Measuring from UK schematic but on US mains - diyAudio
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Old 27th August 2007, 11:58 PM   #1
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Default Measuring from UK schematic but on US mains

Hi, I need to check voltages on my Radford amp... the (British) schematic only has one set of voltages marked, so I'm assuming these apply when using 220V mains. I live in the US and have the transformers wired for 125V. Is there a formula I can apply to the voltages on the schematic to find the correct readings when using 125V AC power?
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Old 28th August 2007, 12:28 AM   #2
mcs is offline mcs  Denmark
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If the transformer is wired for 125V mains, then all the voltages in the amp should be the same (apart from the transformer primary of course).

Best regards,

Mikkel C. Simonsen
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Old 28th August 2007, 12:41 AM   #3
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Ah... really? I guess that makes sense. My Leak Stereo 20 schematic shows two sets of voltages, one for 220V mains, one for 110V, so that's why I expected it on the Radford too.
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Old 28th August 2007, 03:35 AM   #4
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Indeed, all the voltages checked out just about perfectly as marked.

What does it mean in the schematic when it says 350 (at a point which measures 350VDC with a load hooked up), and then 170V in italics next to it? Is the 170V without a load, or something?

Sorry for all n00b questions
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Old 28th August 2007, 04:54 AM   #5
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It could mean that the figure in italics is an AC voltage (if you have a test-tone going into the amp.)

Or,perhaps a standby voltage? (Sometimes common on guitar amp schematics.)
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