does it do THAT much difference?

R

rightbrainnow

New member
quick question. Im satisfied with the tubes in my sebatron vmp4000e, im just curious as to how much difference in clarity, warmth, "feeling", a tube swap can do. I know the unit has 4 12AT7 tubes, but im not exactly sure what brand they are...or how high quality they are...im sure they are just fine. However, this http://www.tubedepot.com/cr-12at7.html has kind of gotten my attention. If i tried a tube swap with something like that, would there really be much of a sonic difference?..is it even worth it? Also..would at 12ax7 tube fit in the seb?
 
rightbrainnow said:
quick question. Im satisfied with the tubes in my sebatron vmp4000e, im just curious as to how much difference in clarity, warmth, "feeling", a tube swap can do. I know the unit has 4 12AT7 tubes, but im not exactly sure what brand they are...or how high quality they are...im sure they are just fine. However, this http://www.tubedepot.com/cr-12at7.html has kind of gotten my attention. If i tried a tube swap with something like that, would there really be much of a sonic difference?..is it even worth it? Also..would at 12ax7 tube fit in the seb?
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how old are the tubes??

youd be suprised how well a tube change can make the amp sound that much better
 
buryher17 said:
how old are the tubes??

youd be suprised how well a tube change can make the amp sound that much better
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well the sebatron is a preamp and its only a couple of months old. However, now that you mention it..the tubes in my fender reverb deluxe are a couple of years old..i should probably look into replacing them.
 
I've had the same tubes in my Fender amp for years now and they're still fine. It's not so much 'time' that takes the toll on tubes, but rather use...

Jacob
 
jkokura said:
I've had the same tubes in my Fender amp for years now and they're still fine. It's not so much 'time' that takes the toll on tubes, but rather use...

Jacob
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But still, you wont hear how the old tubes degraded until you swap them for new ones. Much like guitar strings. They dull very slowly, so you could have the same tubes all your life and never get that "today they really sounds like shit" feeling. It creeps up on you like a bad hangover. I respect your opinion, and while it's partially true, you might reconsider it when you do change your tubes. Then you go: "Fuck - why didn't I do this sooner? How long have I've been playing with bad tubes?"
 
yea, my amp sounded fine this morning. i imagine its a little pricey to replace them all. however, does anybody have any info on the orginal question?
 
rightbrainnow said:
yea, my amp sounded fine this morning. i imagine its a little pricey to replace them all. however, does anybody have any info on the orginal question?
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why dont you just email sebatron?
 
because every time i try and email them, it rejects me as spam or something...i always get the yahoo mailer daemon or whatever....but this isnt about my sebatron, this is about preamps in general.
 
Maybe you can go the other way before you blow $150 bucks on tubes.....

Buy the really cheap ones and see if it makes it sound that much WORSE. Then you'll know if tubes make a whole heckuva lotta difference.....
 
soundchaser59 said:
Maybe you can go the other way before you blow $150 bucks on tubes.....

Buy the really cheap ones and see if it makes it sound that much WORSE. Then you'll know if tubes make a whole heckuva lotta difference.....
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good idea3541351
 
ok, now that im home..the sebatron is stocked with ecc81's buy JJ. maybe ill just upgrade brands to mullard...ive heard they produce a great sound. does anyone see any objections to this?..and do the crynovalves sound as good as the cost is high?
 
rightbrainnow said:
ok, now that im home..the sebatron is stocked with ecc81's buy JJ. maybe ill just upgrade brands to mullard...ive heard they produce a great sound. does anyone see any objections to this?..and do the crynovalves sound as good as the cost is high?
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Mullards can sound great, great midrange and smooth highs. But make sure you get low noise tubes that are also low in microphonics. Matching should be done too, both within the tube and between and among them. And don't sell other, less popular NOS tubes, short. GE, RCA, Sylvania, Valvo, Siemans, Mazda, among others, made great tubes too.

Fortunately, 12AT7 tubes are pretty cheap compared to, say, 12AX7 tubes, except for the Tele's and Gold Lions.
 
sdelsolray said:
Mullards can sound great, great midrange and smooth highs. But make sure you get low noise tubes that are also low in microphonics. Matching should be done too, both within the tube and between and among them. And don't sell other, less popular NOS tubes, short. GE, RCA, Sylvania, Valvo, Siemans, Mazda, among others, made great tubes too.

Fortunately, 12AT7 tubes are pretty cheap compared to, say, 12AX7 tubes, except for the Tele's and Gold Lions.
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in general, is it wise to plug a 12AX7 into a socket where a 12AT7 was? im not sure that it would even fit. Instinctually i would think it would be better to just plug in what the preamp was designed to hold.
 
rightbrainnow said:
in general, is it wise to plug a 12AX7 into a socket where a 12AT7 was? im not sure that it would even fit. Instinctually i would think it would be better to just plug in what the preamp was designed to hold.
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It will fit. All 12A*7 tubes are in a family, all with 9 pins. Most mics and preamps will handle any tube from the family. The main distinction between the family members is gain, called "mu".

12AX7 - 100 mu
5571 - 70 mu (yes, this tube is in the same family)
12AT7 - 60 mu
12AY7 - 45 mu
12 AV7 - 41 mu
12AU7 - 19 mu

The higher the mu, the higher the gain of the tube. Remember, not all preamps and mics that are designed to use a particular tube from this family can use the others. Most can.
 
I wouldn't be inclined to replace the 12at7s with 12ax7s. Although they physically fit and would work, the unit wasn't designed to operate with the higher gain tubes. And good 12ax7s are quite expensive compared to 12at7s. Most preamp tubes really have a pretty long life. We are talking years as opposed to months. If your Sebatron had come with Sovteks or cheap Chinese tubes, I'd say go ahead and change them out for better tubes (I have a VMP-2 that I changed out from Sovteks to GT Mullard copies and real Mullards). With the JJs you have in now, which are better than Sovteks, I'm less certain that any difference will necessarily be worth the price unless you get a real good deal on really good tubes. In my case, it did make a difference in the smoothness of the sound. Reduced the gain a little bit too, which wasn't a problem.
 
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