[HeadphoneAddict]

I think I had very similar impressions of the DACport original vs the borrowed DACport LX + amp.  I also think the DACport uses OPA1611 or OPA1612 opamps, if I recall correctly from what Michael told me at CanJam when the DACport was first introduced.  I agree that the original DACport does seem to have a little bit more warmth and a little less micro-detail in return for a little more euphonic and less analytical sound.
 
As for the Stepdance - I thought the Stepdance, RSA P-51 and SR-71b were all on a similar level of performance which was outstanding for a portable, where the main differences were in power outputs. The P-51 had the least power, Stepdance noticeably more, and SR-71b slightly more than that only if used balanced.  For single ended phones the Stepdance won out for combination of power and quality.  
 
However, at the time I compared them (using Pico DAC and DACport as source) I had two stepdance prototypes with different opamps to test, and both required using my 12-15v external PSU as the battery bay wasn't working yet, buy Jan assured me that the 9v battery would give the same level of power through voltage regulators.  The OPA1611 won out as being the best for everything but HD800, and still acceptable for HD800.  The other prototype was slightly better with HD800 but suffered with everything else.
 
In the end I didn't think I needed to add a DACport LX to my gear, being quite happy with the original DACport since it came out.

 

[zilch0md]

Hey Larry,
 
Quote:

I think I had very similar impressions of the DACport original vs the borrowed DACport LX + amp.  I also think the DACport uses OPA1611 or OPA1612 opamps, if I recall correctly from what Michael told me at CanJam when the DACport was first introduced.  I agree that the original DACport does seem to have a little bit more warmth and a little less micro-detail in return for a little more euphonic and less analytical sound.
 
As for the Stepdance - I thought the Stepdance, RSA P-51 and SR-71b were all on a similar level of performance which was outstanding for a portable, where the main differences were in power outputs. The P-51 had the least power, Stepdance noticeably more, and SR-71b slightly more than that only if used balanced.  For single ended phones the Stepdance won out for combination of power and quality.  
 
However, at the time I compared them (using Pico DAC and DACport as source) I had two stepdance prototypes with different opamps to test, and both required using my 12-15v external PSU as the battery bay wasn't working yet, buy Jan assured me that the 9v battery would give the same level of power through voltage regulators.  The OPA1611 won out as being the best for everything but HD800, and still acceptable for HD800.  The other prototype was slightly better with HD800 but suffered with everything else.
 
In the end I didn't think I needed to add a DACport LX to my gear, being quite happy with the original DACport since it came out.

 
I didn't know the DACport uses OPA1611 (or 12).  No wonder I like its sound, given how much I like the Stepdance.  

 
I was concerned about my impressions in this comparison being swayed by my memory of your earlier comparison of the LX and non-LX, but I think I've steered a straight course, so to speak.   Your comments regarding the DACport being a little better for the HD800 than the DACport LX, make even more sense to me now that I've been able to compare them myself.  Although I've never heard the HD800, I understand it to benefit by a smoother, less than uber-detailed signal, and I can detect a similar "need" when using the Beyerdynamic T1 with the DACport LX, vs. the smoother DACport.  
 
I'm guessing you don't care for using the HD800 with the DACmini CX, either.  (I much prefer my T1 with the smoother, more analog Burson Soloist, and I don't even think the Soloist is a truly great match for the T1 - my ears, my tastes.)
 
Thanks again for all your contributions - I've been a direct beneficiary of your advice one too many times to go without saying this.  

 
Mike

 

[HeadphoneAddict]

Quote:

Hey Larry,
 
 
I didn't know the DACport uses OPA1611 (or 12).  No wonder I like its sound, given how much I like the Stepdance.  

 
I was concerned about my impressions in this comparison being swayed by my memory of your earlier comparison of the LX and non-LX, but I think I've steered a straight course, so to speak.   Your comments regarding the DACport being a little better for the HD800 than the DACport LX, make even more sense to me now that I've been able to compare them myself.  Although I've never heard the HD800, I understand it to benefit by a smoother, less than uber-detailed signal, and I can detect a similar "need" when using the Beyerdynamic T1 with the DACport LX, vs. the smoother DACport.  
 
I'm guessing you don't care for using the HD800 with the DACmini CX, either.  (I much prefer my T1 with the smoother, more analog Burson Soloist, and I don't even think the Soloist is a truly great match for the T1 - my ears, my tastes.)
 
Thanks again for all your contributions - I've been a direct beneficiary of your advice one too many times to go without saying this.  

