Newbie BootHill 5E3 build

Discussion in 'Shock Brother's DIY Amps' started by Supertzar, Oct 1, 2021.

  1. Supertzar

    Supertzar TDPRI Member Silver Supporter

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    Not sure if it is caused by having my media set to only owner can view, I changed it to members only see if that works.
     
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  2. mountainhick

    mountainhick Tele-Meister

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    That did the trick, thanks!
     
  3. Supertzar

    Supertzar TDPRI Member Silver Supporter

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    Good deal I'm still learning my way around here.
     
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  4. Supertzar

    Supertzar TDPRI Member Silver Supporter

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    Finally got time to replace the bad 220k grid leak resistor and double-check everything. Things looked good so started on Rob's Startup procedure using the light bulb limiter got all the way to connecting the speaker and installing power tubes found light stayed bright after Standby switch on. Removed my V3 power tube and light dimmed, swapped V4 into V3 socket and light dimmed also, believe my original V3 tube is bad. Being a newbie I have no spares off to order new set of tubes from TubeDepot. Week has gone by and tubes are going the wrong way across Tennessee according to USPS, I have free time now so I head to GC and find a Groove Tubes 6v6 set there to use while I wait for my order.

    Get them in using light bulb limiter and looks good there, I have sound no redplating so removed the limiter. I have sound but not very loud now I'm scratching my head.

    PT Classic Tone 40-18021
    OT Hammond 1750E
    RCA 5Y3GT
    GT 6V6-R
    Syl 12AX7
    Unk 12AX7

    No limiter

    Wall - 123.6v
    B+ 389.9
    B+1 389.9
    B+2 340.5
    B+3 263.0

    V1 unk 12AX&
    P1 180.5
    P3 1.353
    fil 6.66
    P6 181.0
    P8 1.344

    V2 Syl 12AX7
    P1 169.3
    P3 1.390
    fil 6.66
    P6 213.1
    P7 19.04
    P8 50.2

    V3 GT 6V6
    fil 6.67
    P3 382.7
    P4 339.1
    P8 21.29

    V4 GT 6V6
    fil 6.69
    P3 383.7
    P4 340.4
    P8 21.32

    V5 RCA 5Y3GT
    fil 5.22
    P3 370.9
    P5 370.9

    Anything look suspicious I don't see?
    I posted pics back in post #19
     
  5. Lowerleftcoast

    Lowerleftcoast Friend of Leo's

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    I would expect those voltages. The Classic Tone 40-18021 710V CT has a little higher voltages than the Classic Tone 40-18016 660V CT that I have used.

    I would put a 12AY7 in V1. YMMV.

    Assuming a 250R bias resistor the MPD is ~104% which is fine. How does it sound?
     
  6. Supertzar

    Supertzar TDPRI Member Silver Supporter

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    Not much volume other than that I think it's
    pretty good. I have a 12AY7 I can put in V1.
    I've tried all 4 inputs still not very loud.
     
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  7. Lowerleftcoast

    Lowerleftcoast Friend of Leo's

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    Try the pop test from power tubes back to V1.

    Post a good picture of the input jacks or look for a mis-step there.
     
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  8. Supertzar

    Supertzar TDPRI Member Silver Supporter

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    I'll check that out and get a pic up in the morning.
     
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  9. Supertzar

    Supertzar TDPRI Member Silver Supporter

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    Pop test was good. Changed V1 to 12AY7 voltages a lot closer to typical.
    P1 128.1
    P3 1.99
    P6 129.1
    P8 1.988

    V2
    P1 168.9
    P3 1.318
    P6 208.1
    P7 17.64
    P8 44.5

    20211023_090125.jpg
     
  10. andrewRneumann

    andrewRneumann Tele-Afflicted

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    Shouldn’t P7 on V2 be slightly less than P8?
     
  11. Supertzar

    Supertzar TDPRI Member Silver Supporter

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    Weber Typical Voltages shows V2 P7 should be 17v, P8 to be 45v
     
  12. andrewRneumann

    andrewRneumann Tele-Afflicted

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    Whoa, I guess I have to go and study up on cathodynes. I thought the 1.5K bias resistor would put the grid a volt or two below the cathode. Am I missing something obvious?
     
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  13. andrewRneumann

    andrewRneumann Tele-Afflicted

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    Where are we at with this amp with a lack of volume?

    I’ve been looking at stuff on cathodyne PI’s and that 17Vdc grid voltage depicted on that Weber layout still makes no sense to me. Could anyone explain it?

    Could you lift one end of that old (I assume) carbon comp 1.5K on V2B and check its resistance?
     
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  14. D'tar

    D'tar Friend of Leo's

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    The 1M grid leak will mess with most meters...
    Test at the top of the 56k tail, may look more reasonable
     
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  15. Lowerleftcoast

    Lowerleftcoast Friend of Leo's

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    This might 'splain it...

    https://www.thetubestore.com/lib/thetubestore/schematics/Fender/Fender-57-Deluxe-Schematic.pdf

    The schematic shows 17.4VAC. That is if there is 100mVAC signal at the input. I am not so sure a DC reading on pin7 means anything worth noting. Of course maybe there is something to it if it is a symptom of the issue we are looking for.
     
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  16. andrewRneumann

    andrewRneumann Tele-Afflicted

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    Wow, I think you may be right about where that number comes from! That is quite a discrepancy. So I’m going to just say that if there is 17Vdc to chassis on P7, then something is wrong. It should be a volt or two less then P8. Would you agree?
     
  17. Lowerleftcoast

    Lowerleftcoast Friend of Leo's

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    I really don't know. Depending on which meter I use, I get weird wild readings when there is AC riding with DC. As D'tar mentioned that reading may be out of place. I would think there would be scratchy pots if there was that much DC there. ?????
     
  18. Supertzar

    Supertzar TDPRI Member Silver Supporter

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    I'll have to recheck that voltage reading as my meter was auto range when I was checking so very well could be AC. No scratchy pots. I'll check after work and update.
     
  19. SacDAve

    SacDAve Poster Extraordinaire Silver Supporter

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    Do you have a pic of the output jacks? Seems a lot of people have a problem with them.
     
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  20. SacDAve

    SacDAve Poster Extraordinaire Silver Supporter

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    I just saw you output jack pick. Hears one of mine Looks OK DSCN0998 copy.JPG
     
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