AVS Forum banner
Status
Not open for further replies.
1 - 16 of 16 Posts

·
Registered
Joined
·
18,503 Posts
Discussion Starter · #1 ·
I know this does not apply to some of the high end gear heads here, but I've run across this twice now.


Last year I wired up a Sony 1270 to a DVDO which was fed an S-video source through a Yamaha A/V receiver that switched 4 S-video inputs. I found that the S-video signal was noticeably degraded by the receiver. Bypassing it brought the image where I expected it to be.


Today I tweaked an Ampro 1100 (Zenith PRO 851) that was fed from a Marantz low end A/V receiver. This time there was a video type buzz through the speakers at all volume levels. (Anyone that has plugged an audio plug into the video output jack knows what this sounds like). I thought at first it was a ground loop, but no! Turns out that as soon as the video cable to the projector was hooked up to the monitor output jack, it introduced a buzz into all of the speakers. I guess the customer has been living with this since the installation was put in about 8 years ago.


Seems ridiculous that these name brand audio manufacturers spend so little effort in the design of their video switching circuitry...


Curt
 

·
Registered
Joined
·
90 Posts
Thanks Curt, I'll have to remember that. The main focus on most a/v receivers definitely seems to be on the audio since that is mainly what they are marketed for.


Did you get that last email I sent your way? We're in the midst of an email migration at work and we've been having some troubles with sending/receiving.


-Jason Pancake
 

·
Premium Member
Joined
·
4,933 Posts
It seems like that is changing now as receivers and preamps are specifying the bandwidth of their video switch and also have to include component video switching.


Cary
 

·
Registered
Joined
·
120 Posts
I've found it very easy to use the Yamaha receiver for video switching too and since I'm not having a line-doubler or a HTPC yet I'm not that worried.

.

Now to the question, How do you guys switch between different video/audio sources (DVD/TV/VCR/Satellite/PC etc)?

What equipment do you use?


Henrik
 

·
Registered
Joined
·
18,503 Posts
Discussion Starter · #5 ·
MOst people will use a higher end INline or Extron switcher, either at the RGB or video/S-video or even component level.


No question that an A/V receiver makes things a lot simpler, but with the two examples I saw, I'd rather be pushing an audio and one video selector button on two different units than with a combined A/V receiver.


I use the video switching on my personal NEC line quadtupler (it has 7 inputs), and have not tried the video switching in my Denon AVR 3801. I'd assume the quality in a Denon is better than in a low end Yamaha or MArantz..:)


Then again, I will eventually be tying everything together with a Crestron touch panel, but those usually go for $10K USD for a good and elaborate system. I bartered and got mine for cheap..


Curt
 

·
Banned
Joined
·
2,582 Posts
HMM?


I guess I have been lucky using the AV receiver as the main "BRAIN" to switch all me AV sources. I have not had a problem either with a CRT machine or DLP with S video switched.


I do make it common practice to use hi end cables as I have learned my lesson about cheep cables years ago. Im not saying your using cheep cables but who knows electronics are funny sometimes.


As for Yamaha receivers, well that would be my problem, I hate em. :)
 

·
Registered
Joined
·
7,137 Posts
Good points Curt...


The sort of crap that most receivers do to the video chain is no surprise really when you consider that good video swichers often cost as much as the A/V receiver that they're replacing...!


I use an Extron 2:1 VGA switcher to switch between HTPC (DVD) and HDTV. Bought it used from a forum member to save some money, but it still wasn't cheap. It's auto-sensing so I don't have to get off my butt to press any buttons... the Pronto does everything for me.


Ebay's a good place to buy used Extron switchers.


Kal
 

·
Registered
Joined
·
667 Posts
For quite some time I was using my Onkyo 575X as a switcher, running to my DVDO, then to my 1272q.


I could not discern any degradation in video quality doing limited testing, but I'm sure there was to some degree.


More recently my HTPC eliminates the receiver from the video chain, however one day I might want/need a VGA switcher in case I end up with a Dish HD receiver (maybe a HD PC tuner card will show up for Dish Network?).


Also, to eliminate the future need for a switcher - maybe I could buy another 5-BNC card for my 1272q and switch with the PJ? (obvious drawback having to run another VGA cable to the pj).


