Flevoman Posted March 5, 2023 Share Posted March 5, 2023 Hello, I own the Melody MDA2, a PP 2A3 tube amplifier, and I want to replace the four 2A3 tubes and I have a few questions about it. I would apriciate it if you guys can help me out. Do I need to buy two matched pairs or a matched quartet, or does it make no difference and can I just buy four pieces? Will any 2A3 tube fit into the amplifier, or are there any differences I should be aware of? Are there any recommended brands or types that perform well? I saw a 2A3 tube that delivered up to 40W. Is this recommended? Quote Link to comment Share on other sites More sharing options...
henry4841 Posted March 5, 2023 Share Posted March 5, 2023 Best if all 4 are matched but at least the two for each channel to be matched. The thing is though most Co. do not use the proper procedure matching tubes. There is usually an adjustment in your amp for matching a specific channel but not the two channels unless you have a balance control. The difference between channels will more than likely never be noticed if not matched. One channel will be slightly more powerful than the other and unless you have test equipment you will never know. Any 2A3 should work. Others will need to answer the other two questions being I have no 2A3 amp. 1 Quote Link to comment Share on other sites More sharing options...
Coytee Posted March 5, 2023 Share Posted March 5, 2023 1 hour ago, Flevoman said: I saw a 2A3 tube that delivered up to 40W. Is this recommended? Was it 40 or perhaps 4.0? I am certainly no tube expert.... but I always thought 2A3's were 'around' 3.5 watts. I'd find it easier to believe that was a typo rather than them putting out 40. Quote Link to comment Share on other sites More sharing options...
Marvel Posted March 5, 2023 Share Posted March 5, 2023 2 hours ago, Coytee said: Was it 40 or perhaps 4.0? I am certainly no tube expert.... but I always thought 2A3's were 'around' 3.5 watts. I'd find it easier to believe that was a typo rather than them putting out 40. JJ 2a3s have a plate dissipation rating of 40watts, but your amplifier would need to be able to adjuct to use the higher plate rating. Assume your amps are push-pull. The Electro-Harmonix 2a3 Gold are great tubes for the money. I had EH and Sovtek I used in the amps I had. 1 Quote Link to comment Share on other sites More sharing options...
Flevoman Posted March 6, 2023 Author Share Posted March 6, 2023 Hey, I can join the site again. It was down for some time for me. Anyway, thank you for the replys guys 👍🏻 Quote Link to comment Share on other sites More sharing options...
Flevoman Posted March 7, 2023 Author Share Posted March 7, 2023 "I don't know how many hours are typically required for tube replacement, but I estimate that my 2A3 tubes have played for about 1200 hours. Would there be a noticeable difference in sound between my tubes and new tubes with this amount of usage? And what should the tonal differences be? Quote Link to comment Share on other sites More sharing options...
Fido Posted March 7, 2023 Share Posted March 7, 2023 1 hour ago, Flevoman said: "I don't know how many hours are typically required for tube replacement, but I estimate that my 2A3 tubes have played for about 1200 hours. Would there be a noticeable difference in sound between my tubes and new tubes with this amount of usage? And what should the tonal differences be? They can last for more than 5,00 hours up to 100,000 hours or over 11 years using the Amp 24 hours a day that entire time 1 Quote Link to comment Share on other sites More sharing options...
Marvel Posted March 7, 2023 Share Posted March 7, 2023 I used my amps pretty much every day for extended time per day and had the same 2A3 tubes in for well over 10 years. 1 Quote Link to comment Share on other sites More sharing options...
Flevoman Posted March 7, 2023 Author Share Posted March 7, 2023 That long??!!!... I'm confused, I really thought that after max 2000 hours you really need to change them. Quote Link to comment Share on other sites More sharing options...
henry4841 Posted March 8, 2023 Share Posted March 8, 2023 A lot depends on how they are biased. Run them hard and it will shorten their life. 1 Quote Link to comment Share on other sites More sharing options...
