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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's avatar
nonoise
10,539 posts
 
The only thing that's keeping me from splurging on a LPM for my OPPO is the results that Dan got over at Modwright. He tried to come up with one himself and it wasn't worth the hassle. He claimed it ran way too hot so he got one of Mr. Lee's unit (like the one that auxinput has) and found it to be good, but still too hot for his tastes.

He says he got very little in the way of measurable differences between the SMPS and the LPM units but that could be written off as sour grapes since auxinout says the LPM unit has started to cool off as it broke in.

The one work around that I"ve done before is to take the upper lid to a shop and have them drill some holes in it to aid in ventilation. You can also go further and carefully have some vent holes drilled in the bottom of the unit for better air flow but just doing the lid top should be good enough.

All the best,
Nonoise
nonoise's avatar
nonoise
10,539 posts
 
Although this is a bit off topic, it still deals with digital noise, and what I'd like to add is to get a very good HDMI cable for viewing. 

I just swapped out a generic, though highly rated, HDMI cable that you can get on Amazon for about $20 and inserted a WireWorld Chroma 7 HDMI cable and it's in another league. Not incremental to anyone with a good set of peepers but Yuuuge. I see now why they say politics is for people too ugly for Hollywood. All the pores and blemishes stand out now. 

Ugh.

Being a news junkie the first thing I noticed is the chyron at the bottom of the screen and how sharp it is along with the scrolling type. Clothing has amazing detail as well. What really surprised me was the catch light in the hosts eyes. You can clearly see the three different spot lights from above reflected in her eyes. And the three fluorescent lights from inside her desk show up individually in her cornea and the whites of her eyes as rectangular. Quite impressive.

The rep at The Cable Co. told me that the 7 series has better insulation than the 6 series and you can consider each line of the 7 to be the equivalent of the next higher line in the 6. Whatever it is, the digital noise is gone from the screen. My plasma used to have that somewhat soft focus compared to a newer LED screen but now it's very competitive, if not their equal. Colors are better saturated and blacks are deeper with finer gradations. I may just put off getting that new OLED but I still can't stand the heat coming off the set.

Tonight I'm going to watch and see what the WireWorld Ultraviolet 7 HDMI does for my blu-ray viewing. It should be nice.

All the best,
Nonoise
auxinput OP
2,920 posts
 

@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.

yoby
538 posts
 
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. 
toddverrone's avatar
toddverrone
840 posts
 
Hey, thanks for this thread. I was checking out the Oppo LPSs as well. Good to hear some feedback
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