previous: Trace I'm sure I'm in the minority here a... -- 9/25/2000 2:38 PM

Re: Trainwreck...built one...a ton of gain 2B expected???

9/26/2000 6:50 AM

BWilliamson

Re: Trainwreck...built one...a ton of gain 2B expected??? quote: "really not sure why people would spend in and around $5K for this tone(?) Am I the only one who feels this way???"     kinda have to agree with you here--I wasn't as impressed as I thought I should have been. The gain was over the top, but I couldn't coax much of a clean thru this amp.     Now, the original schem was supposidily based on the Callaham clone, reading Mook's West Coast Amp-Shootout. The description of that amp is it's just a gain machine.     So I'm guessing we're missing something. According to Holger(if I'm remembering correctly) when he showed the schem to KF, we were really close--but not quite. I personally think that's what we are missing.     When preparing my clone up, thinking about your tweaks for Marshall's--mainly the MV. I thought playing with the 3rd stage cathode resistor might help control some of the gain. It does seem to tame the beast a bit, I don't think it sounds as good as it should.     Thinking of going after the feedback resistor next to see what that does. But I keep reading how KF amps are staged so that the power amp clips right before the preamp, and that's where tha magic lies. Seem to get way too much signal from the preamp for that to be happening. Going under the next assumption that with all that signal coming from the preamp--the driver's being overloaded. Since we're not quite sure which tap or even if that 100K FB resistor is right, to me seems to be the next experimentation opportunity.     quote: "I think the .001 (I believe) coupling cap works well with low plate voltages but it could be bumped to arond a .02 if there's more than 450V on the plates"     I've posted about this ad-nauseam. But I don't like the .001 personally.     But I agree with your gain assement. I currently running a 5751 for the first two stages, and a 12au7 for the third. Sounds really great, but still don't have quite the clean when backing off the guitar I really am looking for.     bw

 

Replies:

BWilliamson I should add, I've never played a m... -- 9/26/2000 6:52 AM Trace q{kinda have to agree with you here... -- 9/26/2000 2:10 PM