Just listening to this great pre-"Who's Next" gig and marvelling at Entwistle's sound. Non-reverse and the Hiwatt rig sounds great, it's not as dark sounding as his T-bird & Sunn rig a bit later (I like that too). Lot's of great songs they were soon about to drop from the set such as "Pure And Easy" and "Too Much Of Anything" and I even like "Water" here even if it's a plodding hippie rock number that does the band injustice.
With this in the background I was wondering if Entwistle used Hiwatts in the "Who's Next" studio sessions too or did he acquire the Sunn gear for those? The sessions started in May '71 and all the pics I've seen from the "Who's Next" tour have the Sunn rig.
Never seen any pics from the studiosessions 'though. Entwistle's recollections vary about the basses he used (P or Thunderbird) but a lot of the tracks sound like T-Bird to me when compring to his earlier Precision work. "Going Mobile" for example is a very clear T-Bird.
There's a pic from The Young Vic in the liner notes of "Who's Next" deluxe 2CD which is dated the 5th of May 1971 and shows Entwistle playing a P-Bass through the Hiwatts but the dating is incorrect (it's from 11/15/1970). The 4/26/1971 was their last at that venue.