martin manning wrote: ↑Mon Jul 16, 2018 11:03 pm
Tony's layout specifies PT 026554, which is an export unit designed for use with a FWB. It does have a separate bias winding. Assuming the PT part number is correct, the errors I see in the layout are that the bias winding leads on that PT are brown, the red/yellow CT lead should not be used, and the dual primary connections are incorrect or incomplete (they may be correct, but hidden inside the bell).
Martin
Just wondering why he needs the wiring layout on the 554 when he has a Bassman PT
I should know better than to jump into a thread that is so confusing?
Turns out that he used a Bassman 100 PT
Tony
" The psychics on my bench is the same as Dumble'"
Yes several discussions going on at once here. The Bassman PT is all good now, but Andre was initially misled by looking at the layout and wired it up as a FWB. There are some errors and omissions in the layout, though, as I noted above.
martin manning wrote: ↑Tue Jul 17, 2018 1:26 am
Yes several discussions going on at once here. The Bassman PT is all good now, but Andre was initially misled by looking at the layout and wired it up as a FWB. There are some errors and omissions in the layout, though, as I noted above.
So he thought that just because he was building a 102 and used the layout that happen to have a transformer with a FWB that that's what he was supposed to use
So that explains why I was confused. Sanity check verified!
Btw.
There are some errors and omissions in the layout, though, as I noted above.
My advice then is for those who don't know how to wire a power transformer burn down your house or blow yourself up then don't use my layout!
Tony
" The psychics on my bench is the same as Dumble'"
Peace guys!!! My amp is now working as it should (not fine tuned yet). Voltages are perfect now. All I had to do, was to connect the Yellow/Red CT and the HT came down, and the negative bias supply returned.
Idiots like me, are here to keep you guys on your toes !
Andre, didn't you initially have the anode ends of the diode strings tied together and grounded too? You'd have to to get the voltage you reported. BTW, you're not the first one to make this mistake. Luckily, no injuries or damage other than smoked components resulted, as far as I know. This may be good luck, as over-voltage or reversed polarity on electrolytics can cause them to explode. Use of a current limiter, a Variac with voltage monitoring, and safety glasses on initial power up is highly recommended.
Tony, everyone should understand that layouts and schematic can contain errors. With time, they get noticed and corrected. It's very true that anyone going their own way with a different power transformer and rectifier arrangement is responsible for their actions.
martin manning wrote: ↑Tue Jul 17, 2018 10:19 am
Andre, didn't you initially have the anode ends of the diode strings tied together and grounded too? You'd have to to get the voltage you reported. BTW, you're not the first one to make this mistake. Luckily, no injuries or damage other than smoked components resulted, as far as I know. This may be good luck, as over-voltage or reversed polarity on electrolytics can cause them to explode. Use of a current limiter, a Variac with voltage monitoring, and safety glasses on initial power up is highly recommended.
Tony, everyone should understand that layouts and schematic can contain errors. With time, they get noticed and corrected. It's very true that anyone going their own way with a different power transformer and rectifier arrangement is responsible for their actions.
It's very true that anyone going their own way with a different power transformer and rectifier arrangement is responsible for their actions.
Martin
He wired a different transformer to my layout and had 800V sitting in a chassis and blew up a cap.(Thank god he had a light bulb on it)At this point I want to go in and erase all the Sec wires from my layouts and edit "Consult your wiring diagrams for proper install of your transformer"
Tony
" The psychics on my bench is the same as Dumble'"
It's very true that anyone going their own way with a different power transformer and rectifier arrangement is responsible for their actions.
Martin
He wired a different transformer to my layout and had 800V sitting in a chassis and blew up a cap.(Thank god he had a light bulb on it)At this point I want to go in and erase all the Sec wires from my layouts and edit "Consult your wiring diagrams for proper install of your transformer"
Tony
I don't think martin's implying that, I think your layouts are perfect, and greatly appreciated. There ended up being confusion between the actual transformer and the one in the layout. I don't think you'd need to change that at all. I agree with the sentiment that if they can't realize there's a specific part number on the layout, they're in the wrong hobby/career.
I made a pretty similar error with a Vox AC100 amp I built and Sluckey helped me there, it seems a pretty easy mistake to make when you're a noob.
It's very true that anyone going their own way with a different power transformer and rectifier arrangement is responsible for their actions.
Martin
He wired a different transformer to my layout and had 800V sitting in a chassis and blew up a cap.(Thank god he had a light bulb on it)At this point I want to go in and erase all the Sec wires from my layouts and edit "Consult your wiring diagrams for proper install of your transformer"
Tony
Tony, I don’t believe that would be necessary. I f%&#$ up!! Believe me.. I will not make that mistake again.
It's very true that anyone going their own way with a different power transformer and rectifier arrangement is responsible for their actions.
Martin
He wired a different transformer to my layout and had 800V sitting in a chassis and blew up a cap.(Thank god he had a light bulb on it)At this point I want to go in and erase all the Sec wires from my layouts and edit "Consult your wiring diagrams for proper install of your transformer"
Tony
Tony, I don’t believe that would be necessary. I f%&#$ up!! Believe me.. I will not make that mistake again.
martin manning wrote: ↑Wed Jul 18, 2018 11:18 am
Ya he's great, and good at demonstrating how burning something up is a useful learning experience!
Indeed I've learnt more from doing things wrong than if I'd done them right in the first place. Trouble shooting is THE best learning if you're not starting from the place of a schooled EE. Also personally speaking, practical hands on learning is so much more fun than dry book reading
As long as you don't permanently damage yourself or others it's all good fun.
Funnily enough, I was sat working in my studio yesterday when there was a loud POP and the power tripped, my UPS meant I saved my work and turned off my computer. After a bit of investigation with my trusty mustimeter, I found a bad bulb in one of my LED ceiling downlighter bulbs( I tested them all ). I took it apart and the electrolytic cap had exploded causing a short.
Looking good. No need for fancy dovetails when it's going to be tolexed. I've screwed and glued all my cabs and they're just fine. Counter sink the holes, fill with body filler, sand then route the edges.
M
Last edited by norburybrook on Fri Jul 20, 2018 9:39 am, edited 2 times in total.
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