Tubes?

  • Thread starter Thread starter ecktronic
  • Start date Start date
ecktronic said:
I'm looking to get some new tubes for my Marshall JCM2000 DSL50 guitar amp.
I play quite heavy music, and I'm looking for a good set of tubes that will compliment a set of Vintage 30 speakers.

I'm looking for an upfront sounding tube with nice clear but not harsh high end, smooth high mids and clean low mids and a tight yet meaty low end.
Anyone got any suggestions?

Cheers,
Eck
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Tubes are a fine tuning and 100% subjective. People put too much into tubes. If the amp doesn't already do what you want, tubes won't make it.
 
ecktronic said:
Thats what the experts advised me to get.
Why would he say that I needed it if I really didn't. Its not like hes making much extra money from 1 balanced tube compared to an unbalanced tube.

Eck
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First off, I want to say sorry- I've been bouncing in and out of here, and maybe not giving complete enough answers or coming off the wrong way. And though I wouldn't call myself an expert, I have been playing, building, and doing repair and mod work on tube amps for a long time.

There is nothing wrong with buying or selling a certain tube to use as a phase splitter. What gets me is the idea that you should, or that doing so will be better for your sound. Truth is, any decent tube will work as a phase splitter. If a certain tube is so out of whack you couldn't use it as a phase splitter, I'd bet you would have an issue with it no matter where you plugged it in. Because guitar amps are very tolerant beasts. This is one of those things that got started somewhere and is now accepted as truth by some. So no offense to Eurotube, they seem to have decent product and support, but they are basically charging you money simply to sell you a tube that isn't a complete piece of junk, and spreading a questionable idea around.

It's good you want to do good by your amp. And certainly new power tubes are probably a good place to start since it was used when you bought it. Just realize the phase splitter isn't any different than any other tube, whether or not you like the sound is up to you.
 
Cheers man.
The price they gave me for a full re-tube with some nice tubes was very good, so its all god.
Eck
 
Without a question... www.eurotubes.com Great advise from Bob and amazing prices. I re-tubed my 5150 with JJ's for half the price of my last re-tube (groove tubes at the music store...What an idiot!!!!) I absolutlety love the JJ's in my modded 5150! Round, warm, and ballsey!
 
boingoman said:
It's good you want to do good by your amp. And certainly new power tubes are probably a good place to start since it was used when you bought it. Just realize the phase splitter isn't any different than any other tube, whether or not you like the sound is up to you.
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I'm not an expert on tube apps, either, but it occurrs to me that there is one thing that is different about a phase splitter tube, and that is that one side of its output goes to the "push" power tube(s) and the other goes to the "pull". It seems to me that it would be important for the two sides to be balanced in output for an amp running in class AB, just as it is important for the push and pull power tubes to be balanced.

That said, is it a common thing for a 12AX(orT)7 tube not to have the same output characteristics on both stages? I don't know, but it seems to me that since they are processed together in one package, they'd stand a pretty good chance of being always the same.
 
ggunn said:
I'm not an expert on tube apps, either, but it occurrs to me that there is one thing that is different about a phase splitter tube, and that is that one side of its output goes to the "push" power tube(s) and the other goes to the "pull". It seems to me that it would be important for the two sides to be balanced in output for an amp running in class AB, just as it is important for the push and pull power tubes to be balanced.

That said, is it a common thing for a 12AX(orT)7 tube not to have the same output characteristics on both stages? I don't know, but it seems to me that since they are processed together in one package, they'd stand a pretty good chance of being always the same.
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It's the long-tailed splitter circuit- the two sides split a constant current in a mirror fashion, ie as one goes up the other goes down. Their current output is therefore fairly tightly balanced, regardless of how each side would perform separately. Closely-matched plate resistors are the critical part- they are what controls the output voltage, since the current is constant.

edit- The cathodes are hooked together and grounded by a common resistor. Both outputs are driven by signal on one grid only. So when one is going positive, the other is going negative, as the cathodes split the available current.
 
boingoman said:
It's the long-tailed splitter circuit- the two sides split a constant current in a mirror fashion, ie as one goes up the other goes down. Their current output is therefore fairly tightly balanced, regardless of how each side would perform separately. Closely-matched plate resistors are the critical part- they are what controls the output voltage, since the current is constant.

edit- The cathodes are hooked together and grounded by a common resistor. Both outputs are driven by signal on one grid only. So when one is going positive, the other is going negative, as the cathodes split the available current.
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Ah, thanks. That's actually pretty clear. I'm impressed. ;^)
 
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