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Should I replace my 400+ tubes?

Discussion in 'Amps and Cabs [BG]' started by Tim1, Jul 20, 2007.

  1. Tim1


    Sep 9, 2005
    New Zealand
    I have a near new Mesa 400+. I have searched and read up on the pros and cons of the various tubes. The only alternatives available to me here in New Zealand are JJs, and the dealer is able to match them to Mesa specs. I know the JJs would be an improvement but my question is - would you wait for the Mesa's to wear out or replace them now? I would replace all the tubes, pre and power amp. Someone who has done this might be able to tell me how significant the change would be and how the sound will change. I run it through one or two SWR Goliath 3s and play mainly blues using a 69 Fender Jazz or 68 Telecaster bass.
  2. I haven't had the pleasure of owning a 400+, but I've had many tube amps since my 1st one in 1973! IMHO-leave the original ones in there til their worn out-OR- buy a set of new ones & replace the stock ones & keep 'em for spares!!! I don't quite understand why youre 'only alternatives are JJ's'????? They're a great tube but thru the net U can access virtually any tube U want. There are many stores available & even many ebay sellers that are reliable & with good prices. In saying that-JJ's ARE probly one of the top ones IMHO!!!!!!
    I recently changed a set of six RUBY EL34's outta my old amp, replaced 'em with a matched sextet of Electro Harmonix(EH)EL34's the sound difference was minimal-almost undetectable -to me anyway! to cut a LOOOOONG story.... the EH EL34's nearly ALL blew up within 6 hrs playing time(less than 2 gigs)-so $240AUS-abouts down the drain.
    SO I got onto Bob at Eurotubes.com &-after LOTS of research- decided on a set of JJ KT77's-a superb tube!!!! My tube tech rebiased the amp for these new tubes & I was set!
    Again the sound difference was minimal- a bit deeper lows was about all if I was "pushed" could say was different!!!!!!!
    The main thing-IMHO- was that the amp was now back to her reliable old self-as she had been for 15 yrs B4. I could now go 'safely' to a gig, knowing the amp was fine!!!!
    I cannot rate Bob & www.eurotubes.com highly enough-great customer service & fast & safe delivery!
    BUT- U can contact Watford Valves in the UK, Tube-depot-USA....heaps. Is your problem-finding a reliable tube tech?

    But My general answer to yr "should I get new tubes" Question IS ..... NO!!! :)
  3. The pros and cons of various tubes (bar from stability issues) are only going to have very minor and subtle effects on the sound.

    LIke rodl2005 says, just leave the original tubes until something goes wrong and you need new ones.

    If you really want to tamper a bit, buy a new preamp tube or two. You should be able to get a variety off the net. Much cheaper and will make more of a difference than changing the power tubes.
  4. Hi, Tim1.

    +1 for the advices the previous posters gave. If the amp is "near new" there shouldn't be any problems with the tubes.

    However it sounds to me that You have doubts about the current tubes? If so, why not take the amp to a good tech for a once over, preferably one with a tube tester, to determine the shape of the tubes (and the amp also). That way You'll probably save some money and have the amp perform at its best. Some of the current manufacturers are forced to use less than perfect tube sets to keep the cost of the amp down and by doing so, have competitive prices.

    AFAIK tubes by MESA = Sovtek, me not like at all, but living next to USSSR/Russia and having seen tons of bad Sovtek tubes floating around might make me "a bit" biased ;) .

    A good set of power tubes should last anywhere from 5 to 50 years so there's really IMHO need to replace tubes just for the sake of replacing them.

    In any event IMHO a tube amp, specially older ones, should see a tech in a regular basis naturally depending of the usage. A problem / deterioration spotted early can save the transformers from smoking. All other components are more or less over the counter items, but quality transformers are really hard to come by.

    For Your question: NO don't change the power tubes unless there's something wrong with them.

    Experiment with the pre tubes if You want to change/improve/fiddle with the gain/tone stages.

    Just my 0.02€
  5. lavaman67

    lavaman67 Supporting Member

    Feb 13, 2006
    Ypsilanti, MI
    If you really want to tamper a bit, buy a new preamp tube or two. You should be able to get a variety off the net. Much cheaper and will make more of a difference than changing the power tubes.[/QUOTE]

    +1! I went with Tung Sol 12AX7's in the preamp section and they kill. The stock Sovtek(Rebranded by Mesa) 12AX7's just plain blow. I took a couple of EH 12AX7's out of my SVT-CL and swapped them out before I bought the Tung-Sol's and those even made a significant difference. Much better than the stock low grade Sovteks. Now that being said, Sovtek makes some good tubes. The Sovtek 6L6WXT+ are a really good 6L6 for the money. As far as JJ's, my interaction with Bob from Eurotubes was nothing but good. My issue with Eurotubes is all they sell is JJ's, so what is he going to say when comparing it to another tube. I have no doubt they are good tubes, but when all you sell is JJ? :rolleyes: It doesn't make you very impartial. Again, just like I Got a Mohawk suggested, start with the preamp tubes first if you really want to experiment. If you have to do two at time start with the V1 & V2 section. That’s where you are going to notice the most difference. By the way, what do you have in the power section now?
  6. godspeed68

    godspeed68 i'm here for the sound Supporting Member

    Mar 24, 2004
    Chicago, IL
    I know these are slightly different amps, but FWIW, I replaced the 6550s in my Mesa 400 (non plus) with JJ KT88s from Bob @ Eurotubes, as well as the preamp tubes (12AX7s) with JJ ECC83s's, all as recommended by Bob, and I am...well...lets just say that extremely pleased is an under-statement.

    If you read through his website, you can pretty much see why he's only selling Teslas. Because he believes they are the only ones worth his time selling.

    Whether you buy a better set of tubes now and use the stock ones as spares, or you wait until the old ones blow out to buy anything new, its all up to you man. Personally, I wouldn't own/gig a tube amp with out spares...I mean, anything really can happen. But thats just me.

    Good luck!

    btw - killer rig!!!


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