Author |
Message |
Snaper
Joined: Feb 28, 2014 Posts: 217 Location: Hungary
|
Posted: Fri Sep 05, 2014 2:38 am Post subject:
Buchla 160 - Need fresh eyes |
|
|
Hi Guys,
Just started to use LTSpice, and the first what I've tried is the Buchla 160 Noise source.
Actually, I can see different noise waveforms at the output, but they're week...just a few negative nanoVolts.
Could somebody check this?
(Schemo PDF and LTSpice files attached)
Description: |
|
Download |
Filename: |
160Noise.pdf |
Filesize: |
13.23 KB |
Downloaded: |
449 Time(s) |
Description: |
|
Download |
Filename: |
160Noise.zip |
Filesize: |
2.35 KB |
Downloaded: |
377 Time(s) |
|
|
Back to top
|
|
|
gdavis
Joined: Feb 27, 2013 Posts: 359 Location: San Diego
Audio files: 1
|
Posted: Fri Sep 05, 2014 9:11 am Post subject:
|
|
|
If I'm not mistaken, that is an open collector noise source circuit which I don't think is a good place to start with spice. Spice simulation is based on mathematical models of the basic characteristics of circuit components within specifically defined operating conditions.
The use of a BJT as a noise source is outside the normal operating parameters, taking advantage of the underlying physical properties of the device, and not well modeled in spice.
If you want to learn spice, start with something more basic like a simple opamp circuit, basic filter or maybe a simple oscillator.
The thing you have to understand about spice in general is that it's "idealized". It handles the basic properties that define the majority of a devices operation and are easily modeled with simple mathematical equations (at it's core spice is relatively simple, just a calculator), but real devices have a lot of little quirks that can't be easily characterized or modeled. Some of these quirks have some limited modeling and there are tricks you can do if you need to introduce something specific into your simulation (someone might even know one for this noise generator), but that is more advanced, not beginner stuff. _________________ My synth build blog: http://gndsynth.blogspot.com/ |
|
Back to top
|
|
|
Snaper
Joined: Feb 28, 2014 Posts: 217 Location: Hungary
|
Posted: Fri Sep 05, 2014 10:12 am Post subject:
|
|
|
I see.
I dont like breadboarding, thats the reason why I made this up in spice.
If Im clear, it is possible that the circuit could produce good noise in the real world? |
|
Back to top
|
|
|
blue hell
Site Admin
Joined: Apr 03, 2004 Posts: 24079 Location: The Netherlands, Enschede
Audio files: 278
G2 patch files: 320
|
Posted: Fri Sep 05, 2014 11:09 am Post subject:
|
|
|
Snaper wrote: | If Im clear, it is possible that the circuit could produce good noise in the real world? |
Yes, but you may need to try several transistors - as you are using them in some out of spec mode ... _________________ Jan
also .. could someone please turn down the thermostat a bit.
|
|
Back to top
|
|
|
Snaper
Joined: Feb 28, 2014 Posts: 217 Location: Hungary
|
Posted: Fri Sep 05, 2014 11:26 am Post subject:
|
|
|
I see. |
|
Back to top
|
|
|
Fernando
Joined: Dec 30, 2006 Posts: 286 Location: Barcelona & Emporda, Spain
|
Posted: Sun Dec 04, 2016 3:38 pm Post subject:
|
|
|
Anyone built the 160 circuit recently?
Which voltage range at it's output? 1.22V or hotter? |
|
Back to top
|
|
|
fluxmonkey
Joined: Jun 24, 2005 Posts: 708 Location: cleve
|
Posted: Sat Dec 24, 2016 12:13 pm Post subject:
|
|
|
i've built it, and have PCBs available: http://fluxmonkey.com/fluxmerch_gear.htm. I don't remember the output level measurement, but its designed for standard buchla audio levels, ie line level, which is i believe 1.2v.
Fernando wrote: | Anyone built the 160 circuit recently?
Which voltage range at it's output? 1.22V or hotter? |
_________________ www.fluxmonkey.com |
|
Back to top
|
|
|
Fernando
Joined: Dec 30, 2006 Posts: 286 Location: Barcelona & Emporda, Spain
|
Posted: Sun Dec 25, 2016 12:51 pm Post subject:
|
|
|
Thanks Bbob, I suspected about the usual 1.2V output level, but just would like to check from an actual circuit
fluxmonkey wrote: | i've built it, and have PCBs available: http://fluxmonkey.com/fluxmerch_gear.htm. I don't remember the output level measurement, but its designed for standard buchla audio levels, ie line level, which is i believe 1.2v.
Fernando wrote: | Anyone built the 160 circuit recently?
Which voltage range at it's output? 1.22V or hotter? |
|
|
|
Back to top
|
|
|
|