USB Regen from UpTone

[Antoine]

The default SMPS PSU that came with the Regen was a dealbreaker for me in my system.

Here are some quotes of what I wrote on CA:

Same here Rocky, at least part of it. I hear more low level detail with the Regen Amber and improved dynamics however it all also feels a bit more clinical, bland/less colorful, perhaps sometimes even a little agressive now. Voices sound a bit less natural, less "magical musical", presentation is slightly less relaxed. A slight edge to voices and cymbals previously gone seems to be back again with the Regen in place.

After the installation of a 12V LPSU (BOTWS with SBooster module):

The magic seems fully back again here and more, goosebumps all over. This listening to the Regen with the 12V LPSU I mentioned. A loud, cheering and applauding audience sounds like that again instead of an annoying source of 'white noise'. Also the strain, slight edge in the highs is gone again. I'm listening louder then ever while enjoying it more than ever. Very happy again.
 
Conclusion: IMHO the Regen is great but it needs a really good quality power source, a better one than the supplied SMPS to shine! Can't wait to see with what kind of PSU add-on Alex and John come up with, I hope it can even beat the best LPSU!

Confirmed! Everyone still using that stock SMPS supply with their Regens: get rid of it! (and any and all others in your system!) 


http://www.pinkfishmedia.net/forum/showt...ost2689811

As expected the Regen switch mode power supply (SMPS) is a disaster area, I avoid SMPS PSU's because they are nothing but a huge bag of hurt and should not be allowed anywhere near a HiFi system... They can be designed for low noise, but then they become far more expensive and requires a skilled designer.

The SMPS PSU supplied with the ReGen tries to "obscure" its RF output noise by VERY crude spread spectrum in an effort to ease EMC tests. My measurements show the switching frequency hopping around between discrete "spot" frequencies - just so crude.

Forgive me, things like this make me so down as I work so very hard to design a "correct" product then I see devices like this selling... Apparently the Regen guys claim this is a low noise SMPS design - if true, then it only begs the question what Crxp is considered "normal"...

Regen PSU noise measured with a "nothing special" lab linear PSU - note the 8KHz related USB noise currents on the PSU rail.



I added 3 modifications to the Regen PCB to reduce the USB packet noise, otherwise the same as above with the linear PSU:-



Now the "standard" non-modified Regen PCB with its Switch Mode Power Supply:-



Note the massive "clumps" of spread spectrum SMPS noise!!! You really don't want these HF noise currents circulating around your HiFi system!

As above with SMPS but with the modifications to the Regen design to reduce the 8KHz USB related packet noise on the PCB, for the most part we are left with the rather nasty SMPS noise:-



Zoom FFT of the SMPS noise, here you can clearly see the discrete SMPS switching carrier "Bins" as it VERY crudely hops about in an effort to hide itself from the averaging peak sweep detector used during EMC testing. Spread spectrum works well if correctly implemented with a true random carrier - but not here where its clearly just hopping about between a few discrete spot frequencies.



IMO, "off the shelf" SMPS designs have no place in HiFi systems. I've read reports of owners using the SMPS reporting "Brightness" and that's a VERY typical sonic signature of unwanted RF currents being injected into the HiFi system.

This is not aimed at the ReGen specifically, just at "off the shelf" SMPS designs in general. Although I strongly suggest that the Regen should never have been provided with an SMPS as this PSU can have a greater negative impact on a systems performance then the original issues the Regen is trying to resolve.