Will there be another run of PSUs going through the system soon as they're sold out at the DIY Store? Another member is sharing an extra he has with me (much appreciated!), but if things go as member tales tend to dictate, there's likely another build behind this one!
Hello, I’m building the F5T-v2 and have a question about the thermistors in the power supply line and ground circuits. I read the Nelson Pass F5T-v2 article and he states using CL-30 type in the line side and a CL-60 on the ground circuit. I saw another schematic with some notes on it stating all these values should be CL-60. Can someone clarify what is the correct values? I have several CL-30’s at the house. Can they be used or should I order up some C L-60’s? Thank you in advance.
CL-60 would be better. Spec sheet shows CL-30 2.5 Ohms at 25C and CL-60 10 Ohms at 25C. The CL-60 will do a better job at limiting the inrush current at turn-on.
Another newb question.. I’m getting close to completing my F6, the transformer arrives on Tuesday. I’m building the light bulb tester, but I can only find a 60 and 150 watt incandescent bulb scattered around the house. Will either of those work, or do I need to eBay a 100 watt one? (Inflated prices I might add, if only I’d known!)
No problem. I have asked many more easy question, and will ask many more in the future.
(I you come across a 100w or 150w bulb , you could try rhem too. But when they’re too high a wattage, you won’t be able to see anything unless there really is a short in your build’s circuits...)
(I you come across a 100w or 150w bulb , you could try rhem too. But when they’re too high a wattage, you won’t be able to see anything unless there really is a short in your build’s circuits...)
I only have one 60 watt and one 150 watt. Didn't even realise they've become so scarce lol.
Thanks for the reply, it's much appreciated. There's so many questions! 😱
Thanks for the reply, it's much appreciated. There's so many questions! 😱
Dim bulb tester? Variac? I must be too confident, never having used either. Then again, the amp did catch fire once...
If the bulb tester doesn’t work out, you can always measure your way towards safe start up with a dmm. First on secondaries, then bridges, then PSU. Always just switching on for a second or two to read voltage.
But the bulb tester is absolutely the safest route. There is a fine line between not being scared of heat, and having things blow up. I should know...
Good luck!
Andy
If the bulb tester doesn’t work out, you can always measure your way towards safe start up with a dmm. First on secondaries, then bridges, then PSU. Always just switching on for a second or two to read voltage.
But the bulb tester is absolutely the safest route. There is a fine line between not being scared of heat, and having things blow up. I should know...
Good luck!
Andy
😀 thanks Andy. I do have a friend who is going to video call me before switch on. He's built many amps since being a teenager, so good to have him on board! I'd like to keep my eyebrows if possible!
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Finally got everything I needed to throw my transformer tunnel together. Would love to hear what yall think.
Looking good, man! Looks like a job well done on the PSU boards, and creative thinking on the tunnel.
Andy
Andy
Nice!
(If you were to go fully unhinged, you could install custom baseplates (steel-panels) were you could align the cap banks to form a straight line... but that’s the pedant in me speaking...)
(Maybe this could be achieved just by turning one of the sides inward—like the ones on the diode-side?)
(If you were to go fully unhinged, you could install custom baseplates (steel-panels) were you could align the cap banks to form a straight line... but that’s the pedant in me speaking...)
(Maybe this could be achieved just by turning one of the sides inward—like the ones on the diode-side?)
I know, right? However, the way that the second row of caps on one board lines up with the heatsinks of the other in this configuration makes me think that if I were to align the center rows, the outside rows would no longer be aligned. I think it would be pretty easy to do with some spacers on standoffs. I have the clearance and it may even be beneficial to get the PSU boards that much further away from the transformers, although I'm hoping the tunnel will provide enough shielding that I shouldn't have to worry about that anyways. If I had them both face the same way then every row would line up, but I think the practical benefits of shorter runs from the PSUs to the amp boards outweigh my/our mild OCD ;p
Indeed, sometimes technical details are more important than mind-comfort. haha.
I have, btw, built my PSU in a similar but simpler way — rectifier & cap bank sitting above the tranny, minimum space (a mere few mm so that they're not touching each-other) and nothing in-between. It's quiet.
And pls do not remind me how many times I dissected the PSU or its alignment in the chassis to try to get them into the symmetric axis, or get the shortest possible wires. (OCD, yeah yeah yeah) 😀
I have, btw, built my PSU in a similar but simpler way — rectifier & cap bank sitting above the tranny, minimum space (a mere few mm so that they're not touching each-other) and nothing in-between. It's quiet.
And pls do not remind me how many times I dissected the PSU or its alignment in the chassis to try to get them into the symmetric axis, or get the shortest possible wires. (OCD, yeah yeah yeah) 😀