[tzjin]

Thanks Chefano!
 
Since 16 ohm EPH-100 is eight times the impedance of the output, the frequency response is affected. Typically, a warmer, boomier sound results.

 

[bobeau]

Quote:

You'll have to help me with this. I appreciate your getting the numbers, but I have no idea what they mean.

 
Well, the rule of thumb I've seen is you want output impedance to be 1/8th or less than headphone impedance, but this isn't a hard set rule as it varies by load, but a general rule.  I'm not sure how the load of 49 ohms plays into this.
 
I guess this means a headphone should be 38 ohms or greater for this unit?  
 
Someone correct me if I'm wrong here, but this seems to be the issue I'm experiencing.  All my other headphone outs I've used this with (MBA out, E17, and O2) measure < 1 ohm, and they all have a pretty similar signature, fairly tight and crisp, but the better ones with more clarity/dynamics/detail.

 

[bobeau]

Quote:

Which MBA do you have. I had read on CNET that one of the newer MBA's had an improved Audio out from the earlier versions. I don't remember what was changed, just that something had been upgraded, My MBP is a Mid '09 and I am (at about 50+ hours burn in so far) getting a clear improvement from the DF vs the MBP direct. I will do a direct comparison to the NuForce uDAC2 once I get past 200+ hours. Funny, I connect the uDAC2 to the MBP via an AQ cable..

 
I am using a new 2k12 11".  The audio out is surprisingly good, I'm not even sure if I might prefer it to my E17 with the EPH-100 as well.  I think I've just out of hand dismissed it as being not good due to confirmation bias from hearing how craptastic Macbook audio outs are over the years.  I'm coming around on this now as I've tested it against the Dragonfly and scratching my head wondering if my hearing is shot or something... then I see the article on Voldemort's blog and it's beginning to make sense.  It struggles with the Thunderpants of course and does seem like it could be a bit more refined, a little etchy, but overall does the trick pretty well.
 
There is no doubt though that the DF -> O2 -> EPH-100 is a class or two above... man if I could just get that sound through the DF hp out I would be in heaven

 

[longbowbbs]

Quote:

 
There is no doubt though that the DF -> O2 -> EPH-100 is a class or two above... man if I could just get that sound through the DF hp out I would be in heaven

 
Reminds of one of the photos Mkubota1 posted from the Tokyo meet. A guy had about 5 devices strapped together for his portable rig. It was about 7 inches high.. Sometimes you wonder what it takes to have some simple high quality portable sound.
 

 

[LizardKing1]

Quote:

Alright, with 20 hours under my belt of listening I'm shipping this guy back.  I'm not getting the changes to the signature I was hoping for.
 
To be clear, it actually sounds pretty fantastic with my Thunderpants... not quite to the level of O2/ODAC - it's just a bit lean/flat by comparison, but just a bit, which is pretty outrageous considering it's entirely USB bus powered and barely drags down the battery on my power thrifty MBA.  The DAC portion to my ears outshines the ODAC and running the Dragonfly -> O2 is absolutely stellar - very detailed, lack of digital hash, dynamic, tight, crisp... a dynamite pairing, both with the Thunderpants and EPH-100.  The DAC implementation here is crazy good for the price and convenience.

 
I don't understand. If you're running the DF's headphone-out into the O2's line-in shouldn't the fact that you're double amping just have the DF's issues? It's not like you're using a line-out, so it's hard to say for sure how good the DAC is because you're not bypassing the amp.
As for sounding better, is it because the DF has a high output impedance and that only matters when the headphones are the load (in this case it's the O2)? By the way, don't mistake my ignorance for arrogance.

 

[MickeyVee]

Interesting.. if you take a look at what Jude liked the DF with, they're high impedance cans.  I'm thinking of getting the DF for my HE400 (45 ohm) and v-Moda M80 (28.5 ohm).  I'll have to give it a good listen to before I commit. (also have the FiiO E10 (rarely used), E17 and Audioengine D1).  Looking for a very portable solution with my Macbook Air so I'm hoping the DF & M80 would be a good combo.
Quote:

 
Well, the rule of thumb I've seen is you want output impedance to be 1/8th or less than headphone impedance, but this isn't a hard set rule as it varies by load, but a general rule.  I'm not sure how the load of 49 ohms plays into this.
 
I guess this means a headphone should be 38 ohms or greater for this unit?  
 
Someone correct me if I'm wrong here, but this seems to be the issue I'm experiencing.  All my other headphone outs I've used this with (MBA out, E17, and O2) measure < 1 ohm, and they all have a pretty similar signature, fairly tight and crisp, but the better ones with more clarity/dynamics/detail.

