5.1/7.1 Amp Seperate

**Daveburt714** · 10-24-2009, 11:09 AM

The owner of the company I work for redid his Home Theater and gave me a really nice B&K preamp. This thing cost over ~$2500 a few years ago and I would like to use it.
The only bad thing is a matching B&K Amp cost ALOT of money, even on EBay the cheapest I could find was $1000 used...

If nothing else I'll try using it with my 5.1 Sony reciever, but I just wondered if anyone had any ideas for a nice/cheaper Amp seperate?

It supports ALL Dolby Formats plus THX and NEO6. One other question for anyone who might know, do you think it would be an improvement over my Sony Reciever even if I did have to use it's amp?

Thanks....... Dave

Heres a couple pics:

**jason str** · 10-24-2009, 11:45 AM

Find some used Adcom amps, you can usually find them for reasonable prices and they sound great.

I recommend the GFA 5400 (2 channel amp) if you can find one.

They make 2,3 and 5 channel models also.

Sell your sony to help pay for your new amps.

**EniGmA1987** · 10-24-2009, 12:06 PM

WOW. Thats really nice. One of those would be perfect for me. I dont use any HDMI, all component and optical or RCA analog inputs to my receiver. and I have all seperate professional grade amplifiers that have XLR inputs, so those XLR outputs on that amp would be perfect for me. No more suck RCA to XLR unbalanced cables. Ill have to look into getting one of those for me, or if you cant afford using it or end up not wanting it ill gladly take it off your hands.

As for it being an improvement over your Sony receiver, absolutely. Unfortunately the Sony would hold you back considerably. First because those balanced XLR outputs would have to be changed down to unbalanced RCA connectors to go in to the multichannel input on your Sony. Also, the amps inside your Sony are some hardcore suckage. You would be way better off buying a bunch of 2 channel amps and going straight from the XLR outputs on this unit to the power amplifiers. Unfortunately that can get pricy fast for some decent amps. A favorite among the garage band and home theater crowd (the midrange home theater, not the insane HT people) are Behringer power amps, the euro power line. They are fairly cheap power amps with decent power ratings. Or Peavey just came out with some new amps that are really cheap. However, they don't quite produce the full wattage they specify, but it still would do a lot better than your Sony.

EDIT: here are the cheapest amps you could get that are decent/good:
http://www.sweetwater.com/store/detail/IPR1600/
They say 1600w total, but in reality you will probably be getting about 350w per channel @ 4ohms. Again, you will need one of those amps for every 2 channels of audio you have. So if you run a 5.1 system you will need to buy 3 of those amps.

EDIT again: These would also work:
http://www.sweetwater.com/store/detail/XLS202/
http://www.sweetwater.com/store/detail/GX3/

However, I have had 2 Crown XLS series amps go bad on me (XLS602s), and 2 QSC amps go bad on me (an original PowerLight PLX3002 and a USA1310). Thus I no longer like to use those brands as much, however I do trust QSC more than Crown. Out of 30 QSC amps I have either owned or used in the past six years, 4 have gone bad. 3 out of 4 Crowns I have used or own have gone bad. I prefer Crest Audio and Lab Gruppen.

Oh and remember, if you cant afford to use this in your system or if you just dont want to, I will take it off your hands

**Daveburt714** · 10-25-2009, 10:31 AM

Thanks for the info folks!

I hooked it up to my Sony for the time being (Multi In) and watched Transformers last night. All I can say is WOW...

Sounds much better than the Sony reciever itself, the seperation and crispness of the sound is amazing!

Buying amps is going to be a little pricey but I think I'm convinced it's worth it.

Any comments on these amps?
Technical Pro LZ-1100
http://www.abesofmaine.com/item=TPLZ1100~item.htm

My only consern would be the noise level of the amps, but I guess I could put them in a closet or something.

**jason str** · 10-25-2009, 11:21 AM

What kind of speakers are you running ?

The Adcom will be silent, they use fins for the heatsink.

Get some used stuff, a good quality used amp will be better than a bottom basement unit.

**EniGmA1987** · 10-25-2009, 05:07 PM

low quality amps are the worst investment you can do, I learned that first hand. I bought some cheap $120 amps rated for a little over 1000 watts, and they sound HORRIBLE. not only do they clip at extremely low volume levels, they cant produce anywhere near the power the amp is supposed to be rated for, and the signal sounds bad, especially the higher frequencies. Do yourself a favor and dont get anything except a real brand name companies amps.

QSC
Crown
Crest
SoundTech -> not a respected company, but oddly enough the best sounding amp I own.
Berhinger
Peavey
Yamaha
Mackie
Samson

are your "brand name" professional amps, although many of those are not great quality brands. I just listed all the main ones. Sure you can also get lots of smaller companies hifi home theater amps and they will sound amazing, but generally those cost a great deal of money and are probably out of your price range.

