Pre-amp and amplifier Q&A

I do not claim to be an audiophile just love music and would like to help some of you out and maybe learn something myself.I started 4 years ago with a Denon 3808ci coupled with a Crown xti 2000 pro audio amp for the front mains.Speakers are JBL Studio L series pair of L890's up front,LC2 center,L820 surrounds,L8400 sub.


I listen to music at pretty loud levels sometimes -10db to 0db and noticed that the front mains had a smell of electrical(plastic)burning.I lowered the gains on the Crown amp to half to solve this.Anyway my 2 year old grandson was over one day and turned the gains to full and i did not notice it and the next time i used the system the front main speakers failed(I have since rebuilt the L890's with all new factory parts)so I had to connect my old Cerwin Vega AT15's temporaraly.


The Crown xti 2000 is rated at 480 wpc @8ohm's and 800 wpc @4ohms.L890's have 8ohm impedence and AT15's have 4ohm impedence.One thing I hated about the Crown amp was the persistant ground loop hum that I could never seem to solve and I tried everything.Also I did not have a dedicated 20amp ac outlet for my system.I sold the Crown amp to avoid the said problems and also sold the Denon 3808ci.


I purchased the Onkyo TX NR-5007 to use as a Pre-amp and bridged the front mains to give me 140x2 wpc to both front mains.This set-up sounded great but would clip sometimes at high levels.I was thinking it had to do with not having a dedicated outlet for the system and maybe taxing the large toroidal power supply in the Onkyo which drives all the channels.So I installed a seperate 20 amp wall outlet for the Onkyo and this solved the problem.Still thought I could use more power for the front mains with a seperate amp which would also not tax the power supply from the Onkyo freeing it up to drive the rest of the channels.


I purchased the Emotiva XPA-2 for the front mains and I love this amp.No more ground loop hum(could be a common problem with pro-audio amps ?).System sounds great now and no clipping at high levels.I remember clearly the sound quality of the Crown and compared it to my XPA-2 and believe me there is not much differance in the sound quality.But the Emotiva has no hum and does not seem to want to harm my front mains(no smell at high levels).The trade-off is that the XPA-2 weighs 75 pounds the Crown was about 20.


Anyway what I am trying to get at is use common sense when putting together your system and I hope some of you can learn from my experiences(mistakes).You do not need to spend a whole lot of money for a great sounding system.I am not rich and work hard for my money and I know many of you are in the same boat.Micheal J Human has a great AMP FAQ which you should all read.