No one asked you or anyone else to do anything at all. If you want to challenge an observation run the experiment and report your results. That's the scientific method. What's the final evaluator here? Ears or meters? I have yet to hear a great sounding Fluke 77 meter.
Electrolytic vs film caps for smaller values.
- Thread starter warpie
- Start date
Help Support GroupDIY Audio Forum:
Ricardus
WILL SOLDER FOR FOOD
Ears are the weakest link in the chain. Period. Your ears suck (all ours do) and our brains lie to us.
Maybe one of the most ridiculous replies I have ever read.
No. I do double blind tests and invite others in on it and a 3rd person to flip the switch.
Thank you. If you can't trust your ears I wouldn't ask you to be my recording engineer or do mastering. However you may be a great repair tech.
This is getting ridiculous.
Dissipation factor is defined as a loss. Yes, it's measurable and to my ears noticeable. But you're welcome to use whatever capacitors you like wherever you choose.
Significance is in the ears of the "behearer".
Last edited:
Ricardus
WILL SOLDER FOR FOOD
I trust my ears to a point, but I also know they suck. Science taught me that. But that said, I'll take the pepsi challenge with anyone in a hearing test.
Now excuse me, I have to go play some music through my Fluke meter, since apparently that is a thing.
Perhaps you missed the irony of my Fluke analogy. You may have taken that too literally.
Ears are limited, that's true, but they are the only things we have for listening. In addition, I can't listen through your ears and vice versa. And our hearing changes over time. At 71 I have hearing loss, almost everyone does. But in my 20s I could hear sounds above 20khz.
That said, there are different categories of audio where some characteristics outweigh others. Communication audio ( speech) has limited bandwidth for the purpose of carrying on conversation that's intelligible. You don't need bandwidth of 20 hz to 20 khz for that. More like 300hz-3Khz as was adequate in plain old telephone service (POTS) and you can tolerate 10% THD and still understand the source human speaker.
MP3s are highly digitally compressed which necessarily removes less noticeable information for the sake of of small files size for commercial success. AAC and MP3 are different forms of compression and AAC (Apple) is better sounding to most people. Most people are ok with that.
Hi fidelity means truthful representation of the original event, and there are levels of quality that in some instances are measurable. Some are not measurable but you know when you hear it it sounds exceptionally great or mediocre. The term is used very loosely and there are no Hi Fi police.
Most audio we accept as enjoyable is 99 and 44/100ths percent perfect. That leaves 56/100th that needs work.
I used to have the same attitude about wire until I did some listening tests and found OFC offers better fidelity to my ears. OFC speaker binding posts, are the similar. Pure silver sounds different, etc.
All amplifiers don't sound the same, likewise, speakers, microphones, wire, tubes, transistors etc. And almost everything analogue is microphonic to some degree.
Take a capacitor in series with a power supply 25 volts or more to charge the cap and a suitably sized resistor, 100k to a meg. Hook a scope up across the cap. Now tap the cap with pencil and watch the scope trace bounce. Microphonics!
Now connect a cap, in series with a 4 ohm current limiting resistor to the output of an amplifier and run some square waves to it. Caution the amp need to be stable to do that. Odds are very good at some level and frequency setting you will here the cap vibrate. Sweep the frequency source with sine waves and you'll find acoustic resonances within the range of hearing. Microphonics!
Tap a tube in an amp an you'll hear it at some volume setting.
My point is there are very few perfect components, (if any !), that don't introduce some variation in the signal that wasn't there to start. Depending on the application some are worth dealing with and some are not. There in lies the art of good engineering for the appropriate application.
Audio has only 1 detector of any consequence - ears.
Yes it is a loss of energy but that does not necessarily imply a loss of information (in the sense that data compression eg conversion to MP3 does).
Do you have evidence of this?
No need to. It's by definition of a filter. Think about it
Now if a component/circuit is adding harmonics then that is essentially a distortion/saturation device. That's a different issue.
It is pointless to argue with people about what they say they hear on the internet. Without rigorous double blind testing that reaches statistical significance it is just hear-say (pun intended).
