or Connect
Head-Fi.org › Forums › Equipment Forums › Headphone Amps (full-size) › Any Hifiman EF2A tube rolling guides?
New Posts  All Forums:Forum Nav:

Any Hifiman EF2A tube rolling guides?

post #1 of 19
Thread Starter 

Hey guys,


Finally just picked up an EF2A and am really excited about changing out the tubes once it arrives.  I was wondering if any of you guys out there can give me a cliffnote version on some of the other tubes I can use with this amp and basically what I can expect from each one.  I'm going to be using them with a pair of Denon D2000's if that will help.  Right now I'm mainly trying to decide between a pair of NOS Mullar CV4010's or Raytheo 6AK5W's.  Has anyone here used both of these tubes and can tell me which generally they liked better?  Also other suggestions of other tubes is greatly welcome too and if you could also provide me with where I could buy them at for the lowest price, that would be great too.


Thanks guys!

post #2 of 19

Which headphones will you be running yours with?  I also added the HF-2A to my collection last week.  However, I have the stock tubes, that are well burned in since I purchased the amp used.  I currently like what I hear from the stock tubes with my Fostex T50RPs, HE-400s and HE-5LE headphones.  Seriously, I'd run the stock tubes for a while before jumping ship on them.   


I forget the exact number to match the tubes correctly.  However, there's a possibility of the tubes being the same as those for the Little Dot 1.  I have to confirm this myself, though, so I'm a bit reluctant to even make that statement, yet.  


When it comes to my EF-2A, I much prefer to use the amp section by itself and feed it from my iPod.  I was running it from the USB connection on my computer using Foobar and WasAPI  this weekend.  However I thought that Foobar needed quite a few EQ adjustments for me to get a good sound out of the amp / DAC.  Then again, the DAC features a Burr-Brown chip, but I don't think it's one that's highly regarded, but more run of the mill type of chip.



post #3 of 19
Thread Starter 

I'm going to be running the amp with my Denon D2000's.

post #4 of 19
Thread Starter 

anyone else here happen to try both the Raytheons and Mullards and can give me their opinions on each?

post #5 of 19

I just purchased the EF2A from a member here on Head-Fi and he included the stock tubes and also some Raytheon 6AK5 tubes. At this point in time I can't tell much of a difference comparing the two sets. The sound about the same, although the stock tubes are a bit bigger a glow a bit more :) So at the moment, I prefer them.


In the future I'll probably buy the Mullards just to add them to the collection and compare those, I've heard good things about them.

post #6 of 19

I just started playing with the tubes again, and something interested I just noticed.....

I plugged in 1 stock tube and 1 of the Raytheons, the sound is about the same as any of the other configurations but the channel imbalance at low volumes is gone. It seems to have a perfect balance and the gain seems smooth from 0 - 10. Interesting, but a good thing I guess! I just came to accept the channel imbalance and learned to live with it since it was a wide-spread issue.

post #7 of 19

I have the EF2a also and I noticed a bit of high end harshness when I first got it, but someone here suggested I let it burn in for a while and I will have to admit, the sound (with the stock tubes) has smoothed right out and it sounds really good to me. If I was to try and improve the sound I don't know what I would do, so I am sticking with the stock tubes.

post #8 of 19
Originally Posted by HPiper View Post

I have the EF2a also and I noticed a bit of high end harshness when I first got it, but someone here suggested I let it burn in for a while and I will have to admit, the sound (with the stock tubes) has smoothed right out and it sounds really good to me. If I was to try and improve the sound I don't know what I would do, so I am sticking with the stock tubes.


I just purchased 2 more sets of tubes. I picked up NOS Tung-Sol and CBS/Hytron 6AK5 tubes. So now I have the stock chinese tubes, Raytheon, and the prior 2 mentioned.


