Upsizing capacitance doesn’t always bring about improvements, and can create other problems if taking things too far. When replacing aging caps, especially main power supply caps, uprated voltage is fine, and sometimes, the temperature ratings, as there are situations where that spec. may be close to operating temps. Increasing the temp. ratings can give a bit longer life. Sometimes it is more difficult to just find a replacement cap that even fits the space requirement with same or better specs.
I am sure there will be many other suggestions given in due course.
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Upsizing capacitance doesn't always bring about improvements
Very true..
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@rickysnit It’s typically not good practice to increase the capacitance of any circuit by itself without adjusting the design of the rest of a circuit. In some cases, people may do so say in a speaker crossover, but it can introduce both improve and degrade the sound. Generally when replacing a capacitor, you will want to stay within 5-10% of its rated capacitance, as most capacitors and circuits are designed to sway this amount. The voltage rating on the other hand is there for safety / integrity purposes. If you increase this on a capacitor, you’ll just end up with a capacitor that has a larger form factor with no sonic benefits, but if you unit fries due to a surge, this capacitor might live where others might fry out.
What people often do is upgrade to different capacitor brands and models in a similar way to how people roll tubes to tailor the sound. In this case people will generally stay within the same capacitance and voltage values as the original capacitors.
Often times manufacturers put in lesser quality capacitors to meet price points. They may feel the end result in these designs meets their expectations and don’t push further. Much of the DIY community likes to tinker here, and I did so myself when it was easier for me to access improvements this way instead of purchasing better performing gear.
Here is a website that’s been around a long time that document’s one person’s experiences and ratings in capacitor rolling for speaker crossovers. I find his observations to be valid when using these capacitors in other places like preamps and amps.
https://www.humblehomemadehifi.com/Cap.html
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You speak the truth! And thanks for that, great link - I'll have a read..
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For tube amps, it is not a good idea to stray from the original capacitance values for the power supply. You can damage the amp. Higher voltage values are OK, though.
For solid state amps, things generally aren't quite as sensitive, but you can still quickly get to the point where the capacitance is a mismatch for the capability of the power transformer and rectifier circuit.
A final note for capacitors in speaker crossovers -- changing the capacitance value here will affect the crossover frequency and thus the speaker's overall response. Presumably, you bought the speakers because you liked the way they sounded. You may or may not like the way the changes affect the sound.
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I've upsized large 4 filter caps on Accuphase E202 integrated amp on capacitance, temperature and voltage. The idea is to keep discharge time relatively similar. If the FACTOR of discharge time goes like 2...3x faster through the resistor, you'll need to replace it to the larger resistor. In my case the difference was tolerable only by 12% faster. Therefore I didn't change any other circuit components.
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I have to assume we are talking about filter caps...
You have to be careful as bigger caps = more current draw and more stress on the transformer and upstream components.
Personally, reduced ESR and higher temperatures are a bigger factor in upgrading these than the capacitance. Higher temperature caps have longer endurance ratings generally speaking, so if I can fit a 105C cap in place of an 85C cap I will.
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Best practices: If it works, leave it alone.
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People spend months or years designing amps and other people who think they know better want to "improve" on the design. Where's the facepalm emoji? Sheesh.
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Measure the capacitors with a good lcr meter to see if they have degraded due to age
Replace if they are more than 10% low. Otherwise leave them be.
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People spend months or years designing amps and other people who think they know better want to "improve" on the design. Where's the facepalm emoji? Sheesh.
I used a car analogy in another thread, have always had the same logic on auto "upgrades". Take wheels for example, somewhere you have an engineer who dedicated their LIFE to the field and maybe months/years on any specific car only to have someone think they know better - it's a valid point!
On circuit design, absolutely. What prompted my post is every other capacitor DIY story, we have people increasing capacitance! On average, more negatives than positives (pun totally intended)..
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As others have mentioned you better know what you're doing if changing capacitance. I will occasionally upgrade for temp, voltage or tolerance, this mostly in power supplies.
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- ESR increases as electrolytics age, so renewing can have benefits. Measured C maybe well within spec, but ESR is likely off the chart on 20 year old caps.
- Capacitors are purpose designed, so ensure using the correct type.
- Replacing electrolytic and mylar with Teflon or Polypropylene is a sonic free lunch. Matching also pays dividends if the drivers are matched.
- ESR increases with voltage, so multiple parallel smaller caps can provide dividends. This is easier to implement in older / hand wired tube gear than modern SS or PCB tube.
- Take any rating by listening with a grain of salt. There are innumerable uncontrolled variables that come in to play when swapping LS XO capacitors and ALL impressions are only valid for that system only!
- ALL systems should have a soft start to reduce inrush current.
- Tube amps can benefit from a B+ soft start allowing heaters to warm before full B+ is applied.
- Fake capacitors abound, so buy from reputable sources like Mouser, Digikey, Parts Connexion, etc.
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I would not change to higher capacitance and temperature, voltage maybe after looking the service manual.
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Why not? Some devices definitely have under temperature rating caps, particularly within a rack or under another component or heavy load or 24/7 operation.
105°C caps have 4x the life at rated temperature vs 85°C.
Modern caps pack more C in the same space, so increasing C and T while reducing ESR is a Win-Win-Win.
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It depends where you are referring to . IHave been into Loudspeaker mods for years ,and without question are upgrades in Sonic performance ,with Capacitors Resistors sometimes inductors, wiring, connectors. For the vast majority of Loudspeakers use cheaper parts quality ,why cost.
this is true also in electronics , types ,electrolytic in power supplies ,which should v be bypassed with a decent quality .1uf poly cap it smooths the upper frequency noise ,and quality here too very important like using a Elma Silmic cap much smoother ,or top Nichicon caps , even Clarity,or Mundorf 4 pole caps .
for coupling caps where a good poly cap, or top Copperfoil like World class Duelund ,which BTW I have been using for years I just exchanged the very hood Jupiter copper foil for the much better and muchBigger DuelundTinned Copper foil paper oil in my preamps output section , they take many hours to settle in but well worththe efforts.
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