little bit low Voltage (11,78 V) - effects of Sound etc.

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mtz
 
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Joined: Fri Jun 19, 2015 6:10 am

little bit low Voltage (11,78 V) - effects of Sound etc.

Post by mtz »

Hello everyone,

just build an xox and it works and sounds nice in my ears so far... :)

Just have a Question related to the Voltages to the Specialists:

The 12V Output of mx xox is a little bit low (11,78 V).

Would a gain to solid 12V have an effect of the Sound?

And is the low Voltage a Problem for the Circuit? The Microcontroller, the eprom or any op-amps?

Should i try to get real 12 V?

Thanks!

Mattes

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antto
 
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Re: little bit low Voltage (11,78 V) - effects of Sound etc.

Post by antto »

the "12V" voltage of the x0x is typically ~11.85V because iirc it is generated from the "5.33V" with an opamp with a gain of 2.222
so 5.33*2.222 is approximately 11.85V
now, if yours is slightly lower (assuming your multimeter hasn't went nuts) you should check your "5.33V"
if that has went lower than normal - then you should adjust it (TM6) and note that this would detune your VCO pitch, so you'll have to also retune the VCO afterwards

things should still work fine even if it's 11.78
the digital section (microcontroller and such) are supplied from the 5V line.. the 5.33, 6, and 12V lines are used by the analog synth section

[EDIT] the formula i think is:
Vout = Vin * (1 + R178 / R179)
Vin = 5.33, R178 = 2200 ohms, R179 = 1800 ohms

5.33 * (1 + 2200/1800) = 11.84V
Last edited by antto on Sat Aug 15, 2015 1:16 pm, edited 1 time in total.

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mtz
 
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Re: little bit low Voltage (11,78 V) - effects of Sound etc.

Post by mtz »

Ok, im pretty sure i have the korrekt 5,33 V - so i will leave it as it is for now and continue bubbling acid soundz, yay :)

Thank you...

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