Hifiman EF5 Review

Tube and Opamp Rolling.

In my tube rolling quest, I found out that the stock RCA Clear Top tube is actually very good performer. It has a very balanced presentation, with a slight emphasis on the midrange. The clarity is very good, and it strikes a good balance between a mellow lush sound to an energetic and dynamic sound. The soundstage performance is likewise very good. As it is, the RCA Clear Top ranks very high on my recommendation list.

Sometimes, when switching to another tube, you get a certain boost in one area, such as a more lively sound, or a more forward presentation, or low end boost, but often you will also suffer changes in other areas that the stock RCA tube does well. So far I haven’t really found one tube that betters the RCA Clear Top on every aspect. Hence, tube rolling should be seen more as a sidestep, or a change in sound signature, rather than an “upgrade”.

There are a lot of different choices for 12AU7, and even a certain brand would have different variations of the 12AU7 tube. For instance, Telefunken has the “smooth plate” and the “ribbed plate” version, and even between those two versions, there are OEM brand version of the Telefunkens. Then you also have the fake Telefunkens, which sometimes can be very hard to spot depending on how well you’ve known Telefunken tubes for. Another popular 12AU7 choice is the Amperex, which has three different versions depending on production year. The earliest versions comes with the Treble Clef logo an are produced in the 50s. Then you have the Bugleboys which are produced in the 60s, and finally the World logo for the 70s production. Other popular brands also include Mullards, Tung Sol, CBS/Raytheon, RCA, Sylvania, and GE. The choice for tube rolling is quite endless, and every one of these tubes will implant their own signature to the EF-5’s sound output. I guess we can be thankful that the EF5 only uses one 12AU7 tube, which makes tube hunting a little easier, since you don’t need to get matched pairs of the tube.

Here are some of the tubes that I tried with the EF5: (special thanks to Poeng and JA for the 12AU7 tube loaners)

  • RCA Clear Top (Stock). Slightly warm, good tonal balance from top to bottom, with slight emphasis on Midrange. A little grainy and mellow sounding.
  • Telefunken Smooth Plate: Smooth, thick midrange and bottom, weighty bass punch. Forward and grainy vocal.
  • Tung Sol Black Glass: Forward treble, slightly recessed upper midrange. Tight bass. Good clarity, solid state like. Crisp, but vocals get sibilant easily.
  • RCA Black Plate (Early version): Low end boost. Full and weighty bass. Grainy vocals.
  • Mullard Short Plate: Wide soundstage. Full bodied bass and midrange. Weighty vocal, slightly sibilant.
  • RCA Gray Plate (Late version): Similar to the Clear Top RCA, but more forward vocals, slightly less mellow, punchier bass.
  • Philco Short Black Plate: Midrange oriented. Very intimate yet smooth and non sibilant vocals.
  • International ServiceMaster Smooth Plates: Like the Philco Above, but with more weight on the vocals and bass.
  • Philips Ribbed Gray Plate: Midrange oriented, clean and non grainy. Slightly sibilant vocal. Clear treble. Full bodied midrange.

If you were to ask me, I really find the stock RCA Clear Top tube to be the best all rounder performer. I personally enjoy the Tung Sol Black Glass, but it makes the EF5 more solid state sounding, and it doesn’t nearly have the mellow and smooth tube sound that the stock RCA has. I suppose Hifiman did choose a good stock tube for the EF5. Tube rollings are fun, however, and you can experiment by trying to find alternate tubes that you can use to change the signature of the EF5. I don’t think that the list of tubes I had put up is the definitive list. Rather, they were the tubes that I had available for the testing purposes. The cost of 12AU7 tubes vary anywhere from $10 to $75 (or more), depending on how rare or how desirable a tube is. The ones or my list are nothing too rare, and most of them are fairly easy to get.

To access the opamp (next to the two gold colored heatsinks), remove the hex keys that hold the acrylic panel.

 

For opamp rolling, it’s important to take note that the EF-5 supplies close to 34Volts to the opamps. I wasn’t aware of this when I started rolling opamps on the EF-5, and as a result, I fried an AD8066 opamp (too bad, it was a good combination with the Tung Sol Black Glass) which maxes at 24V. Another popular opamp like the AD797 are also out of the operating spec. The popular OPA627 opamp, however, is a good match with the EF5, and also highly recommended for an upgrade over the stock OP275 opamp for a more refined and higher resolution sound quality.


