[w0lverine]

Hi all,
 
I generally listen to music while on the computer with my Philips Fidelio L1 (love it!) plugged into an Asus Xonar DX or directly to my h/c amp Denon 1911.
I read here and there that both the DX and Denon were not top of their class in terms of headphone driving and I must admit that I'm quite disatisfied by my Denon's output, lacking definition.
Given my setup, I wonder if my cans would benefit from an amp ?
 
I also listen to music on the run with Cowon J3 and Westone UM2 with custom molds, and i've struggled with the volume being too high, maybe a portable amp would also help ?
 
I think my number one priority is versatility, I would like to plug it to my computer, amp and portable player (not a deal-breaker if not possible)
 
Thanks !

 

[ProtegeManiac]

  Hi all,
 
I generally listen to music while on the computer with my Philips Fidelio L1 (love it!) plugged into an Asus Xonar DX or directly to my h/c amp Denon 1911.
I read here and there that both the DX and Denon were not top of their class in terms of headphone driving and I must admit that I'm quite disatisfied by my Denon's output, lacking definition.
Given my set-up, I wonder if my cans would benefit from an amp?

 

That might be true for the Denon receiver but I'm not sure how much better you can get past the Xonar DX for the L1 and UM2. What are you using as a source for the Denon? Is it part of an HT system and you just want to be able to use headphones with it when you can't use the speakers? Check if the Denon has any digital outputs/pass through from the digital inputs, you can then use a DAC-HPamp with it that can work off the digital output from the Xonar DX (assuming you have them in the same room).
 

  I also listen to music on the run with Cowon J3 and Westone UM2 with custom molds, and i've struggled with the volume being too high, maybe a portable amp would also help ?

 

Now there's another problem - the Westone UM2. You'll need to find a portable amplifier with variable gain settings and has a low gain setting useful at least for IEMs in general, otherwise you'll still end up with the same issue. Note that being portable alone does not totally help in that regard - others can have crappy potentiometers (and analog potentiometers have a channel imbalance at very low settings) along with a still too-high gain setting, so what will happen instead is that while it won't be too loud right away, chances are that at your listening level there might still be a good deal of imbalance.

 

My Ibasso D-Zero luckily has that sweet spot for my Aurisonics ASG-1.3 - at one left-right sweep of the slider from zero it doesn't have any imbalance and is my comfortable listening level too. However go more than 1/3 of a turn past that and it's loud enough to blow out eardrums (which is why I slide it back down to zero when I finish using it).
 
 

  I think my number one priority is versatility, I would like to plug it to my computer, amp and portable player (not a deal-breaker if not possible)

 

I'd recommend the D-Zero MkII since it's a nice value for money, however you mentioned having a Xonar DX. The problem there is that if you use USB you will completely bypass the DX and its DSP - that means no gaming audio processing like virtual surround. And then there's using it with the Denon - again, check what outputs it has first, both analog and digital.

 

Off the bat though I'd look into the Ibasso D12, or any of the Schiit products that the product description says works with IEMs, but those will be separate DAC and amp as their discrete analog components easily pick up noise according to Schiit (so that's why, save for the recent Fulla, none of their products have both DAC and amp inside the same chassis).

 

 

 

[billybob_jcv]

I have owned the Westone UM2 for many years. They honestly do not need to be amped, and I have never found an amp that would work well with their combination of very low impedance and very high sensitivity. In my experience, they have ALWAYS sounded better (or at best the same) without the amp. All the amp does is make volume control more difficult (as you have discovered).

 

[w0lverine]

Thank you guys for taking the time to answer !
 
Quote:

That might be true for the Denon receiver but I'm not sure how much better you can get past the Xonar DX for the L1 and UM2. What are you using as a source for the Denon? Is it part of an HT system and you just want to be able to use headphones with it when you can't use the speakers? Check if the Denon has any digital outputs/pass through from the digital inputs, you can then use a DAC-HPamp with it that can work off the digital output from the Xonar DX (assuming you have them in the same room).

 
My computer is the source for the Denon and its speakers (through optical / PCM). Unfortunately it doesn't have any other digital output, but I read that some people use the "zone 2" (analog) output to feed their DACs. Doesn't it defeat the purpose of a DAC ?
 

My Ibasso D-Zero luckily has that sweet spot for my Aurisonics ASG-1.3 - at one left-right sweep of the slider from zero it doesn't have any imbalance and is my comfortable listening level too. However go more than 1/3 of a turn past that and it's loud enough to blow out eardrums (which is why I slide it back down to zero when I finish using it).

Does the sound quality suffer from low listening level on this kind of amps ? For computers, mp3 players, guitar amps, isn't low power = low performance a physical limitation ?
 

I'd recommend the D-Zero MkII since it's a nice value for money, however you mentioned having a Xonar DX. The problem there is that if you use USB you will completely bypass the DX and its DSP - that means no gaming audio processing like virtual surround. And then there's using it with the Denon - again, check what outputs it has first, both analog and digital.

Correct me if I'm wrong, but only a pure headphone amplifier (not DAC) would take analog signal as both input and output ? Because you need to bypass the existing DAC, right ?
 

