Musings on Switching Power Supplies (LPS for Oppo / DirecTV/ Radiance)


So, this whole story begins about a couple months ago when I was watching a satellite television show on my HT system.  While I was watching, I noticed that my Oppo bluray player was still on (I often turn everything on in the beginning to warm stuff up and/or listen to music).  Well, I hit the remote button to turn off the Oppo and a weird thing happened.  The sound got a little bit better.  It lost a small bit of that digital “solid-state” harshness / brightness.  I then thought, “wait a minute, something is going on here”.  The next thing I did was, even though my Oppo was powered off in “stand-by” mode, I went and just unplugged it completely.  The sound actually got a tiny bit better after that.  Now I have read postings that say switching power supplies can cause noise in other devices when they share the same circuit/outlet.  I never really gave it much thought, but apparently this is definitely a thing.  My Oppo is plugged into the same outlet as me left surround amp, which is a completely different circuit than my HT processor and other amps.  However, the switching power supply in my Oppo BDP-103 was still causing havoc in the system!

I have four dedicated 20 amp circuits for my HT equipment.  I also had two other devices that still contain switching power supplies:  DirecTV Genie satellite receiver and a Lumagen Radiance video processor.  My DirecTV was plugged into the right surround outlet and the Radiance was plugged into the same outlet as my Krell S1200 HT processor.  So the next step was to pull those out and connect them to regular house outlets (which are different circuits and not even in the same subpanel).  I could see immediately that I lost some of the video quality through HDMI.  The picture was not as sharp and it introduce a little bit of noise into the image.  However, it did improve the sound even more (got rid of more of that digital harshness).

So what to do next?  Well, of course get rid of all these switching power supplies and, somehow, implement linear power supplies!

auxinput

@nonoise - good call.  I have been using the following cryo-treated Neotech HDMI:

http://audiosensibility.com/blog/products-2/digital-cables-occ-copper-and-occ-silver/#!/Neotech-NEHH-4200-HDMI-1-4-Cable/p/17895256/category=4059160

So far, it has done very well and I haven't had any ambition to upgrade.  However, I would consider a Wireworld Starlight 7 or Silver Starlight 7 in the future if I did upgrade.

The "7" series is definitely better because the new insulation has a lower dielectric.  Other insulation such as PVC has a higher dielectric and will absorb electrical energy (meaning the digital pulses will be weaker once they hit the other side).  This can cause signal error or other issues.  This is not so critical with low frequencies such as bass.  However, in the extremely high digital transmission frequencies of HDMI, this becomes a critical element.  It will also affect higher audio frequencies (such as anything above midrange frequencies).  Lower dielectric material such as teflen or foamed Polyethylene (like the Neotech and Audioquest cables use) is definitely much better.

Hi auxinput: Try one of these https://www.amazon.com/DTECH-Unique-Transparent-Ribbon-Design/dp/B01GRF321K/ref=sr_1_1?ie=UTF8&q...  just for grins, return it if not impressed. This cable bested cables like the silver plated one from Apollo AV. 
Hey, thanks for this thread. I was checking out the Oppo LPSs as well. Good to hear some feedback
Thanks for the thread. I’ve been using a 203 modified by Stereo Dave’s and very happy with the sound quality, feeding a PS Audio Directstream dac and ATC active speakers. The 200 series is still not described on their site, but the methodology is similar as for earlier models. For TV, for anyone with cable, Jensen’s cable filter for about $70 accomplishes the video improvements described in this thread, practically no matter which HDMI cable is being used.

I’ve got a 205 on the way, found cheap on a Canadian ad site, and look foward to playing with that. I’ll probably add OppoMod’s HDMI/I2S card, as I haven’t been blown away by the audio quality of the external cards offered on eBay, although the performance is to some degree HDMI cable dependent (and requires a second cable vs. an internal card). The alternative is an s/pdif run to the dac, which wih the right cable can be very good, but a lot more expensive.