Thanks Greg. I've recently gotten very interested in playing better guitar (most of which is practice) and am trying to update my arsenal. I'm thinking a Marshall DSL-15C, but curious if swapping EC's would be worth while. Marshall seems to have pretty good picks on their tubes. B Stock units are only $500. Might be able to swing that at tax return. The one I played had the most wonderful, sweet reverb I almost walked out with it...
Can someone tell me what the function of the preamp tubes and the output tubes are and how they relate (or is that a novel?)?
How Tube Amps Work | Premier Guitar
I'm personally not a big believer in swapping tubes around for tonal considerations. Just give me good healthy tubes that work. I will sound like Greg beating away at my strings no matter what.
There is a huge difference between
types of tubes. A 12ax7 preamp tube will have much more gain potential than a 12au7. An EL34 power tube has it's own unique characteristics compared to a 6L6, which is different compared to a 6550. So types of tubes are quite different.
Then you have similar tubes from different brands. With power tubes, I think, just my opinion, different brands of power tubes can have some effect on tone. Winged-C EL34s have a tonal character that JJs don't have. Which is better is up to you, but they can be different. And this only applies to amps that are 1) used loud enough to get the power tubes cooking, and 2) have power section circuitry that allows the power tubes to break up more easily. Your potential Marshall DSL is not really one of these types of amps.
Then you have preamp tubes. This is where, supposedly, all the magic is supposed to happen, and tube rolling has the most impact, but I'm not a believer. The 12ax7/ECC83 is the most common guitar amp preamp tube, and people shit their pants over swapping out tubes looking for that special combination. This tube is darker, brighter, has glassier highs, etc. Blah blah blah. It's cork sniffing. This is most common with NOS tubes, and there is probably something to it with those old, and expensive tubes. Modern production tubes though are pretty much all the same to me and I spend no time worrying about it. There are way more important things that effect tone much more profoundly IMO than a combination of preamp tubes. It's funny to me how many people spend their time swapping out dozens of tubes looking for minuscule effects on tone while they may have no idea what speakers are in their cabs. Raising or dropping your pickups 1/8" in height has more of an effect on your sound than a stupid preamp tube.
Don't worry about tubes. They won't make you play better, and they won't make you sound better. They may have some slight impact if every other variable is already meticulously perfected. Just use good tubes and rock the fuck out.
Just my 2 cents on tubes.