Hifiman EF5 Review
3 (60%) 6 vote[s]

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103 Comments

  • Reply August 19, 2010

    Jose

    Hi Mike,

    You finally did it! certainly took sometime. I really liked the warm sound of the EF5 with the HE5 and K701 for some time, but after a while it sounded too incoherent with the K701 which is still my reference; I had to change to the HA-160 after selling the HE5. The EF5 is THE match for the HE5s, but it loses a lot of coherence when using dynamics. Great read as always Mike!

    Jose.

    • Reply August 19, 2010

      Mike

      I know man, I'm guilty as charged. It took me a while to gather those 12AU7 tubes.

      I actually thought that the EF5 does wonders to the Beyerdynamic T1, since it smooths out the treble and adds mid and bottom end body. I didn't try it with the K701 though. Perhaps it's a bad match.

      • Reply August 3, 2011

        Stanton2110

        i know this is going back 11 months ago now but just tried the EF5 with the LCD-2 and it does sound really good very smooth sounding so far.

        • Reply August 4, 2011

          Anonymous

          Yes, thanks for sharing Stanton. I think the EF5 is an amazing amp, just a bit buried down among the newer amp releases.

  • Reply August 19, 2010

    Bram

    Nice review mike!

    Based on what I gathered in your review, EF5 surely worth every pence of it as you even ended up make a comparison with amplifiers which has twice the price of EF5, such as Burson.

    Now I'm just wondering. How about EF5 vs Woo audio 6? As both of them might be on the same level, or do you think not so?

    Abraham.

    • Reply August 19, 2010

      Mike

      The EF5 kicks the butt off of your WA6 dude! HEhehe just kidding.. Well I would need to do a formal EF-5 vs Woo6 review. But just a short comparison, the Woo6 is more dynamic sounding, EF5 is more mellow sounding. Woo6 also has a very strong bass performance, and without A-Bing the two, I think the Woo6's bass is punchier.

      Lend me your Woo6 and I'll do the comparison. 😀

  • Reply August 19, 2010

    Bram

    You shocked me with your first sentence! Hahaha.

    Wow, I thought WA6 is the one that has tubey-er sound as woo's amps were famous for that house sound. But if truly ef5 is the one that is less dynamic than the wa6, presumably less transparent and with less quality imaging also, I will be grateful! (Oh I'm being too biased here)

    I think you should A-B them as soon as my wa6 arrived, and sure Headfonia readers are also curious of their comparison 😀 Both of them seems to be ruling under $1000 tube amps and we definitely need to know your preference between them. I personally choose my wa6 hahaha.

    Cheers,

    Abraham

    • Reply August 19, 2010

      Mike

      I think the two amps will appeal to people looking for different sound. Also, the WA6 is roughly double the price of the EF5 (especially with the Sophia Princess).

      As nice the EF5 is, the WA6 still wins on build quality. The EF5 has a monstrous gain, and that's what the WA6 doesn't.

      Anyway, that's just some random comparison points.

  • Reply August 20, 2010

    Professor00179

    If this AMP was just a little bit cheaper… Looks very interesting. However, due to the price I am limited to things ~$80 cheaper. So far the plan is to go with Corda Swing. On the other hand I have noticed that there are many new DACs and AMPs introduced to the market. Probably when I will finally build my system there will be something much better comming out in the same time…:D Let's hope that is not the case.

    • Reply August 20, 2010

      Mike

      Just a little over your budget huh? I think you can afford to raise the budget by $80 😉

  • Reply August 21, 2010

    Alan

    Mike

    Very nice review of the EF-5!

    The combination of the EF-5 with my HE5-LE is superb.

    I investigated upgrading the EF-5 with an OPA627 opamp and came across a Burson Audio web ad that promoted their HD Audio opamp as "a better substitute for an OP627 opamp".

    Any speculation on how the Burson HD Audio opamp could sound in an EF-5?