JR
JR
- Joined
- Jul 8, 2010
- Messages
- 513
Wouldn't the dominate distortion mechanisim in capacitors be related to signal current?
The distortion of an interstage coupling cap passing low signal currents is far more difficult to measure than the distortion introduced by an undersized capacitor in a passive speaker crossover.
Just asking for a friend...
The distortion of an interstage coupling cap passing low signal currents is far more difficult to measure than the distortion introduced by an undersized capacitor in a passive speaker crossover.
Just asking for a friend...
Agreed. But there's no way of telling what audio information is lost and how it would be skewed in relation to amplitude or frequency. 'Lytics are primarily electro chemical devices with electrolyte in between 2 pieces of al foil. The electrolyte changes with time, along with charge migration as electrons find their way into the etched foil, which is a rather slow process (days, weeks, months) know as "forming". One of the reasons audio gear needs to "break in" before performing at its best.
Or non linear. Active and passive filters, I guess.No need to. It's by definition of a filter. Think about it
Or maybe some people are just double blind.
You respond to a comment that was not addressed to you.
I invite you to check post #136, where MadJack explicitly wrote: "I don't produce evidence for my self."
Then, in his post #154, he asks: "Do you have evidence of this?".
Do you think my opinions are totally unfunded? I don't have to justify myself, but with over 50 years in pro audio design, I think I am informed.
As to running the experiment, do you think I've never done it?
All ears/brains are different.
All Fluke 77's are quite similar.
If I need to evaluate distortion, I'd rather use an AP.
Tell your friend I would think this may true but it would vary with current and voltage. Bigger is easier to measure. Use polypropylene caps and avoid the electrolyte! Bigger, more expensive but nicer to the ear. Look at the page I posted about film behavior.
A speaker xover cap generally does not have a DC voltage on it. Tube OTL amplifiers with output caps generally do. Many ss and tube preamps do as well. SS circuits use a lot of 'lytic DC blocking caps. Cheap "non polarized" speaker xover caps are 2 'lytics back to back in series in one package, i.e. pos to pos or neg to neg. A 'lytic will conduct current in one direction and not the other. Hook one up to a dc power supply backwards and see how long it takes to fizz out. Wear safety glasses if you do. You have a firecracker there. That's why there are vents built into them. Back to back, i.e. non polarized caps block the leakage current in each direction. Leakage is much higher in a 'lytic than a film.
I'm repairing an all tube headphone amp that is made for Stax electrostatic cans. The output voltage is 450 v p-p and that's sitting on top of another 200 v dc. I have to replace aged 'lytics that are 40mfd @ 450 v in the neg feedback path and there are 4 channels of this. So I have to find good quality 'lytics that can withstand 600 V in case of an output tube short. A polypro cap is physically too large to fit. Those caps sit at idle with 405 volts on them. So I will most likely put in a 'lytic bypassed with a smaller polypro. If I had the room there would be 4 polys in there.
That's what 60 years in electronics have taught me.
My apologies. I didn't research his thread. Seems like a contradiction. Added bass response would be an easy one to measure. I'm sure you've done your homework over the years as your success is evident.
So - How do you evaluate the quality of sound in your designs?
Abbey is the kind patient one... don't wear him out.
JR
JR
AFAIK the typical distortion mechanism in capacitors is voltage coefficient, or capacitance changing wrt terminal "voltage". In some configurations that terminal voltage is driven by changing current but I've never seen capacitance change specified in current terms. Current can cause terminal voltage changes when working into ESL and ESR, but a fairly indirect way to quantify it.
In a typical lightly loaded DC blocking application the terminal voltage change with signal is minimal. Small terminal voltage change means small distortion.
As if you have a friend (kidding).
JR
I thought the "golden ear" vs. "meter reader" debates died off last century.
I can measure things that I can't hear, and I was always able to measure things that I could reliably hear. That said human ears (like mine) are not always that reliable. It's easier to trick human hearing, than bench test equipment.
JR
Similar threads
