[kalla]

Quote:

Yeah, there's always gonna be some headphone that doesn't work well with some amp. As for the RCA inputs being too loud, it depends on the source's output voltage, and what I recall trying with the EF2 are the Pico DAC-only, iBasso D10 and D4, andNuforce uDAC's which weren't too loud.

So is there any amp you recommend for IEMs. Let's say with the budget under $200. Will the amp improve the sound or just a good DAC is enough?
 

 

[HeadphoneAddict]

So is there any amp you recommend for IEMs. Let's say with the budget under $200. Will the amp improve the sound or just a good DAC is enough?
 

Well, the thing is that a lot depends on what you will use as a source, and whether it needs to be portable or not. I noted in my review that the DAC in the EF2 sounded better than feeding the amp with my MacBook 3.5mm jack or my 4G Nano, but that the Pico DAC takes it even a notch higher.

In my case, my EF2 works well with IEM and I still have it. Granted, I don't use it much since I upgraded to a DAcmini, but I still think the EF2 is a good value. Most inexpensive DAC/amps will have some channel imbalance at very low volumes with IEM, but some are better than others. My EF2 is one of the good ones for IEM, but the channel balance at the lowest volumes is not as good as with my RSA amps or Pico Slim. But it's better than the low volume balance on something like my Meier Headsix, original uDAC or HDP.

As for other options, For IEM I've been fairly impressed with the iBasso D4, which has a DAC that performs close to the Pico DAC, and a very transparent and spacious sounding amp. It's not as warm, euphoric and romantic sounding as the EF2, nor is it as powerful, but it's in your ballpark price range ($219) and is a good all around amp for most IEM and many full size phones. Low volume channel balance is not any better than my particular EF2.

 

[kalla]

Thanks for the info.
Well I'll use it with my laptop, so I prefer something with good DAC integrated. The powerful amp is not important with IEMs,too. The EF2A's dac seems not so good due to some reviews I read before. Have you tried the FiiO E7/E10 or even the new E17? Are their DACs better?? They're much cheaper,too.

 

[MSnyder85]

Quick question! I My setup is Asus Xonar Essence ST RCA to RCA HifiMan EF2A (on CD not DAC) - Sennheiser HD650. I've noticed when I run my cans through the Xonar that everything is fine but when I run it through the EF2A there is a channel unbalance (The left channel is louder than the right). Does burn in solve this or should I return it?

 

[liamstrain]

Do you get the imbalance only when the volume knob is turned pretty far down? 
 
It could be poorly matched tubes. Have you tried swapping the tubes to see if the imbalance swaps sides? If that is the case, then I would get new tubes. 

 

[MSnyder85]

No I haven't had the chance to do that yet. Does the amp need to properly be burnt in?

 

[liamstrain]

Tubes do change a bit over time, but I don't think it would be enough to balance out an audible channel imbalance. Try swapping the tubes first. 
 
Things to also check - does it happen both from the CD in and the USB in... does it change depending on the volume position. Also, if it only happens through the CD in, try a different source as well. 
 
Just to narrow down possible culprits.

 

[MSnyder85]

As of right now I notice that it actually happens with Foobar 2000, is this normal? I'm using ASIO.

 

[calipilot227]

Quote:

As of right now I notice that it actually happens with Foobar 2000, is this normal? I'm using ASIO.

Maybe check the balance control in Foobar? I experience a channel imbalance at lower volumes, but once I turn it up past the 9 o'clock position, it goes away.
 

 

[MSnyder85]

How're you liking your EF2A? Did you change out the tubes on it? Well I changed it to WASAPI and no problems whatsoever! I don't even get the pop crackle that I'd get when clicking another song! ASIO =FAIL!!!

 

[liamstrain]

Glad you got it sorted.
 
I do like my EF2A... I replaced the tubes with NOS Mullard 4010/8100 tubes - I didn't spend a lot of time with the stock tubes to do a true comparison between them, but I do like the sound I get. Fun little amp. 

 

[MSnyder85]

That'll be next on my to buy list! I swear ever since I joined this forum I first bought the HD428, now I have the HD650 and all that other stuff!

 

[MegaMushroom]

I do need to get a new set of tubes... The stock tubes to me feel like they don't give me the full sonic experience this amp could give me.  Never mind the fact the left tube appears to take its sweet time warming up compared to the right one.  

 

[calipilot227]

Quote:

I do need to get a new set of tubes... The stock tubes to me feel like they don't give me the full sonic experience this amp could give me.  Never mind the fact the left tube appears to take its sweet time warming up compared to the right one.  

I liked the results I got by replacing the stock tubes with some NOS Raytheon tubes, slightly warmer sound, larger soundstage. Overall, it sounds more refined, and at $30 for a matched pair on eBay, I would highly recommend it.
 

 

[jerVic]

Quote:

Thanks.  I'd heard about the possible issues with USB ports being shared with other things (keyboard, mouse), so I tried a number of different ones.
 
I think this is a problem with the amp. as well.  Hopefully Head-Direct will do right by me.

And they did.  After a few emails back and forth, and a bit of a delay because of Chinese New Years, my replacement EF2A arrived today.  Works, and sounds awesome!
 
Thanks, Head-Direct!