypass the rack for Steeler to Trilogy tone.
The basis of Yngwie's sound is POWERTUBE distortion, not preamp, although his sound is starting to lean towards that side of late.
Also if you want the Facing The Animal or Concerto tone then you need to get a Fender Roc Pro head or combo, and go from the preamp line out into the Marshall head [in place of the Dod250 or TS-9 Tubescreamer]. *This was basically used as an elaborate
overdrive pedal.