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Review of Elekit TU882R: Tube headphone amp

post #1 of 88
Thread Starter 
Day One – June 23, 2009

Recently I saw a post by Victor Kung on this new product. He posted for volunteers interested in listening/testing the amp and I jumped at the opportunity. Mr. Kung agreed and I received the unit today. I proceeded to unpack and commenced the testing. What you see below is the first of various posts to come on the Elekit TU882R.

The concept behind Elekit is IMO quite interesting; the company sells a vacuum tube stereo headphone amp that arrives in modules and parts that the owner puts together. This approach allows the owner an exposure to DIY and should start the juices flowing to further projects. Furthermore it lowers the cost of the amp and thus makes for an affordable product to budding audiophiles.

Although the unit I received arrived fully assembled I could not restrain my self from reading the 15 single sided pages instruction booklet. The instructions are easy to follow and start with the tools needed and a couple of pages identifying components. As the instructions progress the easy to follow diagrams direct the builder through the process. They also include a technical section with a schematic and specifications which would come in handy for future troubleshooting or perhaps for the not faint of heart mods! Of course those who modify this or a unit by any other manufacturer would loose the warranty, so please do not take my comment to imply or infer that modifications are permitted or encouraged.

The tubes used are the 5670/2C51/396A types, which are plentiful and quite inexpensive for NOS tubes. I found the unit to run quite cool to the touch and quite appealing in an understated way. To me amps like the Elekit and Mapletree are quite appealing in their industrial and utilitarian way.

Operationally the unit offers a lot of flexibility; first the RCA input has a pass through feature, which helps those of us who wish to use the same source to feed to amp without having to purchase splitters. In the front panel you will find a second input using a 1/8” jack, very convenient for those who would like to use an iPod or an iModded iPod to feed the amp using their dock line out. This input takes priority over the RCA input in the rear; so do not plug anything into the 1/8” input jack in the front if you plan to listen using the rear input.

Right below the 1/8” mini input in the front faceplate there are three additional input jacks. Two are of the 1/8” variety for low and mid impedance headphones, the third is a ¼” jack which can be used to connect low/mid/high impedance headphones. The impedance selector for the ¼” jack is on the rear panel of the amplifier adjacent to the loop out RCA’s.

If you wish to read more about the amp from the vendor’s perspective you should go to: http://www.head-fi.org/forums/5452305-post1.html

By the way, before I get to into the unit or the review here are a couple of pictures of the amp.





I will be doing this review in various stages with various targeted audiences/uses. The first one is for those looking for an office, den, or nightstand rig. In this case the source would be an iPod or similar via a line out doc. I used for this first stage a 160 Gb iPod Classic and an ALO Bamboo line out dock filled with Apple Lossless Files.



I went kind beyond mid-fi by using a pair of Grado RS-1 with buttons I have had for about 4 years. BTW, since I am not the first user of this Elekit TU882R I am going on the premise it is fully burnt in. I should also mention that for the first couple of days I will be using the stock tubes and will later install a pair of WE396A valves included for testing.

For music I started with Michael Franks - Abandon Garden and followed it with Yellowjackets – Altered State.



How does it sound? To say I was surprised would be an understatement, the sound is very mellow with an organic dare I say cohesive sound that exudes a level of smoothness that in my case helped me unwind following a hard day at the office. Using the iPod via the ALO Bamboo line out makes for a very compact and user-friendly setup, which is IMO, an outstanding combo to relax the user do the friendly way it presents the music.

The bass is tight and punchy without being overpowering. The mids are sweet and with enough detail to bring out the music, yet the smoothness of the presentation makes for a very mellow and enjoyable experience. The air between the notes and openness brings out a very natural and engaging soundstage, which combined w/ the smooth mids not only enhances the presentation but also keeps you listening to more and more music.

In the next stages I will use a Meridian 506.20 cd player and a Monarchy NM24 playing Apple Lossless files from my computer. I will use these sources to further evaluate the musical presentation including the treble extension and soundstage. If the amp continues to scale up w/ the better sources this will be a really nice addition to most of us looking for a single ended tube based headphone amp.

Before I close this first installment I will add that the RS-1 kept its composure at all times and its treble presentation was both very smooth and engaging. The amp was dead silent in high gain w/ the source paused and the volume at max.

Day Two – June 24, 2009

Today I hooked up my modded Denon AH-D2000; this unit has received the MarkL mods plus a set of his Bubinga Wood cups. Lastly it sports a ten foot long silver plated re-cable terminated in a ¼” neutrick plug. Here is a picture:



For the first round of music (still using the iPod via the ALO Bamboo Dock) I chose Diana Krall’s All For You: A Dedication To The Nat King Cole Trio and Joe Pass’ Appassionato.



I felt the presentation was just as good with Denon headphones and the mids were just as sweet as with the RS-1. Diana Krall’s voice was just spot on and the piano’s bass notes were just as punchy and detailed as I could ask for. As you can read I was very happy with the sound reproduction.

