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JTM45 tube swap

pariahpariah Posts: 596
edited March 2004 in Musicians and Gearheads
A friend of mine has bought a JTM45 without trying it (yeah, yeah, give him a hard time - he won't read this;)) and it turns out it overdrives way too fast for his style (mainly a John Frusciante-revival)... he likes the character of the amp though. Now he's thinking about swapping the KT66's for 6L6's, however he's worried that it will affect the original character of the amp too much. Would it? What would be alternatives?

Thanks on his behalf...
"Until you realize the importance of the banana king, you will know absolutely nothing about the human-interest things of the world."
Post edited by Unknown User on

Comments

  • Pacomc79Pacomc79 Posts: 9,404
    Do not swap the tubes out!!! Those are great tubes and expensive too!

    Sell it or trade it. Tell him to look at old Fender Twins. 85 to 100 watts is perfect. Or find a bigger old 100 watt Marshall Major (KT 88's or JMP (EL-34) or A Hiwatt DR 504

    The JTM 45's are low wattage amps their brillance is thier smooth early breakup. Tube swaps won't matter much except for the tone, If he want's more headroom he should get a louder amp.


    6550's would be a better swap but it would kill it really. Don't do it. Get a different higher wattage amp with more useable headroom.


    If he must change anything go for a low gain preamp tube do NOT CHANGE THOSE POWER TUBES!!!

    12AT7's might work to give you a little more clarity.

    http://www.thetubestore.com
    My Girlfriend said to me..."How many guitars do you need?" and I replied...."How many pairs of shoes do you need?" She got really quiet.
  • pariahpariah Posts: 596
    Exactly what I was thinking.... and exactly what he didn't want to hear. Oh well, he has to face the truth sometimes. God's punishment for buying an amp blindly, based on samples and three anonymous JTM-posessors who think they know what they're talking about... bad luck for him.
    Thanks anyway :)
    "Until you realize the importance of the banana king, you will know absolutely nothing about the human-interest things of the world."
  • Pacomc79Pacomc79 Posts: 9,404
    sure thing, I'd just hate to see a classic get changed like that. The tubes are a huge part of that sound. It's not like the thing is not worth a ton of money as it is, he can trade it in for almost whatever he wants.

    see http://www.plexipalace.com they would be very interested.
    My Girlfriend said to me..."How many guitars do you need?" and I replied...."How many pairs of shoes do you need?" She got really quiet.
  • pariahpariah Posts: 596
    Just talked to him on the phone, he doesn't seem very willing to sell it... his choice. He can be a quite a moron sometimes when it comes to his gear but he's a nice guy and he wanted to thank you anyway. He'll end up settling for a way too overdriven sound and pretending it sounds like the Peppers. As long as he's happy with it...:)
    "Until you realize the importance of the banana king, you will know absolutely nothing about the human-interest things of the world."
  • Pacomc79Pacomc79 Posts: 9,404
    Tell him before he swaps tubes to look into a good compressor first that would help him achieve that bright attacked tone. We can suggest those too. Also in case he dosen't know the trick yet tell him to try linking the two inputs 1 into 2. This gives it a little presence boost and it sounds a bit better. Where ever he bought it from should know how to do it. You just link them with an instrument cable on the front panel no sweat. Also before he swaps tubes out, check the wattage on the speakers. Getting higher wattage speakers will cause the amp to break up later.

    What kind of guitar does he play?
    My Girlfriend said to me..."How many guitars do you need?" and I replied...."How many pairs of shoes do you need?" She got really quiet.
  • mccreadyisgodmccreadyisgod Posts: 6,395
    Any 4x12" cab with Celestion G12T-75 speakers will help that clean headroom...

    http://www.musiciansfriend.com/srs7/sid=040304012312150131025144963900/g=home/search/detail/base_id/36216

    But what that dude really needs is a 100-watt Marshall that has much better headroom. A mid- to late-70's Fender Bassman 50, 70, or 100 will also do nicely... and the Bassman was Jim Marshall's blueprint for the JTM45.

    http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3708599375&category=38074
    ...and if you don't like it, you can suck on an egg.
  • pariahpariah Posts: 596
    Originally posted by Pacomc79
    Tell him before he swaps tubes to look into a good compressor first that would help him achieve that bright attacked tone. We can suggest those too. Also in case he dosen't know the trick yet tell him to try linking the two inputs 1 into 2. This gives it a little presence boost and it sounds a bit better. Where ever he bought it from should know how to do it. You just link them with an instrument cable on the front panel no sweat. Also before he swaps tubes out, check the wattage on the speakers. Getting higher wattage speakers will cause the amp to break up later.