When I receive the other 2 sets I'm going to be doing some extensive testing and listening. I will post my results in a couple weeks once they are all burned in and I can do a fair comparison. I'm pretty excited for the Hytron's, I've heard great things about them.

post #9 of 19

I've been having a great time comparing all the tubes in the EF2A and I still have a lot more testing to go before the tubes are fully burnt in.


But here's  what I can say about my first impressions of all 4 sets that I own.


Stock Chinese Tubes:


These tubes were sent to me pre-burnt and sound better than I expected. The tubes have a good amount of low end but the highs are little piercing. Even though they performed better than expected, these are my last choice.


Raytheon Tubes:


These tubes were also sent to me pre-burnt so I cannot say how they compare to being used right out of the box. What I did notice, however, comparing directly to the Chinese tubes is that the Raytheons have a deeper lower end and a much more pleasing high-end. Not nearly as shrill as the Chinese tubes. A nice improvement.


Hytron Tubes:


The Hytron Tubes sound about on-par with the Raytheon tubes at the moment and I hope to hear a noticeable improvement once they get some more use. But all-in-all they are pleasing across the whole audio spectrum with a good amount of impact. Very happy so far with these tubes as well.




This is the stand-out tube for me so far. Right out of the box it sounded AMAZING! Tons of low end, crystal clear mids and highs and absolutely no distortion or hiss at any volume. I was really surprised to hear such a dramatic difference compared to the other 3 sets that I have, but the Tung-Sol's just make my music sound more "powerful". I've heard good things about the Tung-Sol's and I bought them on a whim, and I'm very glad that I did! If they continue to sound better, I can't see myself changing out these tubes!



MORE COMMENTS TO COME (after further testing)



Now I'm very curious about Tung-Sol tubes. If anyone has experience with this brand of tube I would like to hear your thoughts on how they compare to other tubes you've heard from other manufacturers. I find them to be a stellar sounding tube so far!

post #10 of 19

To comment on the Tung Sol tubes:


I replaced the original tubes with these:

Tung-Sol 5654/6096//6ak5W/6J1/EF95


Bought them at: http://www.ebay.com/usr/tubemazestore



I replaced the original tubes because I had some problems listing piano music on the ef2a. When some high tones were played I heard a *crack*...don't know the exact term for it. But it was a disturbing sound. When I rolled the Tung Sol tubes in this problem was gone. 


Actually, these tubes are really a very good upgrade for the ef2a. More powerful sound, not too muddy. I was quite amazed to hear new things in music I never heard before.

Still the best has yet to come, because they're not burned in completely.

post #11 of 19

Does the EF-A2 automatically bias the tubes for you or do you have to tube bias with a meter?

post #12 of 19
I realized that the EF2A uses the same tubes as the PanAm, I just wonder if anybody try any other tubes like the Russian tubes? A friend of mine passed me some Peking tubes, 6J1 matched pairs, I am just waiting to try them out this weekend...
post #13 of 19

I have the stock tubes, with some Raytheons on the way. No real probably with piercing highs, everything seems detailed and well separated, and the channel imbalance isn't noticable at regular listening levels for me. Will let burn the raytheons in, then look into some mullards or Tung-Sol's, perhaps....

post #14 of 19

If you are going to invest in tubes don't invest significant money on ebay unless its a reputable dealer that tests their tubes. A cheap tube within spec can sound better than a revered brand tube that's testing out of spec.  That being said, all tube brand have some pretty significant variances in there tolerance. Ive been dealing with tubes for 25 years and there is a lot of unwarranted hype.  I tend to establish a relationship with my tube vendors and am pretty pleased with most that I am sent.

post #15 of 19

I bought the Raytheons from a top-rated seller (VivaTubes I believe), and the tubes were packaged well and work just fine (got 'em today!). Not much use, but they already sound a bit more refined than stock tubes, a bit more impact with a smoother high end so far. 

New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Headphone Amps (full-size)
Head-Fi.org › Forums › Equipment Forums › Headphone Amps (full-size) › Any Hifiman EF2A tube rolling guides?