Power amp for home stereo...

[toxcrusadr]

No, I'm talking about hum coming out of the speakers, not fan noise. They always seem to hum.

 

[similost]

I gotta ask this question that I'm surprised no one has yet...

um.. what the hell kind of speakers are you building that will "Require Up To 400 Watts"? and rms at that?????

Will these be very hard to drive loads?

Just because a speaker can handle it, doesn't mean you need it...

I've got 700 watt speakers I'm running with about 350 per channel, and I can't even begin to think about adding that much power to them without pissing off half my neighborhood, and that's being serious...

Even to hit 120db in my livingroom which is INSANELY loud, I'm using about 25 to 30watts on my mains, and about 150 on my subs.. or at least a close guess..

 

[bowtie427ss]

...you walk past a PA system at a bar, club, wedding etc. and there's quite a hum coming out at idle...is that not noise? Is it coming from somewhere besides the amp then?

"inserted" noise from noisy front end gear, poorly shielded or terminated cabling, ground loops, poor house grounds, dirty mains power, RF from dimmer packs, etc. etc.. In a portable PA system the opportunities to induce unwanted noise are almost limitless. However, i always managed to keep mine pretty much noise free after i built my own mains power distribution and connected directly to the incoming house mains.

An amplifier that itself introduces noise(easily audible amounts) in the signal path is either in need of service or a very poor amplifier.

 

[4.7inches]

I gotta ask this question that I'm surprised no one has yet...

um.. what the hell kind of speakers are you building that will "Require Up To 400 Watts"? and rms at that?????

Will these be very hard to drive loads?

Just because a speaker can handle it, doesn't mean you need it...

I've got 700 watt speakers I'm running with about 350 per channel, and I can't even begin to think about adding that much power to them without pissing off half my neighborhood, and that's being serious...

Even to hit 120db in my livingroom which is INSANELY loud, I'm using about 25 to 30watts on my mains, and about 150 on my subs.. or at least a close guess..

You get better results at low volumes with a lot of idle. I would never use a PA amp though, not built for the purpose. You have totally different goals when constructing a PA and hi-fi amp.

I´d go for a NAD 208 or Pioneer M90a if I would need another one.
Nad 208 gives out several thousand watts at 1ohm, clean, transparent sounding as well.

 

[motorstereo]

Similost; Your altecs must be around 98- 100db efficient? That would be why 25 to 30 watts would give you 120db. My speakers are in the low 90's efficient and I can't get any where near 120db (not that I've tried) even with several hundred watts going into them.

 

[bowtie427ss]

You have totally different goals when constructing a PA and hi-fi amp.

This may very well be true where "form" is concerned.

However, the functions could not be more identical.

My understanding of the function of an amplifier is to provide voltage gain.

 

[similost]

about 100 to 102 on my LF driver, and 106 on the horn driver... My subs are 100db.. .

Man.. I can't believe all the naysayers when talking about using pro amps. I invite ANYONE over to my place that says they are noisey, don't work well in the home, fans are too loud, don't sound good, and what other myth you may want to keep spreading...

You'd be shocked how quiet Pro amps can be if you have good electric, good cables, and good sources... My system is BY FAR quieter than any consumer hi-fi systems I've had, other than the ground loop I get off my television cable when I turn that source on. Nothing I can to do there other than keep bitching at the cable company. They have gotten it quieter...

I've got 3 SS Pro amps laying around.. all dead silent, and the fan noise on them is super low. One doesn't even have a fan. I've got 3 Tube PA amps. the one running is also dead silent, The two others I need to rebuild, and I'm betting on dead silance there...

Also, as far as how well PA amps sound.. there are people around here that can vouch as to what my system sounds like first hand. I always enjoy watching their expressions and how much they get into listening..

 

[whoaru99]

I gotta ask this question that I'm surprised no one has yet...

um.. what the hell kind of speakers are you building that will "Require Up To 400 Watts"? and rms at that?????

Will these be very hard to drive loads?

Just because a speaker can handle it, doesn't mean you need it...

I've got 700 watt speakers I'm running with about 350 per channel, and I can't even begin to think about adding that much power to them without pissing off half my neighborhood, and that's being serious...

