Yep, the gimmick is an old ham trick. It's used in neutralization, too. I find that with a lot of designs I do, a few pF across the feedback resistor can be used to change a peaked square wave response to slightly overdamped. A gimmick is a nice alternative to a trimmer, taking less room on the board. I start with a long gimmick, and trim it down until I get the desired response. Wire wrap wire with teflon or tefzel insulation makes a pretty decent gimmick, too, and the wire is usually silver plated - a plus...
TNT said:"Not to mention the fact that quite often the PS caps are in the signal path as well so they'd better be good too.."
Depending on how You look at it - I say they are always in the signal path
/
At least the PS caps influence on a stage will be reduced by the PSRR of that stage. I still wonder, what are good caps around 10,000uF if anybody has looked into this?
interesting article
capacitor distortion project
Wish we could get more quantitative results like this. The
ppt presentation is kind of amusing
capacitor distortion project
Wish we could get more quantitative results like this. The
ppt presentation is kind of amusing
more detailed results
more detailed cap distortion results
and look here:
test results
warning: takes awhile to load
more detailed cap distortion results
and look here:
test results
warning: takes awhile to load
changing C
I haven't found this mentioned: Pease article
This would indicate that a physically large capacitor (which would
be more susceptible to vibration then smallish capacitors), and/or
one with a large DC voltage across it, and/or one with a lot of
capacitance would have an extra current component that is a
function of vibration.
This vibration could come from external mechanical influences (causing plate movement), and/or internal influences (sublty
caused by mechanical movement due to attraction/repulsion of
the plates).
Interesting possible cause for the sound of capacitors?
I haven't found this mentioned: Pease article
This would indicate that a physically large capacitor (which would
be more susceptible to vibration then smallish capacitors), and/or
one with a large DC voltage across it, and/or one with a lot of
capacitance would have an extra current component that is a
function of vibration.
This vibration could come from external mechanical influences (causing plate movement), and/or internal influences (sublty
caused by mechanical movement due to attraction/repulsion of
the plates).
Interesting possible cause for the sound of capacitors?
how do you think condenser mics work?
the inverse effect is also well known, wrapped foil/film or metalized film caps in oscilloscope "chopping" power supplies could audibly scream
new ultra hi K ceramic caps do the same
japanese audiophiledom is very concerned by all forms of "microphonic" behavior - to the point of lead foil tape wrapping electrolytic caps
the inverse effect is also well known, wrapped foil/film or metalized film caps in oscilloscope "chopping" power supplies could audibly scream
new ultra hi K ceramic caps do the same
japanese audiophiledom is very concerned by all forms of "microphonic" behavior - to the point of lead foil tape wrapping electrolytic caps
jcx said:
Try hooking up your favorite film cap in series with an 8 ohm dummy load to an amplifier, then play some music. The results are innaresting to say the least and varies with each type/value of film cap.
Make sure the amp is OK with the load or put a couple of hundred watt bulb in series with the amp AC to protect it.
(don't try this if you're prone to electrocuting yourself or don't like troubleshooting blown amps)
Regards, Mike.
^^^^
No idea, however, Steve Bench has a similar article on capacitor distortion: The Sound of Capacitors
No idea, however, Steve Bench has a similar article on capacitor distortion: The Sound of Capacitors
Bateman has a web site with some downloads from his capacitor series; also a pointer to a site where you can purchase a download of the whole series and more -- well worth the price.
Bateman's site:
http://uk.geocities.com/cyrilb2@btinternet.com/index.html
Bateman's site:
http://uk.geocities.com/cyrilb2@btinternet.com/index.html
BrianL said:
Strongly, strongly, strongly recommended. I've been around the block a few times, and ten minutes of reading the inductor section of the site gave me a new perspective on a possible reason for component sounds and perhaps even why inductors tended to fail _shorted_ on some speakers a long time ago.
Brilliant stuff. Frankie-Bob says two soldering irons up!
usually no measurable advantage at all for coupling audio line level to hi Z input, even psu electrolytic don't look inductive til > ~100 kHz
unless your "smaller" bypass cap is big enough to to have Z < the big cap's ESR at audio frequencies; consider 10uF x 1 Ohm ~= 16 kHz, easy to get sub 100 milliOhm esr
if you are coupling to a 50 kOhm volume pot or even higher amp input Z what would "bypassing" even 1 Ohm ESR do for you? ( hint: 1/50K = -94 dB)
unless your "smaller" bypass cap is big enough to to have Z < the big cap's ESR at audio frequencies; consider 10uF x 1 Ohm ~= 16 kHz, easy to get sub 100 milliOhm esr
if you are coupling to a 50 kOhm volume pot or even higher amp input Z what would "bypassing" even 1 Ohm ESR do for you? ( hint: 1/50K = -94 dB)
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