**Capacitors:**

I wasn’t too keen on the 1000-2000hr Samyoung caps and wanted to replace them with either Nichicon or Nippon chemi-con caps. Why do manufactures put shit caps in their products? In quantity, caps cost nothing, and are the first failure point. I would bet money that if Rigol offered a premium version of the DP832 with high quality Japanese caps, all their Samyoung versions would sit on the shelf to rot. The top board upgrade cost $13.46(single piece price). If you buy in large quantities, it’s more than 75% less. So why do they bother with other brands, I don’t get it. We’ll actually I do, it’s not meant to last and they’ll do whatever it takes to get it out the door, that includes not installing the toroidal transformer screws.

Anyways, they only use 5 different types of caps on the top board. I went to digikey and ordered a bunch of different sizes of caps based on voltage, ripple current, and life. I took some measurements with my LCR meter and here’s what I came up with. All the measurements were taken at 120hz. This is just a comparison at one reading frequency to compare the difference. The data sheet specs are also just for comparison, since there’s all kinds of de-rating factors. (freq multiplier .4-.75 at 120hz for the low ESR caps)

**LCR Measurements: (Rated Capacitance/Measured uf/ESR/Ripple/ Life Hrs)**

-OEM Samyoung Capacitors (Ripple Current Rating@120hz)

-35v 100uF KMG x 4: 97.8uf/1.133ohms/168ma/1000-2000hrs

-16v 1000uf KMG x 1: 925.7uf/.2314ohms/680ma/same

-25v 2200uf KMG x 2: 2019.7uf/.1586ohms/1.297amps/same

-35v 1000uf KMG x 2: 962.9uf/.149ohms/1.023amps/same

-63v 10,000uf TDA x1: 10,355uf/.0885ohms/4.4amps/2,000hrs

-Replacement Nippon Chemicon/Nichicon Capacitors: (Ripple Current Rating @100khz; .40 to .75 frequency multiplier@120hz)

OEM 35v 100uf: (Ripple Current Multiplier. 40)

-35v 100uf KYB: 109.63uf/.4215ohms/540ma/7000hrs

-35v 100uf KZN: 97.24uf/.4782ohms/700ma/7000hrs*

OEM 16v 1000uf: (All 25v 1000uf) (Ripple Current Multiplier. 60)

-KY: 1019.1uf/.875ohms/1.91amps/10,000hrs*

-KYB: 996uf/.0625ohms/1.65amps/10,000hrs

-KZH: 1034.7uf/.0466ohms/2.25amps/6,000hrs

-KZE: 989uf/.0446ohms/2.36amps/5,000hrs

OEM 25v 2200uf: (Ripple Current Multiplier. 75)

-25v 2200uf: 2277.7uf/.0298ohms/3.66amps/10,000hrs*

OEM 35v 1000uf: (Ripple Current Multiplier. 60)

-35v 1000uf KZE: 1027.3uf/.0346ohms/2.77amps/5000hrs

-35v 1000uf KZM: 962.8uf/.0385ohms/2.48amps/10,000hrs

-35v 1000uf KY: 937.3uf/.0482ohms/2.23amps/10,000hrs

-50v 1000uf KY: 1039.7uf/.0417ohms/2.92amps/10,000hrs

-50v 1000uf KZN: 1023.5uf/.0325ohms/3.81amps/10,000hrs*

OEM 63v 10,000uf: (Ripple Current @ 120hz)

-63v 10,000uf Nichicon GU: 9465uf/.0727ohms/4.69amps/3000hrs

After weighing the options I choose the ones marked with an asterisk. I was kind of worried about the low esr value, not knowing how it would affect the voltage stability but I’ve been running a power profile on it and it seems ok. Max output ripple is 1-2mv at 30v/2.75amps and the 5v logic power has the same 2mv ripple. I think this is a literal example of "Gilding The Lily"