Yay... another 5E3 build

Discussion in 'Shock Brother's DIY Amps' started by J. Bonkosky, Jun 20, 2021.

  1. J. Bonkosky

    J. Bonkosky Tele-Holic Silver Supporter

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    Hey everyone! I just started a 5E3 build. I had a set of Classictone transformers laying around so I thought why not. It is going to be a straight up 5E3 with a mix of NOS and new parts. This one will be put up for sale once it’s done. I will update as I go. FD788ED6-6145-45F7-AFFE-B3C18A42EB01.jpeg Here is the chassis and a box of junk.
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    I got the board assembled.
     
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  2. Phrygian77

    Phrygian77 Friend of Leo's Gold Supporter

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    You have some really nice parts there, neat work, and then ... an odd assortment of some parts. Why MF on the plates and then CC for the grid stoppers? That's pretty much the opposite of what I'd expect. For MF alone, I see Vishay CMF, PR01, and something else. Were these just parts on hand? You said you're building it to sell, so I'd make it more consistent.
     
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  3. J. Bonkosky

    J. Bonkosky Tele-Holic Silver Supporter

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    Thanks for the compliment. As far as parts selection and placement go, yes most of these parts were items I had on hand. To address the metal film/comp vs carbon comp usage, yes I chose each part for a reason. I have done a fair bit of amp work over the years. In my experience (discounting tubes) most noise and tonal issues in tube amps stem from power supply resistors. Specifically carbon comp plate resistors. I like metal film/comp in those positions as they hold their tolerance and won’t burn. The 56k phase inverter load resistors must be matched for best operation. That is why I selected metal comp. I ran carbon for everything in the signal path because I have a lot of Boeing surplus ohmite and Allen Bradley 5% resistors in the values I needed for the job. And supposedly carbon comps sound better in the signal path. I would say maybe a little? not sure. Probably not. But they work, look nice and fall within their spec, so why not. The Jupiter caps were the big splurge. I have never tried them so I am trying them. They seem well made and have a higher voltage value than needed. I have never used F&T filter caps either. I mostly use Nichicon or a Vishay brand for filters. The spec sheet sold me on the F&Ts. I will post more today as work gets done on the amp. Stay tuned.
     
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  4. Mongo Park

    Mongo Park Tele-Afflicted

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    Nice work looking forward to how this turns out. As far as parts brands/types go this topic is a little deeper into the weeds for my ears. This is a topic of much discussion which I read with interest. I buy all the little bits from one supplier and just go with that. I have not used any carbon comp resistor but have a supply that was given to me I guess I hold pop in a few and see what happens. So I will follow along, watch and learn.
     
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  5. Phrygian77

    Phrygian77 Friend of Leo's Gold Supporter

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    @J. Bonkosky for carbon composition, the voltage coefficient of resistance (VCR) makes them nonlinear. Blenclowe notes that it's around 0.035%/V for 1/2 watt CC. So, they will contribute distortion to an AC signal, especially when the voltage drop is significant, e.g., plate load resistors. The current noise (excess noise) however is higher than another type of resistor, and arguably outweighs any distortion benefits. This is why you sometimes builders use them for the plates loads, and avoid them elsewhere in the signal path, especially at the inputs.
     
  6. J. Bonkosky

    J. Bonkosky Tele-Holic Silver Supporter

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    Sure. But like I said, I had some so I used em. They work and I’m not building a high-fi. I am building a Tweed deluxe that will most likely be cranked into distortion to the point that thermal current noise from carbon comp resistors will make little difference to the over all tone. But I thank you for your expertise and willingness to share. I am surprised however, that you missed my error on the board for the V1 bias resistor. Fixed that one. Anyway, On-ward and upward!
     
