I thought I’d throw my thoughts out there on these products when used with A&S Nautilus.
Reason for purchase: Move away from budget APC surge protector, remove some noise from power. When I turn on a fan in the room, same circuit, I can hear the fan speed pop as it changes from the dial amplified through the headphones. When I turn on the amp, there is a mild hum. It maybe just be the way this amp is, it’s two amps in one, it’s no slouch. Any additional remove of RFI & EMI is a bonus. Cleaning up the sound is an additional bonus. And also cleaning up the ground (no potential ground loops which i have not had an issue with)
This is just my observations and thoughts, no oscilloscopes, no current meters, no db meters, just thoughts and personal opinions.
Equipment & tubes
Macbook air M1> Matrix-x Sabre Pro MQA > A&S Nautilus > ZMF Eikon @ Hi Z
Power > Equi-Core > Deep-Core > wall
Tubes > Tung-Sol 1963 Grey 6550 x 2 > 4033 (12at) > Tung-Sol 5AR4 x 2
I’m going to start with the Nautilus to the wall and Matrix-x Sabre Pro MQA to the Equi and Deep. Turning on the Nautilus, there is quite a noticeable hum compared to yesterday when I was running the amp with the Equi-Core and Deep-Core. Listening to Mumford & Sons Cold arms @ 16 bit 44.1. No real white noise during the song. When the song is down, the background is pretty quiet. Sounds good of course. Turned the fan on, there is a pop between each speed.
Second round, Nautilus to the Equi-Core on it’s own duplex, all other equipment except the mac on the Equi-Core. Turning on the Nautilus seemed a little softer start and hum. I do remember talking with Justin that the Nautilus starting is a pretty good draw and the Equi-core does help with this draw. I turned off the fan before starting this second test. I turned it on while listening to the same Mumford & Sons, no noise from the fan turning on and changing speeds. The sound seems stronger (more impact), louder (volume seems to increase quicker), cleaner and darker when it’s silent. It’s not cheap, I got it while it’s on sale and half the price of the competitors. I personally am sold on it.
Third round is just adding the Deep-Core into the mix, fan off. All equipment except mac (due to the weird power brick and it runs on battery most the time). I will be adding the USBe from Underwoodhifi tomorrow. It’s basically a re-generator of the usb signal. The start up from the amp was the same as the second test, running through the Equi-Core but quieter than from the wall. One notch on the fan was super faint noise when changing speeds. This is being super picky. Back at the same volume with Mumford & Sons, same clean, very detailed sound as before. My thoughts, Deep-Core might be a step over the top that may be skipped. There is an adjustment on the back of the Deep-Core after used for a while that will allow some tuning that may change the sound.
My thoughts on a short test, just pulling everything apart and putting them back again. Also, in regards to thick, high end power cables versus a good server grade power cable which I have access to, I hear no difference and there is less bulk. I personally would bother with the high end power cords. I’ll update this with thoughts on the USBe.