Noise Generator PCBs from JLCPCB with GND Copper Area 

You placed many traces on the underside of the board. If you had moved as many as possible to the top layer, you would have gotten a bigger, more uninterrupted ground plane, which is sort of important for shielding effectiveness. As it's a two layer board, you can also flood any remaining area on the top layer with GND or 5V for even more better. Nice board anyhoo.

Oh come on Julian.. You had the scope out earlier, it's no use saying "Turning the volume up *sounds* like you get more high frequencies".. Let's see the FFT of it :-)

Big ground planes are supposed to reduce noise. Seems quite counter productive for a noise generator, doesn‘t it?

You get a sinewave and square wave, so one that sounds like the ocean is called a sea wave.

While watching you solder the 2N3904, my thought was "Flux is your friend!" It'll help keep the solder separate, just like it does when you drag solder the SMD ICs.

Glad to see the new solder is compatible with them old chips :)

When you seal a vessel you typically seal moisture in not out, good on them for being aware of this and caring enough to counter it.

The only sensible use for a tie clip! Very neat and nicely laid out pcb.

You've created a linear feedback shingle beach sound generator.

Is this deterministic noise or there is a chaos in the circuit making the noise "white" and unpredictable? I can't determine this at first glance. And the circuit is not very explanatory.

Emmmmm You did't show the noise wave form on the scope ? A spectrum analyzer would be interesting to see.

The user library symbol has power pins. They are just hidden. To use them or: a) Unhide them right click symbole -> Edit symbol... -> uncheck Hidden Pin b) How it's supposed to be used to keep it clean, use the same netnames in your schematic. Here (probably) VSS and VDD. Then the pins are automatically connected. Names in the same Edit symbol menu

I'm thinking that the tone shift at the highest amplitude, is down to the speakers amplifier clipping, adding some sonic artefacts as it does so.

if your audio output was the wrong way round just mount it on the other side of pcb.

Hi Julian. At 46 I am pretty old to be making a start into the world of electronics but I have for this past year delved in and I have been building things on breadboard, as being disabled I do not get out much so I have plenty of time on my hands, and the hobby keeps my hands busy. I have not yet soldered up a ready made kit, but I have done a few home electronic repairs like replacing Caps in the TV and so on. I have learned a lot from your videos and enjoy them very much. Do you sell any of the kits you make? and if so are they just the PCB or do they come with all the components? Much love Brother, Ken, UK.

The kink might be caused by the ground loop introduced by the probe. If the ground lead is shorter it might not appear.

If you can put up with always getting exactly the same pseudo-random noise sequence on each power-up, you can just program a PIC chip to simulate a 32-bit shift register with two of its outputs xored to its input. I know 'cos I did exactly that. The final circuit has just the 8-pin PIC and a small speaker connected between one of its output pins (ie a pin programmed to be an output) and ground, with an 18650 as the power supply (since the PIC I used will work down to around 2 volts). If you really, desperately need to filter out any DC, then you can add a small capacitor between the output pin and one speaker lead (or the amplifier, if you need a loud hiss). "Tuning" the circuit to give a slightly deeper sounding hiss involves nothing more than inserting a few "nop" instructions (no operation = do nothing) before the jump back to the start of the loop. Re: Short solder. I usually try using a pair of needle-nose pliers to hold the solder when it gets that short. You can also try resting the last scrap against the pin you're going to solder and applying the iron. (Yes, I'm a bit of a Scrooge too, when it comes to not wasting even that last tiny scrap of solder) :)

Are you having good luck with those headphone jacks? I ordered in 10 of them a couple of years back, and then the quality of the traces was so poor that if my soldering iron drifted over 300C the traces came up and I had to figure another way to get the electricity to the pins. I used bodge wires to go from the pin over the back then to the tab that hooked to the desired part of the earphone plug. Don't think I will try any more of them, even with my new digital soldering iron I just don't trust that board any more.

Disappointed not to see mounting holes, silk screen markings for the power ("+V" & "gnd") and output ("out" & "gnd") connectors, bulk decoupling for the board, and individual decoupling for each chip. Weird that the two chip footprints are using very different pads. Test point for the oscilator output?

Touching things adds capacitance to them, especially when touching multiple nodes at once. You're adding parasitics and the frequency changes. You can add a couple nF to a node with just a finger.

You need not worry about providing a ground plane for the chips. The silicon die is almost always mounted to a grounded metal plate. The ground fill on the pcb is to protect traces from interference. Thus a socket is almost always the way to go.

Iv have never gotten a pen from jlcpcb. Is it random if you get one?

Why digital noise and not analog?

Julian, why not panelize the pcb's? You could get four of those on one 10x10 pcb.... so you'd end up with 40 for the same price...

For what the boards cost you should have bought another 10 without the ground plane to test against each other.

The transistor pads are awkwardly close. This is why you usually see the base pin pulled back a bit, forming a triangle.

you need 2 ics one transtor and a awful amount of passives for a white noize generator? come one 2 transistors 2 resistors and one cap do the job equally good... i build that on a 2 by 3 cm piece of perf board

Cool use of the tie clip! Love it! Say I was going to order some PCB's from jlcpcb but when it came check out, the shipping seemed rather high, well extremely high compared to most of the things I get from China and Laos, that region. Am I missing a button or something, it's not like I need overnight or even rush delivery, a slow-boat from china would work for most of my needs, seems my urge for speed has gone by the wayside in my old age, and the need for funds far outweigh such needs for speed. They look to be great little boards but it's sort of like the adds on Ebay showing a nice phone for 6 bucks then when you see the shipping is $300.00 you sort of understand that it is really click bait.

@Julian Ilett I think the higher amount of high-frequency noise that occurs as the volume is turned up may have something to do with the human ear's tendency to emphasise mid-range sounds at lower levels, as determined in 1933 by Harvey Fletcher and Wilden A. Munson. Their research resulted in the so-called Fletcher-Munson curves, which in turn gave rise to 'loudness' circuits in many types of amplifiers for home use. More info about this can be found here en.wikipedia.org/wiki/Fletcher%E2%80%93Munson_curves Interesting video by the way; are you designing a modular synthesizer? Greetings from Denmark.

Julian would you be able to do a walkthrough on how circuits are created like maybe a guitar effects pedal, explaining how you know how each component is going to behave in relation to each other and how you work out what the end result is going to be? (I'm a big Clive fan as well by the way)

Where is Gerber files

I've been thinking lately about finding the old women's hair clips which were extra long to use for holding in the resistors when soldering. That's if I can find some. They were really long ones.

can i buy 2 of these boards

What happen to your nice soldering iron?

What voltage do you run your iron at?

I made the 909 version of this with 2x 4006 chips and no interference on my breadboard

Naice your video am happy super

Awesome video as always

No more Orac disconnection squeak then? :(

With 32kHz quartz resonator you could get the oscillator much more stable and maybe free up one xor gate and get rid of that transistor.

OOOOOooooooo It's the *TIE CLIP!!!*

You should panelize those boards ;-) Then you are getting 10 panels with several of your boards ...

"Come sleep on the beach, keep within my reach"

I know I’m late to the game... but... if you leave long Legs on all your components sort of as on the breadboard... you may get fun things happening. Hmmmmmmmmm ... ... you might even bypass some traces, making long airborne runs... as on the breadboard. Hmmmmmmm 🤔🧐🤷🏻‍♂️✨ have fun!

Theremin sounds by Julian “Jimmy Page” Ilett

It was talking...

awww no cute theremin muzak anymore :-)

hey cool!

"Loud noises!!"