Anyone using a .007 orifice / .020 mix tube combination with success on a Paser ECL head?  With just the water on, the jet is perfect, with zero flare/haze.  When I turn the garnet on, the jet turns into a super-flared, hazy, spitting mess.  Here's my setup:

Paser ECL head, freshly rebuilt mini on/off valve, works perfect with .013/.030 & .014/.040 combis
.007 ruby orifice, brand new
.020/3 premium mix tube, brand new
150 hpx garnet in a custom-made pressure tank (so I don't have to purge the main hopper/lines)
.075, .100 & .125 metering discs (tried all 3)
1/4 & 1/8 garnet feed lines (tried both)
set at 50ksi

'Normal' logic says that if the orifice is blown, the water-only jet is toast, so I have to assume the orifice is OK.  I have a good vacuum signal at the mixing chamber, and consistent garnet flow out of the mini hopper.

Anyone got any ideas?

Never hear of those discs...did you make them? At any rate if you have good abrasive flow and vaccum I would say check alignment or swap tube and orifice. It is possible to get a orifice that is misaligned. If this were the case it ricochets off the tube wall creating all sorts of issues. Our setup when cutting small parts is .007/.020 .4 lb/min 180 mesh @ 60,000. we use a small abrasive line that Flows Application gurus told me how to make and have an awesome jet.