F5 V3

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Had a little set back tonight.
A little too much much bending action on those wee little input wires on one board.
I thought I was being very conscious about it too.
Anyway, I was fortunate enough to wick the joints and re-solder it in place, holly sucker balls, did I get lucky.
Anyway, this is what I have created.
 

Attachments

  • clamped.jpg
    clamped.jpg
    907.4 KB · Views: 273
  • clamped 2.jpg
    clamped 2.jpg
    925.4 KB · Views: 251
are you using a light bulb? do you have fast blow fuses? what max amperage are they?

if yes to all , you have a short (most likely to ground) somewhere

a simple approach would be to disconnect the power supply from the amp boards

1. test the psu - if it works
2. connect one channel at a time and test
- make sure that neither the positive nor negative rails are continuous with ground before you start.
 
Hi bBel. Thanks for your feed back. I also suspect the power supply, as both channels do exactly the same - no LEDs light up and all 4 x 0.47R/3w resistors get hot and emit smoke plus the 3amp slow fuse blows. But I did measure the power supply before hooking things up. I have to measure it gain. Funny, my builds normally work.
 

6L6

Moderator
Joined 2010
Paid Member
Counterclockwise may be full on. With the power off you need to measure resistance across R5 and turn P1 so that resistance is zero or as low as you can get it, and then do the same with R6 and P2. That is the only way you can guarantee the bias to be set to zero at power up. :)

Also, only have one amplifier PCB connected at a time when testing the amplifier. Any fatal mistakes will only ruin one side instead of both.
 
Thank you, appreciated 6L6.
This pic pretty much somes up why my build took as long as it did.
I call it "project inventory mismanagement".
This is the first time I have taken on a project like this.
Building speakers or even turntables is where my "comfort zone" is I guess.
I have my light bulb tester done and plan on cooking this thing this weekend.
Fingers crossed, I will be listening to it sometime this weekend.
Thanks to all who have helped

Greg
 

Attachments

  • inventory mis management.jpg
    inventory mis management.jpg
    867 KB · Views: 204
Pictures

Here are pictures of my build. I will check the pots later today. Thanks all.
 

Attachments

  • A8F644E7-CEC1-4AB1-98AC-5D0082E00E1C.jpg
    A8F644E7-CEC1-4AB1-98AC-5D0082E00E1C.jpg
    492.2 KB · Views: 184
  • 2328F41F-2E2E-4B3A-A804-4D81C623B74D.jpg
    2328F41F-2E2E-4B3A-A804-4D81C623B74D.jpg
    608 KB · Views: 181
  • 71C17C7A-2837-47C4-8258-2B964FED51F1.jpg
    71C17C7A-2837-47C4-8258-2B964FED51F1.jpg
    601.2 KB · Views: 168
  • CF035CC3-A532-4C13-BD05-531BBBF7541E.jpg
    CF035CC3-A532-4C13-BD05-531BBBF7541E.jpg
    745 KB · Views: 168
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.