NAD jcm 800 2205 tubes

Discussion in 'The Workbench' started by Petejax1234, Jan 12, 2020.

  1. Petejax1234

    Petejax1234 Member

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    Hey guys,
    So I just purchased Nov 85 2205 from a forum member who had owned it for 26+ years. The amp is lovely and I really love it to bits.
    An interesting array of tubes in it which I was looking for some opinions on. So it has two el34 which say nothing other than el34 wk39/09 (have no idea what these could be) v1 groove tube, v2 is totally blank v3 pinnacle I think v4 Mazda v5 solus
    Any opinions on this match up?
    The amp sounds really great but I would love to make it a little more excitable, a little more feedback maybe a tiny bit more gain etc
     

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  2. BanditPanda

    BanditPanda Well-Known Member

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    Congrats on the acquisition.
    Sadly, I have no advice on the tunes for you.
    BP
     
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  3. RickyLee

    RickyLee Well-Known Member VIP Member

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    The main tone shaper will be the first 12AX7 V1. Half of its two triodes is used for beginning of both channels. Then V2 is only used for the Normal channel. I have tried a 12AY7 in V2 with great results for using Normal channel as a somewhat Clean channel. It gets a decent old Fender vibe that way. Other half section of V1 is 2nd stage for Boost channel. So you want your fave 12AX7 type here. For new production and wanting more saturation, try a high gain Chinese 12AX7 there in V1.

    Another important tube is V3 as half of it is 3rd stage of Boost channel, then other half gets slammed with very high voltage is that is the reverb driver tube. A China 12AX7 would be good here as they are very reliable under high voltages.

    V4 is reverb recovery/last final stage or FX loop recovery.

    V5 is the phase inverter.

    I like the Ruby EL34 BSTR quite a bit in any amp really.

    Try running the Boost channel Volume quite high - 7 to 10. It really opens up the Boost channel. Gain to taste, possibly 6 to 7 is always a good setting for me. And many people hit the front of these with a somewhat clean signal boost or good quality overdrive pedal.
     
  4. Petejax1234

    Petejax1234 Member

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    Thanks this is really great info.
     
  5. Petejax1234

    Petejax1234 Member

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    So I’m going to start trying some of these tube ideas tomorrow. What year is your 2205? I used to have one years ago and it was my all time favourite amp. I just wish I had paid some attention to what glass was in it because it was perfect.
     
  6. mickeydg5

    mickeydg5 Well-Known Member VIP Member

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    Some look like vintage preamp tubes. If they perform and sound decent they are keepers.
    If you have other tubes roll them with those. Use the ones that sound best in whichever slot.
     
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  7. mickeydg5

    mickeydg5 Well-Known Member VIP Member

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    Those power tubes look like Shuguang B type.
     
    Last edited: Jan 14, 2020
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  8. RickyLee

    RickyLee Well-Known Member VIP Member

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    Like Mickey stated, don't throw out the old ones just because they might be old.

    :D

    But doing some swapping around with what is already there can be an option as well, if they seem strong. But it would be a good idea to get some new to start fresh. Then you obviously will have spares and can do some sound testing.

    I have two 2205's, both are 1988 made.
     
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  9. Petejax1234

    Petejax1234 Member

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    As far as I’m aware the last owner had it 26 years and had not put in any new tubes in that time but I could be wrong. But I shall do abit of rolling today. I have some ehx, jj and tungsol to mess around with. Would you guys think it would be a good idea to put some new el34 in there or just leave it until I have a problem?
     
  10. Petejax1234

    Petejax1234 Member

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    So the only thing I’ve changed really is I’ve put an ehx in v1 and it’s sounding amazing. What’s really surprising me about this amp is the clean channel, it’s so ballsy and got bags of character, I love it.
     
  11. RickyLee

    RickyLee Well-Known Member VIP Member

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    Sounds like you got it in a better place.

    I like to start with fresh power tubes when I get an amp for the first time. But then that is playing it safe as in taking the amp out for gigs and such. If you are just playing at home with moderate volume, run those power tubes that are in it. I would at least check the bias idle though.
     
  12. mickeydg5

    mickeydg5 Well-Known Member VIP Member

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    It sounds like those power tubes are kicking butt too. If they are 2009 then barely 10 years old and if low hours then should last a long time. Besides, ballsy is a very good sign.

    How do they bias up, where did you set idle bias?
     

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