@hakuzen Do you know of a device that you put between the source/amp and cable to the iem that you can vary the impedance from 1 to 10 ohms? With 3.5mm male output, and female input?
Also, I'm looking to measure output impedance of my DAP, have you done a measurement like that? How do you go about doing it? I was thinking of cutting a 3.5mm cable, and clip a 1 ohm resistor in between ground and one of the channels to see what RMS voltage I get, and figure out the internal resistance from the voltage divider rule. I wonder if this is safe or would I short out the headphone out with such a small load?
Yes, I've measured output impedance of some sources. You can find some of them here:
https://www.head-fi.org/threads/the...st-3-tutorial-in-post-2.800208/#post-12386883
Ended using decade resistance boxes for these measurements, because it's easier than changing resistors and you can set the exact load you like (compared with variable resistors).
Own Time Electronics 1051 (expensive accurate one, got a fabulous deal to get it), and chinese ZX21.
They are expensive. You can get cheaper but less accurate and less durable boxes. Like this (around $14, chinese J2361):
https://www.aliexpress.com/item/33054109967.html
You can try this one, but you'll have to confirm and readjust every setting with an accurate multimeter, because resistance tends to fluctuate, and it's far from accurate. It's cheap and saves you much effort.
You'll also need connectors and cables. Instead of cutting a cable + 3.5mm plug, you can purchase a DIY plug directly, no cable, and use its contacts.
Or you can use balun connectors (like I did); They work well, have low resistance (around 6mOhms average), and aren't expensive.
This kind of baluns, together with following 2mm->4mm banana adapter, and the stackable 4mm banana cables and alligator clips I linked before, are the best combo I could find for measurements (after spending hundreds in worse equipment, which I wouldn't mind to sell for cheap).
You'll also need some adapters, mostly splitters. You can buy decent ones, or DIY them with baluns (no solder) or plugs (soldered), and wire.
With this equipment, you'll be able to "add" output impedance to check frequency response change of balanced armatures; or to add a known load to measure source output impedance.
For measuring output impedance with a voltage divider, I don't recommend going so low (1ohm). It wouldn't be a problem while you use very low power; but you are safer by using 20ohms, for example, and accuracy stays good enough.
So you could use an impedance adapter of 20ohms (together with an splitter, a balun to close the circuit, and another balun for measuring voltage), instead of the decade resistance box, for this purpose. But choose a plain impedance adapter, like the cheapest at aliexpress; Dunu adapters aren't plain, they use small resistors in parallel, so they are useless for this purpose.
Also, will you ever get into measuring capacitance and inductance?
I've started measuring capacitance between positive wires and ground or negative wires. Measurements have been added to my list of cables measurements. You can also measure capacitance between side wires.
It gives you a hint of signal isolation; guess this could slightly affect to crosstalk and background noise; but haven't got conclusive results; you have to consider that amount of cores multiply this capacitance.
About inductance, I'll start measuring it when I get the time for it (I'm very busy now).
Some updates on measuring resistances of cables. I finaly got some pure copper micro alligator clips, but I still feel, I don't have the ideal lead to grapple the right pin on the 3.5/2.5mm jack.
If we take into comsideration a male jack going into a female opening, we have to think about the way the connection is touching. The way the alligator clips touch the metal isn't a precisly the same amout as actually plugging in that will not provide accurate results.
Using a DMM to measure cable resistance ended in futile effort, but learned how important the area of metal to metal contact is in effecting resistance.
I also found the cheap Zoyi ZT109 to be of questionable accuracy. The value of resistance keeps droping in increments of .01ohm very slowly over time. I wonder if it's just an issue of being slow to register? I'm sure it has to do with area of contact with leads. I think leads needs same amout of contact as when plugged in. Resistivity does depend on area of the conductor, thus in this case, amout of surface contact.
Perhaps my testing procedures are not what it should be.
@hakuzen any feedbacks?
Yes, I warned you about those small clips:
these are small copper clips (they don't scratch plugs, they are softer but less secure clipping)
And yes, cheap Zoyi ZT109 accuracy is very questionable. I use to wait till the reading is stable; guess some capacitance is the responsible of the decreasing reading. That's why I ended with YR1030, as mentioned many times.
My measurements journey is plenty of issues, deceptions, and wasted money. That's why I share many options, indicating pros and cons together with prices: to let you choose wiser than I blindly did.