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Discussion Starter · #1 ·
Question guys. I've noticed that certain audio passages during movie playback will start to clip. The system seems to handle transients very well but when there's a sustained portion of audio at a higher level, like say horns during a dramatic scene, I can hear it distort.


I don't think I can blame my equipment necessarily (yet). I've got two Adcom amps, 5503 and 555II for 5 channels of 200W each. My two L/R fronts are (the huge) Polk SDA/SRS 1.2's. The center is a Boston Acoustics (don't recall model).


I'm thinking that power might be the problem. Everything is on one 15amp line. By everything, I mean the amps, preamp, satellite rcvr, VCR, video buffer, etc. Plus, the HTPC is on it *and*, the same line feeds outlets along the same wall but in a different room where I have another computer and peripherals attached.


By handling loud transients but not sustained passages, I'm assuming then any storage in the amp's power supplies is being depleted and I'm depending upon a possibly overloaded outlet. The breaker never trips though.


Would just the addition of a power conditioner help me? Should I run a dedicated line? Both?


Thanks a lot for any help.


Cary
 

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The best money spent is first adding a few dedicated circuits. I recommend 20 amp 10 guage wire. Make sure the circuits are on the same power phase, as this will substantially reduce noise on the line.


If you do a search here at this forum for dedicated circuits you'll find lotsa info.


After you've done the basics with dedicated circuits, sure, there are more tweaks you can add.


I personally recommend that you plug your power amps direct to dedicated wall outlets. That's what I do.


The problem you are describing, one of dynamics and transients, will not be alleviated by using a power conditioner for your amplifiers.
 

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Discussion Starter · #3 ·
Thanks Steve! I'll search...


I was already leaning towards adding an additional line (or two) since there are so many potentially noisy things attached. I just don't relish the though of snaking a wire down the wall from the attic to get to the outlet :(


I guess I just needed some confirmation that it won't be wasted effort and is a really good thing to do.


Cary
 

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And since you are already going to be snaking a line down for at least one more dedicated circuit, why not snake down some extra lines in case you decide to do another dedicated circuit down the line? I would recommend at minimum one dedicated line for your power amps (or even one line for each of two amps), one dedicated line for front end components, and one dedicated line for video display.
 

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Cary, We gotta quit meeting like this! I did exactly what Steve recommended. I don't use amps though, so I didn't do as many. I have an AVR5800, sub, and my HTPC all on one 20amp dedicated line. I have a LD player, my pj, and the Extron pieces on a separate line.


I used Alan Maher's parallel wiring scheme, put them on the same phase, and used hospital grade outlets. I then used his dual twist power cable on the pj...one day I'd like to do the same cord on all the equipment, it's just back burnered for now. I've been too busy tweaking the pj and finishing the room.


All in all it did make an improvement. I can now listen with the volume knob at a bit lower level. I also noticed the pix cleaned up a bit. I think it was monwy weel spent. With the powet cord, the wiring, outlets, etc. I probably only have $100 in the "upgrade" plus whatever my time is worth.
 

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Cary,


I did the same thing Jay did. I ran a separate circuit (20amp, 12g wire (not enough room in the conduit for 10g)) and it made a difference. The sound and video both benefited from the upgrade. I also made a power strip using Alan's wiring. With both of these I believe you will enjoy your system more. Good luck and enjoy.


Greg
 

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Discussion Starter · #7 ·
Great!!! Thanks! Could you guys point me to info on Alan's wiring? I was hoping to get time this holiday to run some wire but sometimes life gets in the way of this hobby. :)


TIA...


Cary
 

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Cary, I used what Alan uses star wiring. I used Romex as Alan said solid or stranded wire could be used for this design. Some people were using silver mil-spec...I didn't go that far.


I used dual runs of Romex, 14Ga which I believe equals 11 gauge when combined. I installed a 20 amp breaker, and then double all of the wiring. In other words, there were 2 hots, 2 neutrals, & 2 grounds. That means 2 wires under each screw at the breaker box. Ideally I think Alan says use one ground, but when I asked him he said 2 grounds like this were OK too. As long as it equals the hot/neutral...so either (1) 10 gaige ground or (2) 14gauge (=11 gauge) and you're in business.


At the outlet, Hospital grade hubbel (or Eagle from Lowes is OK too I think) you use all the screws. There are 2 screws for hot...one wire under each. 2 screws for neutral...one wire under each...and then pigtail the grounds or put a ring terminal on (soldered) to go to the ground on the outlet.


Does that make sense?


For the power cord...I used Carol stranded from Home Depot...I bought 25 feet of white, black and 50' of green. I cut the green in half, and used a power dril to twist the green...one with the black and one with the white. I used a Leviton industrial (can't remember the number) plug and a wattgate IEC connector from Parts Express. I then put it in some tubing for protection.


the wire costs me about $25.00, the outlets are about $11 each. 250' of Romex was $25. The Leviton plug was $9 and the IEC plug was $19. The breaker was
 

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Discussion Starter · #9 ·
Thanks Jay! I still need to figure out the best way to actually get the power into the room. The panel is in the garage and the HT is in the room above the garage. Right now the power to the existing outlet goes up from the panel to the attic (with a wad of other wires) and then down a wall to an outlet. This could be a major pain to replace or add a new one. I might just run a new wire from the panel along the wall and ceiling of the garage and come up into the floor of the HT room from the garage (gear is in a cabinet).


At any rate, I'm sure I'll be emailing you when I get started!! Sounds like you did a lot. It's really encouraging that you got some improvement out of it.


Cary
 
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