I am commenting for my cousin who is traveling today. Together we both have an original SP3A-1 and I also own a SP-3C. Yes the SP3C sounds more modern....but late at night after the original warms up at least 3-4 hours.....wow...good by speakers. Maybe it takes that long for the old power supply caps to charge?? Harry Pearson always thought the complicated circuit in the original added depth, I agree.
But back to this odd bird he/we bought on ebay....basically we were curious what the hell was done to this preamp. FYI, when he pushes the tone control defeat on MAIN LINE OUT2 sounds like an very old tube preamp. Using MAIN LINE OUT1 good grief modern sound, in fact maybe the best SP3 he/we have heard. The closest preamp that we have heard that sounds like this is an SP8 version 1. FYI, the tech who did the mod upgraded the wire to ASHA??? large black wire on Main1 out, he left the old grey beldon on Main2 out. After we have played with this thing we are going to take it to our Tech and have him look the power supply over and see what the hell this Mr. Robin/Rodin did?? I forgot to mention he added an extra small transformer over the A-1 sticker, I assume for the tube power supply.
We were hoping someone in audioland would recognize his name. The preamp was modified in the state of Washington. The sticker inside the preamp is smudged where the B or D is in the middle of the name. This is one strange / unique SP3.....