NAD Jet City JCA20H - Update New Grill!

Discussion in 'Other Amps' started by Filipe Soares, Aug 10, 2020.

  1. Filipe Soares

    Filipe Soares Well-Known Member

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    I've been looking for an amp to learn more about modding tube amps for a few months, after a lot of thinking here it is:

    WhatsApp Image 2020-08-10 at 14.23.57.jpeg

    My first mod is to install a resonance knob. it's a simple job and for these small amps makes a lot of difference.

    my first impressions is this amp does not have a lot of gain as I'm used to. but, that will change!

    I'm thinking about doing the BE-PX, Octal and Capacitor mods from epic mods
    https://www.epic-tone.com/online-store/Jet-City-20H-HV-Mods-p87313323

    I think I can get the info about the caps for free, but the octal and BE conversion I really don't have a clue.

    I know there's a lot of people here with these amps, what mods have you done???



    MOD LOG 10/aug 2020
    Depth Knob and 2 JJAX7

    Update 14/aug 2020
    New grill
    WhatsApp Image 2020-08-14 at 20.47.45.jpeg
     
    Last edited: Aug 14, 2020
  2. J Saw

    J Saw Well-Known Member

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    Perfect candidate for some mods. Lots of info out there as well.
    HNAD.

    Epic is great to deal with BTW.
     
  3. ricksdisconnected

    ricksdisconnected Well-Known Member

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  4. Filipe Soares

    Filipe Soares Well-Known Member

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    1st MOD - 2 JJ 12AX7 in the pre amp position. It sounds so much better, fuller, more gain.
     
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  5. ricksdisconnected

    ricksdisconnected Well-Known Member

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    clips?
     
  6. jchrisf

    jchrisf Well-Known Member

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    I've got a BFG modded 22H. Sounds like a JCM 800 on the clean channel and the overdrive sounds like a hot rodded 800. But on the Hot Rod side the bright switch doesn't work so I'm hoping to increase my amp knowledge and be able to figure out why it is not working and fix it. So it doesn't sound very good at bedroom volumes on the overdrive channel.. too muffled.
     
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  7. jchrisf

    jchrisf Well-Known Member

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    @J Saw have you done any more mods to yours? Are you happy with it now?
     
  8. J Saw

    J Saw Well-Known Member

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    No Sir. Same as in the clip I shared. I am happy w/it :D

    I do have another 20H on standby that I'm gonna do up with one of Epic's
    new boards. Really looking forward to trying a bunch of different things.
    The new boards look killer!
     
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  9. BftGibson

    BftGibson Well-Known Member

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    Congrats, super interested in this journey.
     
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  10. jchrisf

    jchrisf Well-Known Member

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    Where are you seeing the new boards?
     
  11. J Saw

    J Saw Well-Known Member

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    FB. Bryce is sending mine soon.
    They look rugged. You have to be very careful with the stock boards.
    SO easy to lose a trace if your not extremely careful.

    I had to jump a couple of em' on the first amp I modded :D
     
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  12. J Saw

    J Saw Well-Known Member

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    @Filipe Soares

    I would do the depth/resonance mod and the BE mod first.
    I think you will be surprised at the difference.

    Maybe SAT mod after that?
     
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  13. Filipe Soares

    Filipe Soares Well-Known Member

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    do you know were is the bias points for this amp???
     
  14. Filipe Soares

    Filipe Soares Well-Known Member

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    I'm doing the resonance today. I want to bias it to, just to be safe. do you know were are the bias points?? and what bias settings are you using?
     
  15. J Saw

    J Saw Well-Known Member

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    Oh, and some el84m.
     
  16. J Saw

    J Saw Well-Known Member

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    There was a YT vid on the shunt method but I can't find it now.
    18-21.
     
  17. J Saw

    J Saw Well-Known Member

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  18. Filipe Soares

    Filipe Soares Well-Known Member

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    holy fucking odin. it's night and day with the depth knob!!!
     
  19. J Saw

    J Saw Well-Known Member

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    :D Now you have a jumping off point :D
     
  20. Filipe Soares

    Filipe Soares Well-Known Member

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    my bias was waaaay too hot

    494v at B+ and 38mah. it should be somewhere from 17mah to 20mah. now it's in a safe 19mah. the amp is sounding way better
     
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