Capacitor Quality

Capacitor Quality

I’ve seen that capacitor prices have gone crazy. Does the capacitor quality really is that high or worth the money? The best capacitor quality is no capacitor at all! With such money involved, I can easily implement DC coupled circuit, or even get a decent pair of high bandwidth inter-stage transformer.

Anyhow, for those stuck with what they have and have no choices but can play with capacitors only, they’ve no choice but to pay for it. Perhaps they lack the skill; perhaps the chassis lack the space… whatever. I just want to remind them that they’ve reached almost the top of the diminishing return curve, not to mention that some capacitor quality are simply overhyped… There are some that are REALLY good and expensive as well, and those are usually well received by DIYers and used by lots of manufacturers. 

BlackGate High Voltage Capacitor For Tube Amplifier

BlackGate NX Capacitor

BlackGate Standard Capacitor

One thing to take note is that – do not look down on those that do not look good. Capacitor quality does not depend on looks! Some generic brand is surprisingly extremely good! 

What can one do to save them from overpaying? Well, they can use measurement equipment. For those that say that they can hear the difference, well… it’s their blessing (ignorance), not mine. Worse still, they pay a great price for something not great but plain crap! I will rely on proper measurements and extensive listening sessions / experience to keep me sane on paying a big sum of money for nothing but great marketing skills. The results between measurements and listening aren’t that far away, as expected. One that measured great usually will not be far-off from sounding good, if not great, and vice versa. 

What equipment should we use to test capacitor quality? It’s none other than the LCR analyzer. Even normal low cost LCR meter can also help if they have frequency test function, although not a complete range, but that should give an idea on the quality where 100Hz, 1kHz, 10kHz and 100kHz can be measured. So, at such frequencies, look at the actual measured capacitance (to see if it is deviated far away from the specifications, at all frequencies) and check the DF (dissipation factor – the lower the better, at all frequencies).  

For those on a budget, perhaps they can consider a refurbished or used HP 4192A LF Impedance Analyzer

• 5 Hz to 13 MHz variable frequency
• Swept measurement capability
• Gain-phase measurements: amplitude, phase, group delay
• Floating or grounded devices
• Impedance measurement: |Z|, |Y|, Theta, R, X, G, B, L, C, D, Q, Delta, Delta%

J&K Audio Design

18/12/2013 

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