if I may wade in here ....I have the SP3 also , my first impression on hearing it was "great musical midrange it has potential " my Awe-phile pal ( with a harshly critical ear ..came over and listened , he also liked the mids ...but was not too impressed w/ the rest ..
when I suggested we roll a bit ...he said 'go ahead'
I removed the Chinese 12 AX7's and inserted a pair of older ...maybe late 60's bugleboys ( Holland) ...wow what a difference , he agreed , opened up the soundstage , definetely more musical ..we continued to listen
then I suggested another change ..'go ahead' he replied
this time I swapped out the stock 6922's for a very special pair of mid 60's Amperex PQ's (USA) ..Wow again another step in the right direction ..extension in all the extremities ...that was it we made a night of it ...great presentation ..really enjoyable is how my friend put it .
a couple of days later he said to me ..here tryy these as he gave me a little packet ..inside was a pr of old stock 12AU7's also bugleboys , but this time from England
I listened to the system w/out these ...some Ella F , not too bad ..then I put in the BB's ....it amazingly smoothed out the top end , sybillance was gone ..the cymbals shimmered ...WOW
my friend who has a very expensive Atma sphere set up ...confessed that before hearing the SP 3 he was convinced he would not like it ...remarked he cannot believe the value of this unit , it has no right to sound this good at the price !
I agree & have decided to do the "full monte" ...I have ordered all the Parts connexion level 1 components ( see underwood wallys A-Gon ad for Onix ) , hexfreds , bypass caps , new RCA's , silver wire , resistors as well as teflon V caps for the pre cplg. ....I have a vision that this cute little unit can go all the way !