    What kind of guitar does he play?

    He has a CS-2 comp and he linked the inputs... he also has a 4x12 cab with Greenbacks - 100w total speakers should leave a 45(/30?) watt amp plenty of headroom I'd think. He plays a Jap Jaguar... so output doesn't get much lower than that (that's what you mean right Paco?). I finally got him thinking about selling the amp and getting a '59... that would be the 100W Marshall that comes closest to the JTM soundwise I thought (Except for the 100W JTM's but they are impossible to come by here).. please, correct me if I'm wrong. I don't know shit compared to you guys :p
    "Until you realize the importance of the banana king, you will know absolutely nothing about the human-interest things of the world."
  • mccreadyisgodmccreadyisgod Posts: 6,395
    Originally posted by pariah
    he also has a 4x12 cab with Greenbacks - 100w total speakers should leave a 45(/30?) watt amp plenty of headroom I'd think.

    Greenbacks are desired for their early break-up... sort of the one thing he wants to avoid...

    It's funny, for someone who wants a nice clean tone, he's got the ideal rig for dirty playing.

    I'm telling ya, G12T-75's... clean, clear, crisp... exactly what he needs.
    ...and if you don't like it, you can suck on an egg.
  • Pacomc79Pacomc79 Posts: 9,404
    Mig is dead on as usual. Your buddy has bought the perfect Classic Rock dirt machine, and now that I realise we're dealing with a RI and not an original changing tubes isn't that much of a sin but your buddy has the wrong amp and cab for his desires.

    Greenbacks are lovely warm early break up speakers. This is what they are designed for and that is their character. It's not the wattage in this case it's the speaker construction. I just realized the RI JTM 45's are 30 watt RMS amps meaning maxxed out and fully over driven it's pushing about 60 watts, That's not a lot of headroom there even with 5881's which are not really very similar to the KT 88's they used to use before Jim hired accountants to make Marshall cost effective

    The 59 SLPX (Super Lead Plexi) RI is what he wants. Well, that or a used Hiwatt DR 504 (50 watt) or 103 (100 watt Keep in mind this 100 watter will rip your head off 50 watt Hiwatts are the most desired) which he can get cheaper than a new RI SLPX. MIG is also dead on on the speaker Cab. I believe he has the beautiful Marshall TV (tall vintage) Cab. One of my favorites with the greenbacks. GT-12/75 celestions are the ones that fit the tone he desires. My guess is he's liking the character of british or Plexi amps so that's why I don't say try a Fender Bassman or whatever. Keep in mind 100 watts is loud.

    show him http://www.celestion.com for more info on each of the speakers we're talking about.

    Before he swaps the head have him bring both his head and guitar with him to a guitar shop and play it into different cabs with different speakers that could be all he needs is to swap the cab out for slower breakup speakers.

    Middle ground would be my personal favorite the 60 watt Vintage 30 which can be found in the equally attractive 1960AX cab.

    You can usually find these paired with 59SLPXRI's in guitar shops.
    My Girlfriend said to me..."How many guitars do you need?" and I replied...."How many pairs of shoes do you need?" She got really quiet.
  • mccreadyisgodmccreadyisgod Posts: 6,395
    Originally posted by Pacomc79
    Mig is dead on as usual.

    Hey, speakers, man...

    "I'll get a 1959 Strat, run it into a TS-808 and a vintage Plexi head... and a Peavey 4x12" cabinet with Scorpions."