    Last edited: Jun 20, 2021
  7. J. Bonkosky

    J. Bonkosky Tele-Holic Silver Supporter

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    So now we get into the exciting stuff with mechanical assembly and soldering in grounding points. All my tube tube sockets are old cinch brand. I like to install the parts board backing board with a few pieces of rolled up masking tape. Makes the board install easier.
    87E4DB33-FC8C-472F-93C7-653B12EB9614.jpeg 6C2B3B28-D5E4-4EC2-8FAD-CFF08F374ECC.jpeg F7A3A552-A4B7-4D26-B937-3DB1771D659C.jpeg 87074DF9-D5DA-4DC2-8EA2-4C582C77E620.jpeg 8ADF202B-C3BC-47EF-B97D-558D1D5AB096.jpeg
     
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  8. J. Bonkosky

    J. Bonkosky Tele-Holic Silver Supporter

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    Thanks for the kind words Mongo. A lot of the parts debate is pretty ridiculous and not really worth paying attention to. As long as you use a correctly rated part of the proper value you will get great results. The thing to focus on is workmanship. If you can put it together neatly and solidly that is most of the battle. Thank you for your interest!
     
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  9. Phrygian77

    Phrygian77 Friend of Leo's Gold Supporter

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    Nope. I've missed my own errors also. @jsnwhite619 caught this one.

    [​IMG]
     
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  10. J. Bonkosky

    J. Bonkosky Tele-Holic Silver Supporter

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    Be
    Been there done that. I did notice it before powering up though lol!
     
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  11. OldPup

    OldPup Tele-Meister

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    If this is an inappropriate question, please ignore, but how much (ballpark) do you plan on selling the amp for?
     
  12. J. Bonkosky

    J. Bonkosky Tele-Holic Silver Supporter

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    Probably start her off around $1200. See what I can get.
     
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  13. J. Bonkosky

    J. Bonkosky Tele-Holic Silver Supporter

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    Okay! We are moving right along. EE41DF90-00AF-49FC-991A-798FF3BF7FDE.jpeg I got the board mounted.
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    Then I went crazy wiring! Now I need to attach her to a load box and a variac and check voltages. See you soon!
     
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  14. J. Bonkosky

    J. Bonkosky Tele-Holic Silver Supporter

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    So let’s put the nice new Weber 12A125A speaker into the nice new Mojotone cabinet. D7B64A16-64F2-4A53-9E87-55A62CDCFF9D.jpeg A75F5412-CF7D-4C09-B147-48FE1ED5360A.jpeg 14A64A79-5155-4548-9F05-C4A26B89DBD1.jpeg And since we are here let’s put the Chassis in too.
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    I made the speaker lead long enough to hook up to a mini mass attenuator if one would desire to do so.
     
  15. J. Bonkosky

    J. Bonkosky Tele-Holic Silver Supporter

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    DD6F4F60-706F-42AB-A5FF-83AC717EE7D7.jpeg I got her running good! Sounds and looks great! That Weber speaker is a lot more efficient then the P12R I have in my personal tweed deluxe. May need to pick one of those up for mine. Ran the amp with my mini mass and the dirt sounded fantastic. Idles quietly with no weird noises. I am putting her up on CL tonight. And definitely in the classifieds here. Thanks for watching. 72AD2384-0014-4A82-AF1B-2102B2BEE5D1.jpeg 39DF7A60-67BE-4675-8E47-9718741039FC.jpeg C4447181-97A2-4E93-A686-8FDA234B84CC.jpeg
     
  16. D'tar

    D'tar Friend of Leo's

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    If you're selling.... The earth connection should be dedicatet to the power cord earth wire only. You may like to ground the PT CT to the first filter cap (-)

    Great looking build.

    Sound clips always welcome!
     
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  17. J. Bonkosky

    J. Bonkosky Tele-Holic Silver Supporter

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    How would that be any different from how it is now?
     
  18. D'tar

    D'tar Friend of Leo's

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    The earth connection is a "safety" connection and should be permanent, dedicated to one connection.... Earth...The Center tap is a "circuit" connection and is a serviceable connection that may hinder the "safety" connection if/when serviced. It may also render a quieter noise floor when connected directly to the negative side of the reservoir cap. Plenty of info on this with a forum search. No worries... It will work as is. Just my .02
     
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  19. J. Bonkosky

    J. Bonkosky Tele-Holic Silver Supporter

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    The earthing wire from the power connector does have its own dedicated spot on the chassis. Maybe you are noticing the center taps for the HV secondary and heater circuit. They are connected to the same spot.
     
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  20. Heyhey

    Heyhey TDPRI Member

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    Where did you connect the main ground?

    Your build looks great. I just completed my first 5F1, and I’d love to do a Deluxe head next.
     
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