Building An Amp How to Rout Signal Wires

Discussion in 'Building the Classics' started by Rotorcraft230, Dec 24, 2019.

  1. Rotorcraft230

    Rotorcraft230 Active Member

    Joined:
    Aug 15, 2019
    Messages:
    261
    Likes Received:
    179
    So I'm getting ready to build my first amp and was wondering on how to rout the signal wires. Should I lay them against the chassis where I can or have them "float" (don't actually know how else to describe it) from point to point. I know about the heater wires and twisting them and laying them on the chassis. Or does it even matter that much? I want this amp to be as quiet as I can. I'm not in a hurry to get it built but want to focus on the quality of the build. It's a Trinity Triwatt using solid core wire for most of the wiring.
    Thanks Mark
     

    Attached Files:

  2. MickeyJ

    MickeyJ Active Member

    Joined:
    Nov 11, 2019
    Messages:
    303
    Likes Received:
    206
    Think 90 degree angles.
    So if a grid wire has to cross another wire, try and make it do so at 90 degrees, so it directly crosses over the wire it's intersecting ( makes a cross ), you can do these little bends to make that happen.
    Don't run grid wires right next to another wire.

    I think what you're referring to when you use the word ' floating' is the old point to point method where there is no component board, tag boards only and raised ground ' busses' where the grounds get attached to.

    This is quite a skill, not rocket science but possibly not for you.

    These days ( after 1947 with notable exceptions ) component boards hold the components and the wires hug the chassis hard because the chassis itself acts as a shield to reduce noise.

    I dont know what that trinity amp is, but beware of too much complexity, there is too much cross wire chatter, too much induction, too much energy passing from one wire to another. ( because theres just too many wires, that's why pcb can be good ' wires' can be kept so short and stiff not moving close to a wire that it can affect)

    I've seen those images of people building mesa dual rectifier clone amps, and they work, but it looks like it took them a year to build.
    Much cheaper to buy one( but not fun right?)
     
    tschrama likes this.
  3. Rotorcraft230

    Rotorcraft230 Active Member

    Joined:
    Aug 15, 2019
    Messages:
    261
    Likes Received:
    179
    ok so if two grid wires are going to the same area can I run them parallel to each other and when it comes to them intersecting then make sure they are 90 to each other.
    I guess what I mean by "floating" is to not have them close to the chassis. I've been looking at a lot of images of the inside of the amp I am going to build and Im just probably going to do what every one else has been doing. The layout diagram makes it look easy
    thanks
     
  4. MickeyJ

    MickeyJ Active Member

    Joined:
    Nov 11, 2019
    Messages:
    303
    Likes Received:
    206
    Be proud of yourself.
    Tip- if something is being a pain in the ass, like really stopping you dead in your tracks, take a break from it for a day or two. When you return, the solution is much easier to see.
     
    Gblev likes this.
  5. South Park

    South Park Well-Known Member

    Joined:
    Sep 14, 2019
    Messages:
    1,232
    Likes Received:
    927
    The signal wires you want to watch is from the jack to v1 . The gain stage the more gain the more noice . RCA jacks is good wire to use the grid stopper on the tube socket and ground the shield . And star grounding is best
     
  6. ampmadscientist

    ampmadscientist Well-Known Member

    Joined:
    Jun 26, 2014
    Messages:
    14,866
    Likes Received:
    8,725
    Location:
    Start the reactor... Free Mars!
    [​IMG]

    Hold on, there is one more thing you need to know about running the filament wires...
     
  7. MickeyJ

    MickeyJ Active Member

    Joined:
    Nov 11, 2019
    Messages:
    303
    Likes Received:
    206
    "I guess what I mean by "floating" is to not have them close to the chassis."

    Have them run close to the chassis, within reason. Dont make the wire triple the length just so you can run it all the way to the corner and underneath the lip of the chassis, just make the wire hug the chassis and then run up to the volume pot or whatever it is.

    # Grid wires running parallel to eachother.

    No closer than 1cm? More If you can, keep them apart.
     
  8. ampmadscientist

    ampmadscientist Well-Known Member

    Joined:
    Jun 26, 2014
    Messages:
    14,866
    Likes Received:
    8,725
    Location:
    Start the reactor... Free Mars!
    Like this:
    the filament wires (pins 4/5 &9) do not cross or touch the grid wires (pins 2 &7).

    [​IMG]

    [​IMG]
     
  9. Nik Henville

    Nik Henville Well-Known Member

    Joined:
    Jul 18, 2018
    Messages:
    1,128
    Likes Received:
    1,819
    Location:
    Eastern Seaboard, the nook-shotten isle of Albion
    Channel
    your inner
    Dumble...

    :hippie::pirate::uk:
     
    ibmorjamn likes this.
  10. Rotorcraft230

    Rotorcraft230 Active Member

    Joined:
    Aug 15, 2019
    Messages:
    261
    Likes Received:
    179
    all good advice thanks fellas Ill post pictures as I go.
     
