freestompboxes.org

If you need a cheap capacitance meter, check out the kit from Seeed: http://www.seeedstudio.com/depot/capaci ... l?cPath=11

Under $10 delivered, works well, and a fun build.



Mike

.Mike wrote:If you need a cheap capacitance meter, check out the kit from Seeed: http://www.seeedstudio.com/depot/capaci ... l?cPath=11

Under $10 delivered, works well, and a fun build.



Mike

Awesome! Thanks!!

Coool.....
One thread with ten pages now, where I didn´t read a single post.
Hold on guys, I´ll visit you again on page 20.

analogguru

Some stuff dedicated to the comparison of the capacitors
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http://www.cliftonlaboratories.com/capa ... change.htm
http://www.cliftonlaboratories.com/roll ... acitor.htm

Like AG, I haven't read this whole thing, so if it has been covered already, I'm sorry.

I wonder if age has anything to do with this. Studies have been done on African tribesmen and the average joe walking around New York, and in some cases, the folks from New York had half the hearing ability that the tribesmen did--which they [the scientists] said was from the constant loudass noise in the city. I've done hearing frequency response tests--formally, in a doctor's office--and, unlike the average person, my hearing threshold is at something like 17kHz. I never listened to my music loudly or anything like that and at the time of the test I was 22. And, they say frequency response deteriorates at older age for this very reason [the exposure to loud noise]. I bring this up because I've measured the components used in the Drag'N'Flys I've used, and other than them both being identical--including same readings on the batteries--the only difference was that one was built with ceramic caps for the first and last in the circuit, and the other had a polyester and a silver mica, and the difference in noise was very real even with below average frequency response.

I have zero background with this, so I can't give any real explanation. And this is a serious question: what would be the point of manufacturing caps of different dialectics if there wasn't some difference? Wouldn't it be cheaper to just make nothing but ceramics for low voltage applications? Or is the difference noticeable in applications other than low voltage audio? Again, still new to this, so looking for a real answer

Kollaps wrote: I have zero background with this, so I can't give any real explanation. And this is a serious question: what would be the point of manufacturing caps of different dialectics if there wasn't some difference? Wouldn't it be cheaper to just make nothing but ceramics for low voltage applications? Or is the difference noticeable in applications other than low voltage audio? Again, still new to this, so looking for a real answer

Part of the answer there is that different caps have a very measurable difference at high frequency (like in the gigahertz), the frequencies where modern digital systems operate.

I suspect age related deterioration explains part of the difference in perception. I probably have both damage (tinnitis) and the beginnings of age related decrease in sensitivity. My understanding is in general, female hearing is better and at around 40, there is a greater drop in response (which keeps getting worse with age). Possibly circuit configurations is another factor as well? Maybe circuits with lots of feedback and more high freq. response makes nasty distortions more noticable or something. In the end (since you only hear with your own ears however they are at that point in time--unless you're doing something to satisfy someone else) maybe it doesn't matter much what someone else hears or doesn't hear.

CRBMoA wrote:I ordered the kit!

Ditto! What a cool little device. I have capacitance measuring in my DMM, but it's not very sensitive, and it only measures down to about 1n.

Gonna have to rig up some "grabbie" test leads, however. The sockets they show will wear out.

culturejam wrote:

CRBMoA wrote:I ordered the kit!

Ditto! What a cool little device. I have capacitance measuring in my DMM, but it's not very sensitive, and it only measures down to about 1n.

Gonna have to rig up some "grabbie" test leads, however. The sockets they show will wear out.

The kit comes with a two-pin connector that plugs in right above the sockets. The wires are very short (only about 2 inches), but you should be able to get a couple of alligator clips on there without much trouble.

BTW, it's adapter is center positive, so be careful!

Mike

.Mike wrote:

culturejam wrote:

CRBMoA wrote:I ordered the kit!

Ditto! What a cool little device. I have capacitance measuring in my DMM, but it's not very sensitive, and it only measures down to about 1n.

Gonna have to rig up some "grabbie" test leads, however. The sockets they show will wear out.

The kit comes with a two-pin connector that plugs in right above the sockets. The wires are very short (only about 2 inches), but you should be able to get a couple of alligator clips on there without much trouble.

BTW, it's adapter is center positive, so be careful!

Mike

I haven't gotten mine yet, but based on the website, I expect the instruction to be sparce.

Any reason a guy couldn't just flip the leads and make it center neg?

CRBMoA wrote:

.Mike wrote:

culturejam wrote:

CRBMoA wrote:I ordered the kit!

Ditto! What a cool little device. I have capacitance measuring in my DMM, but it's not very sensitive, and it only measures down to about 1n.

Gonna have to rig up some "grabbie" test leads, however. The sockets they show will wear out.

The kit comes with a two-pin connector that plugs in right above the sockets. The wires are very short (only about 2 inches), but you should be able to get a couple of alligator clips on there without much trouble.

BTW, it's adapter is center positive, so be careful!

Mike

I haven't gotten mine yet, but based on the website, I expect the instruction to be sparce.

Any reason a guy couldn't just flip the leads and make it center neg?

Yep... the power jack is board-mounted. There is another 2-pin connector for power, though, so you can hook up a battery or another power jack.

The instructions are sparse. It's one sheet. Half is the features/instructions/specifications/revisions. The other half is a schematic, and a parts list. This is the manual/instructions: http://www.jyetech.com/Products/CapMete ... -02v02.pdf

It really couldn't be easier to build, though. The parts sheet has component values and labels, and the PCB has matching labels. Assuming one can measure resistors (or read the color codes) and can solder, it'll take less than an hour. It's basically just stuff and solder.

