The reviews of the PAT4 in Stereophile years ago put it in the same league as the PAS-3. I got a PAT4 on ebay for $75 that works great. They are old, though and I think it takes a little bit of luck to get a decent one (either 3 or 4) sight unseen. there have been several 3's here on audiogon recently. One thing I have found with old vintage equipment is that the ear of the beholder (ie the seller) is sometimes more charitible than another's ear. Good luck. Also if you can find a Hafler preamp--they are newer and from the same lineage.