  • Reply August 25, 2010

    Earfonia

    Very nice review Mike! Especially with the tube rolling 🙂

  • Reply September 3, 2010

    TheMiddleSky

    Hey Mike,

    I just wondering, is it possible to compare EF5 with other entry desktop amp in this price range ($300-$400)?, maybe like Matrix M-Stage, Corda Swing, and Linearossa K3. Yeah I know it’s about SS vs hybrid, but hey, they’re at the same price range, and I just think people also choose the amp not from SQ only, but budget too. (hope you get my point) 🙂

    • Reply September 4, 2010

      Mike

      That should be a fun comparison to do. I'll see if I can make it happen. 🙂

  • Reply September 22, 2010

    TheMiddleSky

    Hey Mike,

    What you think pair EF5 with K701? I'm using Linearossa K3 now, actually it sound good already, but sometimes I feel I need more body to midrange and adding a little bit smoothness to treble. Oh yeah, usually I listen music at low volume, so I need the clean sounding that can produce nice detail at low volume, K3 can bring this clean sound, I just wonder is the EF5 can do this also?

    I usually listen rock, slow rock, pop, acoustic and vocal jazz.

    • Reply September 22, 2010

      Mike

      Hi Sky, I don’t have the K701 with me to test, but I’m listening to the EF5 with the HD800 now at quite a low volume. I do think that the detail level is quite good, although not as good as my regular listening level. But it may be due to the HD800 as well.

    • Reply September 22, 2010

      Mike

      I also compared the low level detail to the Grace m902 amp. While the Grace is better, I think the EF5 still does very well in terms of low level detail.

      I also tested the EF5 for low level listening with the HE5LE. Same good result there, though the HE5LE is less detailed than the HD800.

      I’m not sure about the Linearossa amp, but I think the character of the amp should fit you, if you’re looking for smoother treble and more mid body.

  • Reply September 22, 2010

    TheMiddleSky

    hmm… looks like I can give EF5 a try, well, when I come to Jkt I think I'll test it at KK.

    anyway, thx Mike 🙂

    • Reply September 22, 2010

      Mike

      You’re welcome to try it out at my place.

  • Reply September 25, 2010

    TheMiddleSky

    Hey Mike,

    What you think compared EF5 to WA6? (both with standard tube)

    and I just wondering, which way is better, between replace my K3 to EF5 (linear upgrade, different taste) or save my money and go straight to get more high end SS amp like Burson HA-160 or GS Solo II? (I’ve tried GS Solo II, and for my taste that amp’s good for K701, just wondering about the other options) 🙂

    Thx.

    • Reply September 25, 2010

      Mike

      Wow that's a lot of choices. I am very unfamiliar with all the amps you've tried, so it's hard to make any recommendations at this point.

    • Reply September 25, 2010

      Mike

      @Sky: if I can give you an advice, I think it's best to audition the amps yourself. Finding the best sound is mostly matters of synergy, and so more expensive may not be necessarily better.

  • Reply September 25, 2010

    TheMiddleSky

    lol, yeah I know audition is the best way to get the best result, but sometimes it's a bit hard to try some things.

    ok, thx Mike 🙂

  • Reply October 28, 2010

    Tash

    Hi Mike,

    Am thinking about trying the OPA627 in my EF-5. Do I need to buy one chip or two? (I'm not next to my amp otherwise I would have a look inside myself, but I'm keen to order it before I go home tonight so I can still get it for the weekend!)

    Thx

  • Reply December 6, 2010

    Joe Lockwood

    Hi Mike,

    Can you recommend any headphone amps up to $2500 that WOULD be a great match for Audeze LCD2's?

    Joe

    • Reply December 6, 2010

      Mike

      Hi Joe,
      If you like the LCD-2 for its bass impact, then the Burson is highly recommended although it's quite far from the $2,500 price bracket. I don't really find the LCD-2 sounding that much better from a Beta22 or a Zana Deux, other than the fact that the amps have different sound signatures.

      Do you like an agressive sound or more into romantic sounding ones?

  • Reply December 7, 2010

    Wharfrat

    Mike,

    Wondering two things: Have you tried the EF5 amp using a Lavry DA-10 as your DAC?
    Also, since the Lavry also serves as a preamp, what affect would there be on the signal and sound quality if I were to use the digital volume control on the Lavry to provide additional gain to the EF5?
    This is with driving the HE5LEs.

