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Author Topic: QSXPS output  (Read 676 times)

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Offline gianluca

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QSXPS output
« on: August 30, 2007, 04:05:24 PM »
Ciao everybody!

During my holidays I terminated my pre-phono (2xQSXPS+QSXM2). I'm really happy and satisfied, but I've a problem with the output of the two QSXPS.

It was impossible to obtaine more than ±11.2 volt from the outputs of the two QSXPS. The only solution that I've find  (temporary solution) it's to connect in parallel at the two R45-R47 (and R46-R48) a 2,2k resistor. Now with the 3 resistors is possible to regulate the output to ±18 volt.

What's do you think, where is my error?

Someone can help me?

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« Last Edit: August 30, 2007, 07:47:02 PM by peranders »
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Offline peranders

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Re: QSXPS output
« Reply #1 on: August 31, 2007, 06:36:10 AM »
If you have a 5.00 volt reference voltage at IC3 and to the input of IC1, pin 5. That's correct. If only R43, 45 and 47 are mounted you should get 15 volts out. R49, P1 is an option if you want to trim the voltage but the values must be calculated so you'll get the right trim range.

If you want 12 V R43 should be 3.9k.

(3.9/(5.6//5.6)+1)*5 = 12

// = in parallel
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