**Daveburt714** · 10-25-2009, 06:18 PM

Thanks for the heads up EniGmA1987. I was a little leary of those anyway. Actually I'm pretty impressed with the sound just using the Sony's amps, the quality is much better than using it's decoders/circuits.

I'm in the process of buying a house anyway so I need to save some cash.
I'll definetly keep an eye on Ebay and Craigslist in case something comes along though!

Originally Posted by jason str

What kind of speakers are you running ?

My speakers are all Infinity's.

SM112 towers for the mains
Center and rears are from a set of surround 750 series
and a 12" powered sub.

Guess you can tell I like Infinity....

**Donnie27** · 10-26-2009, 05:50 AM

Originally Posted by Daveburt714

Thanks for the heads up EniGmA1987. I was a little leary of those anyway. Actually I'm pretty impressed with the sound just using the Sony's amps, the quality is much better than using it's decoders/circuits.

I'm in the process of buying a house anyway so I need to save some cash.
I'll definetly keep an eye on Ebay and Craigslist in case something comes along though!

My speakers are all Infinity's.

SM112 towers for the mains
Center and rears are from a set of surround 750 series
and a 12" powered sub.

Guess you can tell I like Infinity....

Carver-AV-505-5-Channel-Power-Amplifier-80w-x-5

Price: US $211.00 + $41.30 UPS GroundSee more services See discounts?

Don't be fooled by other so called named brands claiming to offer more wattage. Unless you intend to DJ for a nightclub, this real CLEAN 80 Watts per channel is more than enough to cause hearing loss.

Yes, the real AMP will kill that Sony.

**EniGmA1987** · 10-26-2009, 06:55 AM

That is a pretty nice amp, and cheap too! But no balanced inputs...

**jason str** · 10-26-2009, 07:11 AM

Great find on the Carver, they make respectable sounding amps.

Be sure to check your local Craigslist for local offers.

Marantz, Scott, Halfer, Rotel, Krell, are others to look out for.

Sometimes you can find some decent stuff on Audiogon for sale too.

**EniGmA1987** · 10-26-2009, 08:48 AM

Yes those are some pretty good home theater amplifier brands, but I would try and find one with balanced inputs. You have balanced XLR outputs on your high end HT processor, converting down to unbalanced signal will only bring down the quality of the signal itself and allow more chance of interference to affect it. Granted it will be a short cable run so you wont have much chance for interference to enter into the system though those cables, but it would still lower the integrity of the signal to change it from a high quality XLR connection to a regular old RCA.

**psyconut713** · 10-26-2009, 09:13 AM

http://www.emotiva.com/

great for the price, brand new

my buddy mixed this as his surround with his bryston for his mains

http://emotiva.com/xpa5.shtm

**EniGmA1987** · 10-26-2009, 11:00 AM

That xpa5 would be a great choice

**jason str** · 10-26-2009, 05:44 PM

Originally Posted by EniGmA1987

Yes those are some pretty good home theater amplifier brands, but I would try and find one with balanced inputs. You have balanced XLR outputs on your high end HT processor, converting down to unbalanced signal will only bring down the quality of the signal itself and allow more chance of interference to affect it. Granted it will be a short cable run so you wont have much change for interference to enter into the system though those cables, but it would still lower the integrity of the signal to change it from a high quality XLR connection to a regular old RCA.

Home audio will not benefit much using XLR cables since the cables are much shorter and far less likely to pick up interference than the long runs that are used in professional applications, the amp itself will be much more of a factor in sound quality.

**EniGmA1987** · 10-26-2009, 08:59 PM

Originally Posted by jason str

Home audio will not benefit much using XLR cables since the cables are much shorter and far less likely to pick up interference than the long runs that are used in professional applications, the amp itself will be much more of a factor in sound quality.

I realize that, but if the pre-amp is sending out a balanced signal, doesn't it have a signal level of +4dBv? and the unbalanced RCA inputs on some of the amps would have a signal level of -10dBv right? Wouldn't it be best to match the proper voltage/signal levels? If I remember right, it is almost a 12 decibel difference between those signal levels. Which since every 6dB is double the volume, if you were to go from those XLR outputs to the RCA inputs you would be halving your volume, and then halving it yet again giving you only 1/4 volume from if you had just stayed balanced the whole way.

Personally I think it would make a big difference if you bought an amplifier that took full advantage of your special outputs on your super nice pre-amp and you were able to stay with the XLRs. But hey if you want to mismatch voltages then thats your thing...