Then I realized that some users may wish to use an older cd or dvd player as a source should they wish to set up a rig in the den. I searched in my closet and found an older Philips dvd player model DVP5982. I proceeded to connect it using the same cables as the ones used to connect the ALO Bamboo Dock, a set of Silver Sonic DH Labs BL-1 Cable made by Moon Audio.

To maintain some common elements I chose the same Denon AH-D2000 headphones and the music by Diana Krall and Joe Pass (cd’s of course). I was not ready for the totally different experience! Yesterday I wrote that I was hoping the Elekit TU882R would scale with better sources, well it does so in a big way! The biggest difference is … just about every component of the presentation. The largest and more easily recognizable improvements lie with the treble extension, a deeper bass, and a more open presentation of the music. I should also inform that not only is the soundstage wider but thicker as in layers (front to back), I can almost call it three dimensional but I think I will have to listen to other cd’s before making such an assertion.

Please do not take my comments to be in any way a negative critique on the iPod or the ALO Bamboo Dock. Both are outstanding for the intended purpose for which they were design and built. There is no way you could transport 500 cd’s in a battery operated source with over 28 hours of play time in as an small package as achieved by the iPod and ALO Bamboo Dock.

So far, with two days of listening I am very impressed with this amp. So much so I have asked my wife to listen and provide feedback, her response was a smile and a comment on how nice the unit sounds. These statements were made with both the iPod and DVD Player as sources, I concur with her assessment.

More to come …
post #2 of 88
Thread Starter 
Reserved for future additions/comments.
post #3 of 88
finally a review of this unit. Very nicely written and look forward to later impressions.
post #4 of 88
Really nice review, Miguel. I'm the builder of the TU-882R under test and I can confirm for you that the unit and the two sets of tubes I furnished for you are indeed well burned in. Somewhat over 100 hours.

I think your description so far of the sonic properties is spot-on -- very much what I heard using Sennie HD-650s. I am looking forward to your impressions as you increase the resolution of the source material.

Lastly, I will add that Victor's superb English translation of the Japanese instructions made building the full kit a relaxing and fun experience. Absolutely no problems experienced during building, and the amplifier worked without issue from the very first power up. The quality of the Japanese parts furnished by Elekit is absolutely first rate. I've posted a series of pictures during contruction and testing at:

Image hosting, free photo sharing & video sharing at Photobucket

for those who might be interested.

Thanks for taking the time to post your very thorough and well-written review. I owe Victor one that I've been too snowed under to get done.

Steve Z

Disclaimer: No connection with Victor Kung, VK Music or Elekit other than as a very satisfied customer.
post #5 of 88
Hmm I've been anxiously waiting for a review on this unit with more detailed pictures as well to decide on my first headphone amp purchase decision between this and the audiotailor jade.

I'm wondering why this amp doesn't use an IEC AC plug? Would it be relatively easy to mod with an IEC plug? So far the sound seems in line with what I am looking for with my Senn HD600. Look forward to more detailed review with the WE 396.

I'm assuming that this amp is autobiasing as well?
post #6 of 88
Thread Starter 
I have modded the first post to add a 2nd day of review impressions.

yogibearal as far as a two prong or three prong I will have to let a more technical knowledgeable member dwell into the explanation. I remember reading that a lot has to do w/ the type of grounding and isolation provided, this determines if the case is grounded or not. Sorry I can not provide more information.
post #7 of 88
Thanks for the review, mrarroyo. How would you compare its sound with the RS-1's with a solid-state amp like the EC/SS? Which impedance setting did you use with the RS-1's?
post #8 of 88
Quote:
Originally Posted by yogibearal View Post

I'm wondering why this amp doesn't use an IEC AC plug? Would it be relatively easy to mod with an IEC plug?

I'm assuming that this amp is autobiasing as well?
It would be easy enough to do so, however the space behind the existing power cord entry is tight. One could carefully enlarge the cutout for the existing cord to hold a standard IEC 15A inlet. However, the chassis is ungrounded as currently configured. I'd probably experiment with grounded and ungrounded and see which had lowest noise. It would be fun to experiment with different power cords, bearing in mind that the amp, though no featherweight, might not be very stable with stiff or heavy DIY or aftermarket cords.

Yes, the amp is fixed, autobiasing.

Steve Z
post #9 of 88
Any idea how this compares to the DarkVoice 332/336/337? I need to reference this to something I'm familiar with. Thanks. I just love the build and looks - but between this and some other choices out there at the price point and match to my current senn HD600's I'm wondering if its a good combo.
post #10 of 88

Impedance setting and noise

I contacted the North American importer, Victor Kung, and another enthusiast who owns the amp about the trace noise at the high impedance settitng. I should note that this noise is not intrusive, but being a perfectionist I would like to see it banished. I explained that the noise occurred only at the high impedance position and that I felt the gain was excessive there. The response was unsatisfactory. At a minimum Elekit should be concerned that HD 650 cans at the High Impedance setting play loudly at less than 9 o'clock rotation of the volume control. Further research and prompting is needed.
So, Miguel, you have not stated which impedance setting(s) you used during your evaluation of this amp. Did you happen to use the high impedance setting, and if so did you notice some faint noise? Steve did.
post #11 of 88
Thread Starter 
Hi guys, I am currently using: Apple Lossless files => Chaintech AV710 => glass optical cable => Monarchy Audio NM24 => Zu Gede IC => TU882R => AKG K701 re-cabled by Alex w/ a 10 foot V3 re-cable terminated in a 1/4" Furutech plug. I have also just installed the WE396A tubes.

