Is This Enough Ventilation Space for a Parasound A31?

[mattlach]

Hey all,

I just received my HT amp upgrade, a Parasound A31 on Friday. Since they required a signature for delivery, and I likely wouldn't be home (since I work) I requested a hold at the UPS facility for me to come pick it up. To my surprise it was both larger and heavier than I expected, and would not fit in th etrunk of my Volvo S80. (a large sedan) I had to go home, get my Wagon, in a race against closing time, in order to pick it up and get it home.

Once home, I started reading through the manual (great manual by the way, very impressed by everything they have thought of documenting) and came across the section where it warns you to make sure wherever you put it can withstand its substantial weight. Uh oh. Through some miracle of fortune I still had the assembly manual from my old Whalen TV stand I bought years ago, and there it was. Max load bottom shelf, 50LB.

It was time for furniture shopping.

Having just spent more than I had originally planned on an amp, I did not have the appetite for expensive specialized home theater furniture. Much research, many measurements, and a drive to IKEA later, I wound up with a BESTÅ TV unit, six optional STUBBARP legs, and a dividing shelf. (I added the legs to raise it up enough to get the center speaker at a good level, sitting on top of it.

It's not the prettiest setup, but it was cheap, rated for 110lb (which should be enough for the amp and my other components) and will do the job for now, which brings me to my question.

I've been doing some test fitting while I wait for my interconnects and various other items to arrive, and here is how the Parasound A31 fits in the BESTÅ unit:

The manual - while great - does not mention specific measurements of clearance required for proper ventilation. it instead speaks to it qualitatively. You can't easily tell from the picture above, but there is about 2.25" of clearance on either side, and 5.25" above it.

As you can see, I also assembled the unit without the back, so air should be able to flow both the front and the back.

Any thoughts on this? Is this enough clearance, or should I think about investing in some fans? And with an amp like this that has temperature sensing and protective circuitry, does it even matter, as long as I'm not entering overheat shutdown?

Much obliged,
Matt

 

[NorseMythology]

If you are worried about it, check these out

https://www.acinfinity.com/receiver-amp-cooling-fans/?_bc_fsnf=1&DIMENSIONS=17+x+13.5+x+1.5+in.+(43.2+x+34.3+x+3.8+cm)

I just use one of their axial (computer type) fans set on top of my AVR blowing down into the AVR with a dust filter, but it isn't as pretty, especially when you have something like that Parasound!

 

[mattlach]

If you are worried about it, check these out

https://www.acinfinity.com/receiver-amp-cooling-fans/?_bc_fsnf=1&DIMENSIONS=17+x+13.5+x+1.5+in.+(43.2+x+34.3+x+3.8+cm)

I just use one of their axial (computer type) fans set on top of my AVR blowing down into the AVR with a dust filter, but it isn't as pretty, especially when you have something like that Parasound!

I've seen cooling solutions like these, but they are not cheap. I don't know if I could bring myself to spend a couple of hundred bucks on AV cooling, when I could DIY something with quiet PC case fans and a 12v wall wart hooked up to a smart power strip to turn on when the amp turns on for ~$20.

I'm thinking I could hide them on the back, and they won't even be visible.

 

[NorseMythology]

Also I notice the systems that exhaust in the front or the rear are 24db and 160CFM (Cubic Feet per Minute) vs the top exhaust model which is 21db and moves 210 CFM of air.

Or since yours has its heat sinks on the side, perhaps something like this would be more effective.

 

[NorseMythology]

I've seen cooling solutions like these, but they are not cheap. I don't know if I could bring myself to spend a couple of hundred bucks on AV cooling, when I could DIY something with quiet PC case fans and a 12v wall wart hooked up to a smart power strip to turn on when the amp turns on for ~$20.

I'm thinking I could hide them on the back, and they won't even be visible.

It is $99

I got this for mine for $15

 

[Leemix]

Hey all,

I just received my HT amp upgrade, a Parasound A31 on Friday. Since they required a signature for delivery, and I likely wouldn't be home (since I work) I requested a hold at the UPS facility for me to come pick it up. To my surprise it was both larger and heavier than I expected, and would not fit in th etrunk of my Volvo S80. (a large sedan) I had to go home, get my Wagon, in a race against closing time, in order to pick it up and get it home.

Once home, I started reading through the manual (great manual by the way, very impressed by everything they have thought of documenting) and came across the section where it warns you to make sure wherever you put it can withstand its substantial weight. Uh oh. Through some miracle of fortune I still had the assembly manual from my old Whalen TV stand I bought years ago, and there it was. Max load bottom shelf, 50LB.

