Asher Guitars WD Music Products Amplified Parts Mod Kits DIY Nordstarnd Pickups
Asher Guitars WD Music Products Amplified Parts Mod Kits DIY Nordstarnd Pickups
Asher Guitars WD Music Products Amplified Parts Mod Kits DIY Nordstarnd Pickups

My first tube swapping experience

Discussion in 'Glowing Bottle Tube Amp Forum' started by nontiveros86, Dec 5, 2017.

  1. nontiveros86

    nontiveros86 Tele-Meister

    Aug 13, 2015
    Riverside, CA
    Hey, I hope this is in the right section-- I apologize if it isn't!

    Anyway, I wanted to share my experience swapping tubes for the first time. I've always been nervous about opening up and pulling components out of my amplifiers, but now that I have a particular amp for performance and one for practice, I'm okay with accidentally messing one up. Luckily, it didn't come to that. I'll also say that I've been a sort of a tube skeptic, in that I never really believed that changing tubes would give me much of a sound difference. It was at the prompting of a friend that I ordered some up to play with.

    The amplifier that went under the knife for this experiment was a Hughes and Kettner Tubemeister 18. My first tube amp. It came stock with Chinese EL84's and 12AX7B's, two of each. I had found no faults in the sound of the amplifier, but ordered up a couple of tubes to play with.

    The first ones I switched were the power tubes. I put in a couple of matched Tung-Sol EL84's, which were a little bigger than the stock ones, but still fit just fine. I didn't hear much of a difference here, but I doubt that I was driving the power tubes to distort. They also heated up REALLY FAST, and I'm impatient, so I left them in and moved on to the preamp tubes.

    I had ordered a Sovtek 12AX7WB, since it seemed like a pretty standard example of a 12AX7, a Sovtek 12AX7LPS because it's description said it was a good phase inverter tube, and a Sovtek 5751 to play with preamp gain. I took any suggestions in the product description and on the internet as good, since I know very little about these types of electronics.

    I put the 12AX7LPS in V2, which I assumed was the PI position, and left it there. I didn't try any other tubes in that position. I started with the 12AX7WC in V1. It was actually much different, to my surprise. The H&K's have a reputation of being biased towards the highs, which I like-- that's why I use 'em! This combination of tubes darkened the tone noticeably. I probably could have compensated for it in the EQ section, but I left all the controls in the same place for the test to hear the difference. It also seemed to have less punch than the original Chinese 12AX7B.

    Next I swapped in the 5751. I liked this one a lot. It didn't darken the tone at all, and it seemed even clearer than the original Chinese tube. I chalked this up to having 30% less gain, but it could be something else. A/Bing this one with the Chinese 12AX7B, I had the impression that the Chinese tube packed more of a punch than the 5751, but the balance of the tone was very similar.

    For general playing, I actually liked the stock tubes best. But the 5751 in V1 and 12AX7LPS in V2 sounds very nice. I left that combination in, along with the Tung-Sol EL84's, and will continue playing with them to see what new sounds I can discover.

    Overall, a fun time! Even though the differences weren't earth-shattering, I could definitely tell that there WAS a difference, which is more than I expected going in. I'll probably notice more subtleties as I continue playing with the new setup. I'm going to leave my performance amp, an H&K Grandmeister 36, all stock. Since it uses presets, I'd probably just tweak them back to what they sound like right now! I'll use the tubes I took out of the Tubemeister 18 as backups, though, since they're the same as the ones in the GM.

    And that's it! Hopefully this info can help someone somewhere, but I guess it's mostly a chronicle for my own benefit. If anyone has any questions or suggestions, I'd love to hear them!
    3fngrs likes this.

  2. aerhed

    aerhed Tele-Afflicted

    Dec 24, 2016
    Boulder, WY
    And so it begins.

  3. Paulie Walnuts

    Paulie Walnuts Tele-Meister

    Apr 15, 2017
    I have done hours of tube swaps and tried them all. New production and lots of NOS tubes. I can tell you that you are correct you will hear very little difference in changing around new production tubes. The real change can be had with trying NOS older tubes. And you don't have to break the bank to buy them either. Some guys try to pay off their house selling tubes but other sell at reasonable prices too. You just have to shop around and you can find good tubes for near the same money your spending on new production tubes. The biggest complaint about HK amps is they are bright and lack bass. Some old Amperex or Mullard's will help that a lot. One of best tubes in my HK amps is Old Tung Sol black plates. Most bass I've heard on any tube ever in those amps. Take a look at the article in the link and it's not hard to see why the quality of the old stuff is far superior in every respect
    Last edited: Dec 5, 2017

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