Studio JTM???? That would be awesome...

Discussion in 'Marshall Amps' started by Jakeboy, Jun 30, 2020.

  1. Jakeboy

    Jakeboy Well-Known Member

    Joined:
    Dec 15, 2010
    Messages:
    609
    Likes Received:
    380
    Location:
    Missouri
    It would make sense for Marshall to issue a 15 or 20 watt JTM to complete the series.
    Has anyone heard any scuttlebutt or rumors of such a thing. I am almost ready to buy a SV20, but would likely hold out for a JTM type if they were to do so...maybe since the 45 is already only 30 watts they don’t see the need? A cranked JTM is still LOUD though. Just a thought on an amp I’d like to see Marshall sell.
     
    Maggot Brain and tce63 like this.
  2. Kinkless Tetrode

    Kinkless Tetrode Well-Known Member

    Joined:
    Aug 17, 2017
    Messages:
    1,350
    Likes Received:
    1,835
    I not sure how they would engineer the power scaling with the tube rectifier? It might be the same or might be more involved.

    Other than the tube rectifier, the SV20 is probably close enough, because you can just plug in and play KT66s or 5881s. If you really wanted to get down to the details, converting V1 from a split cathode to shared cathode, and changing the slope resistor to 56k should not be too difficult.
     
  3. Jakeboy

    Jakeboy Well-Known Member

    Joined:
    Dec 15, 2010
    Messages:
    609
    Likes Received:
    380
    Location:
    Missouri
    I didn’t think the 6l6 types were compatible with an EL34 pin out?
     
  4. Matthews Guitars

    Matthews Guitars Well-Known Member

    Joined:
    Aug 17, 2019
    Messages:
    2,682
    Likes Received:
    3,929
    No? You'd better tell Mesa, then. Their simulclass amps have been able to swap between EL34s and 6L6s since the late 70s.

    Pin for pin an EL34 and a 6L6 share the same functions pin by pin. Some of the tube operating parameters are different but it's not difficult to configure an amp so that either will run. And let's not forget about all those Marshalls that just require a few basic component swaps and bias adjustments to be able to run EL34s, 6550s, or KT66s. (The KT66 is considered to be plug-and-play compatible with the 6L6.)

    You can't just unplug an EL34 from your Marshall, swap in a 6L6, and go. There's more to it than that. But rewiring the tube socket isn't necessary.
     
    Jethro Rocker, Jakeboy and tce63 like this.
  5. steveb63

    steveb63 Well-Known Member

    Joined:
    Feb 3, 2010
    Messages:
    403
    Likes Received:
    775
    Location:
    Az USA
    Edited due to me being a dumbazz.

    Carry on lol.
     
    Jakeboy likes this.
  6. Jakeboy

    Jakeboy Well-Known Member

    Joined:
    Dec 15, 2010
    Messages:
    609
    Likes Received:
    380
    Location:
    Missouri
    I didn’t know that ....I assumed some rewiring of the tube socket was indeed required on old Marshall’s and Fenders in order to move between 6l6 types and 34s. I learned something new today!
     
  7. Kinkless Tetrode

    Kinkless Tetrode Well-Known Member

    Joined:
    Aug 17, 2017
    Messages:
    1,350
    Likes Received:
    1,835
    With the EL34 you need a jumper wire between pins 1 and 8 that isn't required for the 6L6 pin out. But the jumper wire doesn't matter to the 6L6 so if it's wired for EL34 it still works for 6L6.

    The studios are cathode biased, so you can just plug in and go with those.
     
    Jethro Rocker likes this.
  8. dro

    dro Well-Known Member

    Joined:
    Aug 1, 2015
    Messages:
    785
    Likes Received:
    1,343
    Location:
    Blue Springs Mo
    would much rather have a JTM 20/5
     
    Maggot Brain and Jakeboy like this.
  9. Jakeboy

    Jakeboy Well-Known Member

    Joined:
    Dec 15, 2010
    Messages:
    609
    Likes Received:
    380
    Location:
    Missouri
    Me too...the JTM45 I owned was a completely different sounding amp then my JMP.
     
