Like

How much ventilation clearance for Onkyo stereo receiver?

 

Bronze Member
Username: Dmehling

Post Number: 25
Registered: Dec-08
I have an entry-level Onkyo stereo receiver. I might eventually upgrade my stereo cabinet, so I would like to know a good amount of clearance for ventilation. It currently has maybe 8 inches clearance above, with 3 inches on either side. The rear is open but the front is not. I do not listen to my music beyond moderate levels. The volume knob never goes past the halfway point. A new cabinet would probably have the same clearance above, and the front and back would be open. However, I don't want to increase width. How critical is side clearance? The manual seems to suggest 8 inches on either side, which sounds like a huge amount. I wondered how relevant that was to me considering my maximum volume setting.
 

Gold Member
Username: Superjazzyjames

Post Number: 2252
Registered: Oct-10
8 inches on either side? Seems a bit excessive to me. Is it possible to put the receiver on top of the cabinet or on a shelf that doesn't enclose it? I have both of my receivers mounted on open shelves. The one in the main system is on a glass, wall mount shelf with a few feet between it and the ceiling. The one in the secondary system is on a home made wood shelf with plenty of clearance on all sides. If you are using a turntable which is on top, perhaps a shelf wide enough to put both receiver and TT side by side on that shelf?
 

Platinum Member
Username: Jan_b_vigne

Dallas, TX

Post Number: 17873
Registered: May-04
.

Place your hand on the top of your receiver after it's been playing at a fairly loud volume for awhile. How warm is the top? A few manufacturers bias their output devices to run somewhat warm to achieve better on paper specs. If you can hold your hand on your receiver's top for a few seconds under stress conditions, your present ventilation is sufficient.

Typically, side space is not very important to keeping an amp running cool. The chassis should act like a chimney and raw cool air in from the bottom and expel warm air from the top. If you can increase the space beneath the receiver, you would do more for the system than adding space to the sides.

If the receiver runs warm to the touch, you might consider adding a whisper fan to the top of the receiver to draw more air through from the bottom. In other words, rather than pushing air into the receiver, pull air through the receiver. Use a 12VDC fan and run it from a 12VDC wall wart power supply you can find in any Radio Shack. If your receiver has convenience AC outlets on its rear panel, plug the power supply into a "switched" outlet and it will come on and turn off as you power up the receiver. Looking into the receiver from above you can probably find the heatsink fins inside the receiver. Locate the fan above the heatsinks.


.
 

Gold Member
Username: Magfan

USA

Post Number: 3109
Registered: Oct-07
I wonder if the 12v used for auto-on�.has enough current to run a small boxer fan? That way�the fan would come on with the stereo and you wouldn't have to even think about the possible sonic consequences of one of those poorly regulated, maybe noisy, wall wart power supplies.

If it's an issue�..NOCTUA makes perhaps the highest quality, quietest fans available. To make it even quieter, at the expense of air moving ability, you can run a 12v fan on 9v.
 

Platinum Member
Username: Jan_b_vigne

Dallas, TX

Post Number: 17876
Registered: May-04
.

Leo, I'd be willing to make a bet with you that anyone using a basic receiver wouldn't have a clue the wallwart supply was noisey.

If someone becomes that concerned about noisey power supplies, would they have purchased a receiver in the first place? What's the first and most consistent knock against a receiver? It puts all those parts in close proximity to the noise of the power supply. What's the best way to sell a receiver? It gives you lots of power for low bucks. And, how do you get higher watts? You use a bigger power supply which will put out even more noise. Then you jam it full of more circuits to pick up that noise.

And to make matters worse, since few receiver buyers even understand what a power supply is, there are very few receivers nowdays which even mention shielding their ps. Because they don't. If they use a torroidal, it's for marketing purposes, not for sound quality.

If anyone using a receiver can tell a wallwart makes noise, they're missing a lot of what's happening inside their receiver. If they stay awake at nights worrying, let them buy a rechargeable battery for the fan.



.
 

Gold Member
Username: Superjazzyjames

Post Number: 2254
Registered: Oct-10
"Leo, I'd be willing to make a bet with you that anyone using a basic receiver wouldn't have a clue the wallwart supply was noisey"

Really? Jan, I can assure you that I would notice that noise.

