Post your Onkyo 875/905 temperatures

ttree sound

Active Member
My 875 sits in an open shelf and during this warm spell after it being on for about 2 hours at -17 volume the temp. is displayed as 59/59 with a quiet cooling fan to the left side.

Id be interested to know what temps. other users amps are showing?
 

wiz

Distinguished Member
-17:eek:, thats loud normally have it at -30 to -25. How do you check the temp?
 

ttree sound

Active Member
-17:eek:, thats loud normally have it at -30 to -25. How do you check the temp?

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.:)
 

gixxerman

Active Member
Mines just working off the Sky HD atm (Vol -20), so no real work out there.

Temps show as .......45:42 Fan -
then the 2nd line is...V0 SEC:N
 

Rob20

Well-known Member
Mine says 54/50 and the sound is barely on but the amps been on for an hour or so. + it's early so isn't warm yet. Problem is I only have 70mm clearance with my Alphason stand not the 200mm recommended. V: 0.00 and SEC: H. Whatever that means!? :confused:

Unless H is for hot? notice in the previous post the guy has N. Probably for normal.
 

ttree sound

Active Member
Mine says 54/50 and the sound is barely on but the amps been on for an hour or so. + it's early so isn't warm yet. Problem is I only have 70mm clearance with my Alphason stand not the 200mm recommended. V: 0.00 and SEC: H. Whatever that means!? :confused:

Unless H is for hot? notice in the previous post the guy has N. Probably for normal.

I have found that the amp takes up to 2.5 hours to be fully up to max temp.

I have only 10mm:eek: of clearance above with all sides open though.

Does anyone know what the two different temp readings relate to?
 

tk2001

Active Member
The highest temperature reading I have seen on my 875 is around 67/61. However that is when I have pushed the 875 quite hard and have watched a movie at -10dB and it has been on for a few hours.

Now, after installing a 12cm fan on the top rear-back of the receiver - just resting above where the Reon chip is located - I get a max peak of 46/46 and the entire top area of the amp is cool to touch.

When I am gaming at around -30dB, it runs slightly cooler at 43/43.
 

tjhome

Active Member
my 905 is just ticking over in normal op at the mo on 52/49
 

Rob20

Well-known Member
The highest temperature reading I have seen on my 875 is around 67/61. However that is when I have pushed the 875 quite hard and have watched a movie at -10dB and it has been on for a few hours.

Now, after installing a 12cm fan on the top rear-back of the receiver - just resting above where the Reon chip is located - I get a max peak of 46/46 and the entire top area of the amp is cool to touch.

When I am gaming at around -30dB, it runs slightly cooler at 43/43.

Could you post a link to this fan. How much does one cost? does it just plug into the mains, or activated by temperature!? :confused:
 

glenann

Active Member
So it's quite warm tonight and I have my 875 in, what was the old kitchen pantry, on the top of the rack with a good foot or so of clearance. The temp reading after a full film was 68/62, man it was hot!
As an aside I have been offered a Yamaha RXV-3800 at a really good price, do you think it's worth the swap as it won't cost me anything? Would appreciate any feedback.

Cheers
 

glenann

Active Member
One hundred and eighteeeeeee!


Sorry couldn't resist......
 

tk2001

Active Member
Could you post a link to this fan. How much does one cost? does it just plug into the mains, or activated by temperature!? :confused:

I have been trying out two 12cm (on their own) to see if there is a difference in temperature and noise.

Here is the link to the first 12cm fan (Hiper Fan) I have been intially using with the 875 and cost £8.57 inc P&P but can take upto 5 working days:
http://www.ebuyer.com/product/105137

This is the link to the second 12cm fan (Nexus Real Silent Fan) I am currently using and will probably stick with and cost £7.39 inc 1st recorded delivery: http://www.specialtech.co.uk/spshop/customer/product.php?productid=6030&cat=0&page=1

The first one is slightly more expensive, is noticably more noisier than the second fan (rans at 1500RPM) but lowers the overall temperature by 2-3 degrees more than the 2nd fan.

The 2nd fan is cheaper and is whisper quiet (rans at 1000RPM) compared to the first but adds an extra 2-3 degrees more compared to the 1st fan.

My HTPC is resting on a rack above my Onkyo 875 so I am able to connect the fans directly to my HTPC PSU. However I believe you can buy an adapter from Maplins which can power the fans.
 

ttree sound

Active Member
I've now added another smaler fan to the rear right. I have now a 22cm fan to the left of the amp plus a 12cm fan at the rear.

Last night the temp stayed pretty stable at 46/50 after over 7 hours use.

It would also be intersting to know how much gap you have between the top of the amp and the next shelf above. Mine is only 11mm.
 

tk2001

Active Member
So it's quite warm tonight and I have my 875 in, what was the old kitchen pantry, on the top of the rack with a good foot or so of clearance. The temp reading after a full film was 68/62, man it was hot!
As an aside I have been offered a Yamaha RXV-3800 at a really good price, do you think it's worth the swap as it won't cost me anything? Would appreciate any feedback.