  10. Maggot Brain

    Maggot Brain Well-Known Member

    Joined:
    Dec 13, 2011
    Messages:
    978
    Likes Received:
    1,656
    Location:
    Seattle, Washington
    I would be ALL over a JTM20/5watt.

    One of my favorite amps is 2 watts, so fun to crank it for the nasty good sounds but still be able to hear afterwords.
     
  11. Gene Ballzz

    Gene Ballzz Well-Known Member

    Joined:
    Feb 19, 2013
    Messages:
    2,175
    Likes Received:
    1,840
    Location:
    Las Vegas, NV
    Anyone considering trying a 6550 in place of an EL34 should look closely at their power transformer specs, as the current draw for the heaters is higher for the 6550. Granted, it's not a lot more, but significant, especially if the amp uses four power tubes!

    With that said, any almost any octal with the same (6CA7) or lower (6V6, 6L6, KT66) heater current as an EL34, is totally plug & play in the all three of the Studio Series and even the DSL20, due to the cathode bias setup.

    Just My $.02,
    Gene
     
    Last edited: Jul 1, 2020
    lespaul339 likes this.
  12. dro

    dro Well-Known Member

    Joined:
    Aug 1, 2015
    Messages:
    785
    Likes Received:
    1,343
    Location:
    Blue Springs Mo
    Just wonder if the JTM would sport the GZ34. What makes the JTM what it is.
     
    steveb63 and jeffb like this.
  13. jeffb

    jeffb Well-Known Member

    Joined:
    Oct 11, 2011
    Messages:
    815
    Likes Received:
    1,314
    Does this mean I can run KT66 in my Origin 20???????????????????
     
  14. Johnny 99

    Johnny 99 New Member

    Joined:
    Apr 20, 2018
    Messages:
    2
    Likes Received:
    4
    According to Santiago, yes. I'm running 6l6s in mine right now.....
     
    jeffb likes this.
  15. jeffb

    jeffb Well-Known Member

    Joined:
    Oct 11, 2011
    Messages:
    815
    Likes Received:
    1,314

    Thank you for the reply! I was wondering if I had killed this thread :)
     
  16. Travis398

    Travis398 Well-Known Member

    Joined:
    Dec 7, 2011
    Messages:
    788
    Likes Received:
    1,118
    Location:
    USA

    I think you're the guy that started the rumor.
     
    Jakeboy likes this.
  17. Maggot Brain

    Maggot Brain Well-Known Member

    Joined:
    Dec 13, 2011
    Messages:
    978
    Likes Received:
    1,656
    Location:
    Seattle, Washington
    Marshall spies, Give us a Studio JTM!

    I have dreamnt of owning the JTM1 to get some low volume cranked JTM sex BUT I just can't quite justify the recent prices for a 1 watt amp... Give us a low watt JTM please.
     
  18. Kim Lucky Day

    Kim Lucky Day Well-Known Member Gold Supporting Member

    Joined:
    Aug 22, 2018
    Messages:
    268
    Likes Received:
    658
    I've certainly been on record for a smaller JTM to be added to the Studio Series lineup. The dollars would literally be jumping from my wallet to get one...
     
  19. marshalltsl

    marshalltsl Well-Known Member

    Joined:
    Apr 6, 2012
    Messages:
    614
    Likes Received:
    759
    Location:
    Catalonia
    They did the JTM1 on 2012. I don't think they will do a studio JTM20.
     
  20. Jakeboy

    Jakeboy Well-Known Member

    Joined:
    Dec 15, 2010
    Messages:
    609
    Likes Received:
    380
    Location:
    Missouri
    Agree that any lower watt JTM would need the gz34 rec tube.
     

Share This Page