I knew the Onkyo 875 ran hot but dang !

[Harrison476]

I have been very happy with the Sr875. The performance of the sr875 has really impressed me. But last night I was fooling around in the back of my system and was shocked how hot the receiver was. The heat seems to be in the back –left portion of the receiver. Does anyone know how the components of a receiver will be affected by this high temperature and can you predict the service life with this elevated temperature?
I should measure the actual heat . I can do this accurately since I have a digital temperature indicator traceable to NBS. I am concerned what effect this elevated temperature will have on the service life.

 

[lsiberian]

I have been very happy with the Sr875. The performance of the sr875 has really impressed me. But last night I was fooling around in the back of my system and was shocked how hot the receiver was. The heat seems to be in the back –left portion of the receiver. Does anyone know how the components of a receiver will be affected by this high temperature and can you predict the service life with this elevated temperature?
I should measure the actual heat . I can do this accurately since I have a digital temperature indicator traceable to NBS. I am concerned what effect this elevated temperature will have on the service life.

Get a fan and put it on the left rear part of the vent. It helps a lot.

 

[CraigV]

Un-plug your stove & stop your whining

 

[bigred7078]

yeah definately good advice from Isiberian. Put a couple of low db computer fans back there and it should help.

Thats one of my gripes with Onkyo, sooo freakin hot lol. Otherwise great product with excellent feature sets!

Also what kind of speakers do you have? Are the inefficient to drive anf have a low impedence? Or at least take real low dips? Because if its extra hot, its probably because its having a tough time driving the load of the speakers. If worst comes to worst you can always pick up an inexpensive amp off audiogon or buy new from Emotiva.

-Steve

 

[Davemcc]

It's usually the Reon chip that tends to run hot. Are you running the upconverting function, outputting in 1080p? You may be able to control the heat by running the VP in pass through and letting the display scale the image.

I'm not sure where the VP is on the 875. On my unit, it's on the back right corner (when looking at it from the front). The VP should have a vent directly above it. If you can look into the vent, you should be able to see the chip marked Reon in the cabinet. There is also a way to have the temperature displayed on the front panel. I'll try to find the process specific to the 875.

Edit - Try this procedure. "Press and hold the display button on the amp for 2 seconds then press the standby button whilst keeping the display button pressed then release both and quickly press the tone button on the amp, the temps should now be shown."

 

[Harrison476]

Giveme speed-dont need no Leather seats

Hey Craigv fry eggs??? I could grill a couple of T-Bones with outside done and middle red (rare) in less than 5mins .

Dave-Thats good point about the reon I use it when I don’t need it. I am going to try the temperature reading thing this afternoon when I get home great info, thanks.

Big Red – I push that amp in every way. I’ve got 4 ohm speakers; I run it on 8 ohm setting. I wanted the Emotiva amp but Craigv convinced me I need to work with my room, that I don’t need the extra power.

Here’s the thing. I almost pulled the trigger on a new set of fronts yesterday( mainly for music listening) So If I put the money out for new SongTowers then have to turn around in a rather short period an replace my fried amp . I maybe listening to my boom box.

 

[jostenmeat]

It's usually the Reon chip that tends to run hot. Are you running the upconverting function, outputting in 1080p? You may be able to control the heat by running the VP in pass through and letting the display scale the image.

Dave, the VP on the Onkyo line does run hot. However, it's really the amp section that gets very hot. You might not know, since you use a pre/pro. The heat difference between running 4 ohm and 6 ohm setting is VERY substantial. Once at 4 ohm setting, the VP section is indeed the warmest on top, but this little hotspot is nothing compared to what the amp section is producing.

I'm not sure where the VP is on the 875. On my unit, it's on the back right corner (when looking at it from the front). The VP should have a vent directly above it. If you can look into the vent, you should be able to see the chip marked Reon in the cabinet. There is also a way to have the temperature displayed on the front panel. I'll try to find the process specific to the 875.

It should be on the back right for the OP as well. After all, I think the 875 might be based on the same platform as the Integra pre/pros. And, to boot, my 805 has the same location.

Edit - Try this procedure. "Press and hold the display button on the amp for 2 seconds then press the standby button whilst keeping the display button pressed then release both and quickly press the tone button on the amp, the temps should now be shown."

Harrison, here's a thread I started a while back, and you can see what others might have got as well.

Onkyo Temperature Monitor

 

[MatthewB.]

Actually with the Onkyo 805 and 885 the back right portion generates the most heat, this is where the three video processing chips are stacked one on top of each other. They actually run hotter than the amp section. I bought a computer fan and placed it on the back right corner and after hours o use, my reciever is pretty cool to the touch (even over the amp section which has no fan over it.

 

[jostenmeat]

Actually with the Onkyo 805 and 885 the back right portion generates the most heat, this is where the three video processing chips are stacked one on top of each other. They actually run hotter than the amp section. I bought a computer fan and placed it on the back right corner and after hours o use, my reciever is pretty cool to the touch (even over the amp section which has no fan over it.

I've see this said, a lot.

Have you tried the 4 ohm setting? Curious.

These are a couple of my exasperated posts in the AVS 805 thread.

http://www.avsforum.com/avs-vb/showpost.php?p=16182963&postcount=18970

http://www.avsforum.com/avs-vb/showpost.php?p=16184380&postcount=18975

 

[MatthewB.]

