[bigshot]

The problem with the IEMs is because of the IEMs, not the Mac. Mac's audio output has always been perfect if you use the proper headphones or line out. I use a $500 Mac Mini to drive my whole home theater and it has perfect sound and great performance, and all the software I need comes bundled. Can't get too much cheaper than that.

 

[RRod]

  The problem with the IEMs is because of the IEMs, not the Mac. Mac's audio output has always been perfect if you use the proper headphones or line out. I use a $500 Mac Mini to drive my whole home theater and it has perfect sound and great performance, and all the software I need comes bundled. Can't get too much cheaper than that.

 
I'm actually thinking about getting a Mini to do the exact same thing. The nerd in me wants to get a NUC and put Linux on it, but I have a Mac-using wife so spending the extra $$ on the Mac will help keep the peace.

 

[bigshot]

The nice thing about the Mini is that it's set up to work as a home media server out of the box. No need to configure it or install a bunch of third party stuff. Plug and play. My time is worth more than a $50 savings here or there. Add a couple of Airports and you're streaming all over the house.

 

[bigshot]

But I seem to remember someone around here told me that PCs are being sold with better audio capability out of the box too now. Maybe that isn't true.

 

[cjl]

  The problem with the IEMs is because of the IEMs, not the Mac. Mac's audio output has always been perfect if you use the proper headphones or line out. I use a $500 Mac Mini to drive my whole home theater and it has perfect sound and great performance, and all the software I need comes bundled. Can't get too much cheaper than that.

A good headphone output should not have audible noise when used with sensitive IEMs, and a high sensitivity is not an inherent problem with headphones (in fact, it can be a benefit for portable players with a low peak voltage capability). In fact, by your argument here, I could say that there is no such thing as a noisy amp, since clearly your problem is always that your speakers are too sensitive rather than the fact that the amp is noisy.

 

[limpidglitch]

You can see from the Application Notes (p. 30) what Texas Instruments considers to be appropriate analogue circuits for their fanciest DACs.
One simple inverting I/V opamp circuit per phase per channel, followed by a summation circuit with a 4th order low pass filter. Although I'm sure it takes a bit of tinkering with the exact values to attain the really nice specs, it certainly isn't magic, and some believe it be done successfully even simpler.

 

[bigshot]

  In fact, by your argument here, I could say that there is no such thing as a noisy amp, since clearly your problem is always that your speakers are too sensitive rather than the fact that the amp is noisy.

 
That's true. You have to choose headphones and speakers that match the amp. It isn't the amp's fault if you try to use mismatched transducers. That's like putting semi truck tires on a volkswagen beetle, then complaining that the beetle doesn't corner well.

 

[RRod]

  You can see from the Application Notes (p. 30) what Texas Instruments considers to be appropriate analogue circuits for their fanciest DACs.
One simple inverting I/V opamp circuit per phase per channel, followed by a summation circuit with a 4th order low pass filter. Although I'm sure it takes a bit of tinkering with the exact values to attain the really nice specs, it certainly isn't magic, and some believe it be done successfully even simpler.

 
Thanks for pointing to a specific example, though circuit diagram are still whooooosh to me ^_^ The 2nd DAC may do it more simply, but that price kind of goes against the concept a bit :-o

 

[Harry Manback]

So, enlighten me. Will an O2 amp pair well with grados? Is it even beneficial?

 

[davidsh]

My old MacBook pro 2010 was hissing with just about any portable headphone that I owned back then. Rather annoying

 

[bigshot]

Must have been something wrong with it. Apple would have fixed it if it was under warranty. I've had Macs going all the way back to the Lisa. Never a problem. No sound in the Lisa though!

 

[davidsh]

It isn't an uncommon problem to my knowledge.

 

[RRod]

So, enlighten me. Will an O2 amp pair well with grados? Is it even beneficial?

 
If it's a typical Grado with 32ohm impedance and ~100dB sensitivity, then there is probably no benefit; the cans are easy to drive. Output impedance of the amp is a possible issue, but even the 5ohm output of my old iPod is close enough to the "rule-of-thumb" range.

 

[cjl]

So, enlighten me. Will an O2 amp pair well with grados? Is it even beneficial?

An O2 should drive every Grado headphone on the market perfectly. As for whether there is a benefit? That depends on what you currently use, but as Rrod said, Grados aren't terribly hard to drive.

 

[cjl]

  Must have been something wrong with it. Apple would have fixed it if it was under warranty. I've had Macs going all the way back to the Lisa. Never a problem. No sound in the Lisa though!

Some quick googling indicates that this is a common issue with several generations of macbook, especially when the macbook is plugged in (which indicates it could be something like a noisy ground or power supply when running on AC power, combined with an audio circuit with an inadequate ability to reject noise from the power supply). It's very common on other laptops and other mobile electronics too, since high noise rejection isn't really required when running on battery (batteries give a very clean and stable power supply), and mobile chargers tend to prioritize small size and efficiency over low ripple and noise.