With the source paused and gain in hi I can hear a mid/high pitch whine when I bring the volume to about 11:30 o'clock. I listen between 8:30 and 9:00 o'clock with the gain set at low so I had not noticed that noise until I read the above post. The noise to me is not an issue since I do not see going past 9:00 o'clock any of w/ my current headphones. The hardest to drive headphone I have is the AKG K501 and even with it I do not go past 9:00 o'clock with the impedance set at the middle.

UPDATE: I decide to test where the high pitch noise was coming from, so I fired another amp connected to the same source (Monarchy NM24 DAC) and it too has the same noise. So now I need to trace where it is coming from, but the good news is that it is not from the Elekit TU882R.

Note: Regarding the gain it should be easy enough to change a couple of resistors to lower the gain. That is what I have done in a Musical Fidelity X-Can V2. Although I would think that switching from the high to medium setting should do the trick.

With the supposedly better source the amp performs lovely and the level of nuances heard are spot on. I can hear the valves/lips in a trumpet fluttering in Stan Getz "It Never Entered My Mind".
post #12 of 88
I don't think there is a way to get rid of this noise, especially when you are setting at high impedance and at a loud volume.
This is something we have to accept, I guess; when you are running tubes.
post #13 of 88
Thread Starter 
Quote:
Originally Posted by kukuken View Post
I don't think there is a way to get rid of this noise, especially when you are setting at high impedance and at a loud volume.
This is something we have to accept, I guess; when you are running tubes.
I want to make it perfectly clear that regardless of gain I do not hear any noise when feeding the Elekit TU882R from the Philips DVD Player, the iPod Classic w/ an ALO Bamboo Dock, or the Meridian 506.20 CD Player. This w/ any of the headphones I have (K701, K501, RS-1, HFI-780, AH-D2000, or AH-D5000).
post #14 of 88

TU-882

Quote:
Originally Posted by mrarroyo View Post
Hi guys, I am currently using: Apple Lossless files => Chaintech AV710 => glass optical cable => Monarchy Audio NM24 => Zu Gede IC => TU882R => AKG K701 re-cabled by Alex w/ a 10 foot V3 re-cable terminated in a 1/4" Furutech plug. I have also just installed the WE396A tubes.

With the source paused and gain in hi I can hear a mid/high pitch whine when I bring the volume to about 11:30 o'clock. I listen between 8:30 and 9:00 o'clock with the gain set at low so I had not noticed that noise until I read the above post. The noise to me is not an issue since I do not see going past 9:00 o'clock any of w/ my current headphones. The hardest to drive headphone I have is the AKG K501 and even with it I do not go past 9:00 o'clock with the impedance set at the middle.

UPDATE: I decide to test where the high pitch noise was coming from, so I fired another amp connected to the same source (Monarchy NM24 DAC) and it too has the same noise. So now I need to trace where it is coming from, but the good news is that it is not from the Elekit TU882R.

Note: Regarding the gain it should be easy enough to change a couple of resistors to lower the gain. That is what I have done in a Musical Fidelity X-Can V2. Although I would think that switching from the high to medium setting should do the trick.

With the supposedly better source the amp performs lovely and the level of nuances heard are spot on. I can hear the valves/lips in a trumpet fluttering in Stan Getz "It Never Entered My Mind".
Hi Miguel,
The switch at the back of the TU-882 is not a gain switch, it is an impedance matching switch. We still haven't learned from you which impedance setting you made at the amp when listening to each of your cited headsets. The Denon are low impedance at 25 ohms, so did you listen to them with the impedance switch set to low? The K701 are rated 62 ohm and thus are intermediate low or medium impedance. K501 are 120 ohm, thus Medium setting on the amp. The RS-1 are 32 ohm low impedance. So it seems you haven't heard a high impedance headset with the TU-882 set to High impedance. How then could you comment on the noise present when high impedance headphones are used at the High impedance setting of the amp? Borrowa pair of HD 650 and listen.
The noise I referred to occurs regardless of the volume setting and only when the impedance switch is set to High, which is appropriate for the HD 650 300 ohm nominal impedance. Setting the switch to Medium yields suboptimal sound. Particularly the depth and weight of bass instruments is somewhat diminished and voice is more reticent.
I have not heard a high-pitched whine from any source connected to my TU-882.
post #15 of 88
Miguel, nice review. What is interesting here is that we seem to have a tube amp that if anything works better with LOW impedance headphones rather than high. We have LOTS of headphone amps that work well with high-impedance headphones, so having one that works well with medium-to-low impedance cans is very nice indeed.
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