Non kit 5F2A build

Discussion in 'Shock Brother's DIY Amps' started by Mongo Park, May 16, 2020.

  1. Mongo Park

    Mongo Park Tele-Holic

    Posts:
    776
    Joined:
    Nov 28, 2010
    Location:
    Winnipeg
    I am starting on this build now that I have the parts collected together. Lots of new 5F1’s coming together so I thought I would join in. Much the same thing as the 5F1 but has a tone control. Only mod I will put in is a negative feedback switch. And a bigger speaker.
    Cheers Ron.
     
  2. Mongo Park

    Mongo Park Tele-Holic

    Posts:
    776
    Joined:
    Nov 28, 2010
    Location:
    Winnipeg
    266CF49F-E2CB-4C6B-BD48-F2B67951E3AC.jpeg CD131B9D-CA6A-4C8D-BEF5-F454EC68AC8D.jpeg I had used my dead clown tools and with some drunk monkey welding skills got together a Brake to bend up chassis. It seems to work well if the sheet aluminum is not to thick.
    I have bent up a shape to give the long narrow fender look. It is a little deep, best I could do with the original dimensions I started with.
    • 28394494-51CF-42DD-9D99-623475DF9C68.jpeg CD131B9D-CA6A-4C8D-BEF5-F454EC68AC8D.jpeg 266CF49F-E2CB-4C6B-BD48-F2B67951E3AC.jpeg
     
    rangercaster likes this.
  3. Mongo Park

    Mongo Park Tele-Holic

    Posts:
    776
    Joined:
    Nov 28, 2010
    Location:
    Winnipeg
    Seem
    To have double images posted.
    The shape is looking good. I will bend some 3/4” strips to put on the ends to give it some strength to hold the transformers without bending
     

    Attached Files:

    Nickfl likes this.
  4. rangercaster

    rangercaster Poster Extraordinaire

    Posts:
    6,380
    Joined:
    May 8, 2008
    Location:
    portland, or
    You are a serious scratch builder, Sir !!!
    .... I wouldn't be surprised if you roll your own tubes...

    ;)
     
  5. Mongo Park

    Mongo Park Tele-Holic

    Posts:
    776
    Joined:
    Nov 28, 2010
    Location:
    Winnipeg
    Next drill some holes for power transformer and tube sockets.
    I will leave the other holes for later and see how things will fit.
     

    Attached Files:

  6. Mongo Park

    Mongo Park Tele-Holic

    Posts:
    776
    Joined:
    Nov 28, 2010
    Location:
    Winnipeg
    I have some ceramic sockets for the 5Y3 and 6V6 that should do. I find that I don’t change these tubes much once the amp is up and running. I have a better socket for the 12AX7. Which I find is so tight it is a pain to get the tube in and out. The preamp tube socket also has the option for a tube shield if needed.
     
    Nickfl likes this.
  7. Mongo Park

    Mongo Park Tele-Holic

    Posts:
    776
    Joined:
    Nov 28, 2010
    Location:
    Winnipeg
    I have found some transparency plastic “covering“ in the kids crafts which is perfect for protecting the chassis and I can mark it for layout.
     

    Attached Files:

  8. Lowerleftcoast

    Lowerleftcoast Tele-Holic

    Posts:
    938
    Joined:
    Dec 30, 2019
    Location:
    california
    Looking good! How thick is the aluminum your working?
     
  9. Mongo Park

    Mongo Park Tele-Holic

    Posts:
    776
    Joined:
    Nov 28, 2010
    Location:
    Winnipeg
    I measured it with my Cali pets and it said 33thousandths. Probably not much help and it most likely doesn’t come in that measurement. It is a bit thin but it was what I had. With end reinforcement it seems strong enough. Also when it hangs in the cabinet I will add some bracing at the bottom of the chassis so it is not just hanging on 2 screws.
     
  10. tubegeek

    tubegeek Tele-Holic

    Age:
    59
    Posts:
    952
    Joined:
    Jan 31, 2020
    Location:
    Brooklyn, NY
    Nice DIY bending brake! Following with interest. Great start.
     
