#1
Greetings all,

I've had a Peavey Valveking 112 for quite some time now. Long enough for the tubes to go from a nice healthy orange glow to a sickly cold blue. It's time I replace them and I'm looking to you all for some guidance.

I'm not really asking "What tubes specifically should I put in there?" What I'd like to gain from you guys is the knowledge of what to look for in a tube. What specs/qualities do they hold that tell me what they are suited best for? So either first-hand experience or resources that I can use to educate myself would be great. I've done some google-fu and haven't found too much help, unfortunately.

The Peavey Valveking 112 has 2 6L6GC power amp tubes and 3 12AX7 preamp tubes. I will be using this amp mostly for Jazz. While I do dabble in blues, rock, metal, etc., I'm currently studying Jazz guitar in college, so if I need distortion for some of the heavier stuff I'm into, I'll just look into a pedal.

Thank you for your help.
#2
I think the reason you haven't found much is that there isn't any sort of spec that exists in the way you're looking for. Tube specs are generally very similar (these are standardized devices, after all), and unless you have an unusual circumstance you can generally get away with any brand tube of the same type that's in your amp. Once you know which tubes you can use in your amp, that's pretty much it for spec. Anything after that generally comes down to what you think sounds good. I think what you need to look for are reviews and recommendations. Looking at specs won't help you choose a tube.

Here are the narrow confines of "spec" that you might want to know about.
-Preamp types. There's a range of preamp tube types, from 12AU7 to 12AX7. There's a page here that will tell you about those:
http://www.thetubestore.com/Gain-Factor
-Matched sections: don't bother. Some companies/tube dealers will try to get you to used a matched preamp tube for the phase inverter; there's no need for it in a guitar amp.
-Power tube types: similar to preamp tubes, but with less overlap. Generally you should stick with the type (6L6GC) ; there are some exceptions but in most cases there is little benefit to using another tube type.
-Power tube "rating" and matching. Some companies and dealers rate their tubes by how quickly they break up; this is self-explanatory. Matching power tubes is essentially mandatory, and is the standard way of buying power tubes.
-Some dealers have other tests like low noise, high gain, matched sections, etc; I wouldn't bother with those.

Again, there are no specs that can tell you what a tube is good for. The closest I guess would be the preamp gain factors, but that tells you nothing of the character of the tube. You're going to have to just read through descriptions of the sound of individual tubes, or email someone like Mike at KCA NOS Tubes or Doug at Doug's tubes and ask for suggestions.
#3
Quote by Roc8995
I think the reason you haven't found much is that there isn't any sort of spec that exists in the way you're looking for. Tube specs are generally very similar (these are standardized devices, after all), and unless you have an unusual circumstance you can generally get away with any brand tube of the same type that's in your amp. Once you know which tubes you can use in your amp, that's pretty much it for spec. Anything after that generally comes down to what you think sounds good. I think what you need to look for are reviews and recommendations. Looking at specs won't help you choose a tube.

Here are the narrow confines of "spec" that you might want to know about.
-Preamp types. There's a range of preamp tube types, from 12AU7 to 12AX7. There's a page here that will tell you about those:
http://www.thetubestore.com/Gain-Factor
-Matched sections: don't bother. Some companies/tube dealers will try to get you to used a matched preamp tube for the phase inverter; there's no need for it in a guitar amp.
-Power tube types: similar to preamp tubes, but with less overlap. Generally you should stick with the type (6L6GC) ; there are some exceptions but in most cases there is little benefit to using another tube type.
-Power tube "rating" and matching. Some companies and dealers rate their tubes by how quickly they break up; this is self-explanatory. Matching power tubes is essentially mandatory, and is the standard way of buying power tubes.
-Some dealers have other tests like low noise, high gain, matched sections, etc; I wouldn't bother with those.

Again, there are no specs that can tell you what a tube is good for. The closest I guess would be the preamp gain factors, but that tells you nothing of the character of the tube. You're going to have to just read through descriptions of the sound of individual tubes, or email someone like Mike at KCA NOS Tubes or Doug at Doug's tubes and ask for suggestions.


Wonderful help! It's nice to know that it's (apparently) pretty hard to **** up buying tubes.
#4
It's like strings, really. Once you've got a gauge dialed in you just find a brand you like. Buying a few different brands of preamp tube would be a good idea. V1 is by far the most sensitive position for tone, so you can try rolling a few through there and put the others in the rest of the preamp where they matter less. Cheaper that way. With 6L6GCs, just get Tung-Sol or JJ, can't go wrong with either of those. Getting higher-headroom tested ones might be a good idea for jazz, though it may matter less with your amp.