Has anybody out there upgraded the 12AX7 in an SWR Amp or combo with good results? I was thinking of trying a Harma Cryo tube or even going overboard an installing a NOS Mullard valve. The HiFi and guitar types seem to think these tubes provide a big improvement in sound in their equipment. Can anyone speak from experience on this subject? Has it been brought up before on this or any other bass websites?
Although there is nothing wrong with the tube that came in my SM400S I replaced it with a NOS Mullard. Very nice sounding. THis is where I got it, give him a try. http://www.kcanostubes.com/content/
Why not try a 5751? A bit less gain than a 12AX7, but generally is warmer, and aren't as expensive as 12AX7s.
nice post...is the sm400 realy sensitive to different preamp tubes? i still have the stock GT tube in mine...
I have an SM500 and a Grand Prix...I found both of them to be very responsive to the type of tube that was used. Whether or not you can actully hear the differenc depends on how you cabinet responds. With my Acme cabinets I found the difference profound. With my Epifani cab, I can hear a difference at a gig but it's no big deal. With my Eden cabs...it didn't matter what I used it all sounded like Eden. Not that there's anything wrong with that, if you like Eden. FWIW...I like Telefunken tubes in my SWR stuff.