I have owned the Westone UM2 for many years. They honestly do not need to be amped, and I have never found an amp that would work well with their combination of very low impedance and very high sensitivity. In my experience, they have ALWAYS sounded better (or at best the same) without the amp. All the amp does is make volume control more difficult (as you have discovered).

Okay so I think I'll stick with my first thought : an external volume control to max out the source and adjust the volume through the controller.

 

[billybob_jcv]

I also experimented briefly with adding a "P-to-S" adapter to the Westones. This is simply a 3.5mm M-F adapter that has a couple of resistors inline to raise the impedance to ~45 ohms. They were originally produced by Etymotic to convert an ER4P into an ER4S. You can also get them on eBay in a variety of different impedance values. However, increasing the impedance will also change the sound signature, and I really didn't like what it did to the Westones. It would be easier than using an inline volume control, which is essentially doing exactly the same thing. I think Shure or Koss used to make an inline volume control in a 3.5mm M-F cable.

 

[ProtegeManiac]

Originally Posted by w0lverine /img/forum/go_quote.gif
 
My computer is the source for the Denon and its speakers (through optical / PCM). Unfortunately it doesn't have any other digital output, but I read that some people use the "zone 2" (analog) output to feed their DACs. Doesn't it defeat the purpose of a DAC ?

 

It wouldn't even be possible. A DAC is a Digital to Analogue Converter - that means the input is digital. You can't put an analog signal into that. However if you're using your computer as a source for the HT receiver anyway then just use a DAC and HPamp with the computer and no need to run the HT receiver. Unless you need it for gaming, use USB, then just manually select the sound output device depending on what you'll be using (ie optical with the Denon, USB on the DAC-HPamp). And do you really need ot use the Westones at home? You could just use your headphones, then use the IEMs when you're on the go and with just a smartphone for example. The sensitivity on those will complicate your options. The only reason why I use an IEM at home is because I need total isolation when I'm working.
 
 

  Does the sound quality suffer from low listening level on this kind of amps ? For computers, mp3 players, guitar amps, isn't low power = low performance a physical limitation ?

 

It's only a limitation if you use a transducer that needs a lot more power than what such an amplifier can give it, much less with low THD. Some audiophile tube amps make less than 15watts, like some ultralinear tube amplifiers; or Class D amplifiers with 8watts per channel; or even some "flea amps" with around 3watts. The thing with these amps is  that, in the case of the Class D, they tend to have very low distortion  at their rated output level, so if you use them with high efficiency speakers - well over 90dB at 1w, from 1m - you won't run into any problems. However since not all speakers have the same efficiency these won't work for all of them - unlike for example a more typical but otherwise well-built Class A/B with 50watts of power or a really nice Class A amp with 25watts per channel output, these low power amps have a steeper distortion curve as you squeeze more power out of them. So at for example 5w, you could be getting 0.00001% distortion out of the Class D amp where the Class A/B might have 0.001%; however, get it up to 15watts, and the Class D might be already at 1% harmonic distortion while the Class A/B is still at 0.005%.

 

Think of it this way: a Lotus 7 can only take a four cylinder engine (and is an absolute b*tch to use as anything but a track car), but in a race track that doesn't have a long main straight (and better if it has a lot of corners), it would run circles around a heavily modified, 450hp, nose-heavy iteration of any pony car. Any design has its limitations, but it's a matter of knowing what to use with what and where.

 

 

Correct me if I'm wrong, but only a pure headphone amplifier (not DAC) would take analog signal as both input and output ? Because you need to bypass the existing DAC, right ?

 
Yes but in some cases you can have a one-box DAC and HPamp which can have an analog input that bypasses and DAC and goes straight into the amplifier section.

 

[billybob_jcv]

Yes but in some cases you can have a one-box DAC and HPamp which can have an analog input that bypasses and DAC and goes straight into the amplifier section.

Just to clarify, in ProtegeManiac's example, the DAC being bypassed is the *external* DAC in the DAC/Amp, not the DAC in the PC or phone. An external DAC/Amp can also have an analog line-in that allows it to act purely as an Amp. I know ProtegeManiac knows that - I'm just making sure every one else gets it...

 

[ProtegeManiac]

Just to clarify, in ProtegeManiac's example, the DAC being bypassed is the *external* DAC in the DAC/Amp, not the DAC in the PC or phone. An external DAC/Amp can also have an analog line-in that allows it to act purely as an Amp. I know ProtegeManiac knows that - I'm just making sure every one else gets it...

 
 
Yes thanks for that

 

 

[w0lverine]

Thanks for all the explanation, everything is much clearer now !
You are absolutely right, I do not need to pass through my HT receiver to plug my headphones since my computer is the only source for which I want high fidelity. 
 
I never use my IEMs at home, always on the go, and since they would not benefit from a DAC/Amp, they are out of the question (and my J3 has no need for it). But a USB DAC would perfectly fit my phone, tablet, laptop and desktop computer !
 
I've looked into the iBasso which seems great, thanks !