Optical sounds problems

croftyuk

Standard Member
Hi,

I've currently got the following set up
Panasonic 37LZD85 TV
Panasonic SC-PT860 Cinema Kit
SKY HD

I've got them all connected via HDMI but the the sound is connected via an optical from SKY HD box to the cinema kit. Everything fine until my wife bought me a PS3.

So I connected the PS3 to TV via HDMI and sound to cinema kit via Optical....... but problem as CK only has 1 input. So I bought a Optical switch from Maplins which appeared to work okish (Odd crackling from PS3) for a few days then nothing. Sound is fine if you plug PS3 directly into CK but not via the switch.

Anyway swapped cables etc etc and it turns out to be the switch, I presume the PS3 link has to be 100% spot on as the TV sound works fine through switch. So today I thought, its not ideal, but I'll buy a splitter, anyway tried that and turn the PS3 on nothing!!! Switch SKY on and there is sound. So both a splitter and switch don't work for the PS3 but reading the reviews I see of both they work for other people. Anyone got any idea's as I don't want to have to keep pulling Optical cables out when I want to play the PS3..... Is my PS3 faulty?? I've changed sound settings on PS3 but still the same outcome. TIA
 

COOPERMAN

Novice Member
What make of Sky HD do you have?
iirc the Thomson HD box's optical is on all the time, try switching off the HD box at the wall socket to see if this helps.
 

croftyuk

Standard Member
Its a Samsung box but even without the SKY plugged into the switch or splitter there is no sound from PS3. Its weird... I work in IT and I can't work this dam thing out :(
 

feaviolp

Novice Member
I'd try plugging the PS3 into the other side of the splitter (where Sky currently is) and also, as Cooperman says, switching off Sky at the wall (in fact I'd go one further and unplug Sky from the optical splitter altogether so you just have PS3 into spliter then out and onto the CK.

One question though - is the splitter supposed to work like that? I thought splitters were one in many out rather than many in one out? I guess it ought to work OK as long as only one of the inputs is active at a time, hence the idea to unplug Sky in case optical is always on as suggested.

To answer the other half of your question though - it doesn't sound like there's a problem with the PS3 because it works fine when plugged in directly. So it's sending the optical signal fine - from there on it's just the cables and splitter/switch.

Also - have you taken the switch back to Maplins? Sounds like a faulty one to me...

Finally - I've just checked the manual for your TV and as I suspected it has digital audio out. So why not take the optical output from the TV into the cinema kit? That way whatever you're watching on TV is what you'll be hearing i.e. the TV is doing the switching based upon it's HDMI audio input :smashin:
 

croftyuk

Standard Member
Sorry don't think I've explained myself so good

SKY HD Optical directly into CK - Works ok
PS3 Optical directly into CK - works ok

SKY HD & PS3 Optical X 2 into both splitter and switch - Only SKY HD (which I was calling TV) works

SKY HD Optical only into both splitter and switch - Works ok

PS3 Optical only into both splitter and switch - No sound

So basically the PS3 optical will only work if pulled directly into cinema kit. I guess I will just have to unplug them when I want to swap but still crap. Cheers for replies guys.
 

COOPERMAN

Novice Member
Have you tried swapping optical cables, it could be a faulty cable n the ps3 causing signal degridation when plugged into splitter?
 

croftyuk

Standard Member
Yeap Cooperman we have swapped them with each other and have even bought a bloody expensive one (Well my wife did whilst I was away for the weekend). When plugged into splitter or switch with any of the cables SKY works but PS3 doesn't. It really doesn't add up why it only affects the PS3. :cool:
 

COOPERMAN

Novice Member
Only other thing I can think of is that the PS3 is giving out a weak optical signal. How long have you had the PS3?
Did you buy it local, can you exchange it to see if a new one would have the same problem?
 

dekoded

Novice Member
Could it be some muck or fluff inside the optical 'catflap' door on the PS3?

Maybe just enough to block some of the light but not all?
 

feaviolp

Novice Member
What about my idea above of taking the optical out of the TV instead of Sky and PS3 seperately? No need for cable swapping that way.