Flevoman Posted March 8, 2023 Author Share Posted March 8, 2023 14 hours ago, henry4841 said: A lot depends on how they are biased. Run them hard and it will shorten their life. I have set the bias to the value stated in the manual, which is between 30 and 35. And then I personally stick to the lower end, around 30/32. But if I understand correctly, tubes with the allowed bias value will last many thousands of hours without significantly deteriorating in sound quality? Quote Link to comment Share on other sites More sharing options...
henry4841 Posted March 8, 2023 Share Posted March 8, 2023 My understanding is most want, build, their amps for 5,000 hr. tube life. That being said though many do not. The amount of current being run in the tube determines tube life. 1 Quote Link to comment Share on other sites More sharing options...
Flevoman Posted March 8, 2023 Author Share Posted March 8, 2023 Okay, thanks for the explanation. So as I understand it now, it's pretty pointless to replace tubes after only 1200 hours with the expectation that the tubes will audibly improve. However, that doesn't mean I'm not still interested in trying out tuberoling 😉 1 Quote Link to comment Share on other sites More sharing options...
henry4841 Posted March 8, 2023 Share Posted March 8, 2023 3 hours ago, Flevoman said: However, that doesn't mean I'm not still interested in trying out tuberoling 😉 Tube sellers will love you. 🙂 Serious though, tube rolling is popular because everyone can do it. I would not expect a real noticeable difference if both brands are quality built. But it can be fun. Quote Link to comment Share on other sites More sharing options...
Flevoman Posted March 9, 2023 Author Share Posted March 9, 2023 "Hmmm... So I probably won't hear a difference between my old and any potential new tubes. And I'll probably hear little difference between different brands of tubes... This way my motivation for tube rolling is brought to an all-time low." 😄 Quote Link to comment Share on other sites More sharing options...
henry4841 Posted March 9, 2023 Share Posted March 9, 2023 Subtle differences possible if hearing is good enough. Doubtful most can tell difference in truly blind A/B test. Major builders of tubes want to do their best to sell more tubes like any other business. I have always read one must hear an original Western Electric 300B to truly know what a 300B should sound like. Always thought it to be true but doubt that statement now. Probably more hype than anything else but at the price of those old tubes I will never know. Statement sure raised the price. Looking at the modern 300B tubes one can see how the cathode is much differently made than most other tubes. Impressive looking when you look at the details of design. One thing for sure the original WE tubes last and last. I would not expect that with modern made 300B tubes. 1 Quote Link to comment Share on other sites More sharing options...
lighting guy Posted March 9, 2023 Share Posted March 9, 2023 In the late 2000's I bought a pair of WE 300Bs for my Wright Mono7s. They were from the late 90's when Westex reintroduced them. This was before they got "really stupid" in price. I had been listening to Sophia meshplates. My impression was "meh", I thought they sounded smooth but dull. I sold them to a friend (but kept the wood box!). I now run TJ Full Music carbon plates, I think they have the best synergy with the 6sn7 drivers in my system. Flevoman, I think you'll notice the biggest sonic changes from rolling your preamp tubes or your amp's driver tubes, depending on your topology. 2 Quote Link to comment Share on other sites More sharing options...
Flevoman Posted March 9, 2023 Author Share Posted March 9, 2023 Thank you for the advice. Do you mean trying a different brand or a completely different type of tube (if that's even possible)? Quote Link to comment Share on other sites More sharing options...
lighting guy Posted March 9, 2023 Share Posted March 9, 2023 35 minutes ago, Flevoman said: Thank you for the advice. Do you mean trying a different brand or a completely different type of tube (if that's even possible)? Trying a different brand. I'm no expert at this, but I know some amps allow you to roll different types of power tubes, which may require re-biasing or even changing internal circuit values- not something I'm familiar with. I once had VRDs, but never rolled power tubes. Instead, I played with the 12ax7s. If you have a tube preamp without tone controls (as I do), you might try playing with the signal tubes (usually a 12a type or 6dj8) FIRST, before you play with the amplifier. That gives you the most change, IMHO, without breaking the bank. But beware, the tube rabbit hole is deep! 1 Quote Link to comment Share on other sites More sharing options...
lighting guy Posted March 9, 2023 Share Posted March 9, 2023 Flevoman, I just looked up your amp and I saw it's an integrated, so no preamp. Also, I see the little signal tubes are something I'm not familiar with so my above post is probably not very helpful to you. Sorry. 1 Quote Link to comment Share on other sites More sharing options...
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