I think the C137 mod will do a whole lot more for changing the tone than changing tubes.
Tubes swaps for me are fun, but they're more a matter of swaying an amp that you love towards a position that you love more than fixing an amp that you don't.
Sometimes it's a crapshoot. Luck of the draw.
If you know you like JJ's, I'd stick with JJ's. Preamp tubes aren't super expensive. And it's JJ preamps. Very low risk from buyin a few spares off ebay sellers.
But I do recommend you try some different tubes. It's just like guitar strings. JJ's...
I wouldn't say the 60 is lower output than the 81. I'd say they're around the same.
Techincally, all of them are the same output because the 9V the preamp runs at limits how much they can put out. But some of them feel/sound hotter because the pickup part itself is hotter before it hits preamp...
Tung Sols are brighter and with less midrange clutter/stuffiness than JJ's. Cool tubes, but I like Svetlana 12AX7SV's better than TS's. They've got the same kind of clear/clean midrange as Tung Sols, but are not as harsh up top as TS's can sometimes be.
Everyone is going to have their...
I'm not sure? I bought it new some time ago, though. Around the same time I got my TS808, so it must be from the mid-late 2010's. I don't have it with me right now, so no way of checking until probably the weekend. But if it's one of the ones that can't be modded, no biggie. I can just hunt...
I love the TS808. I just think the SD-1's steeper low-end rolloff gets along better with certain amps like Rectos. I do, however, feel the voicing gets a little edgy and not as smooth even when you set the tone knob to (loosely) match the brightness on a Tube Screamer.
I know the SD-1 is close...
Agreed. Look in the Classic. Voice 1 is a nice and bright PAF-type ala Duncan '59B, Voice 2 is a fat mid-focused hotrod a la Duncan JB. Both voices are not direct clones, just inspired by.
They're the most passive-sounding actives I've tried.
I wouldn't agree that the SLO is an apple and a 5150 is an orange.
I'm not going to get an argument wether there is some magic to SLO's that 5150's have or not. There probably is in the room. Plenty of good recordings made with the SLO too. But saying the SLO and 5150 aren't related is simply...
I like the Black Winter with a 250K volume pot. Tames the rasp a bit, but it leaves you with the tight low-end rolloff. Try it if you haven't.
I also have the Nazgul at hand, and I ran that one with a 1Meg pot. Kinda hard to balance out. I feel it's a bit low-mid heavy, and the attack isn't as...
Also on the clips debate, well-mic'd clips like this do give you an idea of how an amp records. For me, that's as important as how an amp sounds in the room.