Mine took a couple of weeks to get here.

Mike

Kollaps wrote:Wouldn't it be cheaper to just make nothing but ceramics for low voltage applications? Or is the difference noticeable in applications other than low voltage audio?

First, one should remember that oftentimes caps are not used for audio purposes. And even though we use them in low voltage applications, they are oftentimes used in incrementally higher ones. Long story short is that some dialectric types are cheaper to manufacture at different voltages, and then used to cover a multitude of applications.

It also comes down to practicality/cost with manufacture at different amounts of capacitance.

Bottom line is that in many (maybe most) instances, to view dialectrics for the purposes of low voltage audio is kind of looking at it backwards, or in a very atypical way of using the component.

Capacitors do truly seem to have at least mildly audible differences at much higher voltages. This is borne out when auditioning different types of dialectrics in tube/valve amplifiers, where preamps are typically decoupled at around 200VDC or so, upwards of 500VDC.

The silver mica thing is interesting, because most testing has revealed different characteristics than ceramics and other dialectric types, but only up in the megahertz and gigahertz ranges - way beyond what even super humans would be able of detecting. Not to say that an audible difference doesn't exist in the median hearing range, but interesting just the same.

FWIW, I've always contended that our favorite recording of "holy grail gear" tend to be done with old tube/valve amps that are absent of fancy caps with unobtanium dialectric construction, silver micas, etc. When I'm building a replica of an old design, I use cheap ceramics like the originals for the small signal caps.

oldgravity wrote:

Kollaps wrote: I have zero background with this, so I can't give any real explanation. And this is a serious question: what would be the point of manufacturing caps of different dialectics if there wasn't some difference? Wouldn't it be cheaper to just make nothing but ceramics for low voltage applications? Or is the difference noticeable in applications other than low voltage audio? Again, still new to this, so looking for a real answer

Part of the answer there is that different caps have a very measurable difference at high frequency (like in the gigahertz), the frequencies where modern digital systems operate.

Exactly right - and when I design gear at 10 MHz, 100 MHz and 30 GHz, I use very different components. However, the differences at 1 kHz are neither measurable nor audible for the same value of component.

dai h. wrote:I suspect age related deterioration explains part of the difference in perception. I probably have both damage (tinnitis) and the beginnings of age related decrease in sensitivity.

I have both tinnitus and a notch at around 2kHz or so. But in my case, it has actually made me more sensitive at the surrounding frequencies, since hearing loss tends not to be a linear phenomenon.

In my case (and according to my audio medical specialist), there are certain frequencies above the notch in my hearing that get distorted atypically, to the point of almost being painful at higher spl's, and overly augmented at lesser ones. Translation - any upper level frequencies or harmonics that I perceive to be unpleasant seem to effect me more than the youngster next to me with 100% hearing.

My specialist has also mentioned the brain's ability to create biofeedback to counteract some audio damage, and that not all damage in the case of tinnitus and similar actually occurs at the nerve in the inner ear itself. The brain is capable of generating these signals as well. It would stand to reason that a modulation between what the brain is generating and what the ear is reproducing are capable of causing a noticeably enhanced audible perception.

...At least much of this is what my specialist has concluded, who has spent his entire (long) career researching the phenomena of hearing damage and it related real world effects. And it seems to be borne out by a team of specialists within the facility that he works at.

MoonWatcher wrote:
FWIW, I've always contended that our favourite recording of "holy grail gear" tend to be done with old tube/valve amps that are absent of fancy caps with unobtanium dielectric construction, silver micas, etc.. When I'm building a replica of an old design, I use cheap ceramics like the originals for the small signal caps.

EXACTLY Some real sense at last!!! Just for fun, I built a clean top boost stage (quite mild top lift) with a single stage BC109C. I built two of them - one with mojo components, and one with modern parts. The ONLY audible difference that anyone could hear was the slightly increased noise of the one using carbon resistors. The components were selected to have exactly the same values. The only other difference was that the bias point of the mojo one would change very slightly with temperature as the bias resistor values would change slightly, but the the change was small enough not to affect the operation of the circuit.

real world pedals, amps, etc. as far as I can tell don't comport to the ideas outlined some of the more technical articles (less distortion, more stability, etc.). You find BOTH "better" (from a conventional sense) parts (film, certain types of film, mica, etc.) and "worse" (cheap ceramics, alu electros, tantalum, or whatever) in equipment that people like or have liked. For example guitar amps have used "good" mica, and "cheap, 'bad'" ceramics, "good" polystyrene. I was googling stuff recently on mods for the MXL603S mic which has a circuit apparently based on a Schoeps mic (seems to be some sort of classic or standard as a mic), and I was slightly intrigued (when I found a guts pic on the web) to see that the Schoeps used "bad" tantalums for output coupling (although not surprising and probably completely normal from a conventional sense considering the small space/volumetric efficiency and leakage?).

.Mike wrote:If you need a cheap capacitance meter, check out the kit from Seeed: http://www.seeedstudio.com/depot/capaci ... l?cPath=11

Under $10 delivered, works well, and a fun build.



Mike

Oh my, I like that site and the crazy stuff they sell. Gotta get the cap meter, and hey to round out the shipping how about another $200 of goofy electro-gadgets. Just to round up the shipping.

Thanks for the link.