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Gear / Technical Help => Playback Forum => Topic started by: vwmule on August 30, 2011, 10:48:47 AM

Title: iMac to stereo buzz
Post by: vwmule on August 30, 2011, 10:48:47 AM
Moved my computer close to stereo and hooked the two via mini > RCA. It's great though I can hear a distinct electronic buzz when no music is playing. Can that harm my stereo or speakers? And what can I do to avoid that? I have an Apple wifi device that can stream to stereo but haven't gotten it to work and would rather have a hard connection anyway.
Title: Re: iMac to stereo buzz
Post by: page on August 30, 2011, 10:51:22 AM
Just about every computer I've had (mac or PC) did that in some form or another. It might be a ground issue, or it might just be the analog components in the imac. The easiest way to resolve it is to get a cheap DAC and use either USB or optical out.
Title: Re: iMac to stereo buzz
Post by: ScoobieKW on August 30, 2011, 10:56:44 AM
Sounds like a grounding issue, two options.

1. Get a groundlift plug.
2. Get an external A/D interface.

I like #1 for the price, but #2 for quality. Audio output circuits in consumer computers are typically noisy. Two many power stages, and circuits crammed into a small space, that plus an emphasis on economy and good enough for most lead to compromises.

Wireless streaming to your reciever can work, but adds in a whole nother A/D and D/A step and adds compression to the data.

Title: Re: iMac to stereo buzz
Post by: vwmule on August 30, 2011, 11:43:50 AM
Can y'all recommend a DAC?
Title: Re: iMac to stereo buzz
Post by: dnsacks on August 30, 2011, 11:50:22 AM
what brand/model receiver are you using?  Many newer units that support 5.1 playback have d>a converters built in.  I believe the IMAC can send an optical digital signal too.

Title: Re: iMac to stereo buzz
Post by: DigiGal on August 30, 2011, 01:07:53 PM
Does your stereo have optical digital inputs?  On all newer iMacs the audio output jack also doubles as an optical output as well as being analog.
Title: Re: iMac to stereo buzz
Post by: page on August 30, 2011, 02:04:04 PM
Can y'all recommend a DAC?

The cheapest right off the top of my head is the nuforce udac2 (http://www.nuforce.com/hp/products/iconudac2/) at around $110 if you shop around. It has the RCA line-outs and doesn't require it's own power (USB powered). iBasso has one (http://www.ibasso.com/en/products/show.asp?ID=73) that's around that price as well that's a bit more portable but runs off of a usb charging battery.

I saw one lately that was around $50, but I can't remember what. You might browse ebay if you're looking on the cheap.
Title: Re: iMac to stereo buzz
Post by: vwmule on September 03, 2011, 10:37:34 AM
Thanks for all the responses. My Yahama Natural Sound receiver is going on 10 years old but it has an optical in (for sat TV or DVD). I'll give that a shot.
Title: Re: iMac to stereo buzz
Post by: bryonsos on September 03, 2011, 10:41:56 AM
Here's a converter in the YS:

http://taperssection.com/index.php?topic=145892.0
Title: Re: iMac to stereo buzz
Post by: page on September 03, 2011, 02:23:16 PM
Here's a converter in the YS:

http://taperssection.com/index.php?topic=145892.0

wrong direction
Title: Re: iMac to stereo buzz
Post by: audBall on September 03, 2011, 02:52:55 PM
I really like my Musiland 01 Monitor USB.  I got it on ebay for about $50 used.  It'll fit in your pocket, so it's great for on-the-go.  24/96 compatible and sounds pretty damn good. 

-RCA Out
-Headphone out (works best with low/med impedance headphones)
-Toslink Out

http://www.musiland.com.cn/index.php/Product/show/id/140
Title: Re: iMac to stereo buzz
Post by: DigiGal on September 03, 2011, 03:03:43 PM
Does your stereo have optical digital inputs?  On all newer iMacs the audio output jack also doubles as an optical output as well as being analog.

Thanks for all the responses. My Yahama Natural Sound receiver is going on 10 years old but it has an optical in (for sat TV or DVD). I'll give that a shot.

Going optical directly out of the computer to the stereo should eliminate your hum problem and the need for any external DAC.  If the hum is still there then the stereo itself likely has an issue. 
Title: Re: iMac to stereo buzz
Post by: keytohwy on September 03, 2011, 07:39:37 PM
All good advice here. 

I took it a level further and got an Airport Express.  It, too, has an optical out and allows you to keep your Mac anywhere (provided you have a wireless network) in the house, and playback form there.  Then you are wireless from the Mac to the Airport, and optical into your receiver.  Works great for iTunes.  If you want to stream other music sources to it, I HIGHLY recommend AirFoil which will stream any audio source on your Mac to your Airport Express.

Airport Expresses can be found on eBay for $50-ish.

keytohwy
Title: Re: iMac to stereo buzz
Post by: vwmule on October 03, 2011, 09:52:23 PM
UPDATE: I got a six foot optical cable from Amazon (Belkin brand) and am now running 24 bit audio from the iMac to my stereo. No buzz whatsoever.

Thanks for everyone who helped.