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**Offical** Yamaha RX-V665 AV Receiver thread - Page 13

post #361 of 1926
I would have to imagine that at least one of the HDMI inputs can be used with a non-HDMI audio stream. But, indeed, the way they stripped out what is really basic functionality (assignable inputs) is pretty disappointing.
post #362 of 1926
With a pre-out voltage of 1.0v, could it be used with an external amp with 29db gain structure and and input sensitivity of 1.6v? Not sure of the math but it looks like it would cut the amp output by almost half??

Another thing I have noticed in all of these recievers with pre-outs. Few if any have pre-outs with a high enough output to effectively drive a high wattage amp. Onkyo, Sony, Yahama all put out a paltry 1.0V. Seems like the sweet spot is around a 100watts.
post #363 of 1926
Well so far, no luck. I went through the manual 5 times and still cannot get audio to the receiver and into the headphones. I am pretty disappointed. I was really looking forward to trying out the silent cinema but it does not look like it is going to happen. Thanks all for the help. The return is not going to be a fun process.
post #364 of 1926
Quote:
Originally Posted by infoman1 View Post

With a pre-out voltage of 1.0v, could it be used with an external amp with 29db gain structure and and input sensitivity of 1.6v? Not sure of the math but it looks like it would cut the amp output by almost half??

Another thing I have noticed in all of these recievers with pre-outs. Few if any have pre-outs with a high enough output to effectively drive a high wattage amp. Onkyo, Sony, Yahama all put out a paltry 1.0V. Seems like the sweet spot is around a 100watts.

It would definitely limit your amplifier output. Power is related to the square of the output voltage. 1.6 volts would produce approx 2.6 times the power that 1v produces.

So if the amp puts out about 250 watts into 8 ohms ( I assume given that gain,) you only get 100 watts with an input voltage of 1v.

As for many receivers having a low pre amp voltage, Gene over at Audioholics has mentioned that before.

By my calculations, you need a 32 dB gain to hit 200 watts into 8 ohms with 1v of input.

With a gain of 31 dB, you need 1.1 volts.

With a gain of 30 dB, you need 1.3 volts

If you want the math, these are your stock formulas -

Voltage gain given dB gain -
[(dB gain) / 20] raised to the 10th power

Necessary voltage for x watts of output into 8 ohms -
sqrt(x * 8)

Given your needed voltage gain to hit your amp's rated power, and given the gain given in the amp's specs, you can calculate input sensitivity, or the voltage need to drive the amp to full power -

(input voltage needed for full power) / (voltage gain)
post #365 of 1926
Quote:
Originally Posted by batpig View Post

I would have to imagine that at least one of the HDMI inputs can be used with a non-HDMI audio stream. But, indeed, the way they stripped out what is really basic functionality (assignable inputs) is pretty disappointing.

I really can't understand why Yamaha dropped such basic functionality, because we've already seen several common cases that need it. Denon would clean up at the low end this year if only they had pre-outs. I don't think that many people ever use the pre-outs, but they want them "just in case".
post #366 of 1926
Quote:
Originally Posted by rdgrimes View Post

The 665 has a volume range from -40 or so to +15 or so. Your previous AVR probably had a different range. -28 is actually pretty soft, I'd be running it closer to -15 to -20.

I just checked and mine goes down to -80.
post #367 of 1926
Quote:
Originally Posted by MichaelJHuman View Post

It would definitely limit your amplifier output. Power is related to the square of the output voltage. 1.6 volts would produce approx 2.6 times the power that 1v produces.

So if the amp puts out about 250 watts into 8 ohms ( I assume given that gain,) you only get 100 watts with an input voltage of 1v.

As for many receivers having a low pre amp voltage, Gene over at Audioholics has mentioned that before.

By my calculations, you need a 32 dB gain to hit 200 watts into 8 ohms with 1v of input.

With a gain of 31 dB, you need 1.1 volts.

With a gain of 30 dB, you need 1.3 volts

If you want the math, these are your stock formulas -

Voltage gain given dB gain -
[(dB gain) / 20] raised to the 10th power

Necessary voltage for x watts of output into 8 ohms -
sqrt(x * 8)

Given your needed voltage gain to hit your amp's rated power, and given the gain given in the amp's specs, you can calculate input sensitivity, or the voltage need to drive the amp to full power -

(input voltage needed for full power) / (voltage gain)

I've been reading that Wyred 4 Sound amps have an input stage that raises input impedance to 60.4k Ohms. PS Audio has an input stage of 50k Ohms. They both say that this allows their amps to be easily driven by virtually any pre-amp, even with low output voltage.
I don't understand any of this. Does it make sense to you?
post #368 of 1926
The line input model is to use an output with low impedance into an input with high impedance.

My understanding is that you want a high input impedance to minimize current flow. In this way, all the amp cares about is voltage.

50k vs 60k does not sound like a big difference.

