Onkyo 805 and 875

[20Glove]

Ok, all of the reviews on the Onkyo 805 or 875 is that they sound great... look great but run VERY HOT.

I am wondering if it running hot means that the system is working too hard and if that means listening time should be less? I usually listen to music or watch tv at a -30 to -20 Db for about 4-5 hours at a time. Watch a DVD at -18 to -12 Db for about 2-3 hours depending on length of the movie.

Also, if the system is running hot, does that mean that the system will not last as long over the years?

Is the $500 price difference worth it? I mean it looks like the 1080P upscaling with REON Processing and 10 extra watts per channel is the only thing that is different.

 

[MDS]

Very hot compared to what? The more powerful the receiver the hotter it will run and the more ventilation it requires. That is a fact and will be the same for all receivers in the same class.

If you read the manual for the 805/875 it recommends that you have 4" clearance on each side and at the rear and 8" on top to allow adequate airflow. How many people have racks that can accomodate that kind of spacing? If it can't breathe adequately, it will get hot.

 

[20Glove]

I will be putting it on top of the audio rack

I will be putting the Receiver on the very top of the rack, wide open all the ventilation it can get. So are you saying that I do not have to worry about the heat?

People that were comparing the heat were comparing it to other onkyo 800 series and a lot of them were comparing it to the Denon 3800 series (alot to the Denon 3805).

Also, between the 875 and the 805, does anyone think the extra $500 is worth spending as it looks like you only get 10 extra watts per channel and the REON Processing of 1080P upscaling.

Let me know.

Thanks!

 

[MDS]

I'm saying a certain amount of heat is to be expected with a powerful receiver. It may be hotter than others but not hot in an absolute sense that would indicate a defect. I see this particular criticism a lot but I have never had any Onkyo receiver that I would classify as too hot.

I don't think $500 extra is worth it for the 875 vs the 805 but then again what is it about the 805 that appeals to you? The 7xx series is and has always been the sweet spot in the Onkyo lineup where you get the most bang for the buck.

 

[Thunder18]

One thing regarding the heat these unit create...I've seen a few threads on other forums indicating that if you disable the RIHD which is the function that enables the receiver to turn on certain similarly equipped TV's via the HDMI connection, the unit will run cooler. I believe I read one guy measured something close to 100 watts power draw at standby with this feature enabled! Disabling it not only reduced power draw, but also caused the unit to cool down much faster when turned off because it didn't have to be ready to turn another component on all the time.

 

[Seth=L]

The TX-SR805 doesn't get excessively hot if properly ventilated. The Circuit City in town has theirs on all day at moderate levels and it remains relatively cool.

Out of all the receivers you have looked at in the $1000 and up range the TX-SR805 is the most logical purchase IMO. It has the features, power, and good price to be an outstanding deal (can be had for around $900). I would not pay $500 more for the Reon and certainly not for the extra 10 watts printed on paper. Even if it does have 10 more watts per channel you will never know they are there.

My pick for this year is the Onkyo TX-SR805 as the best value receiver around the $1000 price range.

 

[20Glove]

Choose 705 over 805...

I looked at both models. I thought the 805 was a GREAT buy. It appeared to have better stereo quality sound with the high end Burr Brown DAC's, THX Ultra 2 (805) versus THX Select (705) which from my understanding is better for medium to big rooms, The 1080i upcovert (805) versus 480P upconvert (705), and the 30 watts per channel so the receiver can be listened too at lower volumes and work less. I thought these options were definately a positive and worth the extra $200.00.

The build quality between the 2 appeared to be night and day. 805 is a beast and 705 is kinda flimsy in comparison.

But cannot see justifying the 805 to 875. I mean $500 is a lot of money for extra HDMI input, REON processing chip, and 10 watts per channel.

 

[Seth=L]

Sounds like you have pretty much narrowed it down from your listening tests and comparisons. If you have any more questions feel free to ask.

 

[20Glove]

Heat

Seth,

I have seen this receiver in 3 different stores...

My circuit city does not have the receiver hooked up to anything but is plugged in to a wall outlet for power, and is on all day and it was relatively cool. But it is not running anything but the power supply.

Another store I went to that had it... they were running a movie with it.. and it was burning up... it was in a pretty crowded AV case though.

But the last store had it... and it was not being used at the time I came in but was on Standby and it was very cool. Then we sat down and watched about 10 minutes of a movie... then listened to about 10 minutes of music... then about 5 minutes of Sirrius... and it was on the top of the rack wide open with endless ventilation... and that thing was Burning up.... I compared it to a Yamaha... just as hot... and then to a Sony 3200es pretty cool... then to a Pioneer VSX-82TXS and that was in the middle heat wise between the Sony and Yamaha and Onkyo.

The salesmen said it was pretty normal for receivers that big and within or over the $1000 price range to be hot to the touch. He said Sony was more out of the ordinary then the rest. He said he used to sell Rotel and Acram and they ran even hotter than the Onkyo.. but i thought he was being a salesman!

Thanks!

 

[20Glove]

Seth another question...

Is an extra $500 for the Denon 3808 with the same amount of Watts... but you get the Gui Interface, the Ethernet for streaming music, which if easy to hook up would be a GREAT benefit, the 1080P upconvert, and the DDSC, which is the sound enhancing chip in the Denon worth that extra $500?

And I guess... is the Denon worth the extra $500 for piece of mind that it is a DENON product and not an Onkyo product?

Let me know.

I guess I am down to the 805 versus the 3808 again!

thanks!

 

[Seth=L]

Seth,

I have seen this receiver in 3 different stores...

My circuit city does not have the receiver hooked up to anything but is plugged in to a wall outlet for power, and is on all day and it was relatively cool. But it is not running anything but the power supply.