If someone becomes that concerned about noisey power supplies, would they have purchased a receiver in the first place? What's the first and most consistent knock against a receiver? It puts all those parts in close proximity to the noise of the power supply. What's the best way to sell a receiver? It gives you lots of power for low bucks. And, how do you get higher watts? You use a bigger power supply which will put out even more noise. Then you jam it full of more circuits to pick up that noise.

To purchase a receiver or move up the food chain depends on one's budget.

As for sections of a receiver being close to the power supply. If it was a Sony, RCA, Panasonic, Yamaha, etc., probably. However, as an owner of both a Denon and Onkyo stereo receiver, I can tell that there is no noise from the power supply getting to other parts of the receiver and I don't believe for even 1 second that stereo models made by Marantz, HK or Pioneer have this problem either.

"If anyone using a receiver can tell a wallwart makes noise, they're missing a lot of what's happening inside their receiver."

Nope! Not true. If a person can't tell that a Wal-Mart PS makes noise, the person probably doesn't have very good hearing.
 

Platinum Member
Username: Jan_b_vigne

Dallas, TX

Post Number: 17877
Registered: May-04
.

I'd take your bet. Tell me, what does wall wart power supply noise sound like when the ps is inserted into the same AC circuit as the receiver? How is that different than the generic noise coming from a receiver's power supply? How about when there's a class D amplifier in a receiver. What sort of power supply noise would that unit produce?

It's a price competitive market for receivers. I never had one client inquire about power supply noise when I was pitching them a receiver. Quite literally, 99% of them wouldn't have known what part of the receiver was the power supply. I've sold Onkyo, and HK, and Marantz and all the lines you've mentioned. Once multi-channel amps were included in receivers, power supply noise was a consideration left behind. Stereo receivers are considered low end products - not much technology included - now days by all but the most unusual line such as Outlaw - which retails one receiver in their line of separates.

Receivers are a compromise. That is a fact. Even the best lines would tell you that as would any receiver manufacturer that also retails integrated amps and separates. This is what they would tell you, not what I'm making up to slam receivers. Even McIntosh, when they built a receiver, told you it was not the best they could build. The larger the power supply, the more likely it is to inject noise into other circuits. The closer a circuit sits in relation to the power supply, the more noise it will pick up. Look inside any receiver and you'll see a jumble of circuit boards with traces running around the interior to make manufacturing cheaper, not to truly minimize noise. How many receicer use simple E core transformers? They are the dirtiest of all but also the cheapest.

Are some receiver lines better than others? Yes, and no. They are still receivers which must compete on cost. Many receivers are built on similar chassis designs which are used for several models with more and more features as the cost increases. Today, the vast majority of receivers aren't built by the company retailing them. One plant may turn out NAD on Monday and Pioneer on Wednesday. Take off the name plate and most people couldn't tell you which amp is which. Those are the realities of the market now.

Don't get insulted because I said something you didn't like about receivers. They are what they are. If that's what you use, you are looking at the same trade offs as any other receiver user.

Though superior specifications don't always lead to higher quality sound, there's a reason a separate pre amp will generally measure better when it comes to S/N values. Add a low level phono section and the chances increase as sensitivity and gain in the phono circuit increases.

Of course, looking at a receiver's S/N ration, you really can't tell what weighting system was used to provide a more favorable measurement for the product. But power supplies and low level circuits do not mix well. That's just a well known fact and saying otherwise doesn't change the facts.



.
 

New member
Username: Bchambers

Post Number: 2
Registered: Mar-14
Can you help with this?

https://www.ecoustics.com/electronics/forum/home-theater/719286.html
 

Platinum Member
Username: Jan_b_vigne

Dallas, TX

Post Number: 17878
Registered: May-04
.

Do you mean, can I tell you what each of those cables attaches to? And, how do you make a system work when all you have are a bunch of unlabeled end run cables?

No, I can't. Certainly I can't do so over a forum. I can give you several options though.

First, try to locate the installer who wired the house. Many times these systems are pre-wired by the builder and they contract out to installers to do several houses in the same area. If you can locate the builder, they may have information on who did the job. At the least, they could tell you whether the house was pre-wired or done after the house was completed. One type of install would be slightly different than another and could give you some clues when you begin searching down where each cable runs.

If there's home automation involved and/or a security system tied in with the sound system, then you have narrowed down the number of possible installers in your area. Check with some neighbors. They probably bought a house with similar systems. They may have some information on who did the work or who they hired to finish the work after they moved in.