  11. Mongo Park

    Mongo Park Tele-Holic

    Posts:
    776
    Joined:
    Nov 28, 2010
    Location:
    Winnipeg
    I got my least favourite part done. The cutting of the hole for the plug. I made a template but it always needs some file work and the file makes a horrible screeching sound.
    Oh well it is done now. On to the fun parts. I got the tube sockets bolted in. I am thinking a small pop rivet gizmo would make much quicker work of this than nuts and bolts. Also they would never vibrate lose.
    Photos not in sequence, but you get the idea.
    I will next mount the powers transformer and wire it up. That way I can turn on the powers transformer and check to see how to place the output transformer. This is always a juggling act to place everything where it does not effect the other parts but keep them close enough that they can connect in a practical sense.
     

    Attached Files:

  12. Mongo Park

    Mongo Park Tele-Holic

    Posts:
    776
    Joined:
    Nov 28, 2010
    Location:
    Winnipeg
    Thanks for the kind words. The heart of the brake is a pair of door hinges. It seems plenty strong. If I bolt it to my workbench I can lift the whole workbench bending a thicker piece. In the end it cost less than one chassis after exchange, shipping and taxes.
     

    Attached Files:

  13. Mongo Park

    Mongo Park Tele-Holic

    Posts:
    776
    Joined:
    Nov 28, 2010
    Location:
    Winnipeg
    Here is my power transformer, from Matt at Musical Power Supply. Beautiful products this man makes.
    This is rare for me almost all my builds have power transformers from old radios and such. I had this store bought one and it did fit perfectly on to the chassis, as well it had 5F2A qualities about to that would make a perfect killer amp. I am good with big iron even it it departs from the original vintage sound that small transformers can contribute to.
     

    Attached Files:

    tubegeek likes this.
  14. Mongo Park

    Mongo Park Tele-Holic

    Posts:
    776
    Joined:
    Nov 28, 2010
    Location:
    Winnipeg
    Got delayed with the weather warming up but had some more amp time today. I got the powers transformer mounted.
    I have some funky eastern block military switches that I could use one for the on/off.
    Of course I got the pilot light and on/off switch backward and the holes are not the same size, so it goes. I think it is better with the on/off furthest away but the chassis has lots of room. I will go with it.
     

    Attached Files:

  15. Mongo Park

    Mongo Park Tele-Holic

    Posts:
    776
    Joined:
    Nov 28, 2010
    Location:
    Winnipeg
    Wired up the heater supply to the 5y3 as well as the high voltage from the power transformer.
     

    Attached Files:

  16. Mongo Park

    Mongo Park Tele-Holic

    Posts:
    776
    Joined:
    Nov 28, 2010
    Location:
    Winnipeg
    Next I installed a ground for the B+ power supply. I sanded the chassis and used a lock washer for a good connection. I have this old soldering iron my father use to use once a year to fix a lamp cord or something. As a kid I thought it was a cool thing. I figured it had enough heat to solder the ground to the chassis. In the end it didn’t seem to work well but it was nostalgic to plug the old thing in.
     

    Attached Files:

  17. Mongo Park

    Mongo Park Tele-Holic

    Posts:
    776
    Joined:
    Nov 28, 2010
    Location:
    Winnipeg
    Across from the ground bus I placed a old school tag strip. One of the tags is a ground which I can use as a ground for pin eight of the power tube. I guess it could go to the ground bus but this is closer to the 6v6 tube and it is on the strip.
     

    Attached Files:

  18. Mongo Park

    Mongo Park Tele-Holic

    Posts:
    776
    Joined:
    Nov 28, 2010
    Location:
    Winnipeg
    Got the filter caps in. I put a temporary shrink wrap on the ground so I don’t connect a filter cap to it. Got 16,8,8,8 not quite to the schematic but should do the trick.
     

    Attached Files:

  19. Mongo Park

    Mongo Park Tele-Holic

    Posts:
    776
    Joined:
    Nov 28, 2010
    Location:
    Winnipeg
    Got the resistors connected up to complete the B+. 2 watt for the first one and then 1 watt.
     

    Attached Files:

  20. Mongo Park

    Mongo Park Tele-Holic

    Posts:
    776
    Joined:
    Nov 28, 2010
    Location:
    Winnipeg
    I went back and re did the 5Y3 and added the backup diodes from Rob’s site.
    Big kudos to rob so much great information on his site. It is hard to see them in the photo but they are tucked in there.
     

    Attached Files:

IMPORTANT: Treat everyone here with respect, no matter how difficult!
No sex, drug, political, religion or hate discussion permitted here.


  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.