The actual guitar sound is quite clean, so I would stick with the low power pickps, Stormy Monday's or PG Blues will get this sound. My A5 Mule/A4 Stormy Monday can also get it. The overall sound is from running the amps hard. I have stood in front of Paul Kossoff's stack when he was playing at St Georges Hall in Bradford in the early 70's (they used to have side stage tickets in those days), and can tell you that he used the amp a lot for his sounds, he would change the volume when he was playing (holding long notes helps with that).