using Kustoms in Europe [message #14291] |
Fri, 10 September 2010 09:56 ![Go to next message Go to next message](/FUDforum/theme/vk30/images/down.png) |
Bill
Messages: 64 Registered: March 2002 Location: Kansas
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Member |
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MY friend in Europe needs to use his Kustom K50 with the
240volt/50 hz power they have there. I figured one of the cheap power converters could best be used (around $15), but he wants to maybe replace the transformer inside instead. Anyone have any info as to what he should use? I don't have a K50 schematic to see what the secondary power specs are.
Bill C
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Re: using Kustoms in Europe [message #14348 is a reply to message #14291] |
Thu, 16 September 2010 10:18 ![Go to previous message Go to previous message](/FUDforum/theme/vk30/images/up.png) |
stevem
Messages: 4758 Registered: June 2004 Location: NY
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Senior Member |
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Note that the 33 volt spec is the loaded voltage at the current level the amp pulls out of the pwer supply/ Transformer at idle.
If you or your friend is goind to replace the amps PT you will need one that can output a unloaded to 15 to 20 more volts than the that 33 volt spec!
This is what I found out about the power supply in a first serise Frank / K200 head.
This amp runs on a 40 volt + and - rail supply set up.
With 118 volts going into the PT the unloaded voltage out was 99.6.
The unloaded power supply rails where +47.9 and a -48.2.
In light of this you can see why I am saying you need at least 15 to 20 volts more of unloaded voltage to satisfy the amps full output wattage needs.
Note that the use of a PT that can output 10 percent or more current than the amp needs to make its max wattage will lead to the power supply voltage being higher then the needed idle level of 33 volts.
This is tricky stuff as most Kustom main rail filters are rated for only 10 volts more than the power supply idles at, so it is better if anything to have the power supply voltage sag a bit then to have the un-needed extra volatge blow out filters and may be even transistors, or cause other strange circuit happenings.
This is why modern regulated power supplys are such a blessing!
[Updated on: Thu, 16 September 2010 10:29] Report message to a moderator
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