    I am thinking of using it to power a slew of orthos…LCD-2, Thunderpants and their highly esteemed ilk….as well as provide some improvements to the dynamic cans I have an eye or two on: T1s and the Ultrasone Ed9s.

    Thanks for your comments to date, esp on the op amps and tubes…I have a bias for tubes, but am getting a solid state education of late due to the ability of SS amps to provide me with the SPLs i need to hear certain frequencies without causing a bit too much low end masking of details. Long story there.

    • Reply December 8, 2010

      Mike

      Hey Wharfrat,
      I don't have the DA10 around, but I think it should be enough by itself to drive the LCD-2. The Audez'e is not that difficult to drive unlike the HE-6.

      Of course you can send the signal out to an EF-5 if you want to get the hybrid tube flavoring of the EF-5. With analog potentiometers like the one on the EF-5, I've always liked the sound better if the pot is on maximum volume level. Then I would control the volume through the digital end (like through your Lavry).

      • Reply December 11, 2010

        Wharfrat

        I am seeing more headphone enthusiasts looking at ways to use DACs or preamp outs into their dedicated can amps to enhance certain sound characteristics…but you are the first to discuss how the volume control relationships could be a part of the pairing….thanks for the enlightenment. In fact, I am going to hook up the Lavry to my Cyber-20 as soon as I can get the necessary interconnects. Will report back what I experience, FWIW.

        • Reply December 11, 2010

          Mike

          No, this is not quite like that. Nothing to do with certain characteristics of the volume control. I'm just saying that because most analog pot has "issues" at lower levels, and that the signal coming out of your source is better off not going through any attenuation at the potentiometer. Hence, when I'm on a computer set up, I tend to max the volume on the amplifier and control it through Itunes.

          Of course, it's good to have Benchmark Audio stating the fact that the Itunes volume control causes no audible distortions:
          "The volume controls in iTunes versions 7.X and 8.X will not cause significant distortion. The user should not hesitate to use the volume control in iTunes v7.x and 8.X".
          http://bit.ly/ewbCt4

          And even if theoratically it has distortions, I still find it to be less than the distortions from the typical analog pot.

  • Reply January 14, 2011

    @LievenVranken

    Would you choose this amp over the Darkvoice 3322?

    • Reply January 14, 2011

      Mike

      I have no experience with the Darkvoice. 🙁

  • Reply March 21, 2011

    blankdisc

    Hi Mike,
    Thanks for the review. It’s one of the best reviews i have ever on the internet, and i have read a lot in the past couple months.
    Just recently bought the HE-4/EF5 combo. How easy is it to grade the opamp? never done that before. is it just like the tube which you can easily pull and plug in a new one? Could you also recommend a place to buy the OPA627? There seems to be a lot of different types, and not sure which one to get. Thanks!

    • Reply March 22, 2011

      Anonymous

      Hi Blankdisc,
      Very easy to do. Just take off the top acrylic plate, and pull out the
      opamp. You can see the picture here: (it’s the chip that says “OP275”)
      http://static2.headfonia.com/wp-content/uploads/2010/08/hifiman_ef5_04.jpg

      You can pull it out with just your fingers, though it may be very stiff
      and hard. Having a pair of pliers that can fit in the space helps a lot.

      As for getting the OPA627, here is a copy from the other article:

      ——————————————————————————
      Some people have compared different versions of the OPA627, and one
      version is supposedly better than the other. Frankly I have to call
      around to check which version that is, as I don’t quite remember.

      Anyway, about the OPA627, you need to get TWO of the OPA627, since each
      chip only operate in “single channel”, meaning one opamp won’t cover a
      stereo signal.
      This one is a good one to get:
      http://search.digikey.com/scri

      Then you need to solder TWO of those OPA627 into ONE “SOIC to DIP” Adaptor.
      http://cimarrontechnology.com/

      (I just noticed that there is an option to “Add two OPA627AU” into the
      Browndog Adaptor — so you can get everything in one vendor.

      The soldering is not for the beginner, as you need to be very precise
      when soldering those SOIC chips.