 
Mike

 
I'm pretty picky about the amp or DAC I use for the HD800.  You should read the HAP-100 review I just posted (with impressions of the DAC-100).  The DACmini as source paired with a warmer amp is still good with HD800 (such as Woo WA6, Amphora, HAP-100).  But the DACmini's built-in amp needs a smoother warmer DAC to be a match with the HD800 (such as using the original DACport or Stello DA100).
 
The DAC and the Amp inside the DACmini are both excellent, but when used in combination with each other I wouldn't recommend the HD800.

 

[jinteddy7]

Does the Dacport LX need an external amplifier if i would like to drive Grado SR325i's? If i use the audio jack for my macbook pro at full volume, the Grado SR325is are driven optimally. Does the LX offer a slight amplification over using the audio jack for the macbook pro or would it be better to get a dacport instead with a built in amp. The reason is that i move around often within studios and would like something portable and one-off instead of hooking up multiple devices. 

 

[zilch0md]

Quote:

Does the Dacport LX need an external amplifier if i would like to drive Grado SR325i's? If i use the audio jack for my macbook pro at full volume, the Grado SR325is are driven optimally. Does the LX offer a slight amplification over using the audio jack for the macbook pro or would it be better to get a dacport instead with a built in amp. The reason is that i move around often within studios and would like something portable and one-off instead of hooking up multiple devices. 

 
The DACport LX is just a DAC without an amp and thus has no volume control and is very loud into efficient headphones or IEMs when you connect them directly.  You'll have to use software to bring the volume down, but this will only reduce the bit depth of the signal sent to the DACport LX, which means you will be reducing dynamics.  
 
In other words, directly connecting anything other than an amp to the DACport LX is not recommended.
 
From what you've written, I'm think you'll be very pleased with the DACport (the DAC + internal amp).
 
Mike

 

[Fungus]

Can somebody confirm if the same 8 times impedance rule applies for the dacport lx which has the stock 10ohm impedance since it is just a stand alone dac, not an amp. Will I need to upgrade to the 1ohm mod to avoid of the change of sound signature with low impedance headphones/iems despite paring with an amp that is less than 1ohm output? 

 

[MrSlim]

  Can somebody confirm if the same 8 times impedance rule applies for the dacport lx which has the stock 10ohm impedance since it is just a stand alone dac, not an amp. Will I need to upgrade to the 1ohm mod to avoid of the change of sound signature with low impedance headphones/iems despite paring with an amp that is less than 1ohm output? 

Just to clarify, you plan on using the Dacport LX to feed an amp, which will then be driving your low impedance headphones/iems right?
 
If so, the 10 ohm impedance will not be an issue.  It is the impedance ratio between each pair of devices that is the real issue.  So, in the case of Dacport LX -> Amp -> headphones/iems , the Dacport LX 10 ohm impedance will be driving the high impedance(usually >1K ohms)  input of the amp, and then the hopefully low impedance (1 ohm or less) output of the Amp will be driving your low impedance (~16 to 32 ohm) headphones/iems.  It is important to check the output impedance of the amp you are planning on using. An O2, with a .1 ohm output would be a good example of a low impedance output.  

 

[Fungus]

  Just to clarify, you plan on using the Dacport LX to feed an amp, which will then be driving your low impedance headphones/iems right?
 
If so, the 10 ohm impedance will not be an issue.  It is the impedance ratio between each pair of devices that is the real issue.  So, in the case of Dacport LX -> Amp -> headphones/iems , the Dacport LX 10 ohm impedance will be driving the high impedance(usually >1K ohms)  input of the amp, and then the hopefully low impedance (1 ohm or less) output of the Amp will be driving your low impedance (~16 to 32 ohm) headphones/iems.  It is important to check the output impedance of the amp you are planning on using. An O2, with a .1 ohm output would be a good example of a low impedance output.  

Thanks for the confirmation MrSlim. I'm planning to feed the dacport lx it to my c5 which has the same output impedance as the o2. 

 

[Fungus]

I'm using the dacport lx to feed my (jds c5) but need a 1/4 to 1/8 inch interconnect cable which is a hassle since no places seem to sell it. I just don't stand why Centrace choice to stick with the 1/8 since it's only an amp and not used for directly plugging in headphones like the dacport with has the build in amp. It only came with the 1/4" to RCA cable which is no help whatsoever and so I'll need to dish out extra money sigh. 

 

[Fungus]

On windows 7, I'm suppose to turn both the itunes and windows digital volume to max and adjust the volume on the amp? 

