DIY talk

Discussion in 'DIY' started by Cspirou, Jul 25, 2021.

  1. Cspirou

    Cspirou They call me Sparky

    Friend
    Joined:
    Sep 27, 2015
    Likes Received:
    6,516
    Trophy Points:
    113
    Location:
    Northwest France
    I could have sworn there was a general DIY thread but I couldn't really find it.

    Anyway, this is for questions and comments that don't really merit a dedicated thread but are interesting or useful nonetheless.
     
    • Like / Agree Like / Agree x 3
    • List
  2. Cspirou

    Cspirou They call me Sparky

    Friend
    Joined:
    Sep 27, 2015
    Likes Received:
    6,516
    Trophy Points:
    113
    Location:
    Northwest France
    Starting myself;

    Is there a reason for encasing electronics in epoxy besides trying to prevent cloning?
     
  3. Woland

    Woland Friend

    Friend
    Joined:
    Jan 13, 2021
    Likes Received:
    760
    Trophy Points:
    93
    Location:
    a friendly land
    Water resistance. The circuit board of my coffee machine is like that.
     
    • Like / Agree Like / Agree x 4
    • List
  4. Beefy

    Beefy Almost "Made"

    Joined:
    Apr 10, 2021
    Likes Received:
    686
    Trophy Points:
    93
    Location:
    Canada
    Also vibration resistance. Important if you are going to send your amp into space.
     
    • Like / Agree Like / Agree x 3
    • List
  5. Thad E Ginathom

    Thad E Ginathom Friend

    Friend
    Joined:
    Sep 27, 2015
    Likes Received:
    9,465
    Trophy Points:
    113
    Location:
    India
    I used to make that stuff in one of my hippy-days jobs. I think the brand name was eco-fill. IIRC it might have been an American company, but had sales and some manufacturing facility in West London, UK.

    A couple of guys from the same house worked there, running the huge-rollers machine that mixed and fused the mix. I made up the mix.

    Weird business: almost every batch failed inspection and was chucked out! One day there was an almost perfect batch. The lab guys from upstairs were quizzing me: "Please, please, try to remember what you did different!" I couldn't: it had been just another mix to me.

    One of the ingredients was a very fine carbon powder. It took a week of baths to get it out of the skin pores, so I looked permanently like a 19th-century chimney sweep.

    The place was very low on safety standards, and the day the three of us left, the foreman (who was even related to the MD) left us alone in the office with the phone book pointedly left open at Factory Inspectorate!

    Anyway, not entirely offtopic, but not very useful, this has been My Life In Potting Compound...
     
    • Like / Agree Like / Agree x 4
    • List
  6. dBel84

    dBel84 Friend

    Friend
    Joined:
    Sep 27, 2015
    Likes Received:
    2,518
    Trophy Points:
    93
    • Like / Agree Like / Agree x 2
    • List
  7. Woland

    Woland Friend

    Friend
    Joined:
    Jan 13, 2021
    Likes Received:
    760
    Trophy Points:
    93
    Location:
    a friendly land
  8. randytsuch

    randytsuch Facebook Friend

    Joined:
    Oct 13, 2017
    Likes Received:
    206
    Trophy Points:
    43
    Location:
    Los Angeles, Ca
    I've seen potting used to prevent arcing in high voltage circuits, especially at high altitudes (airplanes).


    On the diy front, I'm considering building a Class A, pass or firstwatt clone amp to drive my HE6SE's. Might be my next project.

    Randy
     
    • Like / Agree Like / Agree x 2
    • List
  9. Cspirou

    Cspirou They call me Sparky

    Friend
    Joined:
    Sep 27, 2015
    Likes Received:
    6,516
    Trophy Points:
    113
    Location:
    Northwest France
    • Like / Agree Like / Agree x 4
    • List
  10. Beefy

    Beefy Almost "Made"

    Joined:
    Apr 10, 2021
    Likes Received:
    686
    Trophy Points:
    93
    Location:
    Canada
  11. Cspirou

    Cspirou They call me Sparky

    Friend
    Joined:
    Sep 27, 2015
    Likes Received:
    6,516
    Trophy Points:
    113
    Location:
    Northwest France
    • Like / Agree Like / Agree x 2
    • List
  12. Cspirou

    Cspirou They call me Sparky

    Friend
    Joined:
    Sep 27, 2015
    Likes Received:
    6,516
    Trophy Points:
    113
    Location:
    Northwest France
    Yeah. It seems like his other was a proof of concept. Single rail power supply so capacitors on the input and output. Plate voltage on the nutube is only 24v also.

    On the Sangaku it's a full blown regulated dual rail power supply with B+ at 70V and 40V at the plate. 3rd order distortion is 20dB lower on the Sangaku than the simpler amp.
     
  13. Beefy

    Beefy Almost "Made"

    Joined:
    Apr 10, 2021
    Likes Received:
    686
    Trophy Points:
    93
    Location:
    Canada
    Indeed. But after a bit more thinking about this, I'm really just a bit bummed about the use of output OPAMPs here. As someone who built several Millett hybrid derivatives with the discrete diamond buffer output, this just seems a bit less fun to put together.
     
  14. Armaegis

    Armaegis Friend

    Friend BWC
    Joined:
    Sep 27, 2015
    Likes Received:
    4,993
    Trophy Points:
    113
    Location:
    Winnipeg
    I suppose one could always put sockets in and DIY a discrete opamp?
     
  15. Beefy

    Beefy Almost "Made"

    Joined:
    Apr 10, 2021
    Likes Received:
    686
    Trophy Points:
    93
    Location:
    Canada
    I've never really looked that closely at discrete OPAMPs, are there any suitable for unity gain current buffers?
     
  16. Armaegis

    Armaegis Friend

    Friend BWC
    Joined:
    Sep 27, 2015
    Likes Received:
    4,993
    Trophy Points:
    113
    Location:
    Winnipeg
    I don't know any off the top of my head other than the pre-made ones by Burson, Sparkos, NewClassD, Sonic Imagery, etc...

    There's a few more in the music/guitar world, but I'm not really familiar with them.
     
  17. Cspirou

    Cspirou They call me Sparky

    Friend
    Joined:
    Sep 27, 2015
    Likes Received:
    6,516
    Trophy Points:
    113
    Location:
    Northwest France
    I'm not sure if First Watt amps have enough voltage for an HE6. A typical First Watt supplies 25W into 8Ω which will give you 4W into 50Ω.

    I mean 4W should be enough but I know people that look for more
     
  18. randytsuch

    randytsuch Facebook Friend

    Joined:
    Oct 13, 2017
    Likes Received:
    206
    Trophy Points:
    43
    Location:
    Los Angeles, Ca
    Thanks for the warning. Haven't made any progress, but I hope to soon.

    I suppose I could make a higher voltage power supply, with lower bias current.

    Randy
     
  19. Cspirou

    Cspirou They call me Sparky

    Friend
    Joined:
    Sep 27, 2015
    Likes Received:
    6,516
    Trophy Points:
    113
    Location:
    Northwest France
    Pete Millett is really just a tube guy. If you look at his catalogue almost none of his solid state circuits are discrete, preferring to use monolithic components whenever possible. This goes for opamps, regulators and CCS loads. He's often used switch mode supplies as well
     
  20. Armaegis

    Armaegis Friend

    Friend BWC
    Joined:
    Sep 27, 2015
    Likes Received:
    4,993
    Trophy Points:
    113
    Location:
    Winnipeg
    It's probably enough, but most of us want the bragging rights... o_O
     

Share This Page