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hello all, i have a topping e50 used only as a dac. I've read everywhere that using it with the topping p50 power supply improves performance. Do you think that's true? the fact that you recommend the same topping, always attentive to the measures, gives me some perplexity. Are there scientific foundations that justify such an improvement? Thank you
I have the E50, and I've powered it with my bench linear regulator. It's very fast and very quiet! I didn't listen to it though (I was measuring how many mA it requires during playback, and, with USB, for 16/44.1 it's about 372-376mA, and for 24/192 it's about 388-392!) It doesn't matter that I didn't listen though - as long as you don't have an extremely dirty 5V supply (ie. one that's full of noise from switching transistors, probably because it's old and capacitors are dried out, so unable to filter properly), the E50 will not benefit from an external linear supply. Why not? Inside of the E50, the 5 volt you give it gets bucked and boosted (lowered and raised) by switching voltage converters (transistors) which switch on and off extremely fast, hundreds of thousands of times per second. Each time the transistor switches on, there is a brief peak which overshoots the target voltage. This is absorbed by the filter capacitor. The amount of overshoot is related to the size of the transistor, the amount of current, and the filter capacitor. Since similar sized transistors are used in both the E50 and USB power supplies, similar sized capacitors are used. The filters inside the E50 will not see the noise from the standard USB power supply as much different than its own noise, so will eliminate it just as much as it eliminates its own noise. This is why it doesn't matter!
(the overshoot, if too high, is what can come through the op-amps and affect the sound with whining sounds and such. also can cause undesired operation of digital parts if severe enough)
I had some problem with my E50 when I powered it from the same device I was using to feed it audio over USB. What I had to do was plug its power USB cable into the USB charge port on the side of my chair, and I was good to go - no noise! So I would recommend not powering the E50 from the same device you're sending it audio from. Another PC would even be fine (except in unusual circumstances)
The E50 sounds good for its price! I paid $200CAD while it was on sale... Very happy with it. It sounds better than my G5 (which also uses the ES9068AS), and MUCH better than the E30 II which I also have (uses AKM AK4493S).
The headphone amplifier I use with it is the L30 II, which, unlike the E30 II, is ah-MAZING! I also have the L70, and the E30 II has 97% the sound of the L70, and is not quite as loud, but unless you have 600 ohm headphones which are also very inefficient and you're also hard of hearing....
Yeah, just remember to not power the E50 by the same PC/whatever, that you're sending sound from!
