im not sure about which head Geddy was using then but when I had Sunn Model T its tone reminded me of his tone on Exit Stage Left. you might want to check one out. Entwistle used coliseums as well as Squire but i had read that he liked coliseum lead heads for bass.
as far as models:
these two are the oldest
black and silver/gray face (300?)
coliseum has polarity switch (mine thumps at power up, others have noticed on their coli heads) three (contour?) lo/hi or brite/norm switches low, low mid, hi mid, treble and vol controls
black and silver/gray face 880
i have never seen one in person but i imagine (judgeing from the photo here in the gallery) that it has a larger eq section or effects? sorry i dont really know about this one.
i think this was just before Sunn got bought out
black panel w/red logo (300?)
same controls as b&s/g face but no polarity switch (or power up thump) as far i know there is not a difference in the voicing of the circuit. mine does sound a little different from my b&s/g but i chalk that up to just being two different ones as they both sound like coilseums (like Marshalls they all sound different but they all sound like Marshalls)
after Fender
black panel white letters
has expanded (maybe different) eq section and i think a comp.
please correct me guys if i am wrong about any of this. slade
