For a tube preamp DC blocking output cap position, what sonic difference does a higher voltage rating in a capacitor provide? In other words, is there any advantage sonically to using higher voltage rated caps over a lower voltage one of the same brand and model / part number, where all else is equal except voltage rating?
John Broskie of TubeCad sells Cornell-Dubilier 942C series caps to go with his Aikido kits. He says that the higher the voltage rating on these, the better they sound. My subjective experience says this is true, but I haven't done any blind testing to confirm this. I have no idea if this applies to other brands of capacitors, but it's an interesting idea.
Plus if there is some sort of massive failure the amp doesn’t get barbecued! I always use 630v caps just so I don’t have to think about if 400v or 250v is enough where the cap is in the circuit. Relatively cheap insurance.
Sounds like a plan. However higher voltages usually mean bigger and more expensive caps.
Most engineers would answer none. I higher voltage cap will have thicker/better insulation/dialectic material one would guess & maybe a tad more inductance, but we're talking about pico henries possibly. At audio frequencies the capacitance of the cap itself together with the grid leak resistor dominates frequency response, at RF the tiny extra amount of inductance might make a small difference.
There might be a small difference in THD but I'd wager non a human ear can detect. That said for some amp design and building is part engineering part voodoo part trick cycle-ary. A £30 big cap with groovy gold lettering sounds better to some. Being a poor peasant I buy caps rated for 630v which in most parts of the circuit of an amp with 450v ish HT/B+ are sufficient and made by reputable manufacturers at the lowest price I can find and have been happy, chaps with deeper pockets may find pleasure in buying more expensive types.... funny old world innit.
Andy.
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These days, I'm inclined to use 1kV caps for coupling. While my amps are cold, sone of them will have almost 900 volts across that cap.
Bigger and more expensive? Maybe. 20 cents isn't expensive though.
https://lcsc.com/product-detail/Pol...CHAMPION-MPP105K1000D262112B2315_C270293.html
Bigger and more expensive? Maybe. 20 cents isn't expensive though.
https://lcsc.com/product-detail/Pol...CHAMPION-MPP105K1000D262112B2315_C270293.html
Of course!
Someone selling parts/kits online has the smarts to convince their potential customers that they're intelligent and right about their offerings.
The truth about something, and the hype rarely mean the same thing.
But I find it all marketing nonsense, judging from my own decades of working on equipment.
The "he says" doesn't mean a thing to me.
Post #5 here sums it up pretty well.
Wiseold,
A bit cynical about Broskie don't you think? If you look at the price Broskie sells these for and Mouser's prices, he (Broskie) is not marking them up much. His is more of a service to customers so they don't have to source parts from various vendors. If you don't like Broskie's parts choices then most of his kits are a available board-only. BTW, I find his C-D recommended caps, both the 940C and 942C to be sleeper bargains and a good midway point between cheap polyester or polypropylene caps and the "big name" expensive ones.
Just my 2 cents,
S.
A bit cynical about Broskie don't you think? If you look at the price Broskie sells these for and Mouser's prices, he (Broskie) is not marking them up much. His is more of a service to customers so they don't have to source parts from various vendors. If you don't like Broskie's parts choices then most of his kits are a available board-only. BTW, I find his C-D recommended caps, both the 940C and 942C to be sleeper bargains and a good midway point between cheap polyester or polypropylene caps and the "big name" expensive ones.
Just my 2 cents,
S.
Listen, I've been in the audio/video service business for decades, and with that comes exposure to, and experience with, thousands of products, and their components.
It's got nothing to do with being cynical, I base my comments on reality, things I've seen over time, and results of same.
Test instruments on my bench confirm real-world conditions, yet the internet community loves to add their own perception to things, including sellers trying to make a buck.
I sometimes tend to come across as a grumpy old man of 69, and have been labeled many associated names.
In my opinion, it's an inherent part of the internet's 'virtual' understanding and its limits.
As for marketing, of course one would praise a product, it's the way to sell things since the Pyramids were built.
But, and I refuse to enter into another "capacitor debate" thread, things like these are way over-hyped and silly.
The nitpicking of something simple gets annoying to guys like me who know better.
A+ Unfortunately it's a sad thing to say that there is a very low bar to admittance into this hobby. And the internet. .... It's a public swimming pool.
When you start a sentence with, "Listen" speaks of intolerance and, "I know better than you." Must be nice to be so sure of one's self. I'm 70+ but still try to keep an open mind. Not saying Wiseold and 20 are necessarily wrong but different people have different experiences. If you don't like the public pool, build one for yourself in your own back yard.
A higher voltage foil capacitor does have a bigger size and it may be more prone to capture radio frequency noise and hum in a high impedence circuit, this may negate any eventual sonic advantage. I select the capacitor voltage value at 20% to 50% higher than the B+ supply with no load at maximum supply mains voltage.
I have to be sure of myself.
Dealing with customer equipment as a professional, they depend on me to do the right thing, and I don't want any liability lawsuits tarnishing my reputation.
I'm strict, yet not a nitpicking obsessive.
Often when someone thinks the know it all and have nothing to learn they really know less than they think. There is always something to learn. The wisest men used to think the world was flat, right?
