## Spice simulations of the paper circuits

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nrrrd
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### Spice simulations of the paper circuits

Has anyone had a go at simulating any of the paper circuits in LT Spice?

I'm trying the Lil Sidrassi one, but it's not working at the moment. That might be due to my relative newness to electronics and Ciat-Lonbarde circuits.

If anyone has done it, could they share their circuits and analysis settings, please? That'll give me a better idea on what to do. Thanks.

Edit: I've now got the Lil Sidrassi working in LTSpice. I'll post more when I've done more investigation of the (simulated) circuit.
Last edited by nrrrd on Wed Apr 10, 2019 10:33 am, edited 1 time in total.

nrrrd
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Well, I had a go at a simpler circuit, a 3-roll from the Rollz-5.

Here the circuit in LTSpice:

And here's the output (taken from the out1, out2 and out3 nodes):

I'm puzzled as to why the output is negative voltage? Is this the same on the physical circuit?
I haven't currently got the parts to breadboard the circuit, but should be able to get some by the weekend.

nrrrd
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Breadboarding it and reading the thread on the Plumbutter has confirmed that the output of the Rolls should be negative.

nrrrd
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I've been doing some Spice simulations of a single oscillator of the Lil Sidrassi paper circuit:

The main thing I discovered is that the 1Meg resistor also affects the frequency of the oscillator. So this can be replaced with a variable resistor (trimpot) or a normal pot.

I did a number of simulations for the different frequencies outlined on the paper circuit (mountain sub to ultrasound), with a number of different capacitor values and resistor values. Here's a table (the resistor values were 1Ohm to 1MegOhm). Interestingly, the different resistor values had no effect on Mountain or Subbubbass. mHz = milli Hertz!

Code: Select all

``````Description            Hairy Capacitor  Period       Freq
Mountain sub           100uF               180s         5mHz
68uF                111s         9mHz
47uF                 76s          13mHz
22uF                 36s          27mHz

Subbubbass             10uF                 16.5s        60mHz
6.8uF                11s           90mHz
4.7uF                7s             128mHz
2.2uF                3.2s          302mHz

Subbass                1uF                   1.67s to 3.74s   578mHz to 600mHz
0.68uF              1.20s to 1.28s   781mHz to 829mHz
0.47uF              931ms to 3.4s   292mHz to 1.0Hz
0.22uF              408ms to 525ms   1.9Hz to 2.44Hz

Bass                     0.1uF               182ms to 312 ms   3.2 to 5.5Hz
0.068uF           108ms to 287ms	   3.47Hz to 9.25Hz
0.047uF           82ms to 97ms        10Hz to 12Hz
0.022uF           46ms to 222ms       4.5Hz to 21Hz

Treble                   0.01uF             31ms to 174ms       5.5Hz to 31.6Hz
0.0068uF         107ms to 288ms     3.46Hz to 9.28Hz
0.0047uF          87ms to 97ms        10Hz to 12Hz
0.0022uF          45ms to 221ms       4.5Hz to 22Hz

Ultrasound             0.001uF           560us to 67ms       14Hz to 1.78kHz
0.00068uF        403us to 67ms       14Hz to 2.47kHz
0.00047uF        395us to 157ms       6Hz to 2.52kHz
0.00022uF        109us to 158ms       6.2Hz to 9kHz

Radio Ultrasound	0.0001uF	47us	21.3kHz	@1Meg
``````
Next step - breadboard it and see if it's correct that there is such a large range for the "Ultrasound" set of capacitors.

Andramelek
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Nice info! Thanks!

notmiserlouagain
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nrrrd wrote:Breadboarding it and reading the thread on the Plumbutter has confirmed that the output of the Rolls should be negative.
EDIT:erased false remark, what is that power supply?
If it is +9VDC/0V, I can´t see how you would create negative voltage without using a dc-dc converter/inverter...?
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