Electrolytic capacitors inferior?


I was skimming the reviews of the Oppo 103 on Amazon and came across an interesting 1 star (negative) review.

The first interesting feature of the review was that the reviewer had not actually purchased the Oppo 103 or even heard someone else’s unit. He had considered buying one but decided not to after reading an earlier negative review on Amazon about quality control problems (the earlier reviewer had to return two units before he got a third one that worked correctly).

The second interesting feature of the non-purchaser’s review was that, after he decided not to purchase the Oppo, he examined a photo of the inside of the unit in the Amazon product description and discovered that the unit used electrolytic capacitors, which he considered inferior. He had this to say:

“Why on earth wouldn't the company use solid capacitors on the circuit board? I thought that within recent times all high end equipment frowns on the use of those old school and problem prone electrolytic capacitors as they have developed a notorious reputation for spawning all sorts of device malfunctions.”

Not knowing much of anything about capacitors, other than they can store electricity and reject DC, I search the forums at Audiogon and read a little at Wikipedia. It seems that electrolytic caps: can last anywhere from 5-20 years; can sound different from manufacturer to manufacturer; usually contain a liquid electrolyte but can have a solid polymer electrolyte; are less expensive than film capacitors.

All the discussions about capacitors on Audigon related to amps and pre-amps - no mention of their use in sources like a disc player.

As a result of all of this, I’m interested in any answers you have to the following questions:

1. Does an electrolytic capacitor last longer in a low power device like a player than it does is in an amp? Please disregard the possibility that the player may be obsolete before the caps need to be replaced.

2. Do electrolytic capacitors malfunction, as opposed to dying, more often than other types of capacitors?

3. In what way can the choice of capacitor, as to either construction or manufacturer, make a difference in the sound of a player? Would an electrolytic capacitor produce inferior sound compared to some other type of capacitor? How about when used in higher power devices like amplifiers?

4. VH Audio sells V-Cap copper foil-fluoropolymer capacitors for some amazing prices. What's the cost range for electrolytic capacitors?

5. Is Oppo’s use of electrolytic capacitors in the 103 unusual for a better quality DVD player? Put another way, is Oppo cheaping out or is the Amazon reviewer just being picky? As an aside, the cost a few V-caps equals the retail price of the Oppo 103, but maybe there are cheaper alternatives for non-electrolytic capacitors.
dougmc
For signal transfer functions; film capacitors(Teflon, polypropylene, polystyrene) are regarded as vastly superior, acoustically, but electrolytics are cheaper. Some prefer the sound of oil/paper caps in that function. David Hafler Corp(for instance) used electrolytics, on their DH-200, DH-220 and DH-500 driver boards, but offered polypropylene upgrade kits, that replaced them all. Aluminum electrolytics are used, by almost every equipment manufacturer, as power supply filter caps. Most of the problems that manufacturers have had with aluminum electrolytics, in the past few years, have arisen from those manufactured in China and Taiwan(http://en.wikipedia.org/wiki/Capacitor_plague)(http://www.niccomp.com/news/companypress/passive_comp_10_02.asp). ARC did have issues(SP-6C, SP-8, D-40, D-90B and some D-79B power supplies/poor welds, broken positive terminal tabs & electrolyte leakage) with Cornell-Dublier caps(then American and reliable,for ARC), for more than 20 years. After consulting with Cornell-Dublier's Engineering and Quality Control people & ARC having added a vacuum-submersion test to their procedures; 50 to 60% of the caps were still failing(bubbling through faulty seals). Some bad ones still made it into consumer hands and ARC untimately switched suppliers. I own three Oppo disc players, and have not had an issue, in six years of use. To blanketly condemn companies, for the use of electrolytics, is pure stupidity. To avoid their presence; one would be forced to abandon the use of virtually all electronic audio components.
Dougmc, Life of electrolytic cap is a function of temperature. At room temperature they last 50+ years cut by half for every 10degC temperature increase. It is simply drying of electrolyte. The other factor is design that doesn't overstress them (max ripple current) and finally time they are left unpowered since without voltage present electrolyte eats-out dielectric (aluminum oxide) lowering breakdown voltage.

Electrolytic cap in power supply can affect sound in power amps because of their inductance and serial resistance (ESR) especially with large variations of current (class AB). Preamps, DVD players etc. are operating at low constant power supply current and low temperature where electrolytic caps are fine. They are used practically everywhere and if reliability would be an issue we would have massive failures in mass produced electronics.
OOPS! I should have proof-read my post this morning. With my misplaced parentheses; I made it sound like ARC had trouble with C-D caps for 20 years. They had proved a reliable vendor, for 20 years, before any problems arose.
Sounds like the Oppo review itself was a troll.

Electrolytics can have the same audio performance as film caps if they are set up correctly (there are plenty of examples in the last 40 years where they are not, which is why they have a bad reputation). So if Oppo did their design homework (and it appears they did, as Oppos are regarded as good bang for the buck in digital audio playback) then the electrolytic caps are likely not causing any sonic degradations.
Thanks for the responses, guys. Lot’s of good information.

A couple of thoughts on your comments.

1. The Amazon negative reviewer may not be a full fledged troll. More like a combination of two things: (i) a little knowledge is a dangerous thing and (ii) the internet is a great way to show off how knowledgeable (you think) you are.

2. On the subject of heat reducing the life expectancy of an electrolytic cap, the prior generations of Oppo players had a fan for cooling. Some owners complained about the fan noise, and the fan has been removed from 103 and 105. Wonder if this will have any effect on the capacitors.

3. From the Wikipedia article linked in Rodman99999's comment I learned that manufacturers provide life span specs for given temperature environments and current loads, so designers of electronics are not working in the dark. A failure of a cap is really a flaw in the design of the circuit, the point that Ralph made. An exception would be the defectively designed caps coming out of Taiwan in the mid-2000's.