Studio Pre problems and tube questions

[Can Of Bass]

Hello, new to the board as i have just recently purchased a Studio Pre, an amp i've wanted to have for a very long time. I got her a little beat up and i want to spend a little time and effort on her to get her all gussied up. First situation i have is the volume, its cutting on me, about 50% or more randomly in the middle of playing, big bummer. I've read in this forum or else where for the studio pre thats usually the sign of bad tubes, if so than i really want to put some good tubes in there but i'm not sure whats the best rout to go for this specific amp, If not does anybody have any idea what this could mean? i play bass through this amp (save the opinions on me doing this, i choose to for a reason) and the music is heavy and very gainy. the low end sounds good, not too bassy, the high end is bright (with switch on) and i like the tone so far (could have a little more gain possibly) now my situation is i've also read some stuff about mesa amps being set where portions of the circuit only accepted chinese tubes, and others russian. possibly this is only for newer amps but i got no distinction so i'm questioning it. Basically, if i could, i live near and awesome tube store where i could get quality NOS 12ax7's, sylvania's or something american. Would this be fine? anyone try it before? anything information can help me really, just want her restored to her former glory.

thanks a bunch.

 

[r_cod_81]

I've also read some stuff about mesa amps being set where portions of the circuit only accepted chinese tubes, and others russian.

This rumour really smells of utter, utter bollocks to me. I'll happily stand corrected if I'm wrong but is a 12AX7 not a 12AX7 regrdless of country-of-origin?

I would say change the tubes though, especially if it's really old/ 2nd hand. I've not got round to doing that to mine mine yet as the tubes look fairly new and sound fine (apart from some minor crackling but I'm lazy...). Mine currently has GTs in, I 'll probably get a set of E-Hs as I get the impression that JJs don't sound great.

I did change the reverb tube though as it was really not working well.

Interesting you're using it for bass, I'd imaging it could sound great for that, a lot of guitarists find it to be rather boomy/ flubby.

Have fun!

 

[Can Of Bass]

Well interesting enough when i opened up my studio pre (if they go from left to right on the ciruitboard like i think they do) my V1 and V3 tubes are JJ's and V2 and V4 are the mesa stock, could just be by chance but it made me want to inquire about said myth before i put all one type in. If anyone has any experience with Sylvanias or any NOS tubes for that matter let me know your experiences it would be really helpful. If i don't end up getting sylvanias i was thinking Electro-Harmonix just from reputation. Yeah so far it sounds great for bass, haven't really matched it up to an awesome power amp so only time will tell, my band is two bassist and a drummer, we create a tonal dynamic with him taking the "bass" tones and me the "guitar", he plays a sunn300T and is tuned to C standard, me the studio pre (and i'm looking for a 2:95 or 3:95) and i play in D standard. I take the upper tone if we play octaves, and i take the filth if we're playing a chord tone. its fun.

 

[elvis]

Tubes are not space-age technology. In fact, they're not even jet-age technology :lol: . They are not made to such a tight spec that the amps can be practically designed for one special type. Quite the opposite, in fact. Tube specs are so loose that the amps have to be designed for a wide tolerance. Some users go for what they like best, others go for the cheapest tubes they can find. Preamp tubes in particular are easiest to swap, since they don't have much ability to damage the other circuitry, unlike the power tubes.

One problem that comes up often for older amps is bad LDRs. They are optical switches used in most Mesa amps. The SPs are so old, I recommend changing LDRs as well as the tubes.

 

[BCy2k]

FWIW I just changed both tubes in my V-Twin rackmount from really bland sounding Groove Tube 12AX7-Cs, to ANOS Phillips 12AX7WAs and the difference was immediately night & day better than the Chinese GT stuff. If you go the NOS or ANOS route just try to make sure what you're buying has been well tested. YMMV, but all 6 voicings of my V-Twin sound dramatically better. It's incredible really. When it comes to preamp tubes, I'm a NOS believer at this point.

 

[r_cod_81]

Cool - glad ypou love your new tubes!

As I understood it, the original point was that tubes from different countries would not work in certain Mesa amps. While they may sound different and, thus, be different to everyone's tastes, they still function.

Go with the ones you like the sound of - it's your music - and **** everyone else

Rock on brother!

 

[jonamojo]

get a couple NOS sylvania/RCA off of ebay and experiment maybe you'll like the russian/chinese stuff better. I have a quad pre I tried everything the only foreign tube that sounded any good was the tungsol but there to unreliable. You can still find jan phillips for a pretty reasonable price, I use mullard I63, telefunkens, RCA's and sylvania's and GE's and hell ya you can tell the difference when I throw a sleeve of JJ's in there pick attack is different,breathe is different, distortion is different but I suppose many may be going for that sucked up mid sound.