It was time for furniture shopping.

Having just spent more than I had originally planned on an amp, I did not have the appetite for expensive specialized home theater furniture. Much research, many measurements, and a drive to IKEA later, I wound up with a BESTÅ TV unit, six optional STUBBARP legs, and a dividing shelf. (I added the legs to raise it up enough to get the center speaker at a good level, sitting on top of it.

It's not the prettiest setup, but it was cheap, rated for 110lb (which should be enough for the amp and my other components) and will do the job for now, which brings me to my question.

I've been doing some test fitting while I wait for my interconnects and various other items to arrive, and here is how the Parasound A31 fits in the BESTÅ unit:

The manual - while great - does not mention specific measurements of clearance required for proper ventilation. it instead speaks to it qualitatively. You can't easily tell from the picture above, but there is about 2.25" of clearance on either side, and 5.25" above it.

As you can see, I also assembled the unit without the back, so air should be able to flow both the front and the back.

Any thoughts on this? Is this enough clearance, or should I think about investing in some fans? And with an amp like this that has temperature sensing and protective circuitry, does it even matter, as long as I'm not entering overheat shutdown?

Much obliged,
Matt

Open front and back and looks like nice air above also. Should be fine unless you live in a very hot place, my a31 is very cool running and never gets hot. Its a bit wrong that my old processor marantz av7005 and the new av8805 i replaced it with runs hotter then the power amp.

Edit: just try and feel the amp every now and then at the beginning and you will know if its good or not.

Sent from my iPad using Tapatalk

 

[PENG]

I've seen cooling solutions like these, but they are not cheap. I don't know if I could bring myself to spend a couple of hundred bucks on AV cooling, when I could DIY something with quiet PC case fans and a 12v wall wart hooked up to a smart power strip to turn on when the amp turns on for ~$20.

I'm thinking I could hide them on the back, and they won't even be visible.

Just get a couple of the small Infinity fans or one larger one and blow the air from the back to the front. With only 2.5 inch clearance on top it won't work well putting fans on top.

The Halo amps have very good ventilation because the inside is quite empty for the A21 and A31, and the well vented top sort of work like a supplemental heat sink. They are heavy by choice as they use the same chassis for the A51. The issue is that they do run quite warm because of their so called A/AB design that sounds good on paper and in theory if you don't listen louder enough for it to output more than a few watts average.

 

[mattlach]

Open front and back and looks like nice air above also. Should be fine unless you live in a very hot place, my a31 is very cool running and never gets hot. Its a bit wrong that my old processor marantz av7005 and the new av8805 i replaced it with runs hotter then the power amp.

That's really strange. These don't even contain amplifiers, right?

 

[Leemix]

That's really strange. These don't even contain amplifiers, right?

Ye no power amp sections as such


Sent from my iPad using Tapatalk

 

[mattlach]

Ye no power amp sections as such

I wonder what produces all that heat? Or maybe it's just because they don't have as much in the way of heatsinks.

 

[Leemix]

I wonder what produces all that heat? Or maybe it's just because they don't have as much in the way of heatsinks.

They do have quite a lot of processing power i suppose. They might amplify the signal a little also for a lot of channels after processing. So as you say without heatsinks or fans itll get hot in there.


Sent from my iPad using Tapatalk

 

[slipperybidness]

Open front and back and looks like nice air above also. Should be fine unless you live in a very hot place, my a31 is very cool running and never gets hot. Its a bit wrong that my old processor marantz av7005 and the new av8805 i replaced it with runs hotter then the power amp.

Edit: just try and feel the amp every now and then at the beginning and you will know if its good or not.

Sent from my iPad using Tapatalk

I'm in agreement here. If this were me, I wouldn't worry about it unless it becomes a problem. Use it, enjoy it, and check the heat every now and then to see how hot it really gets.

 

[M Code]

The Parasound amplifiers are well-designed and overbuilt...
U should be fine, what makes an amplifier heat up is largely based upon output stage bias settings, loudspeaker load/sensitivity and the average listening volume level. Ez to check.. After playing the system @ ur average volume levels place ur hand on the amplifier's top cover if warm all is well, but if hot then more ventilation is required...

Just my $0.02...

 

[PENG]

That's really strange. These don't even contain amplifiers, right?