      Lastly, *dumb me* I just did a quick check on Coolfungadget’s shop, and
      he sells these already ready to use:

      http://coolfungadget.com/store

      Getting it from coolfungadget seems to be the most logical choice, but
      it’s up to you.

      Cheers.

      ——————————————————————————

  • Reply May 30, 2011

    Edvard

    Am I right to assume that the “OPA627AU with Class A Biasing Mod” at Coolfungadget is just “plug and play” with EF5, no soldering required?

    Ed

    • Reply May 31, 2011

      Anonymous

      Yes, If you see a resistor already soldered to the opamp, that means no soldering is needed.

      • Reply June 6, 2011

        Edvard

        Okay. Just when I was about to oorder I saw that they had the ”
        Burr Brown OPA627AU x 2 on Browndog Adaptor (DIP)” too. Would both the earlier mentioned item and this one fit? Im not quite sure what class A biasing mod means.  You are no library of knowledge, but on the subject on headphones you seem to be 🙂 I hope you get payed for that.

        • Reply June 6, 2011

          Anonymous

          That OPA627AU on browndog adaptor should fit, but what was the other item? Sorry I am on my email program and can’t track the earlier posts.

          • Reply June 6, 2011

            Edvard

            It was OPA627AU with Class A Biasing Mod and it costs 5 $ more(20$) which is still really cheap

            • Reply June 7, 2011

              Anonymous

              Thanks. I don’t quite remember if I’ve fitted a class-A biased op amp on the EF-5, but the difference in space requirement is just a single resistor and I think it should fit just fine.

            • Reply June 7, 2011

              Anonymous

              Edvard, I think you can get the Class-A version for the EF-5. I just
              looked at the picture of the EF-5 and I’m quite certain the opamp will fit.

              http://static2.headfonia.com/wp-content/uploads/2010/08/hifiman_ef5_04.jpg

          • Reply June 7, 2011

            Edvard

            Thanks Mike. I  ordered the Class A Mod.

  • Reply July 17, 2011

    Tim

    Hi Mike,
    Have you tried pairing the EF5 with the LCD-2?
    I feel that the LCD-2 midrange is distant and not engaging/forward enough, do you think this EF5 could solve the problem? 
    Would it be too mellow and bring haziness/veil over the LCD-2 transients/pace and detail resolving capability?
    Thanks mate!

    • Reply July 18, 2011

      Anonymous

      Hi Tim,
      Unfortunately I haven’t. But I don’t think it would be a good pairing.
      The EF-5 would not quite veil the LCD-2, but the pace would be somewhat
      affected.

      What you said about the LCD-2 is just the way the LCD-2 is, I suppose.
      The newer version manages to push the midrange a little more forward,
      but the midrange neutrality is better on the older version, I feel.

      If you have access to DIY, an LM1875 Gainclone in fact is one of the
      nicest amp I’ve used with the LCD-2. It would also help to bring the
      midrange forward.

      • Reply July 18, 2011

        Tim

        Thanks Mike.
        For non-DIY route, any other midrange-centric amp would you recommend?
        Do you think the Zana Deux, Woo or M-Stage have emphasis on midrange or not?
        Thanks.

        • Reply July 18, 2011

          Anonymous

          For a non-DIY amp, the Burson is the best pairing I’ve heard for the
          LCD-2 yet. Not saying the Burson is the same as the LM1875, but it just
          happens that those two amps are my favorite for the LCD-2 so far.

          The Zana Deux has a forward midrange, but somehow it sounds off with the
          LCD-2.

  • Reply July 17, 2011

    P. J.

    The amp is now 500$. They have upgraded certain stuff but 100$ is quite a jump.

    • Reply July 18, 2011

      Anonymous

      Thanks for the info. Didn’t know that.

  • Reply August 5, 2011

    Jake Analog

    Mike, how suitable is the EF5 for driving high impedance cans like DT880 600ohm, which I’ve heard benefit from full OTL tube amps.

    And not sure if you cover this elsewhere on your site, but what’s your general feeling on hybrid amps such as this versus full tube or full SS amps?  Where do they fit in and when are you best off going with a hybrid?
    Thanks!

    • Reply August 6, 2011

      Anonymous

      Hi Jake,
      High impedance is always easier to drive than low impedance, and so the EF5 should have little problem driving the 600 ohm Beyers.

