powered tower setup - beginner help?!

[robpass]

Hello. My name is Rob, from Australia.

I recently upped my home stereo to a pair of RT1000i powered towers, and set them up on my dedicated Yamaha 2 channel amp (for music only at this stage, not HT).

I've had them one week and they're single wired on monster cable, the amp is soon to be upgraded, but when going to sleep, i noticed an electronic humming from the speakers, one in particular. It seems to come from the power amp at the back, even when unactivated (they turn on when they sense amp signal), and signal cable removed. When I switch them off at the wall they stop humming, ofcourse. Down the back, and from the bass port is where the noise comes from. Is this normal? Has anyone else experienced this? And should I turn them off at the wall all the time when not in use? It is reasonably quiet, but has me worried!

My second question is recommendation of amp power per channel. I'm interested to consider NAD at the moment, or marantz? I'd rather the no bells - and - whistles option and go 2 way. Does anyone have a similar setup and recommend a particular model? The speakers are rated at 250w peak, suggesting i'd probably want about 120 / 140watt per channel amp I guess. I have a particularly dynamic sound taste, in that i like the highs and lows, and I want something with grunt that'll out-pace the towers before running out of steam. I'd rather a single amp, with no pre amp as finances are restrictive, and bi wiring option would be nice.

Lastly, much of my music collection is now stored on computer for daily use, as I prefer the navigation. Is anyone else using such a setup, running computer into amp? Is there a way to restrict the sound to the standard input signal without upgrading to an external USB input? I am concerned to damage amp and speakers. Is this concern valid? And have any reputable brands developed such USB devices inbuilt to amps? As yet I have held out, using only the CD player. It's difficult!

Thankyou for your help.:)

[mantis]

I think the humming your getting might be from your electricial system.I would plug the speakers into a line condisioner.Is there lights pluged into the circuit your using for the speakers???
Id get them off the wall switch outlet and plug into a normal hot all the time outlet.15 amp outlet is more than enough.

[gidrah]

Hum: I don't have any experience with any powered tower, but would assume the hum is not normal. Not necessarily destructive, just indicative of something amiss. Check out the top right corner "service and parts", Kenneth Swaugger is a heck of a guy that knows his stuff.

Power: Is your Yammie low-wattage? They usually have enough oomph to drive most speakers beyond their ratings. While I like NAD and Marantz, I'd look into a used Carver or Adcom. If your speakers are bi-ampable there's a sweet Sansui 4-channel on E-bay currently. Then again, I'm partial to used for $/sound quality and volume. Then again, I'd buy a used toothbrush to save a dime.

USB: My JVC has USB inputs on the front. I've seen connectors around that will convert USB to RCA. I don't have much music on my small hard-drive to worthy an investigation, but I think this may have come across the FORUM before and may warrant a search.

Good Luck!:)

[OrangeToupee]

NAD C370 (120wX2), you can later bridge it with the NAD C270 for 300wX2 when more money comes in.

What would happen if you purchased an 1/8" jack with an RCA on the other end and plugged that end into your amp's aux. input? Could you play your .wav's and .mp3's that way? Or do you have to use a USB?

[robpass]

Thanks for your replys.

I currently use a 1/8 jack to RCA's and have done for years, however the electrical noise from digital to analogue decoding taking place inside the PC hinders quality, as does the soundcard. Basically i'd love to hear of a reputable manufacurer who makes an amplifier that allows this decoding to take place from a digital out such as USB, using the necessary software. The only requirement is a digital in on the amp itself i beleive, and the correct computer hardware. Have a look at shopper.com for the Creative Audigy Platinum, Onkyo SE-U55, or Stereolink Model 1200. Is there an amp on the market such as the NAD with these receiver capabilities ontop of traditional home audio?

[TroyD]

sounds to me like a ground loop issue.......

BDT

[jcaut]

Possibly just hum from the transformer being "amplified" by the speaker cabinet or its surroundings??

Any transformer that's got power going to it will hum a bit. The hum from each speaker should be about the same, if you eliminate any differences in their surroundings. You might try swapping them left to right, and see if one still sounds louder.

My PSW1200 produces enough transformer hum that it's audible in a quiet room from <3 feet away, but I don't consider it to be a problem.

Jason

[robpass]

thanks guys..

looking into the amp thing more. Although I don't know much about their reputation, JVC release a couple of nice a/v receivers with usb ports designed for direct digital computer input. (ontop of coax and optic DI's).

Harman Kardon are also looking into it. check out their website for the digital computer link. Also see http://www.minidisc-canada.com/hifilink.asp - this is along the lines I was thinking. Just need to get a nice classy amp first! I figure although the digi - computer thing is a high priority, I'm going to get the amp I want with the right power, sound, etc. and just make sure it has a digital in. Then if it doesn't have all the snazzy mp3 decryption stuff I'll just get a peripheral such as those above.

BTW I was listening for the hum again and its minimal. thanks for the feedback on this issue. Other than slight warmth from the amp units (even when off but plugged in) i'm happy with them!