bugie preamp build

arduino based linestage using 12B4 tubes

bugie preamp build

Postby lmaynard » Sat Apr 19, 2014 8:15 am

Greetings to all. I'm starting my build on the budgie preamp. Can anyone tell me what value to set for VR4 ?
Any help will be greatly appreciated.
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Re: bugie preamp build

Postby TomMcNally » Sat Apr 19, 2014 9:40 am

That's the contrast control for the LCD, just turn adjust it for best looking display.

You're gonna love the preamp, I built one last week and it sounds really great.

I'll post some pictures soon. It looks just like Shannon's but with red buttons,
Mouser was out of black ones.
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Re: bugie preamp build

Postby lmaynard » Sat Apr 19, 2014 12:01 pm

Thanks Tom. I appreciate your help.
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Re: bugie preamp build

Postby Shannon Parks » Sun Apr 20, 2014 10:00 am

In circuit, I measure around 1100 ohms from the wiper to ground. Presetting it to that value can be helpful, as a certain percentage of pot rotation will be a blank screen which is no fun on first power up. Would have gone with a fixed resistor, but the 1602 LCD will probably be subbed a lot and will need different values, as well as personal preference. PWM wasn't an option either, as PWM will add noise to the circuit.

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adjusting J2 & J3

Postby lmaynard » Sat May 24, 2014 9:56 am

Greetings To all. I read in an earlier post about setting the value for these two pots( J2 / J3 ). I set mine to 350 ohms. It mentioned the use of a Smart Phone App that generates a sine-wave. I don't have a smart phone and am wondering if there is another way to adjust these.
Any help will be greatly appreciated.
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Re: adjusting J2 & J3

Postby Shannon Parks » Wed May 28, 2014 5:41 am

lmaynard wrote:Greetings To all. I read in an earlier post about setting the value for these two pots( J2 / J3 ). I set mine to 350 ohms. It mentioned the use of a Smart Phone App that generates a sine-wave. I don't have a smart phone and am wondering if there is another way to adjust these.
Any help will be greatly appreciated.
lmaynard


I think you'll be fine at 350 ohms, Larry. You can also check V1 and V2 at pin 9 (the plate). Just make sure this voltage is between 15 to 20 volts. VR2 and VR3 can adjust it if needed.

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Re: bugie preamp build

Postby lmaynard » Wed May 28, 2014 10:00 am

Thanks Shannon!
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I have completed my Budgie pre-amp! It sure sounds great. Thanks for all the help I have received on the Forum.
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