No, I havent tried the 4 ohm setting. I read that with most speakers that this isn't recommended, so I just leave it at 6 ohms and use the fan.

 

[PENG]

They actually run hotter than the amp section.

That may be true for you but he said he pushed his 4 ohms speakers hard so I bet in his case the amp section runs hotter unless he uses the 4 ohm setting to limit the amps output.

 

[Lordoftherings]

1. Put a dual-fan (4") on the top rear right corner (from the front), and connect it to the A/C inlet on the rear of your 875.

2. If your speakers are 4ohm loads, set your 875 for 4ohm loads.
If not, leave it at the default position of 6ohms (page 45 of your manual).

3. To help reduce power consumption while on Standby, disable the "Control", "Power Control" and "TV Control", from the Advanced Setup features (page 99 & 100 of your manual).

4. For better performance in the video output, turn the "Immediate Display" OFF (page 97 of your manual).

5. You can also disable the "Lip Sync" and "xvYCC" features from the Advanced Setup (page 99 of your manual).

6. Leave at least 4 inches (6" preferably) in top of your 875 for proper ventilation, and leave the front and the rear of your 875 on the open (not closed in cabinet).

7. Put your 875 on the very bottom of your rack.

8. Listen to Music & Movies at reasonable volume levels (not defeaning levels).

9. Turn down the heat during the winter in your home theater room, and use your 875 as the one that take care of warming your room. You'll save money in your electrical bill during winter.

10. It's true that the 875 (and 805, 905, 876 & 906) runs hot, but it is normal in their operation, because they have huge power supplies and they just don't have the space to have more heat sinks. Many separate amplifiers and other receivers, like some Denon and Yamaha models, also run hot.

* The 875 is a great receiver, enjoy it.

Bob

 

[Sounds Good]

what else do you have in your cabinet ? refer to my post here... http://forums.audioholics.com/forums/showthread.php?p=558437#post558437


i get around 120 F on the top back left corner of my 876...

 

[Swerd]

Here’s the thing. I almost pulled the trigger on a new set of fronts yesterday( mainly for music listening) So If I put the money out for new SongTowers then have to turn around in a rather short period an replace my fried amp . I maybe listening to my boom box.

Hey that's great to hear that you're close to ordering the SongTowers . They are rated at 4 ohms, but they are an easy load. There is an impedance curve shown for them in this review, they go no lower than 4 ohms. What speakers are you using now with the Onkyo receiver? Some speakers that are rated at 4 ohms, may go quite a bit lower at some frequency, usually in the midbass.

A lot of useful points were made by others about using the Onkyo without always running those various video features that seem to be such a heat source. That may help you a lot.

Is your receiver in an enclosed cabinet? I opened up some large holes in the back of my cabinet that greatly improved passive ventilation without adding a fan. Most cabinet backs are thin masonite or cheap pressboard. They may already have some small openings for wires. With a jigsaw, I cut out a large rectangular area so that my receiver is essentially fully exposed in the back. It also made wiring much easier. I have keep a ceiling fan running all the time. The fan combined with the enlarged rear cabinet opening made the difference.

 

[Davemcc]

I finally got a chance to hear the Songtowers in action. Great speaker for the money but I would strongly suggest to upgrade to the ribbon tweeter. It makes a huge difference in the quality of the treble, like night and day.

 

[MatthewB.]

I just use the dual computer fan I bought online (it pushes cool air down and hot air up) and on the other side I have a simple 4" Wally word clip fan that blows across the top. After having the system on all day yesterday (hey my dsl line went dead when my neighbor clipped the phone line while digging a ditch - moron) anyway nothing to do but watch TV and after 6 hours with both fans running, my 805 ran very very cool to the touch. So I can't complain. Although both fans running does make some noise in my open all round rack, nothing that I can't live with.

 

[Birdman84]

I have been very happy with the Sr875. The performance of the sr875 has really impressed me. But last night I was fooling around in the back of my system and was shocked how hot the receiver was. The heat seems to be in the back –left portion of the receiver. Does anyone know how the components of a receiver will be affected by this high temperature and can you predict the service life with this elevated temperature?
I should measure the actual heat . I can do this accurately since I have a digital temperature indicator traceable to NBS. I am concerned what effect this elevated temperature will have on the service life.

I just bought the SC885P pre/pro and for something that does not have an amp in it, it runs real hot it even runs hotter then my AT1505 AMP if I am not really kicking it. I always left a good but of room around my TS777 because of the heat but since 2000 I had had no problems from it. IF the Pre/Pro is as good i Will have no complaints

 

[Lordoftherings]

I just bought the SC885P pre/pro and for something that does not have an amp in it, it runs real hot it even runs hotter then my AT1505 AMP if I am not really kicking it. I always left a good but of room around my TS777 because of the heat but since 2000 I had had no problems from it. IF the Pre/Pro is as good i Will have no complaints

Yep, the HQV Reon VX video processor does run hot indeed inside your nice Onkyo PR-SC885P Surround Processor.

To help, disable the "Control", the "Power Control" and the "TV Control" from the advanced menu setup.

And for a better picture, turn the "Immediate Display" off.

Your 885 is one of the very best deal in audio, it is that good.
And you can always use a small fan too on top of the hot spot.

Cheers,

Bob