Even to hit 120db in my livingroom which is INSANELY loud, I'm using about 25 to 30watts on my mains, and about 150 on my subs.. or at least a close guess..

Lots has to do with sensitivity and listening distance.

I am running one pair of speakers that is 89-90dB sensitivity from an amp rated 700wpc, and my normal listening distance is about 12ft.

If you run the numbers, that means if I ran the amp to the verge of clipping, at my 12ft listening distance, I'd be doing about 103-104dB average, with peaks hitting somewhere around 113-114dB.

Yes, that's loud, but hardly the insane level some might be inclined to think with 700wpc. And, yes, that's a real 700wpc@8 ohms, 20Hz-20kHz, 0.03% THD from a QSC pro amp.

 

[toxcrusadr]

"inserted" noise from noisy front end gear, poorly shielded or terminated cabling, ground loops, poor house grounds, dirty mains power, RF from dimmer packs, etc. etc.. In a portable PA system the opportunities to induce unwanted noise are almost limitless. However, i always managed to keep mine pretty much noise free after i built my own mains power distribution and connected directly to the incoming house mains.

An amplifier that itself introduces noise(easily audible amounts) in the signal path is either in need of service or a very poor amplifier.

Thanks, I thought it was something like that. I haven't ever heard a PA amp set up at home and obviously had some wrong assumptions.

Sorry for the thread hijack y'all.

 

[whoaru99]

You get better results at low volumes with a lot of idle. I would never use a PA amp though, not built for the purpose. You have totally different goals when constructing a PA and hi-fi amp.

I´d go for a NAD 208 or Pioneer M90a if I would need another one.
Nad 208 gives out several thousand watts at 1ohm, clean, transparent sounding as well.

It's nicely coincidental that you mention the NAD 208. It uses a form of rail switching to achieve it's high power....similar to the way high powered pro/PA amps do.


And, different construction/design goals? Yes, I suppose so to some degree. A pro amp is designed and constructed to take a beating both electrically and physically. Many home amps are designed rather on the frail side in both regards.

But, like bowtie427ss said, the bottom line function of both is to provide voltage gain.

 

[hammr7]

If you really need 400 WPC @ 8 ohms, you can always look for some of the older bridgeable amps. My Crown D150A's are rated at ~ 400 Watts when run bridged. And a pair of them, or even 4 of them, won't set you back by much. They run quiet and are about as bulletproof as you can get.

 

[similost]

That 400 watts on a bridged D150 is kind of a stretch... That is the Total Music Power.. which really isn't all usable.. The unit will start clipping around 320 watts, so that means when your trying for the full 400 watts, you're gonna have some problems..

Also, you have to know your way around electronics to bridge a D150.. you have to make some internal modifications, and not just flip a switch..

I really wouldn't recomend using bridged amps for what the OP is looking to do. You can get much better sound finding some quality amps with the power needed in stereo mode..

 

[Avicularia]

Am i right in assuming you are looking to power 2 sets of Bose 901 series 2 continental ?
If so,you might want to consider a Bose 1800 amp or two ,any series but 4 is best i heard and series 6 is most powerfull,build for the job and sound great.There`s a series 6 amp on ebay at the moment for 32 $ .
To bad i live in the Netherlands.

I have three of these,two series 3 and an original series,the 2 series 3 are also supposed to be driving 2 sets of 901 ,currently saving up to have my second set 901 series 3 fitted with series 6 drivers.(recently bought the series 3 amps and had them fixed,bad speaker relays)
( i live half a hour drive from european hq,they have a service centre,i brought my 901`s and left one hour later with fixed 901`s,brought my 2 series 3 amps,fixed within three days,they know me by name,service is great !)
In my opinion these are the best amps for 901.
If i`m mistaken,you still might want to consider them,because series one bridges easily to some 500 watts @ 8 Ohm.

 

[mulester7]

Am i right in assuming you are looking to power 2 sets of Bose 901 series 2 continental ?
If so,you might want to consider a Bose 1800 amp or two ,any series but 4 is best i heard and series 6 is most powerfull,build for the job and sound great.There`s a series 6 amp on ebay at the moment for 32 $ .
To bad i live in the Netherlands.