Another store I went to that had it... they were running a movie with it.. and it was burning up... it was in a pretty crowded AV case though.

But the last store had it... and it was not being used at the time I came in but was on Standby and it was very cool. Then we sat down and watched about 10 minutes of a movie... then listened to about 10 minutes of music... then about 5 minutes of Sirrius... and it was on the top of the rack wide open with endless ventilation... and that thing was Burning up.... I compared it to a Yamaha... just as hot... and then to a Sony 3200es pretty cool... then to a Pioneer VSX-82TXS and that was in the middle heat wise between the Sony and Yamaha and Onkyo.

The salesmen said it was pretty normal for receivers that big and within or over the $1000 price range to be hot to the touch. He said Sony was more out of the ordinary then the rest. He said he used to sell Rotel and Acram and they ran even hotter than the Onkyo.. but i thought he was being a salesman!

Thanks!

The Sony uses a Hybrid Class D amplifier and is more efficient (dissipates less heat more is retained as useful energy. The Pioneer uses Mosfets, and are more efficient than standard transistors, but not as efficient as the class D configuration as a whole. Having more efficiency has its pitfalls, the Sony doesn't have the headroom of a good Class B or Class A/B.

 

[Seth=L]

Is an extra $500 for the Denon 3808 with the same amount of Watts... but you get the Gui Interface, the Ethernet for streaming music, which if easy to hook up would be a GREAT benefit, the 1080P upconvert, and the DDSC, which is the sound enhancing chip in the Denon worth that extra $500?

And I guess... is the Denon worth the extra $500 for piece of mind that it is a DENON product and not an Onkyo product?

Let me know.

I guess I am down to the 805 versus the 3808 again!

thanks!

Piece of mind that it is a Denon and not an Onkyo?

As I have mentioned on another thread, the Denon does not have the same beef that the Onkyo has (15 pounds less beef). I doubt the power ratings on each receiver are going to me matching.

Other than that the rest would be for you to evaluate. I don't know how much you want those extra features, something only you can decide.

 

[20Glove]

So if I go with the 805....

If I decide to go with the 805... should I run it less than I normally do... I have been running my Denon 3805 for almost 7 hours straight now watching TV through it with digital optical cable and dolby surround at -35Db.

What do you think? Is there amount of time I should be aware of to not harm the receiver?

Thanks!

 

[20Glove]

Power Rating?

ok, here is where my idiotness comes out...

If the power rating on the ONKYO is better than the DENON would that mean that the ONKYO is going to work less or sound better or both?

Like I said... looking for good surround sound and equal sound quality in stereo when listening to CD's and equal sound when listening to SACD's and DVD-A.

Let me know..

You have been really helpful.. thanks so much for this!

 

[Adam]

If I decide to go with the 805... should I run it less than I normally do... I have been running my Denon 3805 for almost 7 hours straight now watching TV through it with digital optical cable and dolby surround at -35Db.

What do you think? Is there amount of time I should be aware of to not harm the receiver?

Thanks!

I would less worried about harming the receiver and more worried about harming your eyes (and brain). Seven hours? Turn it off, man, turn it off!

The receivers with which I'm familiar will set 0dB on the volume knob as a reference point, which is 70dB of output on my Pioneer. With that assumption, then you'd probably end up setting the new receiver at the same volume level (i.e. -35dB) to get the same volume our of your speakers.

I sure wouldn't be worried about running a Denon 3805 for seven hours at -35dB. That shouldn't hurt a thing...again, except for maybe you.

 

[Seth=L]

Funny thing about amplifiers is this, no matter what the amp is doing it is going to produce heat from somewhere. If the Onkyo is being lightly driven or not driven at all the power supply gets extremely hot. In the 805 the power transformer is in the front in the middle, so that area will be hot when the receiver isn't outputting much. Larger transformers tend to get hotter than small ones, so that could account for a large amount of the heat (My JVC RX-DP9's transformer is about the same size as the Onkyo's and it is pretty hot most of the time, but I don't worry about it.) When being driven harder the heat is mostly coming from the heatsink with the high output transistors on it. This actually gives the power supply a bit of a break, it gets to send its stored energy somewhere to be used and gets circulation.

 

[LA_Hoosier]

Question about RIHD

One thing regarding the heat these unit create...I've seen a few threads on other forums indicating that if you disable the RIHD which is the function that enables the receiver to turn on certain similarly equipped TV's via the HDMI connection, the unit will run cooler. I believe I read one guy measured something close to 100 watts power draw at standby with this feature enabled! Disabling it not only reduced power draw, but also caused the unit to cool down much faster when turned off because it didn't have to be ready to turn another component on all the time.

Does this also apply to the Onkyo 705???

 

[Thunder18]

Does this also apply to the Onkyo 705???

I'm afraid I don't know the answer to that, but if you don't have a TV compatible with the RIHD feature, it may be worth it to turn that feature off anyway. I can't imagine that it works any differently between the two models though.

 

[MDS]

RIHD is the latest incarnation of an Onkyo feature called RI (Remote Interactive). The difference is that now it works over HDMI whereas the original RI required analog audio connections (even if you use digital audio connections).

All it does is provide convenience features like turning on the receiver and changing to the DVD input when the DVD player is turned on or you press play on the player. It also will turn off the receiver if a connected device is turned off. It's an ok feature that can come in handy in some circumstances but is totally mitigated if you have a universal remote with macros.

If the RIHD is the cause of the increased power consumption and hence heat, you won't be missing anything by turning it off.

 

[Thunder18]

Thanks for explaining what that is MDS. The bottom line is that even now, the RIHD function is only known to function with a few newer models of Toshiba and Panasonic HDTVs that have a similiar, but differently named feature that allows them to be activated via the HDMI signal of a connected component.