Inherited system - needs a new receiver? power amp?

[jdance]

Hi all,

I have been reading reviews of all kinds of things here but am I still pretty confused as to what I really need. I'm hoping to get some help from some people who actually have some experience in this stuff.

I recently inherited a component system - AR9 mains, an AR4c center, two AR "The Edge" for surrounds, and a JBL S120P subwoofer. I also received a NAD T752 receiver and quite a bit of high quality speaker wire (the stuff has 4 leads for mains and center).

Anyway, I hooked up the mains and did a line-out to the subwoofer (it is self-powered) and fired her up, using the TV receiver (analog) as a source signal, intending to relax and watch The Daily Show for a bit. Things were going okay until I turned it up a bit, and then the NAD receiver turned off. It seemed like a power problem; I fiddled a bit with making sure the power to the receiver was good (its all new wiring anyway) but the problem persists. I ran the system for a while at its startup volume (-18 db) and the receiver's fan was whirling away - easily audible over the speakers. The problem quickly became worse to the point where the system would power down almost immediately, even at -18 db.

I did some research and found this receiver is highly rated but also frequently has these kind of problems - I began to wonder if this is why my friend was happy to give this receiver to me. Given I have no investment in it, I started to look at some alternatives on Craigslist as well as learn more about my new components, but information about receiver/amp/speaker combinations are hard to come by.

So, I am wondering if you could recommend what I might need to be able to drive this system. Is a power amp for the mains something I should look at immediately? Or will a new receiver do well enough for a while? Do you think any of these receivers would be any good for this system? They were all available for sale on Craigslist, but I have not the foggiest idea on which one would work best.

• Denon AVR 2802
• Marantz SR5400 or SR4001
• Yamaha RX-V1070 or RX-V657
• Onkyo DR C500
• Sony STR-DE885, STR-DE985, STR-DE598

There were also a few power amps for sale - there was a Soundcraftsmen 2502 and a B&K ST2140 for sale. There's also a NAD power amp, but I don't know the details on it yet. Also, a Sherbourn stereo amp rated at 100W/channel - not sure the model name.

Thank you all very much for any help you can provide!

[JohnMichael]

Sounds like the AR 9's need more power than the NAD can give. The 9's must be causing the NAD's protection cicuits to trigger. When I sold AR 9's years ago we used power amps of about 200 watts. I would suggest a power amp with a strong power supply that can swing some volts.

[PDN]

That's too bad about the NAD T752. There's been much chatter about their QC problems these past years. I was an NAD man for so long but now I've moved on to Rotel and Marantz. That T752 at 80 watts/ch into 8 ohms all channels driven should be plenty of receiver for your system. I would take it to an authorized NAD service center for a look. If not, then I would go with the Marantz SR4001 provided it's been in a smoke free and pet free enviornment. Just my opinion.

[jdance]

New news... the receiver is behaving itself today. Maybe it was proximity to the subwoofer was affecting it, but it does seem to be capable of doing some amplification today. I haven't been able to get it to power off yet by using the volume knob, but I haven't pushed it past +3 db.

Anyway, the new discovery is the AR9s powered by the receiver (in stereo mode) sounds pretty awful - its hard to place what would fix it, but needless to say it sounds nothing like plugging in headphones into the receiver (Sennheiser HD-595), which I did to make sure the source was okay (I am just using the line out function on an iPod dock right now).

I am almost wondering if it is out of phase but I double-checked the wiring. I am a bit new to the 4-connection setup… on these wires, the + and - are lightly soldered together, so I simply matched those that were soldered together when I hooked up the speakers. For instance, if black/clear were soldered, I hooked up that as negative on the receiver, and hooked up black and clear to the negative posts on the speaker. Seems pretty standard?

Anyway, does anyone know more about this receiver? In particular, this receiver/speaker combination? Maybe a good idea is look around to see if I can audition these speakers and/or receiver in a store to see what they should be capable of...

[jdance]

Heh, I think I just found the problem. I was looking over the cables again and, low and behold, on the right speaker, one of the positive cables came loose and was just making contact with the negative post... bam, you get a short. Those protection circuits were doing their job, else the receiver would be up in smoke. Anyway, I have no problems now, +10 db is quite loud and works fine.

But... the sound is basically all over the place... cloudy, muddy, tinny, bleh. Doesn't matter how loud (or not) I have it. Any ideas? Something has to be wrong. As a basis of comparison I am pretty used to hearing a Bose Lifestyle 30 system - I would expect this to have better and more powerful response - and as I previously mentioned, I have Senne HD-595s for cans. Perhaps the AR9s are underpowered - my friend did have an Onkyo power amp that he didn't want to give me . Would you recommend any of the power amps I listed (I just updated the post to correct what I found)?

Also, do you think upgrading the power cable on the receiver is a good idea? I don't have the original cable and am using a standard computer cable (i.e., the cable is 3 pronged even though the receiver is not grounded). Not sure how much a difference this might make... copper is copper?

[jdance]

More info! I hooked up the rears (AR "The Edge" - 100W satellites) as mains to try to determine if the receiver is the point of failure, but remarkably the rears sound a lot better than the AR9s. I turned up the subwoofer a lot (maxed the crossover and turned up the level to compensate), and while it doesn't sound great, it's not half bad.

Unfortunately, this doesn't determine whether the problem is the inability of the receiver to power the AR9s or the AR9s themselves, but it does seem to rule out the receiver itself as being faulty.

[hydroman]

I would suspect the AR9s. Can you swap with another person's main speakers to check it out?

[jdance]

*gasp* Someone thinks its the speakers. This is new! I am curious what could be wrong with them, though, everything looks fine. Keep in mind these AR9s were probably manufactured circa 2000 - they're not 20 years old.

No, I don't really have anything else, unfortunately. I'm limited to the AR 9s, the AR 4c (except the terminal is broken, need to get it soldered), and the AR Sequels.

[hydroman]

What i meant was to ensure the amp is okay - but it sounds like it is.

If underpowered (NAD shouldn't be IMHO) i would look at a seperate amp for just the fronts (there is a output for the mains, yes?).

But I would listen to the AR9s on a beefier system (bring them to the store) and see if they really are what you like. If nto - then perhaps new speakers on the NAD would be more improvement for the $$. Sell the old speakers... and now you have a great system for a very small investment...