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Old 30th October 2008, 06:32 PM   #1
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Default pt

I am considering this 12ax7 preamp. what kind of the PT should I use? many thanks for help.
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Old 30th October 2008, 07:09 PM   #2
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no help?.
Secondary: 125-0-125 V, 100 mA
Filament winding: 6.3 V, 2 A
.... will this one be ok for it?
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Old 30th October 2008, 07:18 PM   #3
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Default sounds more than sufficient...

that should give you plenty of voltage and certainly current capability for an a_7 preamp in any configuration! Bolt the sucker in there!
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Old 30th October 2008, 07:51 PM   #4
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You're running 0.5 mA in the first stage, 1.5 mA in the second. Another 2 mA for a second channel... plus 6.3V at 0.6A or 12.6 @ 0.3A.
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Old 30th October 2008, 08:50 PM   #5
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Cathod potential of second triod must be approx. 123 v!
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Old 30th October 2008, 08:59 PM   #6
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Default Re: sounds more than sufficient...

Quote:
Originally posted by aardvarkash10
that should give you plenty of voltage and certainly current capability for an a_7 preamp in any configuration! Bolt the sucker in there!

Quote:
Originally posted by Tom Bavis
You're running 0.5 mA in the first stage, 1.5 mA in the second. Another 2 mA for a second channel... plus 6.3V at 0.6A or 12.6 @ 0.3A.
Many thanks for reply..
so. .., Can I also use this PT for M7 if late update? I am a beginner about it, please kindly give me a suggestion. thanks
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Old 30th October 2008, 09:23 PM   #7
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Time out here, we can't spec a PT until you tell us the rest of your PS design. Are you planning to use a full wave tube rectifier, or a bridge? What filtering? To get a good low ripple 300VDC out of a 125-0-125 transformer, you will need to use a bridge.
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Old 30th October 2008, 09:55 PM   #8
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Quote:
Originally posted by leadbelly
Time out here, we can't spec a PT until you tell us the rest of your PS design. Are you planning to use a full wave tube rectifier, or a bridge? What filtering? To get a good low ripple 300VDC out of a 125-0-125 transformer, you will need to use a bridge.
Thanks Brother, yes. I am planning to use a bridge because of there is not a Filament winding at 5V(CT).. ..

so. if I use full wave tube rectifier, what kind of the spec. PT should I have.....
Thanks.
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Old 30th October 2008, 10:27 PM   #9
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Quote:
Originally posted by longji98

Thanks Brother, yes. I am planning to use a bridge because of there is not a Filament winding at 5V(CT).. ..

so. if I use full wave tube rectifier, what kind of the spec. PT should I have.....
Thanks.
Look, I'll ask my question again, what in detail are you planning to build for a PS? How can we tell what transformer to buy if you won't say what rectifier and what filtering you are going to use? An small tube rectifier and a CRC filter will burn a lot of volts. A big tube rectifier and a CLC filter won't.
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Old 30th October 2008, 10:50 PM   #10
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Quote:
Originally posted by leadbelly


Look, I'll ask my question again, what in detail are you planning to build for a PS? How can we tell what transformer to buy if you won't say what rectifier and what filtering you are going to use? An small tube rectifier and a CRC filter will burn a lot of volts. A big tube rectifier and a CLC filter won't.
Thanks Brother
Bridge: IN4007x4(I have some) . prefer CLC.
Tube rectifier: full wave 5u4g. CLC.
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