Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Andybrown on November 08, 2020, 10:40:59 am
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What do y'all think if I: Cut the existing capacitors from the face of the PC board, leaving just enough lead to solder new caps? Hot glue the new ones to the board.
That way, I do not have to remove the crappy Blues Junior cream board at all.
Thanks.
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What do y'all think if I: Cut the existing capacitors from the face of the PC board, leaving just enough lead to solder new caps? Hot glue the new ones to the board.
You would not be the first. In the trade that's called shoddy workmanship. :icon_biggrin:
But sometimes it may be necessary. May I suggest you cut the leads very close to the body of the old caps. This leaves a long stub to work with. The long stub will allow you to put a heatsink between the board and the solder connection, thus preventing the old lead from becoming desoldered under the board.
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What do y'all think if I: Cut the existing capacitors from the face of the PC board, leaving just enough lead to solder new caps? Hot glue the new ones to the board.
That way, I do not have to remove the crappy Blues Junior cream board at all.
Thanks.
Its not that bad to open the blues jr and get that board to open out. they do it here: https://www.youtube.com/watch?v=h9HPkL2MvmY (https://www.youtube.com/watch?v=h9HPkL2MvmY)
and its just like on a hot rod deluxe.. see the 37:00 minute mark: https://www.youtube.com/watch?v=IWSZrRjaL8c (https://www.youtube.com/watch?v=IWSZrRjaL8c)
unplug amp, drain caps, partially disassemble, recap, put it back together. Took me maybe 45 minutes start to finish (im not not that good at this stuff yet)
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while it's out, inspect ALL the solder connections, especially the flat ribbons, 20 bad solder joints and you have a great amp, 100 leans to a bad built amp :icon_biggrin:
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Would it be considered bad workmanship to wire wrap the new capacitor leads to the old stubs using a proper wire wrap tool? it would give a superior mechanical connection to any other method I can think of for making the best in a bad situation. It seems wire wrap has gone the way of the Do Do Bird but I always liked it in old telco gear. Easy to install, easy to uninstall and very reliable from my experience.
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Its not bad workmanship, its the only way to do it safely without pulling traces. This board is especially fragile at the ribbon connection. Try not to flex this connection. BTW you can't hot glue because that amp runs hot--use JB weld clear RTV silicone adhesive. And look...... if it fails the fallback is perfect. Hoffman sells a turret board for the jr. that sounds wonderful and that you can mod till the cows come home. Jim
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Having a long history with BJs, my suggestion is to remove the board intact with the tube daughter board attached, and then properly desolder any components, and re-install as needed.
It is mildly painful to disassemble a BJ, but not technically difficult -- and it allows you to work on the board easily.
Desoldering components is straightforward, if done with some care. Both the cream and the green boards are relatively robust -- I've got ham hands, and have not destroyed any traces yet. You do need a solder sucker to do this job right. Older eyes are helped with magnifying lenses (ask me how I know!).
My recollection is that Bill M.'s website, if it is still active, has some videos on BJ disassembly.