[sdiy] prob with noise circuit?

[Pete]

 Excelent! I knew I should power the 741. I will get back to ya.

Thanks guys
pete

On 5/30/05, Dave Magnuson <resfreq at hoohahrecords.com> wrote:
> 
> 
> ----- Original Message -----
> From: "Pete" <23isgood at gmail.com>
> To: <synth-diy at dropmix.xs4all.nl>
> Sent: Monday, May 30, 2005 4:03 PM
> Subject: [sdiy] prob with noise circuit?
> 
> 
> Hey everybody. I have been trying to get this circuit to work but I simply
> don't understand why I get no sound out of it. This is out of Thomas 
> Henry's
> "Noise Generator Cookbook" In the book he mentions to use a, 2n2712 for 
> the
> transistor or a 2n3904. I am using a 2n3904. I built this basic circuit on 
> a
> breadboard, and im using a 1/4" jack for the output, and a 15v power 
> supply.
> Do I have to apply power to the pins of the 741? It does not specify to do
> so. I attached a pic of the circuit. Im pretty much a beginner on this 
> stuff
> and trying to teach myself. I have rebuilt this thing a few times double
> checking everything. According to the book there should be a good amount 
> of
> noise coming out of this thing. Is there something that I am not aware of
> that im overlooking?
> 
> Thanks
> pete
> --
> 
> 
> Hi Pete,
> 
> You absolutely need to power the 741. If the Noise book is anything like
> the E-Drum Cookbook, then the pinout should be in the back. Opamps will
> ALWAYS need power.
> 
> Looking at the way the inverting input is tied to ground with a 1K 
> resistor
> means you'll want a bipolar supply (+/-15V) not just +15 and ground. If 
> the
> 1K resistor tied to a voltage divider (100K to V+ and 100K to GND), I'd 
> say
> a single-ended supply would be fine.
> 
> Also, transistors used like this usually need to be selected for noise
> output. Some 3904's will create a good noise level... some will be quiet.
> Expect to have to swap in a few different transistors before you find one
> that you like.
> 
> Dave
> 
> 
> 


-- 
listen to my latest tunes,

http://www.cubanpetemusic.com/p23%20Litmus.mp3

www.cubanpetemusic.com <http://www.cubanpetemusic.com>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20050530/2de35ff5/attachment.htm>