 

[bobeau]

Quote:

 
I don't understand. If you're running the DF's headphone-out into the O2's line-in shouldn't the fact that you're double amping just have the DF's issues? It's not like you're using a line-out, so it's hard to say for sure how good the DAC is because you're not bypassing the amp.
As for sounding better, is it because the DF has a high output impedance and that only matters when the headphones are the load (in this case it's the O2)? By the way, don't mistake my ignorance for arrogance.

 
It it using a line out - the jack does double duty.  With headphones it uses the amp, as a line out the head-amp is bypassed.  This was designed to be used as a DAC only.  The majority of folks over in ComputerAudiophile are using this for this purpose to drive speakers.
 
As Gordon wrote on CA: "I did a ton of work on the output stage to make it compatible with both line and headphone. I think it works really well with both as it has more drive than required for line and easily 2x more drive for headphones."

 

[longbowbbs]

Quote:

 
It it using a line out - the jack does double duty.  With headphones it uses the amp, as a line out the head-amp is bypassed.  This was designed to be used as a DAC only.  The majority of folks over in ComputerAudiophile are using this for this purpose to drive speakers.
 
As Gordon wrote on CA: "I did a ton of work on the output stage to make it compatible with both line and headphone. I think it works really well with both as it has more drive than required for line and easily 2x more drive for headphones."

You have to love input from the designer.

 

[bobeau]

Quote:

You have to love input from the designer.

 
I'll be honest, I'm not sure if I'm interpreting this incorrectly and if it is indeed double-amped, nor how that might have an impact when fed to another amp.

 

[longbowbbs]

Quote:

 
I'll be honest, I'm not sure if I'm interpreting this incorrectly and if it is indeed double-amped, nor how that might have an impact when fed to another amp.

The web site is not clear on this. I think a call to Alasdair at AQ is in order. He knows his stuff.

 

[LoveKnight]

I read on CA and if I remember correctly you can use Dragonfly as a DAC. Just turn on the volume to max 100 and use an interconnect cable to an amp or you can use it as a preamp. Maybe the document or manual could state that thing.
 
Thanks bobeau again. Now I know Dragonfly is better than ODAC. I think I am not going to buy an ODAC, just saving money to buy a Dragonfly and I use it as a DAC for a better soulution for me.

 

[longbowbbs]

I read on CA and if I remember correctly you can use Dragonfly as a DAC. Just turn on the volume to max 100 and use an interconnect cable to an amp or you can use it as a preamp. Maybe the document or manual could state that thing.

Thanks bobeau again. Now I know Dragonfly is better than ODAC. I think I am not going to buy an ODAC, just saving money to buy a Dragonfly and I use it as a DAC for a better soulution for me.

The manual is smaller than the Dragonfly...seriously!

 

[Chefano]

Quote:

According to my measurements: 4.77Ohms at 1KHz Sine 0dfs
 
Load Used: 49.9Ohms
Unloaded: 2.084 Vrms
Loaded: 1.902 Vrms
Measured using my Fluke TrueRMS MM.

Thats measurements are wrong, please see the post #321
post #321

 

[kiteki]

According to my measurements: 4.77Ohms at 1KHz Sine 0dfs
 
Load Used: 49.9Ohms
Unloaded: 2.084 Vrms
Loaded: 1.902 Vrms
Measured using my Fluke TrueRMS MM.

You'll have to help me with this. I appreciate your getting the numbers, but I have no idea what they mean.

 
Very little, unless you're using something like the Sony XBA-3 / XBA-4 (12 / 8 ohm), in which case they'll sound a bit brighter and thinner.
 
 

The DAC portion to my ears outshines the ODAC and running the Dragonfly -> O2 is absolutely stellar - very detailed, lack of digital hash, dynamic, tight, crisp... a dynamite pairing, both with the Thunderpants and EPH-100.  The DAC implementation here is crazy good for the price and convenience.

 
I don't understand. If you're running the DF's headphone-out into the O2's line-in shouldn't the fact that you're double amping just have the DF's issues? It's not like you're using a line-out, so it's hard to say for sure how good the DAC is because you're not bypassing the amp.
As for sounding better, is it because the DF has a high output impedance and that only matters when the headphones are the load (in this case it's the O2)? By the way, don't mistake my ignorance for arrogance.

 
The ES9023 has an integrated op-amp inside of it if you looked at their .PDF I linked?  It's like a DAC and amplifier in one, a lot of DAC chips are like that.
 
If they both use this chip, neither the ODAC nor the DF can truly 'bypass the amp' section.
 
If he's connecting both into the O2, the output impedance of the DF doesn't have any effect, whether it's 4 ohm or 40 ohm.
 
If the DF is using additional amplification after the ES9023, like LME49990 (just a wild guess) that could account for the enhancement in sound / higher performance in the DF.

 

[FasterThanEver]

Questions for those using a DragonFly with a Windows PC.  What level of CPU utilization are you seeing in Task Manager while you play music?  What CPU does your PC have?
 
Bill