**Daveburt714** · 10-26-2009, 09:53 PM

Thanks for all the suggestions folks!

I'm still very new to seperates, and I'm sure that Carver is a really nice Amp for the price...
I'm not sure about the importance of the XLR thing. This is only a guess on my part (I'll have to research a little more), but my gut tells me even on a short run it would offer better quality...

One other thing I'm kind of a stickler for is matching components. I had a Bose Center and surrounds on the speakers (with the Infiity Mains) and I was not happy with them at all! It's just me I guess, but Bose speakers have never really impressed me anyway, not sure why I even bought them... No offense intended to anyone, just my preferences.

That Emotiva is beautiful and I'm sure it would be a good choice, unfortunately it's out of my price range for the time being.

Money is kinda tight right now, and as I said before I like matching components anyway. I'm really impressed with this B&K Head! Not sure where it's going to end up, but I'm watching this B&K Amp to see where it lands when it gets close to the end of the auction...

http://cgi.ebay.com/ws/eBayISAPI.dll...%3DI%26otn%3D2

If I could put in a last minute bid for ~$300 and get it I'll probably go that route...

**jason str** · 10-27-2009, 06:11 AM

Whatever you choose will be a big improvement over your Sony, i too dont like to mix and match brands but unfortunately i have never heard that brand of amplifier so cannot comment on the sonic qualities but maybe you could find a local store that stocks the brand and give a test drive.

Good find on the B&K amp, hope it comes through for you so you have some matching equipment.

And stay away from Bose, nothing more than overpriced junk.

**MattiasNYC** · 10-27-2009, 06:16 AM

Originally Posted by EniGmA1987

I realize that, but if the pre-amp is sending out a balanced signal, doesn't it have a signal level of +4dBv? and the unbalanced RCA inputs on some of the amps would have a signal level of -10dBv right? Wouldn't it be best to match the proper voltage/signal levels? If I remember right, it is almost a 12 decibel difference between those signal levels. Which since every 6dB is double the volume, if you were to go from those XLR outputs to the RCA inputs you would be halving your volume, and then halving it yet again giving you only 1/4 volume from if you had just stayed balanced the whole way.

Personally I think it would make a big difference if you bought an amplifier that took full advantage of your special outputs on your super nice pre-amp and you were able to stay with the XLRs. But hey if you want to mismatch voltages then thats your thing...

I could be wrong but the output of a speaker is "speaker-level", and neither the hotter "pro-audio line level" +4dBu or the -10dBV "consumer-level" are relevant. These levels are the ones to concern oneself with when making connections between components such as turntables, outboard effects (compressors etc), micpreamps etc.....

EDIT: Actually, I think I misread the intent here, and you might be right, the output level may be a concern depending on the gear to be connected to it....

**EniGmA1987** · 10-27-2009, 06:56 AM

Yes Mattias, I wasnt refering to anything speaker level or post amp. I meant going from the pre-amp out, to the input stage on the amp, going from a balanced line-level signal, to an unbalanced line-level signal.

Hey Dave, looks like that amp is at $400 right now

But the specs are kinda sucky anyway. much better than your Sony still, but some of the main specs for the amp are:
Power rating: 8 ohms 125 watts @ 1 kHz/ 4 ohms 185 watts @ 1 kHz
Damping factor 150
Slew rate 14 V / )sec

The power rating if you notice is for a straight 1kHz singnal, not a full range signal. I bet a 20Hz-20kHz rating would be around 80-90 watts @ 8ohms. That should still be enough for what you want though,but Im just saying that it is over exagurated a bit.
Damping factor is slightly on the low side of things, if you are getting a seperate amp you really should try and get a damping factor of at LEAST 200, I personally like to look for things over 300.
Slew rate is also a bit slow if my memory serves me right. The slew rate can affect transient response and dynamics of the sound.

Like for instance, QSC brand RMX series amplifiers have a damping factor of at least 300 @ 8ohms, for everything under 1kHz. They also have a slew rate of 40v sec. Im sure you could find some sort of multichannel high end home theater amp with much better specs than that B&K amp you are looking at.

**Donnie27** · 10-27-2009, 10:30 AM

Originally Posted by EniGmA1987

That is a pretty nice amp, and cheap too! But no balanced inputs...

But that AMP is made for something like that Pre AMP this Guy has. If you keep worrying about the Absolute best, you end up with Nothing. This is an Old School 5 RCA input AMP, no BS and no frills. Its made for a Pre-AMP not a recording Mixer. I'm not sure if Balanced Inputs would matter.

I've used the 2 channel version of this Carver Amp and this 5 ch version would be absolutely hard to beat for a quick and dirty killer system.