    Morons.
    ...and if you don't like it, you can suck on an egg.
  • Pacomc79Pacomc79 Posts: 9,404
    Originally posted by mccreadyisgod
    Hey, speakers, man...

    "I'll get a 1959 Strat, run it into a TS-808 and a vintage Plexi head... and a Peavey 4x12" cabinet with Scorpions."

    Morons.

    :) Yeah, I used to sell those with Ampeg 4x12's at 299 a pop. I almost bought one, fullsize cab for 299 the speaker swap would still leave you feeling pretty thrifty. I used to push these things like with the Crate DFX1200's. I figure, they picked out a crate at 299 I think the Ampeg will do them a little better anyway. Shudder. All that volume from a crate. Makes my face twitch.

    Tom Morello uses a 4x10 peavy cab but they ain't scorpions either.

    Speaking of 10's did you see the new 10" celestions?
    My Girlfriend said to me..."How many guitars do you need?" and I replied...."How many pairs of shoes do you need?" She got really quiet.
  • pariahpariah Posts: 596
    Originally posted by mccreadyisgod
    Hey, speakers, man...

    "I'll get a 1959 Strat, run it into a TS-808 and a vintage Plexi head... and a Peavey 4x12" cabinet with Scorpions."

    Morons.
    Fanatic. :D
    "Until you realize the importance of the banana king, you will know absolutely nothing about the human-interest things of the world."
  • mccreadyisgodmccreadyisgod Posts: 6,395
    Originally posted by Pacomc79
    Tom Morello uses a 4x10 peavy cab but they ain't scorpions either.

    Speaking of 10's did you see the new 10" celestions?

    A 4x10" cab for guitar? Who would've thought of such a thing?

    New 10" Celestions? Linky linky, please...
    Originally posted by pariah
    Fanatic. :D

    Why do so many people cut their budget at that location? I just don't get it...
    ...and if you don't like it, you can suck on an egg.
  • pariahpariah Posts: 596
    Originally posted by mccreadyisgod
    It's funny, for someone who wants a nice clean tone, he's got the ideal rig for dirty playing.
    That's what I said. Let's see if het does believe you...

    Paco (and MiG too), thanks for the impressive amount of info and help so far. Nice talking to people who actually know what they're talking about... all the pointless rambling I've heard here. Guitar teachers who swear that JTM stays clean at arena volume, storekeepers recommending 6L6's and CLEAN BOOSTS for Christ sake ("yeah it will increase volume and stay clean nonetheless, no matter how loud you set it to be)...
    "Until you realize the importance of the banana king, you will know absolutely nothing about the human-interest things of the world."
  • Pacomc79Pacomc79 Posts: 9,404
    A clean boost is just going to bring out the P/U's and give you even more breakup the more you boost it. It will enhance the clean tone sure but he's looking for headroom he needs more wattage for that.

    Hell one of the loudest clean boosts I know of is the zvex Super hard on or Super Duper 2 in 1. (>5MEG output) It's got nice sparkle up to half way, anywhere over that and it's kicking the ass out of the pre amp and it will be distorting more which is still very good but no where near what your friend wants.

    for a sample of the Super Duper 2 in 1 in to a Marshall no less.

    http://www.zvex.com. look around. and you might check the Zvex board. Zack is always there and he can further answer your tone questions especially relating to the clean boost.
    My Girlfriend said to me..."How many guitars do you need?" and I replied...."How many pairs of shoes do you need?" She got really quiet.
  • pariahpariah Posts: 596
    Originally posted by pariah
    That's what I said. Let's see if het does believe you...

    Paco (and MiG too), thanks for the impressive amount of info and help so far. Nice talking to people who actually know what they're talking about... all the pointless rambling I've heard here. Guitar teachers who swear that JTM stays clean at arena volume, storekeepers recommending 6L6's and CLEAN BOOSTS for Christ sake ("yeah it will increase volume and stay clean nonetheless, no matter how loud you set it to be" God these guys can be assholes)...
    "Until you realize the importance of the banana king, you will know absolutely nothing about the human-interest things of the world."
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