      The thing with OTL amps is that, most of them have a very high standard of sound quality and that both low or high impedance cans would benefit from them. The only problem is that often OTL can’t drive low impedance due to current shortage.

      Now, full SS to hybrid to full tube. I grew up with solid states, and I believe the best solid state I’ve had was the Beta22. But lately my ears have been looking more for a tube sound, though I still keep the Burson for when I need real bass impact. So consider me mostly a tube guy.

      Hybrids amps previously never attained to the high quality that I hear from full tube amps — but I’m talking about $1K tube amps and up here, while most hybrid amps I’ve listened to are around the $500 range and lower. Then I received the Apex Peak (which is a hybrid), and I am fully convinced that hybrid amps can sound very very good when designed properly. In fact I like the Apex Peak far more than the Zana Deux which was one of the highest regarded OTL amp around.

  • Reply December 14, 2011

    Mr Brewmeister

    Mike, love Headfonia, keep the goodness coming!  I’m wondering if you’ve reviewed the HiFi Man EF-2A Amp/DAC unit and what you thought of it?

    • Reply December 14, 2011

      Mike

      Hi,
      I’m going to try to get an EF2 DAC/Amp for a review. 🙂

      • Reply December 14, 2011

        Mr Brewmeister

        Thanks!  It looks like a good entry point into the world of tube amps, with the DAC to boot and all for $150 – seems too good to be true.  Looking forward to it!

        • Reply February 13, 2012

          Matthew King

           Mike,
          I decided to bite the bullet and ordered the EF-2A!  Decision based on desire to move into tube amplification and coupled with the on-board DAC for $170 it looked like a great place to start.  Reviews on-line are good, the exception being several complaints about seriously high gain – although I noticed that the high-gain complaints all are from more than 1 year ago.  Possibly HiFiMan fixed this problem?  Should arrive in a few days – I’ll let you know how it sounds!

          • Reply February 15, 2012

            Mike

            Hi Matt,
            I am not too familiar with the EF2 but I’ve heard good things about it. Please let me know if the high gain issue is still there.

          • Reply March 23, 2012

            Matthew King

            Mike,
             Just got my EF-2A going after quite a bit of trouble.

            I received it about a month ago.  When I first set it up the gain was insanely high, as noted by several folks elsewhere.  I was able to control this by adjusting the volume on the computer (I guess I’m not a true audiophile then, eh?).  The gain I could live with, but the problem with this amp seems to be a noisy background – it is anything but black.  There is a hiss in the background that increases in volume as you turn the amp knob up and is present regardless of the source and is even present when no source is plugged in.  It was for this reason that I sent the EF-2A back to ALO (as suggested by HiFi-Man support).  In my return I noted the hissing and that HiFi-Man suggested that the unit was bad.  ALO tested the returned unit and said that they could not find the hiss I had noted.  They did note that HiFi-Man had provided different tubes from the ones originally spec’d for the unit.  They sent me a replacement unit and swapped out the tubes for a different model.  As a side note, I have to applaud ALO here because they did all they could to help out with a unit that clearly has manufacturing issues.  They even covered my return shipping despite the unit not being defective.  For my first experience purchasing from them I was very impressed and would recommend them to anyone.  Plus, look at those cables!!!  (insert drooling emoticon here)

            So second time around on the EF-2A . . . gain issue is still there and the noise is still present.  I’ve only had it going for about an hour, so maybe some longer burn-in time will reduce the hiss.  The hiss is annoying, especially at higher volumes, but I do tend to listen lower.  Also, there is a slight channel imbalance that equals out by about 9AM on the dial.  There is a delicate balancing act between lowering system volume to avoid the high gain, but leaving enough volume to clear the channel imbalance range before the hiss gets too loud.  It took a few minutes, but a sweet spot can be found.

