Quote:
Originally Posted by RiverRatt
... I thought I'd share the latest roll. Since I got my newly tested tubes back from Marty, my good ol' RCA side-getters are back in V1 and V2. I've been trying to get V3 and V4 dialed in, but everything I put in there sounded like crap. I had ended up with a Tung-Sol RI 12AX7 in V3 (living on the edge), and some form of Russian 7025 in V4 and I knew the amp should be sounding a lot better than it did - the tone was dominated by this harsh treble sound. Finally it dawned on me... with all this preamp rolling, I'd been neglecting the big boys. I hooked my Sperry up to the test points, and one of my fairly new GTEL34M's was cruising at around 32mV and the other was up around 39mV. I got them back to around 36.5 each, which seems to be the sweet spot, and the magic was back! I'm always telling people if their DSL isn't sounding right, check the bias, and here I go like an idiot, swapping preamp tubes every 5 minutes and wondering why it ain't happening for me. Now I'm good to go until that Tung-Sol craps out...
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Power Tube bias
definitely effects the tone. For my TSL, Marshall recommends 90mV... I've found a pre-amp combination (thanks to Marty) that I really love, and before moving on to another variation of pre-amp tubes, I decided to experiment a wee bit and see how my power tube bias will effect the sound that I know I already love. Personally, I've found that as good as it sounds when biased as recommended, and having the pre-amp / power amp tube combination that I have, it actually sounds even better when I run it with the bias even lower... say around 85-86mV. I think it's cool how all these seemingly small things have such a noticable effect on my tone.
PS. Let us know how those Tungsols work out for you. I have some currents production Tungsols and haven't used them yet... Not sure where to stick them at this point!
