Motu M4 and some resistors in a box:
My test amp is a “pretty good” Audiotrak AT-300 which is the weak point on SNR here. Up-hill climb of resistance in the 68uF cap in the top end is likely due to noise limitations of what this gear is capable of. I could get an even cleaner result if I used my Ncore amp which has an extremely low noise floor.
I give.
Solen 160uF 400V
I tried both of my laptops, are you guys getting those little spikes in the measurement?
When I short the test leads, I get this at the end of the sweep…
I know it’s not much, but it’s there, do any of you guys get a clean line all the way to 20K?
Unfortunetly, you are fighting the noise floor of your computer. A Limp Jig might do better Reet’s setup is rivaling if not besting Dave’s East tester a true LCR meter with kelvin leads.
I have wanted that Motu for a while now might be time to pull the trigger.
When I set the upper Z limit in DATS V2 to 20 ohms, I don’t notice the squiggly noise at higher frequencies. But when I reset the upper Z limit to 3 ohms, a bunch of little bumps show up at high frequencies. Here is an example comparison:
55+55+55uF 630V PP caps in parallel at upper Z limited of 20 ohms:
55+55+55uF 630V PP caps in parallel at upper Z limited of 3 ohms:
looks like the squiggles are always there, just that they are squiahed at 20ohms, and magnified at 3 ohmn.
Not sure how helpful this is but here is what I always get when I calibrate the test leads with DATS:
And this is the calibration with a 0.5% 1kOhm metal film resistor:
I don’t have any really large film caps on hand but this is a Jantzen 27 uF CrossCap and a Dayton 40 uF cap:
I ordered an LCR meter that does ESR, supposed to have Kelvin test leads… we’ll see.
If the ESR meter works for you, got a link to it?
Will keep you all posted
@Tom_S do you have this one? Thought i saw somehting like this in one of your builds?
Yes - same one. Not sure how accurate mine really is, but here’s what I’m seeing comparing it with my DATS V3. Cap is a 56uf Clarity Cap
Wow, huge difference! Good to know, thanks
Only off by a factor of 200 lol. I still don’t understand the interest in ESR of MKP capacitors. MKP type capacitor should be absurdly low ESR by design, unless the part is damaged or broken in some way, which should be easily visible in the impedance plot without looking at ESR. EL capacitor ESR would be of some interest, especially at low frequencies. MET polyester lands somewhere in-between EL and MKP.
I have a handful of different brands of the same capacitor size, 10uF in Solen PA 250V, ClarityCap SA 630V, ClarityCap PX 250V, Rival Polar 400V, as well as Solen MET 160V. All the MKP capacitors were similar enough to be considered equals, basically “off the scale” ESR, and Solen MET was easily measured somewhere in between the MKP and a pair of 22uF EL capacitors in series to make 11uF.
I have a problem where I buy multiple of similar items and then use them to check each other because I dont have the knowledge or background to know if the result is reasonable. As such, I have a number of multi meters and I do think the Fnirsi would be best for what we do here. Simple to use and understand.
I trust my good old reliable Fluke 87 III and confirm capacitance with DATS V3. They always match within 1%. I never sweat the ESR of metalized film poly or foil caps. There are so many other things that are more important that I could screw up way more than a 10th or so of an ohm of ESR.
Just a heads up, I bought mine on sale back in December direct from fnirsi,
for $65.00 USD, and it looks like they still have the same deal.
Thatbis anpretty nice tool for $65. Im trying to resist…
Me too….
I got mine in early Feb, but haven’t used it a ton yet. I did use it to measure every resistor and cap in the Beeny preamp build and it grabs a reading before you can even look up from the clamps to the display. I love that aspect of this meter. Slow responding multi-meters frustrate me, although I admit that’s a selfish first world problem.
Mine is supposed to be here between this Tuesday and next Tuesday
