I have built many ( UK , 230 Volt ) versions of this ....... It is important to use a HIGH wattage bulb , so a functioning unit plugged into it has 98% of your full mains supply .... I use a 500 Watt theatre flood bulb , but you might even use a 1000 Watt flood bulb when testing a HUGE amplifier ... of course you will have to find or buy an E40 ( giant ! ) Edison screw bulbholder , this unit can also be used as a VITAL temporary input ballast for EHT transformers running many types of gas discharge tubes ( Neons , Mercury vapour , Sodium etc... lamps ) ... in addition , you might use this to discover the correct windings of an expensive ( but UNMARKED ) transformer .... accidental mains supply to a 6 Volt winding just gives a bright bulb ! ! .. note ... for the last two suggestions choose a bulb wattage that suits the device you are powering ( 1000 watt bulb is FAR TOO BIG to test a little ( 1 cubic inch volume ) dinky transformer , use a 60 Watt bulb ! .... hope these tips are of help to you and your viewers ...( ? ) .......
Sounds like a sim bulb tester is a no brainer for powering up the amp. Looks like the three of us are building an F5T at the same time. Like meeting other parents in parenting class.
6L6 shows how to build one in his F5T instruction guide on DIY Audio. A fellow on a FB Audio site showed using the plug-in lamp socket on his tester. It's an elegant idea. I wish I could find his post and give him credit.
Very nice! That's cool that you did everything in such a small conduit box, and that the light socket you got plugs into the outlet! I recently built a dim bulb tester as well, but I gave myself enough space to fit a Kill-A-Watt in the output socket. I ended up using a cheap bamboo tray as my project box for the build. Yours is a lot easier to store though! How is the F5 coming along? I'm about half way though building my PSUs, but I'm waiting for a few more bits from Modu as well as a new soldering iron to arrive in the post. I'm using the Modu riser panels sold on DIYAudioStore to make cages for my transformers.
It's great to hear from other F5 builders like you and Drew. I wish I had room for a dedicated Audio bench. No room in the Garage, It has an Accord and two motorcycles stuffed into it. I'm waiting now for a new multimeter to come in. That will give me 3 that I can use at once. One for each bias supply and one for Drain current at the output.
@@NocturneVid66 Nice! Right now I've got a budget DMM and an entry-level scope, thinking if I pick up an entry-level Fluke in the next few weeks I'll have enough instrumentation to comfortably bias. Same here with the bench - I'm enjoying this build but it's starting to drag on a bit, ready to clear all this space back up. Would be nice to have a dedicated workbench to just leave all this stuff out on for as long as needed, without it being in the way. I'd like to be setting bias a week or two from now, but that may be a bit optimistic.
Trying to make the dim bulb tester you made. How I have it wired is the hot wire from the plug is going to the top light switch screw. The bottom light switch screw has a hot wire going to both hot screws on outlet. Natural wire from plug is going to outlet neutral screw. What connects to the 2nd neutral screw?
Sorry for the delay, I was looking for my schematic for the tester. I could not find it but it is in the video on the tester. The second neutral screw connects back to the same screw on the switch as the hot wire from the power cord. The switch is a bypass as you may recall. Remember to wire both the ground screw on the switch and the outlet to the power cord ground for safety. You may have seen that even a 25W Class-A amplifier will light the dim bulb when fully biased. The tester is very handy at catching wiring errors when you first power up your project.
I have built many ( UK , 230 Volt ) versions of this ....... It is important to use a HIGH wattage bulb , so a functioning unit plugged into it has 98% of your full mains supply .... I use a 500 Watt theatre flood bulb , but you might even use a 1000 Watt flood bulb when testing a HUGE amplifier ... of course you will have to find or buy an E40 ( giant ! ) Edison screw bulbholder , this unit can also be used as a VITAL temporary input ballast for EHT transformers running many types of gas discharge tubes ( Neons , Mercury vapour , Sodium etc... lamps ) ... in addition , you might use this to discover the correct windings of an expensive ( but UNMARKED ) transformer .... accidental mains supply to a 6 Volt winding just gives a bright bulb ! ! .. note ... for the last two suggestions choose a bulb wattage that suits the device you are powering ( 1000 watt bulb is FAR TOO BIG to test a little ( 1 cubic inch volume ) dinky transformer , use a 60 Watt bulb ! .... hope these tips are of help to you and your viewers ...( ? ) .......
Sounds like a sim bulb tester is a no brainer for powering up the amp. Looks like the three of us are building an F5T at the same time. Like meeting other parents in parenting class.
6L6 shows how to build one in his F5T instruction guide on DIY Audio. A fellow on a FB Audio site showed using the plug-in lamp socket on his tester. It's an elegant idea. I wish I could find his post and give him credit.
Very nice! That's cool that you did everything in such a small conduit box, and that the light socket you got plugs into the outlet! I recently built a dim bulb tester as well, but I gave myself enough space to fit a Kill-A-Watt in the output socket. I ended up using a cheap bamboo tray as my project box for the build. Yours is a lot easier to store though! How is the F5 coming along? I'm about half way though building my PSUs, but I'm waiting for a few more bits from Modu as well as a new soldering iron to arrive in the post. I'm using the Modu riser panels sold on DIYAudioStore to make cages for my transformers.
It's great to hear from other F5 builders like you and Drew. I wish I had room for a dedicated Audio bench. No room in the Garage, It has an Accord and two motorcycles stuffed into it. I'm waiting now for a new multimeter to come in. That will give me 3 that I can use at once. One for each bias supply and one for Drain current at the output.
@@NocturneVid66 Nice! Right now I've got a budget DMM and an entry-level scope, thinking if I pick up an entry-level Fluke in the next few weeks I'll have enough instrumentation to comfortably bias. Same here with the bench - I'm enjoying this build but it's starting to drag on a bit, ready to clear all this space back up. Would be nice to have a dedicated workbench to just leave all this stuff out on for as long as needed, without it being in the way. I'd like to be setting bias a week or two from now, but that may be a bit optimistic.
Trying to make the dim bulb tester you made. How I have it wired is the hot wire from the plug is going to the top light switch screw. The bottom light switch screw has a hot wire going to both hot screws on outlet. Natural wire from plug is going to outlet neutral screw. What connects to the 2nd neutral screw?
Sorry for the delay, I was looking for my schematic for the tester. I could not find it but it is in the video on the tester. The second neutral screw connects back to the same screw on the switch as the hot wire from the power cord. The switch is a bypass as you may recall. Remember to wire both the ground screw on the switch and the outlet to the power cord ground for safety.
You may have seen that even a 25W Class-A amplifier will light the dim bulb when fully biased.
The tester is very handy at catching wiring errors when you first power up your project.
Please check my earlier videos for location of the chassis Star Ground.