So Sky into TV via HDMI
PS3 into TV via HDMI
TV to CK via optical

No good?
 

dekoded

Novice Member
I didn't realise there was so much to an optical cable:

Today the TOSLINK optical interface has reached its sonic performance potential. What changed? There are three factors that draw the line separating mediocrity from excellence: purity of the optical conductor, clarity of the optical termination (lens), and flexibility without signal loss. When each of these parameters is optimized, and the interconnect is used with quality components, the TOSLINK connection is audibly indistinguishable from coaxial S/PDIF.

The optical fiber material itself must be transparent. The quest for this quality is what drove the audio industry to experiment with the AT & T ST connection in the first place. When constructed from very high purity quartz, TOSLINK interconnects can exhibit a very wide bandwidth - 10MHz is not uncommon in practice. Compare this with the performance of a typical plastic conductor fiber optic cable that reaches its limitations at a mere 5MHz to 6MHz. When the signal is multi-channel audio with advanced word-lengths of 24 bits and/or sampling rates over 100KHz, this bandwidth is especially critical. Essentially, any DVD DTS or Dolby EX soundtrack is best served by a wide bandwidth optical digital audio connection

Quality TOSLINK interconnects must also feature a highly polished and properly fitted termination. One metric of proper termination is the numerical aperture. A numerical aperture mismatch occurs when the launching port has a higher NA than the optical cable. Think of this as the light equivalent of proper characteristic impedance. A NA mismatch causes reflections within the TOSLINK port and within the cable assembly. In general terms a smaller numerical aperture on a TOSLINK cable is better than a larger NA.

Refractive index (RI), while important, is not a parameter the consumer can easily define. Refractive index refers to the light conductivity of the core substrate. Air, for instance, has a RI of 1. When two conductors with differing refractive indices are connected within a network, reflections - and the destructive results of those reflections - are possible. Basically, a TOSLINK cable manufactured from a quartz glass will likely have a much closer RI when compared to the source optical module than one made from plastic. Further, TOSLINK interconnects manufactured from quartz typically boast a step index ratio, or stepped refractive distribution. This factor always enables a better mating of the fiber conductor with the optical source.

Quality TOSLINK assemblies should be made from multiple fibers of a very small diameter. Assemblies using fiber diameters greater than 200 micrometers, or single fiber assemblies as seen on many plastic fiber interconnects, will suffer from much greater signal attenuation and reflection than will multi-fiber assemblies. This occurs from bending the conductor. A facet of optical transmission generally unmentioned in product literature is the degradation of performance due to even mild bending of the interconnect assembly!

Two final manufacturing parameters, which are almost never discussed outside of mil-spec requirements, are the need for minimal core and cladding concentricity error. Those specifications, coupled with measurements of core ellipiticity, are true hallmarks of manufacturing quality. In short, the cable's conductive core should be round and remain round. Further, a non-reflective cladding which also needs to maintain a proper geometric relationship to the conductor should surround it. Don't look for these metrics on the packaging at your local hifi emporium, however. Few manufacturers will publish such specifications.

In conclusion, TOSLINK has come a long way since those heady days decades ago when we first discovered the ability to transmit digital audio data on a beam of light. Contemporary manufacturing processes and materials management abilities allow a level of precision and performance that were unattainable just a few short years ago. A good, recent production TOSLINK interconnect boasting a quality quartz glass substrate, step indexed multi-fiber conductors, low numerical aperture and low-loss flexibility will provide faultless transmission of even the most challenging multi-channel digital soundtrack. And best of all, there is no need to attach a battery to the dielectric!


Maybe I should have spent more on mine!
 

croftyuk

Standard Member
Cheers chaps tried everything and will not work, however tried feaviolp idea and it worked!! Not sure why but I never thought of using an optical from my TV to CK.... I'll blame the Sky bloke who told me to connect the HD to CK via optical. :)

The only thing now is if I'm playing music through PS3 then will have to have TV on or if I want to play music but say have sky sports on TV then I can't, but this is better than swapping optical cables all the time, although still puzzled why splitter or switch wont work with PS3.