It's the gain / input sensitivity you are interested in. You can't figure out gain by knowing input sensitivity. That's determined by the design of the various amp stages in the amp. I think there's usually an input stage, a driver stage and a final power stage. Depending on the design of those circuits, you will get a certain gain. Transistors in those stages amplify a signal to a higher level. There's a number of transistors in the signal path which do that. Input sensitivity only tells you about the input stage, far as I know.
post #369 of 1926
when watching bluray that supports all the hd audio decoders how do you know you are listening to them i have my bd player hooked up with a 1.3 hdmi cable straight to the reciever and then out to my tv with hdmi also. i was told to change my setup on my bd player to pcm or bitstream did both and still have no idea if i am getting the hd sound it will either say pcm on my reciever display or when i hit surround dec. on my remote it will just say straight just curious as to how you are supposed to know if you are listening to hd audio or not. also i have my room setup in 7.1 so i have the extended surround set to dd plIIx so it is in 7.1 all the time.
post #370 of 1926
Quote:
Originally Posted by Scadden24 View Post

when watching bluray that supports all the hd audio decoders how do you know you are listening to them i have my bd player hooked up with a 1.3 hdmi cable straight to the reciever and then out to my tv with hdmi also. i was told to change my setup on my bd player to pcm or bitstream did both and still have no idea if i am getting the hd sound it will either say pcm on my reciever display or when i hit surround dec. on my remote it will just say straight just curious as to how you are supposed to know if you are listening to hd audio or not. also i have my room setup in 7.1 so i have the extended surround set to dd plIIx so it is in 7.1 all the time.

The exact codec is displayed on the amp's front panel. you can also see info in the "signal info" option of the OSD.
post #371 of 1926
so are you saying that it is supposed to say that is it using lets say dts-hd when it is? cause i have never seen that and have been through the setup and manual a million times it just says straight when i hit the surr. decode button on the remote and when i hit info button on the remote it just says pcm if i have it set to pcm on my bluray player or if i have it on bitstream it will say dts but never said any of the hd codecs.

thanks
shane
post #372 of 1926
Quote:
Originally Posted by Scadden24 View Post

so are you saying that it is supposed to say that is it using lets say dts-hd when it is? cause i have never seen that and have been through the setup and manual a million times it just says straight when i hit the surr. decode button on the remote and when i hit info button on the remote it just says pcm if i have it set to pcm on my bluray player or if i have it on bitstream it will say dts but never said any of the hd codecs.

thanks
shane

Consult the 65 manual for the layout of the front display.

Does your player bitstream the HD codecs? Many do not. It may be sending the DTS core instead. The "signal info" function in the OSD will state exactly what the player is sending.
post #373 of 1926
Quote:
Originally Posted by MichaelJHuman View Post

The line input model is to use an output with low impedance into an input with high impedance.

My understanding is that you want a high input impedance to minimize current flow. In this way, all the amp cares about is voltage.

50k vs 60k does not sound like a big difference.

It's the gain / input sensitivity you are interested in. You can't figure out gain by knowing input sensitivity. That's determined by the design of the various amp stages in the amp. I think there's usually an input stage, a driver stage and a final power stage. Depending on the design of those circuits, you will get a certain gain. Transistors in those stages amplify a signal to a higher level. There's a number of transistors in the signal path which do that. Input sensitivity only tells you about the input stage, far as I know.

No, what I was trying to point out was that both of these are much higher than the normal amp which may only be something like 8k or possibly even less. So both the PS Audio and the Wyred 4 Sound amps would be much easier to drive than many other amps.
post #374 of 1926
it said it decodes dolby digital true hd but not dts hd so should i set it to pcm then and let my reciever decode it then? i am sorry if i sound like an idiot this is my first reciever.
post #375 of 1926
Quote:
Originally Posted by Scadden24 View Post

it said it decodes dolby digital true hd but not dts hd so should i set it to pcm then and let my reciever decode it then? i am sorry if i sound like an idiot this is my first reciever.

Yes, I believe if you set it to PCM you should be all set.
post #376 of 1926
what does it mean when it says straight all the time when i hit the surrond decode button on the remote?

p.s. this forum is very helpful

thanks
post #377 of 1926
Can anyone make a recommendation of a reciever product with a higher pre-amp output?
This certainly presents a limitation when trying to drive most any external higher powered amp. Seems like they just put a set of additional jacks on the back panel for sake of having them. It would seem it's a useless cosmetic feature at best. I suppose with that said, the pre-amp sections are most likely designed and paired with there own internal amps, and I believe there in lies the problem. My research shows this isn't even a quoted spec. on a good many of these products, including high end pre/pros.
post #378 of 1926
Quote:
Originally Posted by Scadden24 View Post

what does it mean when it says straight all the time when i hit the surrond decode button on the remote?

p.s. this forum is very helpful

thanks

Straight means the receiver uses the most obvious mode. If it's receiving Dolby Digital, it will decode it, etc. It should apply it's normal YPAO processing to incoming audio.

Straight is different than direct, see the manual.
post #379 of 1926
Quote:
Originally Posted by bsavitz View Post

No, what I was trying to point out was that both of these are much higher than the normal amp which may only be something like 8k or possibly even less. So both the PS Audio and the Wyred 4 Sound amps would be much easier to drive than many other amps.

Well, I don't know. In my mind, and I could be wrong, input impedance tells you nothing.

