Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Draal on October 26, 2015, 09:25:18 am
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For 120v operation it looks like I wire the Brown to the Black and the Blk/Wht gets wired to the Brwn/Wht. My thinking: the Black and Brown connection then gets wired to the White wire of the power cord. The Blk/Wht -Brwn/Wht connection goes to one of the fuse lugs. Other lug of fuse goes to a lug from switch, followed by black power cord wire connecting to other lug of switch. Ground wire of power cord gets grounded at closest PT bolt.
Am I on the right track? Attempting to attach the diagram for the Classictone 40-18027 in 3,2,1...
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That will work but here's a preferred method...
Power cord black (line) to tip of fuse holder. Side of fuse holder to power switch. Other side of power switch to PT blk and brn wires.
Power cord white (neutral) directly to PT blk/wht and brn/wht wires.
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Thanks sluckey!
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> Blk/Wht Brn/Wht
There's a reason those wires have "Wht" on them.
In house-wiring you always go White to White. (The few exceptions are supposed to be re-Identified non-White.)
White is *supposed* to be the less-live side of the wall-wiring. (Often measures 1V-2V to Ground, the other wire is ~~120V to Ground.)
So they *may* have wound that iron so the White-stripe wires have less insulation than the non-White (Black, Brown) wires, which would have the best insulation.
OTOH, "white to white always" is widely ignored in house-wiring. 60% of the outlets in my old kitchen had White/Black reversed. You can't trust wall outlet hot-side. So they have to put dang-good insulation on both (all 4) winding-ends. Your way "will work".
However, given a White, it is probably best practice to connect it (them) to the white side of the line-cord.
In house-wiring, you NEVER (since 1915) switch or fuse the White wire (except with a DP which also breaks non-white). INside a plug-connected chassis, this was historically not-observed. Finding a switch or fuse in the "neutral" side was common, and "safe" because you should always UN-plug before going inside. However newer safety codes are starting to require all switch/fuse in the non-white side, so this is becoming best practice. (But don't chop-up your 1953 classic just cause the fuse is "in the wrong side"!)
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Thanks PRR! It makes perfect sense now. There are a few layouts showing this transformer wired up in differing ways and my brain crashed like an old 386 computer. Better to get the reassurance from experienced builders than relying on layouts exclusively. :worthy1: