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Author Topic: Amp voltage question  (Read 5045 times)

kellar

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Amp voltage question
« on: November 11, 2008, 09:11:35 PM »
I am about to start gathering up parts to build an amp and was wondering what values change when building a amp that is based on 220W voltage (European standard). The schematics I am using are based on US 110W voltage. What will change when going from 110 to 220? Capacitor and resistor values all stay the same? Output and power transformer obviously need to be upgraded to compensate, that much I know. Anything else I am missing?
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WezV

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Re: Amp voltage question
« Reply #1 on: November 11, 2008, 09:15:21 PM »
just the power transformer really

kellar

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Re: Amp voltage question
« Reply #2 on: November 11, 2008, 09:20:57 PM »
Thanks Wez
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WezV

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Re: Amp voltage question
« Reply #3 on: November 11, 2008, 09:27:49 PM »
i say that based on just the one amp i have built... That was a kit and all i needed was a different power transformer. 

HTH AMPS

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Re: Amp voltage question
« Reply #4 on: November 11, 2008, 09:53:37 PM »
like Wez said, it's just the mains transformer you need to worry about - you'll need a 240v primary rather than a 110v one.

you will of course need to ensure that the HT winding is spec'd the same - some have a centre tap, some don't.  the current draw will need to be right too on botht the HT and heater secondary taps.


kellar

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Re: Amp voltage question
« Reply #5 on: November 12, 2008, 04:05:06 PM »
I really have no idea what any of that means but I will figure it out as I go. :lol:

Also, regarding capacitors and resistors, I have the parts list of specific ones but was wondering what the differences are between the values. Are there specific types I should be using? Example being that one of the required ones is a 47uF/350V which is a bit harder to find than some of the others. Is this one of those things where  different resistors and capacitors will give you different results regarding tone?

Maybe I am asking this a bit early. I should really just put the thing together and then experiment with modding it later. Regardless, just curious. :D
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Twinfan

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Re: Amp voltage question
« Reply #6 on: November 12, 2008, 06:34:46 PM »
With all due respect, if you don't know the answers to the questions you're asking, maybe you shouldn't be building an amp?  Electricity can be dangerous!

kellar

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Re: Amp voltage question
« Reply #7 on: November 12, 2008, 07:22:40 PM »
I am a do-it-yourselfer Twinfan. I am also a jet mechanic, very aware of the dangers of electricity. I'll be careful. :D
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hamfist

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Re: Amp voltage question
« Reply #8 on: November 12, 2008, 07:44:49 PM »
Are there specific types I should be using? Example being that one of the required ones is a 47uF/350V which is a bit harder to find than some of the others. Is this one of those things where  different resistors and capacitors will give you different results regarding tone?

Different values of caps and resistors, and even different brands (depending on who you talk to), can make a difference in tone.

Remember that for caps, any Farad value within about 20% of the value you theoretically need will be fine. Also for caps, any value Voltage rating above the value you have been given is good.  So a 600V-rated 47uF cap is just as good (even better maybe) as a 350V-rated 47uF cap.

kellar

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Re: Amp voltage question
« Reply #9 on: November 12, 2008, 07:50:38 PM »
That is exactly what I needed to know Hamfist. Thanks.
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Twinfan

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Re: Amp voltage question
« Reply #10 on: November 12, 2008, 08:06:32 PM »
I am a do-it-yourselfer Twinfan. I am also a jet mechanic, very aware of the dangers of electricity. I'll be careful. :D

Whoops - sorry dude!  :oops:

Good luck with the build  :)  What is it???

kellar

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Re: Amp voltage question
« Reply #11 on: November 12, 2008, 08:12:48 PM »
It's quite alright Twinfan. :D

I am building a 5 watt tube amp based on the AX84 P1. I am adding in an optional switch that will knock it down to 1 watt as well. Should make a nice first amp build and a good tube amp for my apartment.

I could just order the DIY kit, but the website they have is so informative that you can download all the schematics, parts lists, and instructional tools you need to build any of their models. Super informative and it is cheaper to source the parts yourself. :D
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Twinfan

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Re: Amp voltage question
« Reply #12 on: November 12, 2008, 10:34:37 PM »
Nice work!  Let us know how it goes  :)