Not strange at all, the prepro's processing part produces heat, as well as the preamps. Class AB power amps actually do not produce much heat when idling and during normal use when the average output could be just a few watts, may be 10. Again the Parasound amps, especially the Halos, tend to produce more heat because of the class A bias level at low output levels. Without external fans it will be fine with adequate venilation as MCode mentioned, but a fan or two should help it last longer.

 

[Irvrobinson]

I wonder what produces all that heat? Or maybe it's just because they don't have as much in the way of heatsinks.

According to the Marantz web site the AV8805 idles at 90 watts, making it one of the hottest pre-pros I'm aware of. I'm guessing it has a number of op-amps running in Class A mode, not to mention some video processing chips that are powered even when their inputs aren't selected. (With the emphasis on guessing.)

 

[Swerd]

… about 2.25" of clearance on either side, and 5.25" above it.

As you can see, I also assembled the unit without the back, so air should be able to flow both the front and the back.

That should be enough for passive ventilation. Adequate ventilation is all about giving hot air a way to escape. Don't trap it in an enclosure and you should be fine.

Like Leemix, slipperbidness, & M Code said above, try it first in your cabinet before worrying about fans.

 

[AcuDefTechGuy]

According to the Marantz web site the AV8805 idles at 90 watts, making it one of the hottest pre-pros I'm aware of.

That doesn’t seem like good engineering to me.

I’m sure their rationale is much better sound quality than the other guys at the expense of heat and power consumption?

 

[Irvrobinson]

That doesn’t seem like good engineering to me.

I’m sure their rationale is much better sound quality than the other guys at the expense of heat and power consumption?

I dunno, it's a 13.2 pre-pro, so 15 channels of multi-volt line-level amps, and they typically run in Class A. Every audio channel has a DAC channel. Bluetooth and Wifi chips. All of those channels of EQ processing. HDMI, video processing with upscaling... all of this adds up to a lot of chips and the power supplies that power them all. (Power supplies are obviously less than 100% efficient, so they all have a loss factor.) I think 90 watts sounds in the range of what this problem takes to solve.

 

[AcuDefTechGuy]

I dunno, it's a 13.2 pre-pro, so 15 channels of multi-volt line-level amps, and they typically run in Class A. Every audio channel has a DAC channel. Bluetooth and Wifi chips. All of those channels of EQ processing. HDMI, video processing with upscaling... all of this adds up to a lot of chips and the power supplies power them all. (Power supplies are obviously less than 100% efficient, so they all have a loss factor.) I think 90 watts sounds in the range of what this problem takes to solve.

After my experience with the Denon AVP-A1, which is probably similar in terms of power consumption and heat, I would run in the opposite direction.

I guess these Denon/Marantz engineers don’t know how to make high-end pre-pros like the high-end companies such as Theta Digital and DataSAT.

 

[PENG]

After my experience with the Denon AVP-A1, which is probably similar in terms of power consumption and heat, I would run in the opposite direction.

I guess these Denon/Marantz engineers don’t know how to make high-end pre-pros like the high-end companies such as Theta Digital and DataSAT.

Do they make 13.2 prepros with features comparable to those of Marantz's?

90 W for 13.2 actually is an improvement, compared to my AV8801 that has 2 channels fewer with the same 90 W consumption. Compared to their (Denon/Marantz) AVP and AVRs:

AV7703, AV7704 : 60 W
AVP-A1HDC1: 170 - 216 W (approx. only, based on 240 VA specified by Denon, and assuming pf=0.7 to 0.9)
AVR-X4400H, X6400H, SR7012, SR8012: 110 W (X4400H idles only slightly warmer than the AV8801)
AVR-X4520, AVR-X7200WA, X8500H : 125 W

The Denon X7200WA and X8500H are rated a whopping 125 W but the X8500H has more channels, so if you go by those figures they might have improved on power consumption a little too. If you think about the differences between them, it is quite obvious that the heat mainly comes from the prepro section. The power amps, during normal use probably add another 10 to 30 W average depending on the how, and what. An extreme case of the how and what would be for someone who listen to heavily compressed rocks in all channel stereo mode, you can imagine the rest.

I think Marantz can lower their prepros's temperature by a degree or two if they simply make the chassis top better ventilated like their lower AV models such as the 7005 through 7703. Weight is not an excuse, you can see that even the flag ship AVR-X8500H has the better ventilated top and it is 20 lbs heavier, and the X8500H's prepro section is probably very similar to the AV8805's, aside from the HDAM, balanced output and the power supply transformer. So I think the half vented top is probably a cost saving thing, by keep using the same design that they started with the AV8801 in can see in the pictures below that they look identical.