Is increasing capacitance always preferable?

[Sergimm]

I'm making a BOM for a future recap of a Luxman R-1030. In the Service Manual, most electrolytic caps are listed as having a tolerance of +50% -10%. Knowing that, should I always try to generously increase the capacitance of the replacements? Most electrolytic caps today have 20% tolerance (±10%), so it looks like I have a lot of room to wiggle.

My main question is, is higher capacitance (inside the designed tolerance limits) for all caps always better? Or should I stick with the original designer values?

 

[century tek]

You might not be able to get the exact values today but I would stay as close as possible.

 

[Hyperion]

You might not be able to get the exact values today but I would stay as close as possible.

^This.^

Or should I stick with the original designer values?

Yes you should stick with the designer values - in other words the values that are in your unit now. If you randomly, and without knowledge increase capacitor values you will put yourself in a 'World of hurt' I can assure you.

 

[egellings]

Excessive capacitance in power supplies is not a good idea. Peak charging currents get larger, making life miserable for rectifiers and power transformers, not to mention high inrush currents upon power-up. The power switches often get welded 'ON', too. Use the amount the original design calls out. Small increases are okay, as an example, using 1500uF to replace a 1200uF unit.

 

[Skywatcher]

I'm making a BOM for a future recap of a Luxman R-1030. In the Service Manual, most electrolytic caps are listed as having a tolerance of +50% -10%. Knowing that, should I always try to generously increase the capacitance of the replacements? Most electrolytic caps today have 20% tolerance (±10%), so it looks like I have a lot of room to wiggle.

My main question is, is higher capacitance (inside the designed tolerance limits) for all caps always better? Or should I stick with the original designer values?

It depends on the duty and circuit design. But for example if a "stock" cap is 10,000 -10/+50%, then theoretically you could use between a 9,000 to 15,000 and still be "in spec". Just do the math for whatever the value and tolerance of the originals.

 

[blhagstrom]

Increasing voltage is preferable if anything.
Stay with stock capacitance ratings as much as possible.

 

[egellings]

If you want to go with excessive amounts of capacitance, which I think is unnecessary, then inrush limiting is mandatory.