Blues Junior Re-Wire/Overhaul - Questions, Considerations, and Eventual Build Thread

Discussion in 'Shock Brother's DIY Amps' started by Huddy, May 20, 2021.

  1. Huddy

    Huddy Tele-Holic

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    **This is getting completed this weekend one way or another.** :D

    I got a Blues Junior that had a burnt up board that's been sitting for a few months. I'm thinking of doing a parallel V1 EL84 5F6A type deal with a PPIMV.

    Couple of questions

    1. What's the best way mount the the tube sockets to the chassis. Since the original mounting holes were for a PCB they're a bit large and the mounting centers on the tube socket right on the edge fo the original tube socket holes. I have a feeling I'm going to need to fabricate some sort of mounting plate which I'm not excited about.

    2. I haven't found much in terms of circuit for something to just flat out copy... so I'm kinda cobbling a Matchless Lightning and 5F6A together. So I'm thinking (again) Parallel V1, Volume, Cathode Follower, Tone Stack, LTP, Cathode Biased EL84s. I am using the original iron. Any considerations that I need to take into account to make the translation?

    3. Anything else I need to consider?
     
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  2. sds1

    sds1 Tele-Afflicted

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  3. Huddy

    Huddy Tele-Holic

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  4. sds1

    sds1 Tele-Afflicted

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    Thanks! I'm not sure whether to be proud or embarrassed haha! I struggled with that for a couple weeks. It ended up solid though, should last as long as the rest of the amp.

    There are adapter plates for sale as well, not sure how these will fit but maybe this helps:

    https://www.mojotone.com/amp-parts/TubeAccessories_5/Octal-socket-to-9-pin-socket-adapter
    https://tubedepot.com/products/octal-to-9-pin-socket-adapter
    https://www.angela.com/8pinto9pintubesocketadapterplate4386mmto22mmstainlesssteel.aspx

    I Googled "noval adapter plate" for those. There are more results.
     
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  5. Lowerleftcoast

    Lowerleftcoast Friend of Leo's

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    6V6 would allow the heater winding to add two preamp tubes.
    The EL84 uses 0.76A each. The 6V6 uses 0.45A each.
     
  6. Jay Jernigan

    Jay Jernigan Tele-Afflicted

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    A 6V6 Blues Jr with an extra preamp tube? Or two?
    Are you listening, FMIC?
     
  7. Huddy

    Huddy Tele-Holic

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    Thanks! I'll keep those on the back burner for sure. I'm gonna buy some sheetmetal in the morning and test my "fabrication" skills.
     
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  8. Huddy

    Huddy Tele-Holic

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    Two preamp tubes for spring reverb? What would you do?
     
  9. sds1

    sds1 Tele-Afflicted

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    Good for you, honestly this is what I should have done. Good luck! :)
     
  10. Lowerleftcoast

    Lowerleftcoast Friend of Leo's

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    The point is you don't have to stay with EL84 tubes. You have options. Ime a the 6V6 is more akin to the 5F6A but that may not be a concern to you. If you want reverb and/or vibrato it is available when running 6V6 tubes. Other options are higher gain or another channel. How about a low impedance FX loop?

    Today, I would either add reverb or a second channel. Tomorrow I might want added gain. It is like ice cream. What flavor would you like.
     
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  11. schmee

    schmee Doctor of Teleocity Ad Free Member

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    1. There are adaptor plates made to go from Octal to 9 pin. You might find wider spaced tube sockets though that will work instead.
    2. Iron should work if you go EL84 or 6V6
    3. Has anyone done an EL84 powered 5F6A type before? Often you cant just substitute and have it sound anywhere near good. I wonder what you would need to change? (I tried EL84 adaptors in a amp once and never did get it sounding right. Albeit I didn't persist that well)
     
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  12. Huddy

    Huddy Tele-Holic

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    I don't think I've seen an EL84 5F6A before... and in reality it's more Matchless lightning with a Mid control. So I'm kinda going off the Lightning output section. Also I've got it setup so that nearly each component has it's own turret for easy swaps and temporary clip-ins. I have a feeling this is going be a lot of guessing and checking and more long term project... but I want to at least make some sound by Sunday afternoon. Might not be a good/great sound, but we'll cross that bridge when we get to it. ;-)
     
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  13. Huddy

    Huddy Tele-Holic

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    Yup. Time will tell. I'm going to consider the possibility of mounting Octal Sockets in the future when I start cutting into this chassis. Good looking out ;-)
     
  14. schmee

    schmee Doctor of Teleocity Ad Free Member

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    Plates $2, often seen on Ebay also. Weber has them too.
    https://www.angela.com/8pinto9pintubesocketconversionmountingplate.aspx
     
  15. Huddy

    Huddy Tele-Holic

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    ugh... so now I'm thinking I might hold off on this... I ordered CNC at the end of January to putz around with... Just got notified it's shipping today and supposed to arrive tomorrow. It's the perfect piece to practice on. Would have to swap the conversion plate to thicker aluminum. I'm at at a crossroads. Will report back tomorrow.
     
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