Paul
 

·
Registered
Joined
·
2,007 Posts
well i guess it all boils down to whatcha got, i have a sony str-575 digital/audio/video /digital cinema sound/ contol centre receiver and intermittently change over to any audio , video function with no probelms with the sound at all, works really well, it has the ability when the auto is in play to recognize what signal your source is projecting and automatically makes the transition from analog to digital sound without doing it manually and consulting the manual for the desired sound effect to serve your purpose at the time, not exactly the best reciever out there but for what it does i am quite happy with it....................
 

·
Registered
Joined
·
4,539 Posts
I have a similar problem here. I used to use a Sony ES 5-channel DD receiver with no problems and decided to upgrade to a Denon 7.1 DD/DTS receiver (AVR3802). As soon as I plug in my sub to the output, all the speakers buzz. This never happened on the Sony. I pulled out every thing connected to the Denon except the sub and speakers and they still buzzed. So currently I am using a buzzy Denon with my setup until I get another receiver.
 

·
Registered
Joined
·
23 Posts
Odd I am even reading this thread (searching for a recommendation for a company who sells very high quality VGA cables-need a 30 footer). But I did notice this post about a "sub-buzz" from a Denon.


I would describe mine as a low "hum". With any amount of master volume from my Denon 4802, my klipsch sub would give out a constant hum. After a few minutes of monkeyin around, I found that the problem was a poor ground to my mini dish sat system (directTV), after reading about similar issues that folks were having regarding ground loops and noise in audio systems. Anyway, when I dropped the satellite cable off my Direct TV receiver box the hum (or buzz) went away. Hook it back up...hummmmm.


So I went out and took a look at the grounding. It was poor, and I decided to ground the cable out by the sat dish to the main house ground. The hum hasn't been heard from since. Just a thought, might check it out.


Heaven only knows why it only showed up in the sub-woofer channel...
 

·
Registered
Joined
·
2,484 Posts
Interesting post this one. I have been using a Sherwood 959 receiver and have noticed none of these problems. I actually think that tis reciever is very very good in all those respects you are all talking about and the audio quality is very very good.


The problem is that all of these receivers (that I have seen) will not decode Composite video or S video and output them on the Component outputs so I can feed them to the scaler!


What this means to me is that I have to use a video path out side the reciever for most things which is a pain, as I have to switch two boxes (the reciever fro the audio and use the Quadscan as a video switcher) which is very inconveinient.


I just bought a sony IFB1270 switcher with a full set of IFB cards Svideo,RGBHV and VGA so I can do all of my switching outside the receiver and still feed the projector with RGBHV.


Must check if I can input RGBHV into the Quadscan now !!


Graham
 

·
Banned
Joined
·
2,582 Posts
The buzz is not the receiver its the cable tv ground. You need to use a ground isolator to stop the sub and speakers from buzzing.
 

·
Registered
Joined
·
2,124 Posts
If you check the other forums both at this site and others you will find that many recievers are problematic in audio, video or both. Many of the products have glitches and flaws which are sometimes corrected by the manufacturer through fixes or upgrades.

I think the problem stems from the constant increase in features from model year to model year. I went through three differnt brands of reciever before I settled on my current unit. These were not low end products either but middle of the road and I was not even using them for video switching as I feel it will degrade the signal to some degree no matter what. It is better to have as few products in the video chain as possible IMO.

Steve
 

·
Registered
Joined
·
7,137 Posts
Guys,


The biggest reasons why most consumer receiver have video switchers that degrade image quality (to us) is because the switchers in these receivers are marketed to people using 24-50" TV's running at low-bandwidth 480i. Sure, some may be running at (very most) 480p but that's still nowhere near what most of us FPTV CRT owners are doing...


Much higher bandwidth (720p+) and larger screen sizes mean that we see every single flaw magnified...


Kal
 

·
Registered
Joined
·
1,772 Posts
When I bought my avr3300 couple of years ago a main selling factor was the component switching which had been tested to not degrade HDTV signals. Of course now I've got intermittent audio processor problems but no problems with the picture :)
 
1 - 16 of 16 Posts
Status
Not open for further replies.
Top