[valtopps]

Im new to tube amps but i know they need to warm up a bit.

 

[arman89]

Hey Guys! which one do you think will be a better amp for grado 325is', HIFIMAN EF2 or QINPU A3? i won't be using the DAC of the EF2, since i have my own. So, amp is my only concern.  

 

[HeadphoneAddict]

Quote:

Hey Guys! which one do you think will be a better amp for grado 325is', HIFIMAN EF2 or QINPU A3? i won't be using the DAC of the EF2, since i have my own. So, amp is my only concern.  

The EF2 is better with Grado and other low impedance phones like Denon.  With Sennheiser HD600/800 then the A3 is just as good.

 

[MegaMushroom]

I've gotta ask, but HeadphoneAddict... Are the Raytheon tubes worth the upgrade?  I feel like I could get more out of this amp, but I do feel a bit daunted by the price. 

 

[daigo]

Almost any pair of tubes will be cleaner sounding when compared with the stock Chinese tubes.  I used GE or RCA 6AK5 tubes with my sold EF2, fairly inexpensive on ebay, and both provided a nice upgrade to the sound. 
 
Quote:

I've gotta ask, but HeadphoneAddict... Are the Raytheon tubes worth the upgrade?  I feel like I could get more out of this amp, but I do feel a bit daunted by the price. 

 

 

[HeadphoneAddict]

The amp is nice stock, but with upgraded tubes it becomes more refined and moves up another notch in performance.  The stock tubes were better with Denons and Sennheiser HD600 than they were with HD800 or Grado HF-2.  Now it's good with them all.

 

[MohawkUS]

Is this amp comparable to the Valhalla or the Little Dot amps? I'm looking for something for my Ultrasone PRO2900s (40ohms) and I'm not sure where to look. My music of choice is metal, so I've been leaning toward the more forgiving tube amps.

 

[HeadphoneAddict]

Quote:

Is this amp comparable to the Valhalla or the Little Dot amps? I'm looking for something for my Ultrasone PRO2900s (40ohms) and I'm not sure where to look. My music of choice is metal, so I've been leaning toward the more forgiving tube amps.

This is a hybrid amp that will handle low impedance better than the OTL amps like Valhalla or some LD amps.  I think it should be more than enough to do well with most headphones.  I thought it sounded as good as my $350 EF1 amp did when I got it in 2009, just with less power than EF1, but it still has more power than my single ended portable amps.
 

 

[Zsubbo]

Hi !
 
I had some problems with my Hifiman EF2A (with Russian 6N23P-EV tubes). I've tried it with the HRT Music streamer 2+ DAC, but with the Sennheiser HD600 cans the bass  had a terrible distortion, with the Grado Sr225 it was much better but it was still there. Can you help me with this one ?
 
Sorry for my bad english.

 

[HeadphoneAddict]

Quote:

Hi !
 
I had some problems with my Hifiman EF2A (with Russian 6N23P-EV tubes). I've tried it with the HRT Music streamer 2+ DAC, but with the Sennheiser HD600 cans the bass  had a terrible distortion, with the Grado Sr225 it was much better but it was still there. Can you help me with this one ?
 
Sorry for my bad english.

Well, you need to isolate the problem to whether it's the source, the amp, the tubes or the phones.
 
Since it has this problem this with both phones it's probably something else, and not the headphones.
 
Try switching back to the built-in DAC and see if the issue goes away.  If it does get better then the problem is either in the HRT DAC or the RCA inputs of the amp.  In that case, try a different source feeding the RCA inputs and see if it gets better.  If it gets better with the built in DAC and a different source then it's not the amp and the HRT may be the issue.
 
If none of those changes improves the issue, then try swapping the tubes.
 

 

[Reticuli2]

Will they change the gain available for you or swap the pot for a more expensive one with better balance at the bottom?  If I got something like this, I'd want to use it with the HD25 in addition to my other cans.

 

[HeadphoneAddict]

Will they change the gain available for you or swap the pot for a more expensive one with better balance at the bottom?  If I got something like this, I'd want to use it with the HD25 in addition to my other cans.

I do not believe they will customize these, but with the gain they ship with it works well with IEM and full size phones. My amp has a nice volume pot without low volume channel imbalance, so I don't need a lower gain.

 

[BournePerfect]

Wow Larry you're still going above and beyond to help everyone out in this old thread-much appreciated! I've almost pulled the trigger about 5 different times now on this, but can't really find impressions on how it might fare with my AD2K's. Have you heard these or any other AT's by chance with the EF2?
 
-Daniel

 

[Reticuli2]

What is the EF2's input volume in dBFS with USB?  Is it Windows default, so you just leave it at max?  Because it says:
 
"Default computer volume for EF2 USB DAC is 50%. Customer will have to maximize computer volume after connect EF2 as USB DAC."
 
So you put it at 50% and leave it or you just do that for connecting and then change it to max?  That seems like a contradicting or confusing statement for them to make.
 
Any other weird and useful specs you guys know on it?

 

[HeadphoneAddict]

Quote:

Wow Larry you're still going above and beyond to help everyone out in this old thread-much appreciated! I've almost pulled the trigger about 5 different times now on this, but can't really find impressions on how it might fare with my AD2K's. Have you heard these or any other AT's by chance with the EF2?
 
-Daniel

I have not tried the EF2 with ATH-AD2000, which I sold after a few months because I preferred my balanced HD600 slightly more.  The AD2000 seemed like a midrange centric headphone, although bass and treble weren't lacking it sounded a little plain to me.  I'm sure the EF2 would power them fine, as my WA6 was able to drive them no problem.
 
Quote:

What is the EF2's input volume in dBFS with USB?  Is it Windows default, so you just leave it at max?  Because it says:
 
"Default computer volume for EF2 USB DAC is 50%. Customer will have to maximize computer volume after connect EF2 as USB DAC."
 
So you put it at 50% and leave it or you just do that for connecting and then change it to max?  That seems like a contradicting or confusing statement for them to make.
 
Any other weird and useful specs you guys know on it?

When you plug in the EF2 DAC then Windows would default to 50% system volume.  After plugging in you would need to manually turn up the system volume to 100% to get full dynamic range and volume.