that does help indeed and your points about protecting against dirty power is one I hadn't thought about and is reason enough that I will orientate my foils correctly from now on just for that alone so thankyou.
Anyone who starts and can sustain an amp making business has my full and utter respect, seriosly, it's almost as mad an idea as becoming a professional musician!
regarding swapping resistors ...it's a slippery slope to the bottom of that rabbit hole!!!
yeah I went back to playing professionally.What does that tell you! Ha Ha!
BTW.Purple wire and Tolex always sounds best!
Outta here.Good Luck
T
" The psychics on my bench is the same as Dumble'"
I received the DSO Nano V3 oscilloscope which I got just to check the foil orientation of the caps.
I believe my unit is defective given I am getting identical results while hooking the probes to alternate sides as per pic below. I have used a few different caps for testing (.1uF, .02uF, .05uF)
Also I added a picture of the settings used.
Am I missing something or is this unit just garbage?
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I've never used a sine wave to test, I just grip the cap in my fingers and see either a slightly or heavily increased/decreased height of the signal, OTOH you've got possibly the scope in too closely timewise to see the actual noise itself, but not 100% sure. I usually can see the individual noise coming in and changing with my grip etc.
you don't need a scope for this, just put some leads on the other end of a guitar lead and plug the cable into an amp and turn it up. Squeeze the cap and then swap the clips and squeeze again. One way will produce more noise
If you cannot see a large enough induced AC signal by holding the capacitor between your fingers, place the capacitor on top of an AC line cord (that is plugged into the mains wall socket, of course!) instead of holding it between your fingers and you will see a larger signal on the scope. If you are new at this, start with a 0.022uF cap or thereabouts, as it is easiest to see the difference between the two orientations. The induced signal is smaller at 60Hz with larger value capacitors, and is more difficult to see on the scope.
BTW..In the case of some types of capacitors, such as ceramic disks, multi-layer ceramics, or silver micas, there is no "outside foil", because the capacitor is made of a single-layer, or stacked layers of dielectric material and conductor. The orientation of these capacitors makes no difference. Also, some higher-voltage film caps (typically the 1000VDC/450VAC and higher values, such as the Orange Drop 716P high-voltage units) use a "series-wound" technique that has two separate sections, side by side, with a common "floating" connection layer, usually at the bottom of the layer stack. These caps will have no inherent shielding either.
Tony
" The psychics on my bench is the same as Dumble'"
pompeiisneaks wrote: ↑Thu Aug 30, 2018 6:43 pm
I've never used a sine wave to test, I just grip the cap in my fingers and see either a slightly or heavily increased/decreased height of the signal, OTOH you've got possibly the scope in too closely timewise to see the actual noise itself, but not 100% sure. I usually can see the individual noise coming in and changing with my grip etc.
~Phil
Hi Phil, I just tried in a lower timescale and still the same. I am using some NOS Mallory .02uF this time. But the odd thing is that I have almost the same amplitude without anything hooked up as per pics below
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You could have a very non noisy environment? if you don't see the signal waveform change at all when you touch it, then you're not inserting any noise (The idea is your body acts like an antenna, and will add noise, it does in both cases, but it's less on the side if the outer foil is to ground.)
Do you have some really noisy lights? Or a radio? run those near the cap and see if it changes then?
You could test the scope to see if it's dead by inserting a sine wave (There are tons of free apps on apple or google for signal generators).
talbany wrote: ↑Thu Aug 30, 2018 7:52 pm
If you cannot see a large enough induced AC signal by holding the capacitor between your fingers, place the capacitor on top of an AC line cord (that is plugged into the mains wall socket, of course!) instead of holding it between your fingers and you will see a larger signal on the scope. If you are new at this, start with a 0.022uF cap or thereabouts, as it is easiest to see the difference between the two orientations. The induced signal is smaller at 60Hz with larger value capacitors, and is more difficult to see on the scope.
BTW..In the case of some types of capacitors, such as ceramic disks, multi-layer ceramics, or silver micas, there is no "outside foil", because the capacitor is made of a single-layer, or stacked layers of dielectric material and conductor. The orientation of these capacitors makes no difference. Also, some higher-voltage film caps (typically the 1000VDC/450VAC and higher values, such as the Orange Drop 716P high-voltage units) use a "series-wound" technique that has two separate sections, side by side, with a common "floating" connection layer, usually at the bottom of the layer stack. These caps will have no inherent shielding either.
Tony
Thanks Tony, just tried your approach using a .02uF Orange Drop 6Ps current production. The signal oscillates much more with the cap on top of the AC cord (device ON) but there is no difference when alternating the connection between the leads of the cap. The entire signal actually started behaving like a sea wave (not sure how to explain) instead of just changing the amplitude of the signal. I guess this oscilloscope is indeed junk. I will return it and maybe get a vintage one which are not very expensive although take up a lot of space or go for Marcus approach..
norburybrook wrote: ↑Thu Aug 30, 2018 7:12 pm
you don't need a scope for this, just put some leads on the other end of a guitar lead and plug the cable into an amp and turn it up. Squeeze the cap and then swap the clips and squeeze again. One way will produce more noise
M
Marcus is your method something like this (by the way not my pic)? Without the switches how do you work around the loud pops when swapping sides?
I just want the simplest way to do this without having to wait for new parts as I cannot wait to get on with the amp this weekend
I saw this test (video below) which looks even simpler but I think it will be easier to just work on the cable as suggested https://youtu.be/1f-LdpJiAk4
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I just attach two crocodile clips to the plug on one end of a regular guitar cable, one on the tip and one the ground and plug it into an amp. Swapping the cap around doesn't make a pop. I do it near a computer monitor on my desk as that's noisy
norburybrook wrote: ↑Fri Aug 31, 2018 8:59 am
I just attach two crocodile clips to the plug on one end of a regular guitar cable, one on the tip and one the ground and plug it into an amp. Swapping the cap around doesn't make a pop. I do it near a computer monitor on my desk as that's noisy
MC
Thanks Marcus, even easier! I will give it a try tonight!
Thanks 10thTX and Marcus for the help. The method works like a charm. I spent most of the weekend removing the caps testing and putting them back on....so much work! But I am glad I did it.