            So once you get past the hiss, gain and imbalance issues, THIS LITTLE BABY SOUNDS GREAT!  I’ve got it playing Menomena’s album “Mines” thru the DAC on my Beyerdynamic T50p’s, which always have a very crisp technical sound especially on the highs and mids.  The EF-2A is really boosting the bass, as well or better than the bass boost on my JDSL CmoyBB.  And I think the bass is a little cleaner than on the CmoyBB as well.  The sound-stage feels more expansive than directly from the PC or iPod Nano and I’m picking up detail that I haven’t heard before, even through the CmoyBB or Headroom BitHead.  In retrospect I am wondering if the hiss is due to an impedance issue since the T50p’s run at 32Ohms.  I have some older Sennheiser HD595’s that I will try out later.

        • Reply February 13, 2012

          Matthew King

           For some reason couldn’t get my Mr Brewmeister username to register, but rest assured it’s still me.
          -Matt (Mr. Brewmeister)

  • Reply December 24, 2011

    Swbf2cheater

    It is been very difficult for me to find an acceptable amplifier for my HE-500, one with suitable soundstage qualities that do the HE500 justice.  I’m sure you’ve been asked this before many times,  but can you comment on the EF5 vs the Lyr for use with the Hifiman HE500?   I really feel like the Lyr is overkill in terms of power needed, but I also feel that it might not really be doing the job properly for any staging qualities.   I am being recommended the EF5 more than the Lyr in the past few weeks, very temping

    • Reply December 26, 2011

      Mike

      Hi,
      I’ve only tried the Lyr and the EF5 with the Hifiman HE-6, but this would probably also applies to the HE-500. I don’t know what the EF5’s power ratings are, but in terms of soundstage it is far better than the Lyr — very circular soundstage with excellent depth.
      Another one that you may want to take a look at is the Bada PH-12. Also plenty of power for the HE-500, and again excellent soundstage. http://headfonia.com/entry-level-tube-hybrid-bada-ph-12/

  • Reply November 16, 2012

    K.Latta

    Hello, I was wondering where did you purchase your OPA627 opamp from? I recently purchased the EF5 and I’m looking at doing this kind of upgrade, although I have never changed out an opamp before… Is it difficult to swap out?

    • Reply November 16, 2012

      K.Latta

      I found a web site that sells this particular opamp (http://www.digikey.com/product-search/en?x=22&y=14&lang=en&site=us&KeyWords=OPA627+). Do you know which one of these would work well with the EF5? Thank You.

    • Reply November 16, 2012

      K.Latta

      I read a little further in the comment section and I came across the comment about mounting the 2 pcs Dual BB OPA627 on SOIC to DIP Adaptor. I did an eBay search and I found this ad (http://www.ebay.com/itm/2-pcs-Dual-BB-OPA627-SOIC-DIP-Adaptor-/190755222489?pt=US_Home_Audio_Amplifiers_Preamps&hash=item2c69e5b3d9). Will this work with the Ef5? Thanks.

      • Reply November 16, 2012

        Mike

        • Reply November 16, 2012

          K.Latta

          Oh that’s awesome! I like the way this one looks than the one on eBay. I will order this soon for sure, thank you for answering my questions. I’m hoping this upgrade will bring more details of my HE-400 (I’m using the velour pads with a modified cable made by CablePro, it’s called the Freedom Cable). I would say this headphone sounds a lot more neutral and the soundstage I believe is much bigger than using the pleather pads.

    • Reply November 16, 2012

      Mike

      The swap is not difficult, just have to do it carefully.

      I bought mine locally, I think.

      • Reply November 16, 2012

        K.Latta

        That’s good to know. Well I ordered the opamp from the link you provided at tamaudio.com, and I’m really looking forward to hearing how well this opamp sounds compared to the stock. Thanks for the reply.

        • Reply November 16, 2012

          Mike

          You’re welcome K! hopefully the installation goes smoothly. (It should, it’s quite simple.)

      • Reply November 21, 2012

        K.Latta

        Hello Mike, I wanted to know if you used special tweezers to switch out the opamp? The one I ordered hasn’t arrived yet, but I went ahead and took off the top-clear cover to see how difficult the switch would be. I couldn’t take the stock opamp out with my fingers because they’re too big to fit inside (the tweezers I had wouldn’t hold a grip). So I tried to unscrew the front cover, unfortunately one of the Allen wrench screws is a bit clipped and I can’t unscrew the whole front cover.

