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Five channel amp setup help - Parasound A51

I just picked up a gently used A51. I think my excitement about the unit overcame my best judgment, and so now I have some questions I wish I had answered beforehand. But any help you guys can provide would be helpful:

1) The unit is placed inside a wooden media center. (Pottery barn Logan medium to be precise). It has 3 inches of air space on either side, but only an inch and a half of air space above it. The back of the cabinet has a cubby hole for wires - so basically no outlet for air through the back at all. The front is open - no doors. Has anyone used an amp such as this in this type of setup? I'm afraid it will overheat very quickly. I can take off the wood paneling in the rear of the amp for better airflow, but I wonder if even that will be sufficient.
2) I am using Sonance 831s for the ceiling surrounds. My home builder installed 14 gage symphony audio wire that goes from the amp to a volume control buried in the wall, which is set to max, to the speakers in the ceiling - I am guessing a total length of 30 to 50 feet. Is this gage of wire OK given this amp can output 250 watts of power or up to 60 amps of current per channel? Or am I at risk of starting a fire? Also, given the amp is capable of outputting 250w and the Sonance are rated to a max of 100w, am I in danger of blowing out the speakers even if i attenuate the signal coming out of my av7005 marantz preamp?

As you guys can tell, I'm new to the home theater setup so your patience is appreciated. I had an A21 before for my stereo setup but that was placed on the floor with nothing around it (I was unmarried at the time) and so heat was never a problem.

Thanks in advance and looking forward to reading your advice.
aman4kr4
11 responses Add your response
bdgregory
1,712 posts
 
I think you may have a problem with ventilation on your amp.
Maybe a big problem. I'm not familiar with that particular
amp but have owned other Parasound amps and they tend to run
hot. I suggest you set it on a table and power it on for 30
minutes or so. no need to connect anything, just let it idle.
If it's warm to the touch after 30 minutes, it will not be
good to only have 1" above it. You'll need to find
another location, or at least try running a fan over the top.

As for the speaker wires - no problem there, but I would
remove the volume controls. They can't be good for anything
in this arrangement.
rlwainwright
1,904 posts
 
You could try getting a couple of computer fans and then cutting out some holes in the rear panel to allow them to exhaust the heat. This is a fairly inexpensive solution, should cost you about $25 total...

-RW-
aman4kr4 OP
25 posts
 
Got it. Thanks for the quick feedback guys.

I'm not a fan of the volume controls either. Will look into removing.
I think fans may be a good option to try.
theo's avatar
theo
2,680 posts
 
You may alsi consider taking the top cover off the amp to provide more space for the heat to dissapate. That may help some and also you don't mention what is beneath that particular shelf. Is there a way to cut a hole in the shelf to allow the convection of the heat from the amp to draw in cooler air from below? I had a heating issue with one of my amps and the holes in the shelf below solved the issue by at least 10-12 degrees according to my laser thermometer.
kjweisner's avatar
kjweisner
293 posts
 
Definitely get rid of the volume controls. In addition to adding circuitry, they may be rated for lower power (most are). They may or may not be impedance matching which again alters the signal. I don't think you have any worries with the wiring itself as eve 50' isn't that long.
aman4kr4 OP
25 posts
 
I want to avoid removing the cover. I don't event feel comfortable opening the amp... Not yet anyways as I'm not having any issues.

I really think I should remove the volume controls. I don't even know why they installed them in the first place.

Quick question on ceiling speaker placement for the rear channels. The speakers are about 3 feet away from the back wall, but the main seating area is against the wall, so I have the ceiling speakers aimed to the seating area. I'm thinking that should be fine, although not ideal.

I mainly care about stereo anyways...
mribob
229 posts
 
I have a similiar set up with my Parasound A-51 amp, its in a Standout design wood AV cabinet. Its open to the front, and has minimal side clearance, and it runs warm. I also use it as 5 channel amp for my HT rears and center, and have it with long cable runs to my zone 2 outdoor speakers. It's been a reliable workhorse for over 4 years with this set up, and I've had no problems at all with overheating, or having safety therms kick off. Don't open the cover, but you may want to drill larger openings in the back the promote more air flow. I've not needed any cooling fans. I also use the Marantz 7005 for HT and am very pleased with this combo. Good luck, you shouldn't have to worry, just enjoy with a few simple modifications.
Good luck,
Bob
aman4kr4 OP
25 posts
 
Thanks Mribob. I am trying to avoid fans as well as I don't want additional noise. We will see what I can get away with but agree that I will need to open up the back somehow for better ventilation.

Does any part of your amp feel warmer? This amp feels warmer in the back, left part of the top cover than any other part of the unit. Is this normal?
mribob
229 posts
 
Have not personally checked, but it could be where the power supply sits..even though there are 5 seperate amplifier modules in this beast. Seems to be normal.
solo13
8 posts
 
I have the Parasound A21 and mine has never overheated because I have it well ventilated. Maybe try it out for yourself and the owners manual is available on their website.

Their is a hi temp indicator on the right side and will glow red when a channel overheats. In addition, the on/off button will glow red when there is overheating where the owner manual suggests better ventilation for your amp.

Good luck.
aman4kr4 OP
25 posts
 
Thanks solo.
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