Which DAC/amp to get for better slam impact and sub-bass in my Oppo PM-3 ?

[DJ The Rocket]

A DAC by itself should not really add bass. But as monsterzero pointed out, a headphone amp with bass boost can.

This is such a pervasive misconception. It flows from the "all DACs [shoud] sound the same" belief, if I had to guess. But no, there are real differences, and in more ways than one being 'closer to transparent' than another. Two DACs can both have perfectly flat frequency curves and yet sound different. In bass, one can be thinner and another richer, for example.

I agree that an amp with selectable bass boost, if implemented well, can probably get the OP where he wants to be. I don't think getting bassier headphones is necessary in the case of the PM3. The ways in which headphones can become bassier tend to do so at the expense of clarity and detail in the midrange.

I wonder what the OP picked (I haven't read the whole thread yet). I found this while searching for an alternative to the Geek Out V2+, which has superlative bass presentation, but comes with an unacceptable amount of baggage (which I talk about in detail here).. If I can't find anything else that meets my needs in both sound profile and overall sound quality, I'm leaning toward getting another GOV2+ and taking the innards out in order to install it in another enclosure. Hell, even the off-the-shelf ones at Radio Shack represent improvement an order of magnitude.

 

[ProtegeManiac]

Two DACs can both have perfectly flat frequency curves and yet sound different. In bass, one can be thinner and another richer, for example.

 

This is such a pervasive misconception. If two DACs have effectively identical response curves and sound different, it's not the DAC that makes for the difference, and you forgot to measure one thing with that curve: the singal strength of the output. If they have identical flat response but one DAC outputs 1.4v and the other 2v, without making sure that the actual setting is equalized at 1000hz (rather than "yeah I think that's about the same to my ears"), the 2v output DAC will sound better. Otherwise given the response curves are different then they cannot possibly sound that different. You'd have minute differences, true, particularly with imaging accuracy and some notes, but if they measure the same they cannot possibly have such a variance in sound as you describe. In that kind of case the response isn't perfectly flat on all of them. The high pass filter for example can account for what sounds "richer," as you get more midrange by getting a little bit less treble.

 

Also even if that was the case it has a lot more to do with the amplifier than the DAC. Between the 1.4v and 2v DAC you'd have to crank up the amp more on one of them, it has more to do with one set up that has the amp playing slightly louder. And even if you measure the volume output at 1000hz, cranking up the amp on the 1.4v DAC might get the amp to the point where there is some audible distortion and noise. The amp is also the one that has to deal with current and voltage to drive the headphone, and a different input signal strength can mean the amp works slightly harder, just enough for some indistinct but inaudible noise to creep in for example. This is where you hear differences, not two DACs that are both flat. Similarly, two amps that sound the same on a sinesweep playing one frequency at a time (ie, nothing like real music) can sound different if one of them starts running out of steam on one headphone/speaker, since again this is where the test methodology can't absolutely account for real world conditions as the amp has to handle a more complex signal on a load that can be more complex when handling such a signal (vs using a simple sinesweep to measure impedance variances).

 

In short, my point is, either the DACs do not actually measure the same curve, or it's the amp not playing at the same level to account for line voltage variance or it's beginning to distort with one of them.

 

[kittisiri]

Update :
 
I already ended up with Oppo HA-2 and I'm really satisfied.