 

[MrSlim]

  I'm using the dacport lx to feed my (jds c5) but need a 1/4 to 1/8 inch interconnect cable which is a hassle since no places seem to sell it. I just don't stand why Centrace choice to stick with the 1/8 since it's only an amp and not used for directly plugging in headphones like the dacport with has the build in amp. It only came with the 1/4" to RCA cable which is no help whatsoever and so I'll need to dish out extra money sigh. 

I bought a very nice quality 1/4 to 1/8 inch cable from here: http://www.ghentaudio.com/part/d08.html to connect my dacport LX to my O2.  They have a .5 meter one, so you don't have so much cable hanging around.

 

[Fungus]

  I bought a very nice quality 1/4 to 1/8 inch cable from here: http://www.ghentaudio.com/part/d08.html to connect my dacport LX to my O2.  They have a .5 meter one, so you don't have so much cable hanging around.

Looks nice and great price however .5 meter is still too long for me. 

 

[Aradea]

  Head-Fi member kkl10 and I exchanged PMs a couple of weeks ago on the subject of supplying clean power to the DACport LX (or any other USB-powered DAC).  
 
We were discussing the idea of supplying power exclusively from the 5V jack of a Lithium-ion battery pack, such as the Energizer XP8000A or the the longer-lasting and less expensive Anker Astro3 (which can deliver 5V to loads as high as 2 Amps).
 
In one of my PMs, I wrote:
 
To which kkl10 replied:
 
 
Great idea!  That way, only data comes from the laptop and only power comes from the external battery pack!
 
Here's the cable I ordered:
 
 
   
 
 
 
 
 
   
 
 
There are several dual-power USB adapter cables out there, but I ordered this one because its cables are short and I'm assuming that if its made for LaCie, it's probably well-constructed.  
 
The LaCie USB Dual Power Sharing Cable for Rikiki can be ordered from these two sources (and others, perhaps):
 
     http://www.bhphotovideo.com/bnh/controller/home?O=&sku=670128&Q=&is=REG&A=detail
 
     http://www.datavis.com/cgi-bin/product.cgi?prrfnbr=518217
 
Here it is, hooked up to my DACport LX, getting only data from the laptop and clean, 5-Volt, 2-Amp power from the Anker Astro3:
 
 

 
As I've mentioned previously, in the other DACport thread, I keep the Class A DACport LX cool by setting it on an aluminum heat sink.  
 
The analog output of the DACport LX is connected to the RCA inputs of a DACmini CX (at the moment) using a Monster MCL MST2FR Stereo Female RCA to1/4 Stereo Male Cable Adapter and a pair of Emotiva XRCA .5 Meter RCA Interconnects.
 
And what about the sound?   I was really surprised.   I haven't been having any problems with noise coming from my laptop, when running the DACport LX on the laptop's USB power, with my iBasso PB2, for example, while traveling...
 
 

 
A couple of weeks ago, at Navarre Beach, Florida, the Energizer XP8000 battery pack and an XPAL Willy Cable WI16 inline voltage regulator was used to provide 16VDC to my iBasso PB2 (its maximum permissible supply voltage), with the DACport LX getting its power from the USB port.
 
This morning, having swapped the DACport LX between laptop power and external battery power, across several tracks, I was immediately struck by how much more authoritative the DACport LX sounds when using the battery pack.  Dynamics are noticeably improved.  I didn't see this coming.  I had thought I might hear a lowering of the already low noise floor, but instead, with my little 10-inch netbook, where I intentionally read my WAV files from SD cards instead of  using the hard drive, I'm only hearing improved dynamics - as if the DACport LX has more current to work with than it did on laptop power.
 
It might just be that my little laptop's 5V USB ports are "weak" - I know they will not charge my iPad Mini, for example.  USB ports are supposed to deliver 5VDC and handle current demands of at least 500mA, but I've read that some PCs have USB ports that can deliver as much as 1 Amp  (1000mA).   The Anker Astro3 is rated at 5VDC and 2 Amps (2000mA) - plenty of clean, 5V power for a USB-powered DAC!
 
There's no change in the already dead silent noise floor, with my netbook, but I'm thinking anyone who is struggling with "noisy" USB power and wants to remain "transportable" without reliance on AC power, might benefit from this $60 solution (Anker Astro3 + LaCie USB adapter cable), as opposed to something like the $199 iFi iUSBPower.
 
Thanks for the suggestion of taping that 4th pin, kkl10!
 
Edit:  You can easily test if the tape is adequately blocking power from the laptop, just by hooking up your DAC and the laptop connector first - if the DAC doesn't come to life, the tape is still doing the trick.  Connect the external 5V supply and you're good to go, with only data coming from the laptop.
 
Mike

 
I just tried this and currently trying to figure out the difference in sound