I know you know your stuff very well, so this is for most of the others.

@ the OP.

Balanced audio is a method of interconnecting audio equipment using impedance-balanced lines. This type of connection is very important in sound recording and production because it allows for the use of long cables while reducing susceptibility to external noise.

Balanced connections use three-conductor connectors, usually the XLR or TRS jack plug. XLR connectors, for instance, are usually used with microphones because of their durable construction, while TRS jack plugs are usually used for mixer inputs and outputs because of their smaller profile.

For this use shielded or heavy duty RCA cables can pull off and is really all that's needed here.

Good cheap cables?

http://www.computercablestore.com/6_...bl_PID447.aspx

Two Sets of these work great (total of 6 cables). You get all 5 plus one for the separate Powered Sub. You'll NOT get any noise or signal loss worth talking about with these. If there is any Noise or Loss, your ears will NEVER know it.

One of these. Connected to your sound card's Center Sub Out Put if you're using a Computer or the 6th Line straight to the Sub.

The Pre Out of my Harmon Kardon 247 was connected to my Harmon Kardon 730 twin amp's Pre-amp input with the Couplings removed. This gives the Main Left and Right speakers some kick-@$$ serious thump! With this Carver you can get the same thing from 5 channels instead of two.

**Daveburt714** · 10-29-2009, 12:40 AM

Originally Posted by Donnie27

If you keep worrying about the Absolute best, you end up with Nothing. This is an Old School 5 RCA input AMP, no BS and no frills. Its made for a Pre-AMP not a recording Mixer. I'm not sure if Balanced Inputs would matter.

I've used the 2 channel version of this Carver Amp and this 5 ch version would be absolutely hard to beat for a quick and dirty killer system.

Thanks for the input Donnie27...
You may very well be right about the Carver, the price is right and I'm sure it would be much better than using the 5.1 input on my Sony.

In all reality, An Amp is an Amp, and I'm sure the Carver would sound a whole lot better than what I have!

I'll keep you folks posted with my adventures...

I love XS... You folks are the shyt when it comes to tech!

Thanks to all for your help!

**Donnie27** · 10-29-2009, 06:40 AM

Originally Posted by Daveburt714

Thanks for the input Donnie27...
You may very well be right about the Carver, the price is right and I'm sure it would be much better than using the 5.1 input on my Sony.

In all reality, An Amp is an Amp, and I'm sure the Carver would sound a whole lot better than what I have!

I'll keep you folks posted with my adventures...

I love XS... You folks are the shyt when it comes to tech!

Thanks to all for your help!

You're very welcomed and good luck!!!! I love sounds almost as much as I love computers. There's always something better but anything is better nothing is the way I see it. I kicked the Audiophile bug but not an Audio bug as a whole. I enjoy seeing others enjoying great sound systems. I don't care for the "This is better so that sucks" crowd at all.

I mean grade A beef doesn't suck because grade AAA is slightly better.

**Daveburt714** · 10-30-2009, 07:17 PM

Yeah, it's me again...

Sorry for all the noob questions, pretty sure I let a decent amp slip away.
It was a 6x60 watt Rotel for $125, the guy had 2 of them and they both sold before my check hit the bank (less than 24 hrs)...

I've spent most of my time looking for a 5.1 (6 channel amp) because I wasn't sure how well my Infinity sub would react with line level input (I've always ran to the powered in connectors).

To help figure out my options I took a cable and ran it from the B&K head to the Line Level input on the Sub and it shook the frikken walls!
I had to turn the volume on the Sub down to about 1/8th volume just so I didn't make the neighbors mad!

So this opens up a whole new set of options for me.

Seems like a 5 channel amp should be more than enough. I'm not stupid, but I am a little ignorant when it comes to audio, so I appreciate the help...

Anyway, I found this one on Ebay, it's from a guy with "0" rep so I'm a little leary... I've Googled it quite a bit and it looks good to me, any opinions, other than the fact that I would be buying from an untested seller?

http://cgi.ebay.com/ws/eBayISAPI.dll...=STRK:MEWAX:IT

BTW: BOOO!!

Happy Halloween...

**PaganII** · 10-31-2009, 08:01 AM

I use a QSC RMX 1450 for a stereo and it rocks! QSC makes a 4 channel CX404 about 200wpc but is too expensive retail. Much cheaper on ebay. Churches use them for PAs.That Carver looks perfect. Made in USA too I think.
Behringers are knock offs of the RMX.

**jason str** · 11-01-2009, 12:04 PM

Great find on the Adcom, you wont be sorry with that even at twice the cost.

Detailed mids, sparkling highs and solid bass response.

If it does not pan out don't give up, something will come along.

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