I lusted for an Audio Research SP-3 since I picked up a flyer for the unit when it was available new in one form or another. It went through a few changes producing 5 different versions over the decades, the last the SP-3C the rebuilt unit from sending one into Audio Research for a complete restoration. The different versions can be investigated at the arcdb.ws site: http://arcdb.ws/SP3/SP3.html I picked one up in about 1981 for a fair price and enjoyed it for a few years until the volume control kept losing a channel. I ordered the replacement pot from ARC and was completely successful in replacing the two capacitors that came with the stepped Alps volume control and unsuccessful in properly wiring the volume control since I knew nothing about how stuff worked and the instructions from ARC were not informative enough for me back then. Years later, ruffscruff (R.I.P.) on the asylum had a website that praised the unit and had pictures of his 3 and 3C which allowed me to see how to properly wire the volume control. The unit was back in service and sounded great. I've used it off and on over the years but usually use my brother's Audio Research SP-9 II. Additionally, Tom Clone, you remember him, he would come over listen to the gear I have and then go buy something very similar. This led him to acquire an SP-3A-1 and an SP-9 III that has some aftermarket upgrades. Bot better models that what I had and they did sound a bit better. Nothing earthshaking, though. Since then I have recapped and refreshed his SP-3 and have a thread on that on AK. When we did a listening session of preamps, an interesting thing was the difference they all exhibited, Crown DL-2 so clean sounding and some other non-ARC preamps and how the ARC preamps had the same Family sound. The two closest in sound of the few we tried. The SP-3A that I have has the full bloom sound of a tube unit. Using good tubes on the first position in the phono stage and first position in the line stage is recommended and I'm now more able to do that than in the past when I had a new set of Sylvanias in it from the local parts supply house. Can't find that anymore. Anyway, when comparing the -3 to the -9 II it was apparent they were from the same company. The 3 had more tube sound with a bit higher noise as expected from the eight 12AX7 tubes. The 9 MkII, a hybrid preamp uses one tube in phono and one in line both being 6922/6DJ8 and other than cleaner it is missing some of that tube richness I enjoy in my system. That bloom goes well with the cleanliness of the ss power amp and this is how I generally like to use tubes, in the preamp where tube replacement is infrequent vs. in the power amp where the output tubes wear out more quickly and cost a lot more (for regular prices, not vintage NOS tubes). It was surprising how close the -3 and -9 II were and I would be happy with either of them. The -3 is near original with a few RCA jacks replaced but not a wholesale replacement of caps and carbon comp resistors. Maybe some changes there will help the unit. I know that replacing the coupling caps, two pair in the -3, one in the tone engaged output and one in the tone defeat output can make nice improvements. We put Clarity MR caps in Tom's tone bypassed output. He now wants them installed in the tone engaged outputs. The tone controls of the -3 are very nice. I especially like the sonic improvement of using just a touch of the loudness, adjustable like on a Yamaha and others, the slight amount being a small bump top and bottom and probably correct for normal listening. Since I like the Luxman LRS gear, I found my first piece of it at a great price, the 5F70 tone control unit. I've recently been swapping gear, I have put the SP-9 in the system and have the tone control unit engaged since the -9 does not have tone controls. A bit of bass boost and a touch of high end makes the system sound a good bit better using the Dahlquist DQ-10s, sans sub at this time. More changes to come but I'm liking what I'm hearing. Anyone else able to talk about the sound of the Audio Research preamps? I know Jim (ehoove) has a nice description of the benefits of going to a successively newer decade of ARC preamps, he stated he has had three over the years. The ones I discussed are a few generations and dozens of changes to the models between them as well as a failed attempt to move to SS from tube with the SP-4/5 debacle.