Preamp tubes for the JVM (more bite and gain)

Discussion in 'The Workbench' started by Guitarjon, Nov 17, 2019.

  1. Guitarjon

    Guitarjon Member

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    I got my used JVM410H yesterday. It's a great amp! I love the versatility it has to offer and the high gain tones are tight!

    The previous owner had it retubed and serviced recently so the amp now has JJ tubes in all the sockets. I did however notice that the clean and crunch channel didn't have quite as much gain as I was expecting from demo's I've seen. I also feel like the crunch channel is a little dark or I would like it if there was a tad more bite.

    So are there any pre-amp tubes you guys would recommend to get a little bit more gain and bite on the clean and crunch channels? I'm not a tube expert so mixing and matching is something I'd rather not do yet. I'd prefer to buy a set of tubes from one brand to start with.

    Any suggestions would be appreciated.

    Cheers! :)

    Edit: I think if I just change the V1 to an EHX for example I should already get a little bit more bite. Not 100% sure though.
     
    Last edited: Nov 17, 2019
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  2. SkyMonkey

    SkyMonkey Well-Known Member

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  3. Guitarjon

    Guitarjon Member

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    The invoice from the amp tech just said 'JJ 12AX7 V1, 3x JJ 12AX7 etc.'
    JJ's are a bit darker sounding indeed. They worked well for my Dual Rectifier but now that I want to brighten the JVM up a bit more I want to try something else. I did read the the EHX tubes are brighter overall.
     
  4. Emtbreid

    Emtbreid Well-Known Member

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    I changed 4 preamp tubes to JJ last December, and agree, darker tone. I pulled v1 and replaced it with a tung sol. Much improved. And more gain as well... You’d be better off mixing and matching. Get a few different makes and swap them around until you find a combo you like. I’ve heard tung sol don’t mix well in cathode follower positions, so be aware of that. V1 will have the biggest impact for you.
     
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  5. Guitarjon

    Guitarjon Member

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    Great! I just ordered a couple EHX's including a V1 but I also added a Tung Sol V1 for comparing. Should be interesting! :)
     
  6. Emtbreid

    Emtbreid Well-Known Member

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    It’s all personal taste. Tung sol is the only thing I put in v1 aside from the Chinese one in there originally, and the JJ I replaced it with. I’m really digging the tung sol. You may find something different Works better, that’s the beauty of it!
     
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  7. SkyMonkey

    SkyMonkey Well-Known Member

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    I would still check the codes on the actual tubes.
    Perceived gain comes from the pickups too. The demo you watched may have been with a guitar with higher output pickups than yours.
     
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  8. Emtbreid

    Emtbreid Well-Known Member

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    Or pedals. You may hear my amp and say “damn”! But what you may not see is the 10 band eq in the loop and tubescreamer out front. I see folks that do amp “reviews” all the time that use pedals.
     
  9. ampmadscientist

    ampmadscientist Well-Known Member

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    Maybe you should look at this video?


    I spied about 3 preamp tubes that I liked in the video, these were crunchier crispier and had some added low end hunk.
    But comparing the JJs preamp tubes to others, the JJs were not anywhere near the bottom of the pile. They held up pretty good against the other choices.
    It seemed that the TAD preamp tubes were by far the weakest and wimpy-est.

    Not in the video: Sino tubes. I think you should try them.
     
    Last edited: Nov 17, 2019
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  10. pedecamp

    pedecamp Well-Known Member

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    Get some Chinese tubes like Shuguang, Sino, Ruby, PM, etc.
     
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  11. Dogs of Doom

    Dogs of Doom Moderator Staff Member

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    if going w/ all new tubes, I would be inclined to try JJ in V1 & Chinese in the rest...

    I was talking to Santiago & he said that the JJ is the quietest tube, so, using it in V1 helps keep the amp more quiet during high gain. The rest of the tubes, the Chinese are aggressive & the noise isn't as much a factor...

    So, whatever you find, Shuguang, Sino, etc., they are the same. I think thetubestore, sells them as Chinese... :shrug:

    The JVM, a lot of the magic comes from getting the presence dialed in right. Too hot, it can be piercing. Not hot enough, it sounds dull. Just right & it has a certain amount of excitement in the upper harmonics & just screams...
     
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  12. Bloodrock

    Bloodrock Well-Known Member

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    Try a JJ ec823 in V1. It brings the od orange and red modes down to usable gain levels.
     
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  13. dragonvalve

    dragonvalve Active Member

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    Shuguangs will brighten things up. Also some RCA's if you can afford them.

    [​IMG]

    [​IMG]
     
  14. Emtbreid

    Emtbreid Well-Known Member

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    Really? My stock Marshall preamp tubes were shunguang and I thought they made The amp sound dark. Least at first I did. They were original (14 yrs old). I still use an Mxr 10 band eq and tubescreamer to brighten things up ... I have a tung sol in v1 of my dsl401 and JJ In the rest.
     
  15. dragonvalve

    dragonvalve Active Member

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    The Shuguangs don't last too long as with most of the tubes made after America and the rest of the great tube makers shut down production.

    Then yes add some pedals because the tubes can't do it all.

    After that swap out the speakers to coaxials and you'll be wearing ear muffs. Won't even need that MXR for anything but a high freq attenuator.

    [​IMG]
    EMINENCE BETA 12CX 12" Coaxial WOOFER With ASD1001 1" Titanium DRIVER

    [​IMG]
    RADIAN 5312 - COAXIAL
     
  16. mickeydg5

    mickeydg5 Well-Known Member VIP Member

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    Sino is China. Shuguang and Psvane are in China.

    Ruby, PM, Groove Tubes and the likes purchase, resell, distribute tubes which include those manufactured by Shuguang.

    The Ruby, Audio Classic and TAD in Segeborn's video posted above are Shuguang.
     
    Last edited: Nov 17, 2019
  17. mickeydg5

    mickeydg5 Well-Known Member VIP Member

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    A make/model of a tube does not mean it sounds good or exactly the same.
    The strength of the tube matters a lot. Not all tubes are equal.
    Timing with regards to batches can even make a difference.

    You cannot arbitrarily pick one tube and say all tubes such as these sound exactly like this.
     
    Last edited: Nov 17, 2019
  18. Peter McAteer

    Peter McAteer Member

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    I tried that in my DSL15....now the red channel sounds good, instead of like a design flaw.
     
  19. EndGame00

    EndGame00 Well-Known Member

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    You can mix different 12ax7’s to find the right balance...
     
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  20. Emtbreid

    Emtbreid Well-Known Member

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    Interesting speaker.... I ditched the stock celestion gold back for an 83’ G12-65 and love it.
     

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