Members Delmont Posted October 1, 2014 Members Share Posted October 1, 2014 I have a couple of power tubes that are starting to go. When I replace them, how important is it to replace the preamp tubes, too? Thanks! Delwww.thefullertons.net( •)—::: Link to comment Share on other sites More sharing options...
Members onelife Posted October 2, 2014 Members Share Posted October 2, 2014 I used to gig with a Fender Twin Reverb and usually went through a set of tubes every 18 months. On once occasion I replaced all of the tubes halfway through a six night club date. With everything else being the same, the change was so drastic it felt like my guitar strings were made out of different material. Generally speaking, power tubes need to be replaced more often than the preamp tubes. If a preamp tube is noisy or microphonic then it should be replace. With the price of tubes today, I would recommend replacing the tubes as needed. Link to comment Share on other sites More sharing options...
Members Delmont Posted October 2, 2014 Author Members Share Posted October 2, 2014 Thanks, Onelife! You save me a few bucks, at least in the short run. Delhttp://www.thefullertons.net( •)—::: Link to comment Share on other sites More sharing options...
Members RGfretter Posted October 2, 2014 Members Share Posted October 2, 2014 I used to gig with a Fender Twin Reverb and usually went through a set of tubes every 18 months. On once occasion I replaced all of the tubes halfway through a six night club date. With everything else being the same, the change was so drastic it felt like my guitar strings were made out of different material. Generally speaking, power tubes need to be replaced more often than the preamp tubes. If a preamp tube is noisy or microphonic then it should be replace. With the price of tubes today, I would recommend replacing the tubes as needed. As needed! Yes. The pre's are gonna outlast the power amp tubes. Link to comment Share on other sites More sharing options...
Members Delmont Posted October 3, 2014 Author Members Share Posted October 3, 2014 Seems that way. Thought it was worth asking to be sure. Thanks, RG! Delhttp://www.thefullertons.net( •)—::: Link to comment Share on other sites More sharing options...
Members WRGKMC Posted October 5, 2014 Members Share Posted October 5, 2014 I suggest you only change them as a matched quad set and have them biased. (if that particular head has biasing). A matched set ensures the tubes have a balanced output. Changing only one tube is like changing one tire on a car when they are all bald or only changing one spark plug in an engine. Most people (and few techs) don't have a tube tester and a stack of tubes they can go through to find the ones that have matching values. Tube manufacturers do this for you so buy them as sets especially in high watt heads that can easily be damaged by unbalanced tubes. I don't advise buying pairs either. You cant match two sets to each other. Another piece of advice is to number the tubes with a marking on the base so if you ever have to remove them, you get the right tubes back in the right sockets. Bias is set to each socket and swapping them around will not match the tubes unless they just happened to be exactly the same which would be nearly impossible. Even with matched sets the tubes values are only close to being the same instead of wildly different. Link to comment Share on other sites More sharing options...
Members guitarcapo Posted October 7, 2014 Members Share Posted October 7, 2014 I only replace the ones that are damaged as I go along. But then again a lot of my amps are vintage Magnatones that use expensive weird tubes like the 6973. Typically they cost $50 a pop and some of my amps use 4 of them. Modern 6973 tubes suck and just don't work. Link to comment Share on other sites More sharing options...
Members WRGKMC Posted October 7, 2014 Members Share Posted October 7, 2014 If its single ended it really doesn't matter what you use so long as that one tube is in good shape and sounds good.If you have something vintage with oddball tubes you don't have many options so you use what you can find. If they are popular tubes, 6L6, EL34, etc. the options have never been better because there are so many choices. They do make some excellent tubes today, many are much better then some of the vintage ones back in their day and much better then some old worn out vintage tubes you may pay an arm and a leg for. Having a matched set and having them biased properly is paramount if your running a push pull amp. Otherwise you may half of the waveform deformed in comparison to the other which does some really strange things to the sound. Id never advise changing just one in a pair unless you have a tube tester to match it to the other. The current draw for different tubes can be different and it would be like having different plugs in a car. Expect it to run awful with unmatched sets. Link to comment Share on other sites More sharing options...
Members ericspr Posted February 12, 2015 Members Share Posted February 12, 2015 Looking foward to replace every tube on a second hand Crate v3112.It looks like the tubes it has are the stock ones so I ordered the preamp ones from Doug's (good service, asked for recommendations they replied right away). I got the power ones when I bought the amp but honestly dont know if they are matched. I've learned that "The amp uses a self bias circuit (bias is accomplished by a cathode resistor) so you need a matched pair of tubes." So here's a picture of what I got. If someone can tell from what its shown that they're matched I'll really appreciated. Link to comment Share on other sites More sharing options...
Members r0bo01 Posted February 13, 2015 Members Share Posted February 13, 2015 did you buy them as a matched quad? from the numbers, looks like two matched pairs (see wrg's post #6), unless the differences fall within acceptable range. you may be able to get away using 'em as a quad (depending on how loud/long you play). Link to comment Share on other sites More sharing options...
Members ericspr Posted February 14, 2015 Members Share Posted February 14, 2015 I did not. I will try them. If the are not within acceptable range, what might happen? Interesting note: talking to a tech yesterdey and told me that the test process for matched tubes causes degradation. So how life the test takes away from the tube? Wouldnt know. Link to comment Share on other sites More sharing options...
Members Tom Mc1 Posted February 24, 2015 Members Share Posted February 24, 2015 The JJ tubes that are in the picture are a good choice if they are a matched set. Eurotubes supplies matched complete sets for many models of amps. That is if you are looking for JJs. They are on the net. Link to comment Share on other sites More sharing options...
Members Tom Mc1 Posted February 24, 2015 Members Share Posted February 24, 2015 The JJ tubes that are in the picture are a good choice if they are a matched set. Eurotubes supplies matched complete sets for many models of amps. That is if you are looking for JJs. They are on the net. Link to comment Share on other sites More sharing options...
Members AJ6stringsting Posted February 27, 2015 Members Share Posted February 27, 2015 The JJ tubes that are in the picture are a good choice if they are a matched set. Eurotubes supplies matched complete sets for many models of amps. That is if you are looking for JJs. They are on the net. I've had great dealings with them ( Eurotubes) , they know their stuff and they listen to your needs / do their best to help. I have over 8 tube amp heads : Marshall, Mesa-Boogie, Carvin, VHT, Fender .....I'm going to them to get some tubes for my Digitech 2112 very soon Link to comment Share on other sites More sharing options...
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