We have been very, very careful, still, there are a few that we suspected are fakes, although being bought from reputable online seller. We were matching some Vishay high voltage 470UF 450V electrolytic capacitors for tube amplifier use, and 4 of them felt flimsier than the rest of the capacitors. When shaken, we can feel that the internal are not snug or fit the enclosure, like a can inside a can with some space left between them. The capacitance measured OK though, meeting the specifications.
The vibrating "core" is not good for any applications on our standards. Curious us, since we're going to throw such suspicious parts away as they failed QA, why not just open up and take a look! .
Internal does not look as sturdily built like a high grade Vishay capacitors we have in stock. It has only 2 flimsy ALU foil connecting out to the external 2 terminals. Usually, those higher grade low ESR capacitors will have multiple higher gauge foils connecting the 2 positive/negative terminals. We think, probably it is some low grade cheap capacitors being re-sleeved as Vishay 156 PUM-SI capacitors to rake more profits. The capacitance may be OK but the voltage ratings may not, and will risk an explosion if used over its' rated voltage.
To be safe, we'd better stick to our 1st source for components - element14! More expensive, but definitely safer, and is made fresh from the factory instead of being sitting in the storeroom for extended period. Such capacitors long being in storage may still be usable, but the leakage current might have gone up the roof, and requires reforming. Still, we are not going to take such risk.
The end products will be more expensive, but what you pay is what you get! These babies are U$43/pc each. With 6 per channel, 12 for stereo, it is already close to U$516 just for capacitors alone. Quality comes with a price, and extreme high quality is what we strive for. Often we hear people say, why are your stuff more expensive than others? I can just get in China or some online dealers cheaply. Dude, you pay cheaply, you get "cheapies"! Don't come crying when it exploded, sounded mediocre, or something bad happened along the way, like blown amplifiers and speakers go along with it to audio heaven. We've repaired many, and we know what's going on in the cheap audio industry, such as fake caps, re-branded caps, recycled caps, re-sleeved caps, and many more horror unknown to most stories.
Below are some guaranteed genuine Vishay highest grade electrolytic capacitors we ordered for our solid state amplifier. It costs a lot, but is definitely worth it. Check it out:
|Ordering Caps from Vishay|
|Vishay PED-ST Electrolytic Capacitor|
|Vishay 106 Electrolytic Capacitor|
Just how good are these caps? Take a look at the specifications!
- Very long useful life: 20 000 h at 85 °C (even longer life at 40 degC)
- Extremely low ESR and ESL allowing very high ripple current load (very important)
- High resistance to shock and vibration (good for sound)
- Polarized aluminum electrolytic capacitors, non-solid electrolyte
- Large types, cylindrical aluminum case, insulated with a blue sleeve
- Pressure relief in the sealing
- Charge and discharge proof
- High reliability (very important for amplifier stability and longevity)
This capacitor screams of quality in every sense! Did I tell you that the ESR for the 33,000uF 63V unit that we got is only 8 mOhm at 100Hz, and rated current at 100Hz @ 85degC of 23.5A (will be much higher at room temp!)! These capacitors are used in super high end amplifiers such as Soulution, Vitus, Dartzeel, and many other legendary amplifiers - their reliability, quality, and most importantly, voicing (sound) are proven, which is something we heard & like, and have been promoting for our tube amps, now solid state amps.
Sneak preview: we are going to use at last 4 of these per channel for our 100W/8-Ohm, 200W/4-Ohm solid state amplifier, as part of the J&K solid state amplifier line of products. [This guy (amp) is not on the list yet, as it is made for demo for local enthusiasts.] If the chassis fits, we may even throw 6 of these into a single channel! Now that's what I call an amplifier for real men! Be prepared to be blown away.
Till then. Take care, and don't buy fake caps!
J&K Audio Design