  • Reply December 28, 2012

    Kevin Latta

    Hi Mike, I was wondering if you have any contact information with the people who run Tam Audio… I placed an order with them back in November (a OPA627 opamp that you suggested for my EF5 amp) and I never received it. I have tried many times contacting Tam Audio through e-mail and have not gotten a reply. I check with my local post office and national postal head quarters to see where my item is and so far no one can give me an answer. If you don’t have such contacts then I’ll understand and just accept my $15 loss, thanks.

  • Reply February 25, 2013

    Bryan Besler

    Hey Mike I’m sure you’ve said but I couldn’t find where. The opamp for the EF5 is it the OPA627 AU, BP, or AP? I’m looking at them on digikey now.

    http://www.digikey.com/scripts/DkSearch/dksus.dll?WT.z_header=search_go&lang=en&keywords=opa627&x=-1199&y=-51&cur=USD

  • Reply April 30, 2013

    Aditya

    Hello Headfonia,

    would like to know, i just found a very good deal for this amp, for maybe around $250. (2nd hand condition actually)

    is it gonna work if i pair it with HD 650 or HE-500?

    is it an all-rounder amp to work with low and high impedance headphone?

    • Reply April 30, 2013

      Mike

      Yes, yes, and yes.

      🙂

      • Reply April 30, 2013

        Aditya

        wow that’s a fast reply Mike, thanks a lot 😀

        what do you think this one compare with either schiit asgard and lyr based on your experience?

        • Reply April 30, 2013

          Mike

          The EF5 is a smoother amp with a superior soundstage.

          The Schiits have better PRaT but they are not that refined.

          • Reply April 30, 2013

            Aditya

            oh i see, seems like my preferences goes toward EF 5 right now !

            and what schiit do you refer have better PRaT? both of them?

            • Reply April 30, 2013

              Dave Ulrich

              The fact that you can roll both the tube and the opamp with the EF5 will give you a decent control over the sound as well, so if you ever felt the need for a bit more PRaT, I’m sure you could make it happen. Honestly, if it is in good working shape, $250 is a very nice price for this. I am jealous.

              • Reply April 30, 2013

                Aditya

                yep dave, i also didn’t believe what i just saw when surfing on local forum.

                looks like a good deal to me, lets see for the next 3 days should i get it or not 😀

                • Reply April 30, 2013

                  Mike

                  It’s just a matter of hype, really. The EF5 is an old product. Schiits been really strong on their branding.

            • Reply April 30, 2013

              Mike

              Yes both of them.

    • Reply May 7, 2013

      Kevin Latta

      I’m using this amp with the HE-500 on the high gain setting and it sounds excellent, absolutley no complaints. The only tweaks that I have made to this amp was that I swapped out the opamp and the stock tube (the stock is very good by the way).

      • Reply May 8, 2013

        Mike

        Thanks, Kevin.

        • Reply May 10, 2013

          Kevin Latta

          I was reading a blog post about tweaking the EF5 amp beyond just swapping out the opamp (http://www.tweak-fi.com/apps/blog/show/8888897-3-tweaks-for-cheap-#comments) I ordered the Burr Brown OPA627AP with Class A Biasing Mod to see if there would be any significant changes from the OPA627AU. My question is Mike have you ever used this opamp version on the EF5 before? Thanks.

          • Reply May 10, 2013

            Mike

            If I remember correctly I don’t think you can fit a modded op amp in there. Cramped space

            • Reply May 13, 2013

              Kevin Latta

              Space seemed like it was going to an be issue from the way that I saw how the blogger got his version of that particular opamp to fit in the case… Looks like I’ll have to adjust the top cover or I can just leave it off right (I think I saw a pic. in one of your posts with the EF5 top cover off)?

              • Reply May 13, 2013

                Mike

                Yes you can probably trick it to make it fits.

                And yes the top cover does come off

  • Reply December 17, 2013

    Martin

    Hi Mike,
    what do you think about EF5+HD600/650?

    • Reply December 17, 2013

      Mike

      Too mellow, very slow pace. Fine if you like that kind of a sound.

  • Reply September 6, 2015

    Raw Chicken

    Is this amp capable of driving the beyer dt880 600ohms to a decent loudness without turning the volume knot to say 11’o clock or 12’o clock position. Thanks in advance

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