  11. Scumback Speakers

    Scumback Speakers Well-Known Member Sponsor

    Joined:
    Sep 16, 2016
    Messages:
    662
    Likes Received:
    856
    Location:
    Los Angeles, Ca
    More learned amp gurus can chime in. I just followed the Metro amp instructions for this 50w I built in 2007.
    [​IMG]
     
    ibmorjamn and Amadeus91 like this.
  12. Amadeus91

    Amadeus91 Active Member

    Joined:
    Apr 9, 2019
    Messages:
    115
    Likes Received:
    159
    Jim, your a man of many talents.:)
     
    Scumback Speakers likes this.
  13. Scumback Speakers

    Scumback Speakers Well-Known Member Sponsor

    Joined:
    Sep 16, 2016
    Messages:
    662
    Likes Received:
    856
    Location:
    Los Angeles, Ca
    I have my moments. I've built about 7 amps, all from kits, and I followed the pdf build files implicitly, right down to the number of twists in the heater wires and how they were placed. I was pretty anal about measuring every pot, cap, resistor, part, etc. twice before soldering it in. I can thank George @ Metro for most of that. I think credit should be given where it's due, and that should go to George.
     
    ibmorjamn and Amadeus91 like this.
  14. MickeyJ

    MickeyJ Active Member

    Joined:
    Nov 11, 2019
    Messages:
    303
    Likes Received:
    206
    this amp was always going to sound good.
     
    Amadeus91 and Scumback Speakers like this.
  15. neikeel

    neikeel Well-Known Member

    Joined:
    Feb 12, 2014
    Messages:
    3,654
    Likes Received:
    2,077
    The original heater wiring in my 65 JTM45 is more like AMS set up than Jim’s metro build, which is very faithful to the kit instructions, nice job.
    I keep my heater wires up and away (avoiding the big loop on the black wire and not routing the green wires from the PTfrom the lower part of the socket but bringing them in from above and then extending the chain keeping wires tight and twisted hard into the corner of the chassis.
     
  16. ampmadscientist

    ampmadscientist Well-Known Member

    Joined:
    Jun 26, 2014
    Messages:
    14,866
    Likes Received:
    8,725
    Location:
    Start the reactor... Free Mars!
    If you want the most amount of noise: just follow the factory layout.
    Marshall amps have never been what we would call "quiet."

    filament layout stock.png

    filament wiring 2.png
     
    Last edited: Dec 26, 2019
    Peter McAteer and Nik Henville like this.
  17. Rotorcraft230

    Rotorcraft230 Active Member

    Joined:
    Aug 15, 2019
    Messages:
    261
    Likes Received:
    179
    The alternate method looks great. The heater wires going through the center of the socket isn’t a problem. Well your saying it’s better than what the factory does it. This is how Trinity wants you to do it what do you think about the heater wires in this amp? BCD0259E-0C5E-4667-AED6-4D742147AB3A.jpeg
     
  18. ampmadscientist

    ampmadscientist Well-Known Member

    Joined:
    Jun 26, 2014
    Messages:
    14,866
    Likes Received:
    8,725
    Location:
    Start the reactor... Free Mars!
    Anytime 2 wires are parallel =======like this, there is going to be more noise.
    Most amp builders are not familiar with the actual cause of the buzzing noise. Nor do they design amps which minimize the noise.
    Nor do they really pay attention to the noise at all...they just let it buzz.

    1. What they do:
    They bias the amp cold on purpose so that the power tubes act as a noise gate. The tubes shut down when you are not playing and the noise stops.
    But this causes a lot of fizzy cross over distortion in the output. Not a true clean amplifier.
    Does not sound as good as it could if it were biased properly.
    (this is what Verellen does) biases the amp at 24ma per tube, when it should be 42 ma.

    2. They use DC to power the preamp filaments.
    This is a much better method used by Suhr, Mesa, Marshall etc. Pioneered by MacIntosh Labs etc...

    3. Elevated Filaments:
    It lowers the buzzing noise but does not stop the noise.
    I believe this makes the tube sockets more prone to arcing since the isolation between filament and high voltage is lost...it's a crude method.

    4. Cancellation Method
    Used by very advanced builders. The noise is cancelled out by introducing 2 out of phase noise signals into the signal path.
    It works very well but is not understood by 99% of the builders out there. The majority of builders never even imagined that this is even possible.
    Takes a lot of patience to position wires correctly to gain the advantage of cancellation.
    I have cured the noise in many tube amps using this method.
     
    Nik Henville and Peter McAteer like this.
  19. Peter McAteer

    Peter McAteer Active Member

    Joined:
    Sep 9, 2019
    Messages:
    122
    Likes Received:
    119
    Location:
    The North Shore of Lake Ontario
    Good luck with the build!
    Is this your first Trinity kit? Just curious about how good the build documents are, I'm thinking about getting either the 18W or the Tweed.
     
    Last edited: Dec 27, 2019
  20. Peter McAteer

    Peter McAteer Active Member

    Joined:
    Sep 9, 2019
    Messages:
    122
    Likes Received:
    119
    Location:
    The North Shore of Lake Ontario
    Method 4... fantastic idea. Bada-bing!
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice