Pmacaula wrote: ↑Wed Dec 16, 2020 3:01 am
Sorry for resurrecting a zombie thread, but this looked like the best spot to ask a few questions.
...
Would be curious to know if others have measured Orange Drop or other non-axial caps for noise levels based on which way they are connected and if it makes a material difference to the actual noise heard in the amp's output.
Not worried at all that you post in such a good thread....
For what's worth I could read Orange Drops are more sensitive than Mallory 150, on this forum. I had hard times managing to find the outer foil of Mallory 150 (or similar) caps by ear, myself.
ChopSauce wrote: ↑Wed Dec 16, 2020 8:11 am
...I could read Orange Drops are more sensitive than Mallory 150, on this forum. I had hard times managing to find the outer foil of Mallory 150 (or similar) caps by ear, myself.
ChopSauce - thanks !
At first, I tried finding the outer foil end of the 0.1uF Mallory caps using the 'finger squeeze' technique, but the difference was too small or irregular to be confident in the result. The 120V AC ziptie technique yielded a clear and consistent difference for every cap.
Given the difference was only obvious under such extreme conditions suggests that what you say is correct, though for some of us with a touch of OCD, may as well do it 'right' even if it is inaudible.
Last edited by Pmacaula on Wed Dec 16, 2020 5:43 pm, edited 2 times in total.
Although many of us have measured and seen a clear difference and found the outer foil, I personally can't really tell a difference in 'noise floor' between amps where I've carefully installed the caps the 'right' way and just shoved them in willy nilly.
That's not proof in and of itself, I have hearing damage But I've heard many other seem to agree it may make a very subtle difference, but for guitar amps played loudly what difference does that make?
1/4", alligator clips into my interface ---> reaper with a spectrum analyzer on an insert and I had visual and audible confirmation of the outside foils!
The channel peak hold makes referencing the difference easy and my desk chair is much more comfortable than my garage stool
foil tester.jpg
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ChopSauce wrote: ↑Wed Dec 16, 2020 8:11 am
...I could read Orange Drops are more sensitive than Mallory 150, on this forum. I had hard times managing to find the outer foil of Mallory 150 (or similar) caps by ear, myself.
ChopSauce - thanks !
At first, I tried finding the outer foil end of the 0.1uF Mallory caps using the 'finger squeeze' technique, but the difference was too small or irregular to be confident in the result. The 120V AC ziptie technique yielded a clear and consistent difference for every cap.
Given the difference was only obvious under such extreme conditions suggests that what you say is correct, though for some of us with a touch of OCD, may as well do it 'right' even if it is inaudible.
No, thank you.
You also remained me that I have a pair of Orange Drops left, to do some comparison. so (finger squeezing reported using a pocket DSO150 scope):
- with a 22nF/400V 225P the difference in signal deviation is one or two times different between both ends
- with a 22nF/600V 716P the difference (...) is at least one order of magnitude - that is very noticeable!
So at least that 716P OD behaved very differently from the Mallory or "similar" (Roederstein, etc) axial caps I could test.
That confirms what I read and could explain the significantly different experiment reports...
NB: yet the above may sound good, another conclusion of this (very) limited experiment is that the tested 716P appeared to be the only cap to be -*- very -*- sensitive to such a perturbation as the human contact.
(which I wish I knew before assembling my Tweedle Dee board ... )
I thought about this afterwards and felt that it was worth a dedicated post, rather than editing an old post, that almost nobody would notice about.
It will be on another thread, but together with this "outer foil test" that I find very useful to clear the waters around an always debated topic, it would be interesting to measure the characteristics of old and new capacitors (power supply too, I would say mainly) with LCR meters.
What do you think?
The nature of the process may however be less important than the comparison between capacitors - provided the same process is used for each comparison, as long as we do not need to compare results between experiments.
I nevertheless can't help but thinking that manufacturers ceased marking the outer foil because it is not (always) that much important.
Certainly if you manage to finely heap amplification stages - as HAD does - then everything counts, however.
EDIT: typo.
Last edited by ChopSauce on Wed Dec 23, 2020 10:44 am, edited 1 time in total.
Yes, from the data seen here it seems that first coupling (and cathode) cap can be a place to select the right side of certain kind of caps, whilst it can be almost negligible in parts where S/N ratio is less demanding.
Another report I felt worth citing here, for my observations are consistent with it:
erwin_ve wrote: ↑Thu Sep 10, 2020 11:56 am
All the film.caps are positioned with outer layer to lowest impedance. This is very noticable with orange drops...
The 1813 that is in the cathode follower section is not positioned as I couldn't find a outer layer with my scope.
With some spectrum analyzer data coming in, have any of you tested the difference in impedance/outer foil with a resistor in series with the caps being tested? It seems like that would be a good step forward to nailing down what outer foil orientation does in a circuit. Maybe something like 1K, 10K and maybe 67K, like the plate resistance of a 12AX7. Just thinking.
"It's not what we don't know that gets us in trouble. It's what we know for sure that just ain't so"
Mark Twain
After having spent hours to read different forums and Youtube videos, I have found this post that seems very informative.
When I use my scope, I can't get to perfect sinewaves that you get on your laptop: I get erratic measures like these ones:
A given cap orientation:
SDS00001.png
and the reversed orientation:
SDS00001.png
so it is impossible to identify which orientation is the good one, with so garbage curves. For info, my scope is a 200MHz (Siglent SDS-1202X-E), so it should not be the probem.
How do you manage to get your perfect sinewaves ??
Thank you
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Is that a sinewave your inputting , or white or pink noise, as I can’t tell.
If it is a sinewave then what frequency is it and if you can go down to say 160 hz what does the trace then look like?
Also if it is a sinewave then you may just be applying too much signal level into the test program.
One good tip I can pass along in terms of good layout with installing decoupling caps to minimize problems in the down stream chain is this.
The input grid of a tube is a very high impedance as compared to the plate, this can be all too easily proven by leaving the input jack open and placing your cell phone near it or if you have a close enough local radio station broadcasting away and getting into your amps signal path!
To take advantage of this impedance difference you want to place your decoupling cap right at, or as close to the down stream tube socket grid pin as you can.
So to take this to it’s conclusion, preamp plate leads can be long, but grid leads must be as short as possible and this holds doubly true for the PI to output tube leads or the driver to output tube lead in a single ended amp as well!
When you look at the average mass produced non circuit board tube amp under this kind of microscope you will find lots -a-room for improvement, and this unfortunately holds true for a ton of tube amp kits you can by also!!
Another great version of this method that can for instance be applied to Fender BF and SF amps of moving all of the tone circuit parts off the tag board and onto the pots themselves.
This aids a nice amount to the tone of the amp,especially when cranked up above 5 or so with preamp tubes that test really good and as such have the gain level they should and a good amount of this improvement from this mod is due to the removal and or shortening of a bunch of grid wire,
This alone can in the late SF amps allow the complete removal of all the tone sucking .0002 pf caps that where added to these amps to stop oscillation problems!
Last edited by Stevem on Sat Feb 06, 2021 12:01 pm, edited 2 times in total.
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Is that a sinewave your inputting , or white or pink noise, as I can’t tell.
I have just connected the both ends of the caps to the oscilloscope probe and kept the capacitor between my fingers: this is what I have understood from the video.
Maybe I am wrong, but it seems to me that there is no sinewave applied to the capacitor, and that the capacitor is just connected to the oscilloscope probe.
Am I wrong ??
Thanks
P.S.: for the time being, I only want to identify the outer foil (not discussing the implementation in a circuit)
But I've heard many other seem to agree it may make a very subtle difference, but for guitar amps played loudly what difference does that make?
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