KentuckyBlues
73 posts
Mar 26, 2014
12:24 AM
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So my tubes seem to be fine, amp is new, probobly china tubes, which I've been told are not so hot.
been looking at some replacement tube options.
bugera sells a rectifier tube.. Idk what that means, its this.
http://www.guitarcenter.com/Bugera-5U4-Rectifier-Preamp-Tube-109857359-i2540381.gc
they also have a "matched set"
http://www.guitarcenter.com/Bugera-EL34-4-Pack-Matched-Power-Amp-Tubes-H85713-i2540921.gc
what is this and why would I want it?
ok. The tubestore has a 3 options
http://www.thetubestore.com/Shop-by-Amp/Bugera-V22-Amp
the premium package has reviews of people with the v5, and they seem happy. Price isn't crazy, its all the tubes.
the vintage package.. What is going on there.
how would these effect my tone?
is it worth it just getting new tubes, and keeping my working tubes as a backup just in case?
thanks guys
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rockmonkeyguitars
43 posts
Mar 26, 2014
1:26 AM
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can you remind us what amp you are using
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rockmonkeyguitars
44 posts
Mar 26, 2014
1:44 AM
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The rectifier tube (or valve) is what converts the AC electricity into DC. Most modern amps don't use rectifier valves and instead use a solid state rectifier.
If your amp does have a valve rectifier I wouldn't replace it until the old one goes because there isn't going to be a significant change in tone. If the rectifier valve in your amp is a 5U4 I would replace it with a GZ34 when it is time to replace it. Replacing your rectifier will change your voltage and the GZ34 gives slightly higher voltage and less sag meaning you get a bigger bass end that doesn't turn mushy but it's only really going to matter when you are pushing the amp to it's limits.
Regarding matched sets of valves. This is something you need to pay attention to if your amp is both a fixed bias amp AND it uses 2 or more output valves. Matched sets means they check the valves in the factory to make sure they want to use the same amount of current. Not all valves are created equal. Some want to suck up more electricity than others and if one output valve is using more electricity than the other you end up with extra hum and it means that not all of your valves can be properly biased and it can mean that the valves will die sooner.
Some companies will sell matched sets of 12AX7 valves and there is no reason to get them. Your preamp valves are cathode biased so they regulate their own current draw.
When it comes to replacing your valves don't buy into hype. There are a lot of good chines valves. Different brands and models within a brand will have different characteristics. I like sovtek valves in my preamp which is probably what your amp is already using. Many people like to "upgrade" to JJ's or electro harmonix which are both darker in tone but the actual quality isn't that much different. Most new valves are as good as each other and it's all a matter of tonal flavor. Some people prefer Hohner harmonicas while others prefer seydel. It's not that one is better, just different. So you are going to want to get a few sets and experiment. It's only when you get into military grade valves and NOS that you get a massive increase in quality but they also come with a massive increase in price.
Do keep in mind that when you replace your output valves you may (depending on your amp) have to rebias the amp this is something that isn't difficult but can be dangerous. Also be aware that brands like groove tubes, mesa boogie and bugera are actually rebranded generic valves so don't bother with them. If you want a generic valve just head straight to sovtek.
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KentuckyBlues
75 posts
Mar 26, 2014
2:04 AM
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I'm sorry! Its a bugera v22 tube amp.
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my youtube
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rockmonkeyguitars
45 posts
Mar 26, 2014
2:27 AM
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That amp uses a solid state rectifier so you don't have to worry about rectifier valves
It's got 3 12AX7 preamp valves, probably sovtek, and there is nothing wrong with them but there is always room to experiment. I'd suggest playing with these before looking at your output valves. 12AX7 and ECC83 are the same thing what the valve is called may simply depend on the brand. You might also want to consider using a 12au7 or 12ay7 valve in your 1st preamp stage. These are interchangeable with 12ax7 valves but they provide less gain. Less gain means less chance of feedback. Experiment with brands I'd suggest going to a company like TAD or Mojotone and reading their description of the different preamp valves and see what sounds good to you.
Your amp does have a fixed bias so I would recommend you keep your current output valves. When they do need replaced you need to get a matched pair and you will need to get your amp biased by a technician or you will need to learn how to bias an amp on one of the many amp building forums.
Last Edited by rockmonkeyguitars on Mar 26, 2014 2:29 AM
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rogonzab
524 posts
Mar 26, 2014
7:13 AM
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Is a low gain amp, keep that in mind.
I would go whit this:
12AY7 - 12AX7 - 12AT7.
NOS tuber are good, but no always better than new tubes, sometime they are e litle better and much more expensive.
Try new tubes first, when you find a configuration that you like, save money and go for some NOS.
The tung sol 12AX7 and 12AT7 are very good . I have no experience whit any other 12AX7.
The best EL84 for harps are the EH hands down.
Last Edited by rogonzab on Mar 26, 2014 12:28 PM
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Greg Heumann
2659 posts
Mar 26, 2014
7:55 AM
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Hey, Rockmonkey - you're new here - just wanted to acknowledge your informative posts. You clearly understand amps and communicate clearly. Glad you're here.
However I disagree with your recommendation about the GZ34 - for most people, voltage sag is a highly desirable feature in a harp amp - it adds more distortion on the "edges" of notes such as in a headshake. Raising the power supply voltage stiffens the amp and I think works against you for tone. This is probably as much or more a function of the "stiffness" of the power supply filter caps - which is why I recommend not re-capping vintage amps with larger than factory value caps.
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rockmonkeyguitars
48 posts
Mar 26, 2014
12:13 PM
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Thanks you for the acknowledgment Greg.
While I do agree that the GZ34 isn't as warm I still like it better for harmonica (or clean guitar). I like clarity in the low end and I think many harp players end up overly compressed and muddy. We seem to get amps that don't like to reproduce bass and then we turn down the treble and mids and crank the bass. I don't like that sound. I like having an amp equipped for big punchy bass and then turning the mids up to get the distortion. It is a matter of personal preference, but it's what I like. Your argument for the 5U4 smoothing out the edges and giving more breakup is equally valid and in some situation I do follow that path too.
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SuperBee
1825 posts
Mar 26, 2014
1:20 PM
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This amp has gain and master volume, I dunno if there's much value changing to lower gain tube. If there's a feedback issue, try turning gain down on amp.
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Barley Nectar
336 posts
Mar 26, 2014
5:33 PM
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I personally follow rockmonkeys school of thought. Welcome aboard rockmonkey... You must be careful when changing rectifier tubes to raise voltages in an amp. In the above example of going from a 5U4 to a GZ34/5AR4 the subsequent voltage increase across the board, may cause an overvoltage condition in certain components. These components are then subject to failure. This is especially true in vintage equipment. Raising circuit voltages also may lead to increased feedback problems...BN
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KentuckyBlues
77 posts
Mar 26, 2014
9:42 PM
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My amp does not have a rectifier tube, but bugera sells one that works in mine. All bugera tubes are sold "to fit all bugera amps"
buy I don't really know..
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