Without any idea of your location, you might have some luck calling the local audio companies. Or the home automation companies. Often, these two services are shared by one installer nowdays. Security systems are commonly left to another type of installer and you more than likely want to hope your audio system wasn't done by a security system installer. Some shops have their own laborers who do instales and pre-wires, some contract out to anyone willing to climb in an attic and under a house.

If you are not up to doing the work yourself, contract the labor to one of these companies. While each system is unique, most new house are not. If your house is in a recent development area, what went into one, two or ten houses in that development is likely in your house. It's not fast but most good installers can figure out what was done and where cables have been run by backtracking and using some basic logic. Just make sure you get a guarantee for the work they perform.

Finally, you can give the work a try on your own. Contact PartsExpress (http://www.parts-express.com/?utm_campaign=B_Brand_Main&utm_source=msn&utm_medi um=cpc&utm_group=B_Brand_Terms_Exact&utm_term=partsexpress). Tell them you need to trace the location of the cables and they can provide the tools used by installers to do the work. The tools aren't inexpensive but they're easy to use. IMO you'd be better off hiring an installer though. You can no longer use just a 9VDC battery to run down cable locations.


.
 

New member
Username: Bchambers

Post Number: 3
Registered: Mar-14
Thank you for the quick response.

The house next door was built at the same time so I'll see if they have a system installed over there. There is a security system but it appears to be separate from whatever this is. I attempted to contact a local (Tampa Bay, FL) installer company through their website, but got no response. I'll try again.

The only home theater system I've ever used has been one of the home theater in a box setups. Seeing Cat5 involved in a theater setup like this is new to me. And it doesn't help that some of the Cat5 cables don't have connectors on them. Could you see the box that had all the Cat5 wires plugged into it? I Google'd it and it said it was used for distributing phone lines. (But I don't think these people had four separate phone lines being distributed around the house.) Do you know if that could be used to distribute sound from a theater system or data? I don't think it will send data since there is a separate connection labeled data. The reasons I think it is theater related is that the same color Cat5 cables come out of the living room wall and (more Google'ing) I saw some wall mounted volume control panels that used Cat5.

Any thoughts or know of any installers in the Tampa, FL area?

Thank you,
Brian
 

Platinum Member
Username: Jan_b_vigne

Dallas, TX

Post Number: 17880
Registered: May-04
.

I really don't know what the CAT 5 would have been used for. Since it's an easy cable to pull through pellums, its also an easy cable to sue for multiple purposes, including speaker runs. It can be split and connections can be made using series or parallel configurations. It's a convenient cable for use with in wall volume controls and touchpads or remote sensors. However, with home automation systems, it's appropriate to use CAT 5 for basic data transmission.

Try to find a manufacturer's name on the wall plates of any component part of the system. If a plate is, say, from Russound, head to the Russound web page to locate that part. Knowing the specified use for the plate should give you a better idea of how the cabling is intended. Most of the manufacturers who retail these connectors and so forth have good customer support systems and can give you a bit more insight into what might be in the house. They won't be able to tell you exactly what does what or where it does it but they might get you headed in the right direction.

Just remember, installers don't always use convention to make decisions. If a wall plate was designed for data transimssion, it may have been the only part the installer had in their box of stuff when they were trying to finish up the install that day. Therefore, it could have been used for darn near any other system they could make work.

Tracing a system such as yours is a matter of logically breaking it down into parts; audio, automation, data, etc. After you have an idea of what each part does, you can begin to figure out where the cables might run. From there you really just need to wring out the wires and trace them in one way or another back to the home run location. You can get a lot done with a basic DVOM but it's a PITA. That's why the beepers and so forth were designed for the intaller's use. You can often but not always count on some system having been applied to the cable's sue. If a white wire runs to the "+" of one speaker, it probably runs to the "+" of all speakers. Check it though before you make a connection. You don't want to blow up an amplifier just because on installer got lazy. Separate out what the connector/cable might be used for and then once again begin to subdivide what color leg might be used for which connection.



.



.
 

Gold Member
Username: Superjazzyjames

Post Number: 2255
Registered: Oct-10
"Nope. The mass market companies change model lines each and every year. Eventually, most begin to repeat model numbers"

This is your response to my question regarding whether or not the Onkyo TX-840 is a vintage receiver Jan. You are bit misinformed about receivers and your knowledge about them is dated to say the least.