You are mainly interested in input sensitivity as that will tell you how much ouput voltage you need to drive the amp to full power. Input impedance does not tell you this information, so I don't know what use it is to know. If the input impedance was too low, I imagine it could create an issue if the input signal did not have enough current.

Maybe someone else has more information on this topic than I do.
post #380 of 1926
Quote:
Originally Posted by Scadden24 View Post

so are you saying that it is supposed to say that is it using lets say dts-hd when it is? cause i have never seen that and have been through the setup and manual a million times it just says straight when i hit the surr. decode button on the remote and when i hit info button on the remote it just says pcm if i have it set to pcm on my bluray player or if i have it on bitstream it will say dts but never said any of the hd codecs.

thanks
shane

Shane,
On the remote there is a "INFO" button...Use this button to show on the OSD what codac is being decoded. Here is a picture to show you....


http://i41.photobucket.com/albums/e2...s/DSC04103.jpg
post #381 of 1926
that is what i am frustrated about i hit the info button on the remote and i never ever see that and it is pissin me off... i checked the bd player i have it is a samsung bd1500 and it decodes some of the hd codecs but not all so i set it to pcm to let the yamaha decode it am i right by doing so? all my reciever ever says is pcm or dolby digital which is because that is what my directv hddvr is set to. so should my reciever say pcm because i have my bd player set to pcm? also my bd player has the option for pcm, bitstream (re-encode), or bitstream(audiophile) should i be trying one of the bitstreams instead? i have read the manual like a million times with no help. i am just frustrated as to why i never see any of the hd codecs when i hit info.
post #382 of 1926
Quote:
Originally Posted by Scadden24 View Post

... i checked the bd player i have it is a samsung bd1500 and it decodes some of the hd codecs but not all so i set it to pcm to let the yamaha decode it am i right by doing so?

No, you have it backwards. To see the codec displayed on the Yamaha you need the BD player to bitstream.
post #383 of 1926
ok so i set it to bitstream audiophile and it works awesome lets just say rambo in 7.1 is crazy and the display is showing the hd codecs now thanks everyone sorry to be a pain in the ass but i went alittle beyond my budget for the sound system i got and now i feel great about it.
post #384 of 1926
Hey all, I am about to pull the trigger on a 665 for 350.00 shipped....I am upgrading from a HTR5650.....still works great but I really need the HDMI switching features plus the other goodies it has to offer.

I have read the whole forum that many are please with the 665 and some not so happy. I use mine mainly for movies I am using a pair of Paradigm studio 9's on the front with a matched paradigm center and small polk audios in the rear.

I will be inputting a ps3, directv HD DVR, a Sony Blu-Ray & a WII on to a 42' olevia LCD (i know not the best TV but got it DIRT cheap (new fireware will fix WII issue thankfully)

any one care to talk me into pulling the trigger....or even talk me out of it? LOL
post #385 of 1926
It also works in the reverse using PCM, but in that case the BDP1600 on board decoders are decoding the signal and passing in PCM. This is recommended in the manual as in other modes you lose the secondary audio tracks, commentary, etc. Bitstream ReEncode converts the signal to DTS. Not sure of the caveats with that. Its just as easy to let the decoder in the reciever do the decoding since it's likely of better quality anyway.
post #386 of 1926
It really does an outstanding job and for $350.00 you can't go wrong. Power is a little anemic but thats subjective and more than enough for most applications. Make sure you check the version of firmware upon its arrival. There is an update that is pretty easy to aply. J30 I think it is.
post #387 of 1926
Can the 665 do 7.1 plus presence ?
post #388 of 1926
Quote:
Originally Posted by kulims View Post

Can the 665 do 7.1 plus presence ?

No
post #389 of 1926
After working on this problem I had, I finally got the audio part working.

Now I have one last issue.

I have an Xbox 360 and I would like my receiver to take the HDMI video and send it to my LCD monitor like it is supposed to. Except that no video data is showing up. It works very well with my PS3 but not my Xbox 360. I have tried using the HDMI cable from my PS3 and using it for the Xbox and it still does not show the data. I am wondering, is there a way I can reset the video settings on the Xbox 360? Do I need a 1.3a HDMI cable possibly? Does it need a firmware update? I have no idea how to do that update since I have never done it before. Thanks for the help.

Well, I blindly tried to go into my display settings of my xbox 360 to see which HDTV resolution would work. When I selected 480P I got video. So it looks like only 480p works. All of the other option are grayed out. It is so strange, I have had an HDMI splitter and had no problems using that but the receiver won't output anymore than 480p. If I select optimal resoltuion on the xbox menu it will go back to blank. I have also tried to reset the video settings and that still did not work. My monitor is an LCD Samsung SyncMaster 225BW 22". What is going on?
post #390 of 1926
It sounds like your syncmaster doesn't have HDCP the copy protection for HDMI. Many monitors don't as most computers may not have it either. If it is not HDCP compliant then it won't show resolutions above 480P. Some devices like many computers don't use HDCP and it will work fine with those. I'm not sure on the PS3, I think it only needs it for Blu-ray but not games. Check to see if a Blu-ray disc reduces its output to 480P.

Bob
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