Cheers

glenann, I have read that the performance of the Yamaha RXV-3800 is very good and it really does depend what your priorities are.

I don't think the Yamaha RXV-3800 would be an upgrade as such as they have very similar specifications but more of a sideways step.

If I was in your shoes, the only reason I would swap, is if I either didn't like the way the Onko 875 sounds, was really concerned about the heat (which is way I installed a fan) or you much prefer the look of the 3800.
 

tk2001

Active Member
I've now added another smaler fan to the rear right. I have now a 22cm fan to the left of the amp plus a 12cm fan at the rear.

Last night the temp stayed pretty stable at 46/50 after over 7 hours use.

It would also be intersting to know how much gap you have between the top of the amp and the next shelf above. Mine is only 11mm.

The distance between the top of my amp to shelf above is only 10cm but I have open sides on my av-rack. I should also add that my room is climate controlled.

Are you sure yours is only 11mm - doesn't that make it impossible to fit a 12cm on top of the Onkyo in the first place?
 

Ch3tan

Active Member
On a 875, 59/54. It's been on for about 8 hours, volume has been between -35 and -23. Sits on top shelf of a Hi-fi rack with lots of open space.
 

glenann

Active Member
glenann, I have read that the performance of the Yamaha RXV-3800 is very good and it really does depend what your priorities are.

I don't think the Yamaha RXV-3800 would be an upgrade as such as they have very similar specifications but more of a sideways step.

If I was in your shoes, the only reason I would swap, is if I either didn't like the way the Onko 875 sounds, was really concerned about the heat (which is way I installed a fan) or you much prefer the look of the 3800.

Thanks for that. I think that all three reasons are a consideration, especially the heat issue, looking at some of the temp. figures quoted, mine seems to be the hottest!
I appreciate the feedback, anyway, cheers. :)
 

Rob20

Well-known Member
What is the optimum temp range for the 875 anyway?

Also, am I the only one who prefers the volume to go from 1-100!? :D
 

rnem170

Member
After watching Transformers on -27.5db, temps were 43/42 V0.00 (sometimes 0.02) Sec:M.
 

Oli2k

Active Member
Most I've seen in 69/64, it never reaches 70c as I presume the on board fan cuts in.

Oli
 

Technobuz

Standard Member
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ozguy

Standard Member
So my 2nd 905 arrived this week (1st one blew a capacitor 1 sec after turning it on for the first time. nice light and smoke show ;-) ), and boy does it run hot! And that's running in the open with nothing next to it! So I'm getting very nervous about placing it in a cabinet where it will soon reside.

I've heard it ran hot before purchasing it, but I was still amazed by the heat radiating off from the top of it, so I'm now looking at active cooling options for the cabinet that it'll be installed in once the cabinets are completed.

It will be installed in a cabinet with a metal mesh door and at least 4" - 6" above it for airflow (manual says at least 2"). But I've a feeling that there will not be much air flow moving over the unit to cool it through the mesh front.

I've been looking at silent cooling fans but don't know where it will be most effectively mounted. On the side of the cabinet sucking air out (or in?)?, directly on top of the unit pulling air up out of it?

What do you guru's recommend? or how are you cooling the unit yourselves?

BTW I tried the display/standby - tone combinatio but could not get a temp.

Thanks in advance for your advice.
 

Prosperous Dave

Standard Member
I'm a new owner of an 875 and I find it incredible how hot this amp gets even after a couple of hours watching a blu ray. I have it sited temporarily in an old tv unit thats open on all four sides and with my ps3 on a glass shelf 5cm above it. However, I'm going to move the ps3 as I think its getting cooked by the amp underneath it.

Why do these amps get so hot? Surely running at these temps must shorten their lifespans. Would it be possible to install proper cooling similar to the cooling systems in pcs?

Due to the heat being put off by the amp, I'd be worried about running it for hours on end.
 

mwardy

Novice Member
I've been looking at silent cooling fans but don't know where it will be most effectively mounted. On the side of the cabinet sucking air out (or in?)?, directly on top of the unit pulling air up out of it?

I had a surplus 12 cm silent pc case fan, which I just plonked on top at the back right hand side (over the reon chip) drawing air out. Handily, I also had an old power supply that gives voltages from 1.5-12v. Somewhere in the middle it runs fast enough so that the temp dropped by *a lot* but you have to strain to hear it with the volume off at normal viewing distance. Don't remember exactly by how much--maybe 10-12 C?--but it was enough for me not to worry about it any more. Now around 40-42 C.

I don't tend to have it very loud though, which might need more cooling over the transformer. This was with a glass shelf above much nearer than the recommended minimum distance. (Not as close as ttree sound though!)

There are plenty of examples of such fixes and more elaborate ones on this thread and elsewhere, often with pictures.

Edit: the gizmo in your link looks like a neat solution!

BTW I tried the display/standby - tone combinatio but could not get a temp.

It definitely works, though it is a bit fiddly until you get used to it.
 
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