review by Andrew Ballew
I spoke a bit to soon. When it comes to conversation, writing just for myself, or blogging for others, it matters not... stream of consciousness takes over and I have to reach out and grab it and pull it back in. Which is just one of the many reasons I LOVE Chat A.I. It can spit out a well organized, fleshed out and grammatically perfect blog post in seconds, and it's very, very scary at first when you realize a human being didn't write it. The machines are coming alive. If only Alan Turing were around to see.
Anyway, speaking of that blog post where I spoke too soon with my tongue ahead of my brain, you can read it here:
You can start to read about my encounter with the diminutive E1DA Cosmos ADC. Yes, "it's minimalistic" is an understatement, indeed no, there is little documentation, yes, you are gonna have to figure this thing out on your own. And find what software it works with well, what galvanic isolators it works with well or at all, and what computer likes it most.
After a couple days of experimentation I can say a few things. The Cosmos loves ARTA software on my Microsoft Surface laptop, but hates it on My HP All-in-one, both running up to date latest Microsoft Windows.
Getting ASIO4ALL to work is a real bitch to say the least; I finally got it running well with REW, but the numbers it was giving me in the results, even after multiple calibrations, were just completely out of line from the specs of the Cosmos ADC and out of line from the results I got in other programs like Arta, Multitone, and Rightmark. (Rightmark... that is a tricky one to get the Cosmos to sit down with and play nice)
I bought the uber cheap Topping Galvanic isolator to go with it. They won't call it a 'galvanic' isolator but that is exactly what it is. Privately you may find someone from on the inside tell you this is truly the case. It is great because you can actually power it with external clean power. I am not sure at what point the external 5v enters the circuit; technically speaking it doesn't need the 5v outboard power and the 5v that does pass through the isolator should be just as isolated as the data line. There may be some devices that draw more current than the Topping can supply for both itself and the attached device. I can say it actually works quite well; its a tad more finicky than my early generation Intona USB 2.0 hi-speed isolator, but other than getting really hot to touch, I am super impressed for the price. Count this as a USB dongle/add-on that actually does what it says it is supposed to do, and can be shown to affect devices on a scale that can be reliably measured on the test bench.
BUT.. AFTER all the complaining, I am EXTREMELY impressed with this simplistic little Cosmos ADC. It does exactly what it says it does. It is a bare bones ADC designed to minimize all noise and distortion contributions so the DUT is the only contributor to the measurements. (Ideally). Best results come in MONO mode, therefore all my test results you will see here at EuphonicReview.com are in MONO mode. It comes set to mono by default; to change it, you use the small piece of software that can be downloaded from E1DA called 'Cosmos Tweak'. What you will see is a volume control at the top.. It IS NOT A VOLUME CONTROL. Yes, I was fooled too. In reality, if the slider is all the way right, you are in MONO measuring mode, which combines the power of each DAC channel into one for a lower noise floor. If you slide it at least more than 50 percent to the left (might as well just swing it all the way, though) you are in stereo mode.
But DON'T TOUCH anything else you see on this screen other than 'CONNECT AND READ'. All the numbers you see? Those are custom programmed for your specific chip and are integral to its performance. Take a screen shot, or write it down if you change the config. You will need your personal 'default' config. Also, DO NOT FIDDLE with the 'ADC_INT_SELECT'. Just leave the curiosity at the door and DON'T.
You CAN fiddle with the anti-aliasing filters though, each of the 4 individual (or rather, 4 pairs) ADC channels on board can have its filter changed. I have simply left mine set to the Apodizing filter.
On the underside, there is a complete array of dipswitch settings to match as closely as possible to the V RMS output of your DUT. So far in testing an ifI ZEN DAC, and a Topping E70 ESS verion, and Topping E70 AKM version, who all three output a little over 4v RMS, the 4.5v rms setting available has worked out to near perfection.
I wish there was a single piece of perfect hardware with a single piece of perfect software to meet all our hobbyist measurement needs. (There is, but not many of us can afford an Audio Precision). But after learning what does and doesn't work with this ADC, and sorting through what software works great for something, and what software works great for something else, I can in the end say I am EXTREMELY PLEASED with this purchase and addition to the EuphonicReview.com lab. My only slight regret is these are 'binned' for performance, and all the 'class A' devices with the lowest levels of noise and distortion are sold out. So I am stuck for the moment with a 'class B', which according to EIDA claims, is only 2 decibels or so behind in the race. Maybe even less than that.
I am so impressed with the results here, I today placed an order for the EIDA APU preamplifier unit with an AES-17 pre-analyzer notch filter! Both units operating together with allow an even greater level of fine tuning and will push the measurement limits just a bit more in our favor. At these extremely low signal levels, every tiny bit of assistance is a huge help!