REVIEW: Head-direct.com HiFiMan EF2 tube Hybrid Amp with USB DAC - Page 6

Apologies for my ignorance, and THANK YOU for the explanation.

Choosing/finding good albums was already difficult, now add the task of finding the perfect combination of sound repro equips Paucity of funds, perhaps, curtails the ability to experiment with various equips. Head-fi and guys like you that way cover the deficiency. Please bear with us.

I sure hope others get to listen to this amp, for $189 w/ a DAC for those ocassions you need one it is a heck of a price. I will be testing the DAC soon.

I wonder if anyone has compared this amp with the little dot mk2. They use the same tubes so they could be comparable? ld mk2 can use ef95 or ef92 family tubes. I have the ld mk2 and I think that its more engaging than some of my past amps including the gilmore lite and audio gd c2c.

Mine arrived yesterday. It took exactly 4.5 days to get here from the time I received confirmation of my order. Rather amazing considering it came from the other side of the planet!

The EF2 has definitely improved the sound of my Grado SR80i headphones on my crummy old work PC. I had been using the PC headphone out and the sound was somewhat lacking across the board. I knew the SR80is could do better, having auditioned them before buying. I was able to improve the stock PC sound a bit using the Winamp EQ, but I just couldn't really get it dialed in. Now with the EF2 assuming both DAC and amp duties, everything has opened up. I turned off the EQ and have a much more natural sound now.

I'm not an experienced audiophile, just a music enthusiast, so I can't really provide pros/cons of this amp in the same way that the OP has (rock on HPA), but I will say that I do enjoy this amp. Here are a few points I thought about while listening with about 10 hours on the amp:

• Bass has improved. It is a natural improvement, it doesn't over power. On a few tracks, the bass seemed a bit loose. Other tracks were tight, so it could possibly be the encoding (these were MP3 tracks).
• It is not a super detailed setup like I tried at the audio store, but it does have a very nice sound. The audio store demo equipment spoiled me.
• It sounds correct at low volumes. I did not notice any volume balance issues at low volume.
• I can listen at a lower volume than before and retain the sound quality. I had to turn up the PC volume before to get at the whole sound.

Non-sound thoughts:

• Smaller than I expected, which is good for my desk.
• It's a nicer looking amp than the pictures led me to believe. It was expecting it to look a bit cheapo.
• I really like the volume control knob. The detents are very fine and feel great. They do not lock you into too-loud or too-quiet.
• The DAC led is quite a bit brighter than the tubes. I was expecting more glow from the tubes (this is my first tube amp).
• Power switch seems to control the amp only. The DAC led stays on. I assume the DAC is totally powered by the USB.

Since the DAC seems to be powered on all the time if connected, I'm curious if I should disconnect the USB when I leave work. I usually leave the PC turned on. Any thoughts on that?

I'm looking forward to hearing this amp mature as it burns it. I don't know really what to expect. For now I'm resisting the urge to try new tubes until I have many more hours on it. I've seen a few on eBay that I'd like to try, but I'm still reading up on what to look for in a tube.

I'm also looking forward to hearing what other people think with alternative tubes. Perhaps someone with knowledge (and lots of tubes) can start an EF2 tube rolling thread.

Since they use the same tubes as the little dot amps, I suspect the effects on the tubes to the little dots would also apply here. There are a bunch of LD tube rolling threads, you may want to start here...
http://www.head-fi.org/forums/f5/lit...43/index3.html
check out the links on post 39 of this link

I do not know about that! I received mine last weekend. Yes, I am a stinker.

Larry,

I just got my EF2 last Monday. For the burn-in process, do I have to do anything special ?. I am currently listening to it everyday for about 3 hours with volume at 10 o'clock position.

Connecting it with the HD595 + PC + Win Amp + ASIO4ALL, I am happy with the "out off the box" sound quality.

Thank in advance.

So where do I start? The EF2 in my possession has about 135 hours of burn in, 108 hours for the amp section via the RCA input and an additional 27 hours for the USB DAC section and the Amp Section via the USB input.

The amp section has continued to improve and IMO makes for a very engaging and mellow amp. I particularly like its unpretentious method of presenting the music. It sounds far better than its $189 price tag would lead you to believe. In fact it is so nice sounding I have searched and found a set of Sylvania NOS 6AK5/5654 tubes. I hope they help to squeeze more out of this unit.

Now for the USB DAC which I decided to first try w/ my office PC. I plugged it and although it showed right away I could not get any sound out of it. After a while of cursing and getting frustrated I realized I had made a mistake. I had the volume out of Windows Media Player at ZERO. Yeah, what a fool! Anyways after adjusting the volume I put a Blood Sweat and Tears CD and ... ^#%^$#^# ^#@%(* WTF! It sounded horrible to the point I was going to stop using the USB DAC and just write about the Amp Section, but I persevered. This was a good thing because after a short 2 hours the DAC Section was at least listen-able and acceptable by the 6 hour mark. At this point I turned it off and took it home with me to use w/ my home PC.

After the embarrassing display at the office I was able to quickly connect and start using the unit with my home PC. Who says you can't teach an old dog a new trick? Now the USB DAC section has about 27 hours of burn in and it has had a major change from the first time I fired her up. Now it is in the category of second system (den, office, nightstand, etc) and I hope it continuous to improve. I hope to have an update at the 50 hour and 100 hour marks.

BTW, please do not misread my post. Although this is a heck of a nice sounding unit it is not going to be better that an unit costing many times its price. Of course the final word will be after it is fully burnt in and when I have tried the NOS tubes I have ordered.

I do have three inexpensive suggestions to make. These are:

1. Drill holes on the bottom plate to improve ventilation.
2. Place o-rings under the plastic top plate by the screws to improve ventilation by creating a 1/8" or similar air gap.
3. Replace the hard plastic feet w/ rubber type. This will help reduce/eliminate the tendency of the EF2 to slide on hard surfaces (like a desk).

More to come.

Does anyone how it compares soundwise to the aune mini usb dac, I know EF2 is 50$ more, Im considering getting one of these , or is it not fair to compare a tube amp to a SS one? thanks



AUNE Mini USB DAC + Headphone Amplifier MK2 - eBay (item 260435237330 end time Jul-24-09 18:26:26 PDT)