One thing I had to do at 11pm last night was drill holes in my LCD bracket as optical wouldn't go in as it was in the way!! Oh and after taking the TV off I bent my PS3 HDMI so have had to order another 5m one. But at least it is sorted.... so thanks again chaps for all ya input.
 

feaviolp

Novice Member
Glad you got it sorted mate :smashin:

Sorry - I hadn't factored in your possible need to play music on the PS3 while watching Sky. If the set-up you have now is the best compromise for now though then great :thumbsup:. If you ever get around to upgrading your CK (maybe to a seperate Amp / speakers) just make sure the Amp is also an HDMI switch or has multiple optical inputs. Then you'll get best of both worlds :D. Personaly I have everything running into the AMP via HDMI then HDMI from amp to TV and it gives me any sound / picture combination that I want. Obviously costs though :devil:
 

goldwater666

Novice Member
Sorry to hi-jack this thread, but I thought it was better than starting a new one:rolleyes:

I have 5.1 headphones & an amp which both use optical input.

At the moment I am swapping the optical lead from my PS3 between the two depending on gaming or watching bluray / DVDs (headphones for gaming:smashin:)

If I have understood correctly, a optical splitter will take the 1 output from my PS3 and give me 2 inputs. 1 for headphones, 1 for amp, is that correct??

They will not both be used at the same time, so would the above be a solution to changing the lead over?

thanks for your help:thumbsup:
 
Last edited:

RottenFox

Distinguished Member

StuR6

Novice Member
Cheers chaps tried everything and will not work, however tried feaviolp idea and it worked!! Not sure why but I never thought of using an optical from my TV to CK.... I'll blame the Sky bloke who told me to connect the HD to CK via optical. :)

The only thing now is if I'm playing music through PS3 then will have to have TV on or if I want to play music but say have sky sports on TV then I can't, but this is better than swapping optical cables all the time, although still puzzled why splitter or switch wont work with PS3.

One thing I had to do at 11pm last night was drill holes in my LCD bracket as optical wouldn't go in as it was in the way!! Oh and after taking the TV off I bent my PS3 HDMI so have had to order another 5m one. But at least it is sorted.... so thanks again chaps for all ya input.
Personally I had problems with a splitter too; using it the wrong way like you. I had to totally switch off (at wall) the item I was not using; however, my Amp had 2 inputs, so I left the PS3 to a dedicated one. I would've bought a better CK; ah well (its god boogerall IN slots). Therefore using your current setup, I'd take the Switch back and try another one. Much rather do that, than put my TV on evertime I want tunes.

As for the optical cable, wow, big topic. In brief, get the connectors made well and the cable should work fine; therefore a part-cheap one will do, try this shop using the Super or Pro. What does matter, after a decent connector is length - keep it short and kink free. Also, yes, ends must be clean.

Bump!- any help on this guys??

thanks
Your headphones can process/amplify the sound them selves? Do show...
 

goldwater666

Novice Member
Your headphones can process/amplify the sound them selves? Do show...[/QUOTE]

Sharkoon X-tatic v3's....from here

Not the most expensive or the best quality, but they do what it says on the tin - optical input from PS3, 5.1, with comms:smashin:
 

feaviolp

Novice Member
The problem with this set up (if I am correct is) that you won't be getting dolby digital/surround sound. I have had similar problems with my switcher and the above suggested set up works but my amp is only displaying an analogue audio signal. I assume that this is because the HDMI cable going from the PS3 and the SKY HD box is only capable of carrying an analogue audio signal to the TV (I would be delighte to be proved wrong !)

P.S. I think the problem is that the switchers are crap quality and that is what causes the problem
Yeah I think you're right. I made this suggestion on another thread too and someone confirmed that on their TV it was doing exactly as you said - outputting 2 channels from the TV. I had (incorrectly) assumed that it would effectively pass-through the signal so DD in would be DD out. I think this may still be the case in some TV models, but it seems most (and possibly all) will only output stereo.

It's not because the HDMI cable is carrying analogue sound though. HDMI carries the best possible sound; it's capable of HD audio, where optical is not. The problem is that the TV is only stereo so that's what it outputs. I.e. it gets DD (or whatever) from the HDMI fine but then converts that to stereo before sending it on via the optical cable.

Bit of a pain really :thumbsdow
 

feaviolp

Novice Member
Yes that sounds right mate, to be honest your solution is still better than the snap crackle and pop (and silence) that I great through the switcher! I think I need to buy a surround sound system with multiple optical inputs! If there is such a beast.
If you're looking to buy a new surround sound system I'd personally recommend HDMI inputs rather than multiple optical :smashin:
 

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