I have three of these,two series 3 and an original series,the 2 series 3 are also supposed to be driving 2 sets of 901 ,currently saving up to have my second set 901 series 3 fitted with series 6 drivers.(recently bought the series 3 amps and had them fixed,bad speaker relays)
( i live half a hour drive from european hq,they have a service centre,i brought my 901`s and left one hour later with fixed 901`s,brought my 2 series 3 amps,fixed within three days,they know me by name,service is great !)
In my opinion these are the best amps for 901.
If i`m mistaken,you still might want to consider them,because series one bridges easily to some 500 watts @ 8 Ohm.

.....Welcome to AudioKarma.org, Avicularia from The Netherlands....I have respect for a man who believes in Bose 901's and the Bose 1801 amps.....

 

[MunkeyQ]

I'm one of the pro amp guys now...I've got a Citronic PPX450, one of the old iron style British amps.

It's quieter than my recapped SX-1250 and Cambridge A300's power stages. No noise at all, even with the preamp maxed out...well, maybe a slight hum if you listen close enough, but the 20 year old filter caps probably need replacing.

Not sure about the new switching amps as I've never heard any in a hi-fi setting, but big iron pro stuff certainly seems to be nice.

 

[iLUVanalog]

im looking to buy a power amp, to possibly run 4 speakers for my stereo build,
im not opposed to using multiple amplifiers either, the speakers im thinking of building will possibly require up to 400 watts rms at 8 ohms, i may scale this project down a bit. but does anyone here have any suggestions of stereo power amplifiers that may fit the bill? im looking at professional PA amps to be more precise. but im open to suggestion, im just really not sure where to look.
here is one example of something ive been looking at: http://www.qscaudio.com/products/amps/dca/dca4/dca4.htm

NAD makes excellent amplifiers, excellent sound, great dynamic headroom, and reasonably priced.

my only question would be why on earth you would need 400 per channel...just how loud are you intending on going??? is your room really huge? also, are you talking about 400 watts CONTINUOUS or 400 watts PEAK, and are you talking 400 watts into EIGHT ohms or FOUR ohms? it will be a challenge to find an amp with 400 watts CONTINUOUS into 8 ohms without spending a fortune for it. you also need to be mindful of impedance, especially if you plan to run more than one pair of speakers. i have also never heard of QSC, so not sure if you would be very happy with the sound quality.

 

[toxcrusadr]

Forget impedance, he oughta be mindful of his fargin' ears.

 

[similost]

NAD makes excellent amplifiers, excellent sound, great dynamic headroom, and reasonably priced.

...without spending a fortune for it. you also need to be mindful of impedance, especially if you plan to run more than one pair of speakers. i have also never heard of QSC, so not sure if you would be very happy with the sound quality.

QSC are very well reguarded pro amps that can easily provide the power he is looking for, and more.... also at reasonable prices.

 

[MrHeadfirst]

i have since decided to redesign the speaker build im considering. what i had originally came up with seems it will easily be too big...as many have pointed out. im building 2 systems at the moment. im working on a large system for the family use, in the living room, the one with the 2 sets of 901s and a sub. i will use a pa power amp for that set up, for 2 reasons, one being due to i can use one amp to run all 4 speakers. the other just because they require a fair amount of power and i believe under powering speakers is the wrong way to go.
the other system, which i was originally speaking of is supposed to be an actual hifi system for my music room, where i plan to do most of my listening and practicing. its a relatively small room, but i want 2 things from that build, first off, i would really like to have a listening space that provides an excellent quality sound a low to mid range volumes. but will also get loud when i ask it to, in order for me to practice the way i like to. so im still searching and researching trying to get all this engineered before buying things. i am hoping to run a tube pre in to a power amp for that set up in order to achieve the sound i am looking for, qsc and crown both make excellent amps (by the numbers) for this process, however, it will indeed set me back a few dollars. which is why i cant afford to build this over night. when i decide on the drivers for the speakers im building, ill post here for you guys to review and let me know what you all think. i like to build things, rather than buy them, because im a tinkerer.

 

[mulester7]

.....u....can't....have....two....many....watts.....