SET Asylum

DIY SET, LAYOUT - keep short return paths to Ground

71.50.19.36

drlowmu

SET Type 45 stereo amp, layed-out so it has very short return paths to star ground. A preferred way to execute an amp.
Hammond 2.5 VCT Ef XRF has had its leads modded from stock-chintzy 22 AWG crud, to 14 AWG Mil Spec ( blue ) wire.
Finals' Rk is 9.1K, 24 Watt, consisting of two closely matched Mills MRA-12 Rs, each 18.2 K, in parallel.
100% film caps - B+ supply and Rk bypassing.
Have fun building !!
Jeff

Edits: 08/17/16

Follow Ups:

RE: DIY SET, LAYOUT - keep short return paths to Ground - Stuben 13:47:09 08/20/16 (7)
Jeff,

Looks nice. I tend to heat mechanical connections up and fill with solder from experience with intermittent connections...especially earthing.

Stuben
- Yes, That is EXACTLY what I did and do . - drlowmu 16:47:49 08/21/16 (0)
  Thanks !!
  ALL my spade lugs are soldered, actually Wonder Soldered with a 250 watt gun. So, I do what you suggest, and I use a self-locking nut.
  Triode Kingdom has offered a very good suggestion, which I will possibly implement next amp - but I would not ever use 16 AWG, perhaps 12 AWG, and maybe even 10 AWG. Thank you, T.K.
  Jeff Medwin
  
  Edits: 08/21/16 08/21/16 08/21/16
- Yes, it's a poor technique - Triode_Kingdom 15:11:50 08/21/16 (5)
  "I tend to heat mechanical connections up and fill with solder "
  
  Stacking crimp lugs on a bolt is extremely poor practice. A solid ground requires (at least) two solder lugs bolted to the chassis adjacent to each other with a 14-16 ga. bus wire between them. All star grounds should be soldered to those lugs, and nothing stacked or crimped.
  
  --------------------------
  Buy Chinese. Bury freedom.
  - RE: Yes, it's a poor technique - FenderLover 17:48:12 08/21/16 (4)
    Nice idea for grounding. I like the Luminescence grounding scheme. Raised, isolated copper bars. Tied to one point on chassis.
    
    Edits: 08/21/16 08/21/16
    - RE: Yes, it's a poor technique - Cleantimestream 15:56:43 08/23/16 (2)
      that is the technique I employ most of the time... sometimes for 'dead' silence I will separate AC ground {power/filament} from the other ground... sometimes makes silence 'inkier'... sometimes not.
      The Mind has No Firewall~ U.S. Army War College.
      - RE: Yes, it's a poor technique - Tre' 18:33:56 08/24/16 (1)
        
        In Reply to: RE: Yes, it's a poor technique posted by Cleantimestream on August 23, 2016 at 15:56:43
        
        Do you mean holding the circuit ground a few hundred ohms above earth/chassis ground?
        
        Tre'
        Have Fun and Enjoy the Music
        "Still Working the Problem"
        
        RE: Yes, it's a poor technique - Cleantimestream 02:57:11 08/25/16 (0)
        
        In Reply to: RE: Yes, it's a poor technique posted by Tre' on August 24, 2016 at 18:33:56
        
        No, sometimes a 15 Ohm for one of the two, there can be two separate grounds and NO ground loop with the result being a quieter back ground.
        
        sometimes; Tre.
        
        These experiences come from empirical knowledge... I will do something in a heartbeat by intuition or just plain curiosity to learn.
        The Mind has No Firewall~ U.S. Army War College.
    - RE: Yes, it's a poor technique - Triode_Kingdom 07:50:26 08/22/16 (0)
      That method of grounding looks really nice, but it's risky for a one-time DIY build. The star ground system is still the best bet to be sure ground loops don't occur.
      
      --------------------------
      Buy Chinese. Bury freedom.
RE: DIY SET, LAYOUT - keep short return paths to Ground - Johno 00:53:03 08/18/16 (0)
Hi Jeff,
attached is a interesting thread where Rod Coleman discusses the sonic merits of using split bobbin filament trannies to separate primary & secondary & reduce electrostatic coupling. He makes reference to the Hammond 166 series which you appear to be using in the photo.

Cheers Johno

http://www.diyaudio.com/forums/tubes-valves/38248-new-dht-heater-35.html
- http://www.hammondmfg.com/266.htm (Open in New Window)
RE: DIY SET, LAYOUT - keep short return paths to Ground - drummerwill 12:06:51 08/17/16 (3)
Looking like a really good start, Jeff..... What is this SET 45 amp #3 ?
It gets better, every time you build one.......Go for it Dude !

Have fun

Willie
- RE: DIY SET, LAYOUT - keep short return paths to Ground - drlowmu 10:49:53 08/21/16 (2)
  Willie,
  
  No, that was taken 4-2016, as I was building it. So, its my present SET, a Type 45, driven by half a 12AX7, direct coupled, three nice pieces of Cardas silver wire - connecting the two stages.
  
  However, that 4-2016 amp, ( since making " audio " clip leads ), is getting a thorough re-do, (a) adding wire wherever it needs it ( by EAR ) and (b) orientating all the film caps by ear. Lotsa work, no one does !! Stay tuned and I will post photos of that.
  
  Jeff
  - RE: DIY SET, LAYOUT - keep short return paths to Ground - aknaydenov 11:48:46 08/21/16 (1)
    I know how it feels, because I build amplifiers the same way. You have my personal admirations for your methods.
    - RE: DIY SET, LAYOUT - keep short return paths to Ground - drlowmu 14:12:25 08/21/16 (0)
      Thank you !
      Please read my Audio Mentor's biography,.....re Robert W. Fulton.
      Also, I would like to share with you some write-ups I have done, on audio design, mostly tube amps.
      Can you send me your email address, so I can do so? It will be FUN for YOU to read !!!
      Jeff ...... my email is drlowmu@gmail.com
      http://fultonmusicalindustries.com/biography.html (Open in New Window)
      Edits: 08/21/16 08/21/16 08/21/16

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