The Onkyo customer service guy and quite a few members of other forums agree that this is an early to mid 90s model, including some who have had one since 94 and earlier.

There is not one shred of evidence to support the notions that Onkyo, HK, Denon, Marantz or Pioneer change their model lines anymore often than about every 5 years or that they repeat model numbers. Perhaps Sony, RCA, Panasonic and the like change model lines every year, but not the other 5. I have never seen any company repeat model numbers at all.

As for the Wal-Mart power s noise, it's a hum like any other hum caused by an unfiltered electrical device. Very noticeable. If the op so chooses, he can plug his receiver into a power conditioner and the WM power supply directly into the wall. Problem solved.

As for ps noise in a receiver, the Onkyo model, being the 90s model that it most definitely is has a small issue with noise. The chassis isn't very deep, so the parts are all close together. The Denon OTOH, does not have a noise issue. The power supply, tuner, preamp and power amp are spaced far enough apart to reduce "talk" below human hearing.

The bottom line here is that receivers are simply not the hunks of junk that you make them out to be.

Btw, I am not insulted by anything you said in your post. I just don't want Douglas or other receiver owners to feel that what they have is inadequate. Any piece of audio gear should only be deemed inadequate when it no longer satisfies the owner.
 

Platinum Member
Username: Jan_b_vigne

Dallas, TX

Post Number: 17881
Registered: May-04
.

James, you are an uninformed, argumentative fool. I try to assist you in another thread, you thank me for my help and now you want to argue about it in this thread. Yes, mass market receivers change every year. Every year at CES the mass market lines trot out their new models. Been that way for half a century.

As to the rest, wall wart power supplies are "switch mode" types which operate in the MgHz range. Can you hear MgHz noise, james? I never suggested anyone use a "WallMart" ps. You, however, stated anyone not capable of hearing switch mode ps noise "doesn't have very good hearing". Switch mode ps noise is most prevalent in the very highest frequencies and is an artifact of unshielded circuitry and poor ground plane layout. You might want to research asynchronous DAC's and aliasing noise if you want to understand such problems. We're not talking about 60Hz noise, james. But, you don't, you don't want to understand anything. You just want to argue.

We're not talking 60Hz noise with a wall wart. It might occur when there is a faulty ps but this is not the "noise" of a switch mode ps. You think leo would have been warning about 60Hz ground hum? Geeeez! And, leo, I wish to he11 you'd never brought up the topic. james, you seem to think noise you cannot hear doesn't exist since you seem to think you have hearing that is superior to others. You don't even understand power supply noise that isn't 60Hz in nature. FYI, your Denon is the "low end" model from the company which owns it.

I never said receivers were "inferior" or "hunks of junk", as you claim. I said they are a compromise and that any manufacturer building higher quality components would tell you the exact same thing. I'm not going to argue the issue with you, james. You don't know what you're saying but you never care to listen to anything that's said that's contrary to what you believe.

Watch "Cosmos", james. Learn something. Stop being stupid.

Don't begin another of your rages. I don't care about you or your rages or your attitudes. Just let it stop right here, james. Just let it stop.




.
 

New member
Username: Bchambers

Post Number: 4
Registered: Mar-14
Jan,

Thank you very much for the help! This will definitely be a project. I'll take it slow so I don't mess up any equipment. I talked to the neighbor, too. He has a similar system and bought his house as a short-sale, too, so he's had to figure it out as well. He has a buddy that helped him a bit and they are going to be working on it some more in the next few weeks so I'll be borrowing that knowledge when it arrives. Thank you, again!

- Brian
 

Platinum Member
Username: Jan_b_vigne

Dallas, TX

Post Number: 17882
Registered: May-04
.

Good luck, Brian. This sort of job can become a real head banger. Assume the best and pre pare for the worst. You might want to consider some "sacrificial" audio and video components which can be hooked up as a test and, if they blow up, there's nothing really lost. This is more important with audio than video and any cheap amp with the connectors you need would do.



.
« Previous Thread | Next Thread »

Add Your Message Here

Bold text Italics Create a hyperlink Insert a clipart image Add a YouTube Video
Need to Register?
Forgot Password?
Enable HTML code in message
   

Facebook

Shop Related Deals

Directory

Main Forums

Today's Posts

Forum Help

Follow Us