Elekit TU8600

Preface: I know, I know, some of you don't like 12A*7 tubes, some of you think 9.2Wpc is limp dick. I may sound like a shill for a MOT. But whatever. Haters gonna hate.

Elekit is no foreign name to DIYers and a certain number of SBAFers, such as @JK47. Among the North American Elekit fans, Victor Kung (VK) in Coquitlam, BC certainly commands a considerable amount of respect. VK is truly passionate about good sound and no bullshit style DIY. Let me say that as a first time DIYer, I received fantastic mentoring of DIY from VK, as well as his invaluable audio advice and WBT silver solder. This weekend, I had the opportunity to build the Elekit TU8600 LL2770 version under the supervision of VK.

Details of the particular unit I built:
- With Lundahl LL2770 transformers upgrade
- Headphone out jumper set to 2 (should be 6.3 ohm z out, need to confirm with VK)
- Takman 1/2W REX 2% carbon resistor upgrade
- Alps R27 volume pot
- Electro-Harmonix 300Bs+RCA clear top 12AU7+TungSol 12AX7

The build:

The prototype for LL2770s. Without the added support the LL2770s are simply too heavy.


Some parts, tools, manual.


The whole PCB.



VK shows how to bend a resistor for a noob


Left: from Lundahl to VK. Right: stuff awaiting VK's repair.


A boxful of LL2770s.



A wild LL2770 has appeared!


My first solder...


Takman resistors are all here. Luckily I didn't make any mistake here. It took me nearly 5 hours to have these done.
Have all resistors red head in one side!


Day 1 finished. 8 hours+.


The headphone circuit.

 

Day 2...


300B sockets.


Custom made PCBs for the Lundahls. Cables are hand made by VK.


VK making cables.


Half done 2770


Almost, almost there...


To ground


More soldering...


After another 6 hours, this baby is finally singing! Fired it up and no issues!


Lacking the mini-mini hex to fix the pot... But it's finally here!

 

The first time I've encountered an Elekit sound was on the 2013 Vancouver Head-Fi meet, on which occasion VK was a vendor. His 47 Labs model 4753 (http://www.47labs.co.jp/4735.html) playing Teresa Teng feeding into Elekit TU8200DX driving HD650 left me struck with awe - it had an obvious tube warmth coloration and a uber silk-like smoothness (I'll invite @JK47 to explain what this is) that no other amp I've heard to date can imitate - until this TU8600.

And far beyond it.

VK recommended some 50 hours of settling time for the TU8600, and now it's sitting just below 10 hours mark.

And duh, I know I'm wasting this amp to use with the lowly HD650M. And I don't have a ton of amp experience. So go figure.

On the second time I fired up the 8600 (so just after the testing and tubes were not hot), there was a fine layer of haze - something I've experienced with (and was strongly prominent on) AMB Beta 22. The soundstage was crammed, and no planktons were popping up. Timbre felt metallic on some instances. I decided to leave it cook for a few hours. Yet several attributes have been evident:

- The 8600 is quite. For HD650M with nothing playing, I'm turning the volume stick (for now) nearly half way to hear a distant hiss.
- It's not susceptible of interference. I had 2 cellphones and 1 PC tower and PS3 and PS4 sitting around it. And no hum.
- This amp should be able to drive virtually any headphone on the market, given it's not an ES.

Fast forward - now I'm sitting at 10 hour mark, and things have improved considerably.
- The haze has gone. It's not the blackest background I've ever heard, but more than enough to call it a blackground.
- The uber silk-like as TU8200DX is nearly back, maybe not so emphasized as 8200DX. Like 90%. I can't draw a conclusion if it's a good or bad thing for now, because I expected it so much...
- It shares a surprising similarity of sound signature with Sonett 1. Both are colored in the romantic tubeness sense, but near non-colored FR-wise. I detect an artful emphasis on the higher midrange part, a certain feature of Japan-Fi. Yet there is still occasionally, some shoutiness. Combined with the slight warm of Gungnir Multibit, the 8600's end product is a rich, tube-ly romantic sound highly suitable for female vocals. Yet I'm discovering new textures in male vocals as well.
- The metallic timbre is gone. However, there seems to be a playful roundness to bass timbre, which I tend to think as Sony organic influence. I don't know what's happening on the 8600. I was expecting Moffat Bass (TM) as usual... yet here I am. Attack, sustain and decay won't leave me mouth open wide (like what I experienced on Andromeda), but the right combination leaves the whole presentation comfortable. Basshead look elsewhere, this is not your amp.
- The soundstage is not super uber wide. It is however taller and deeper than any amp I've heard so far, and I think not by a small margin. It's made HD650M more like two miniature speakers hanging around my ears. Layering, imaging and separation are on par if not surpassing the Moon HA430, which means that it's also the best I've heard by far. Going by distant memories, I find the Mjolnir 2 was super uber wide, but near flat. The Black Diamond was compressed but rich. Yet non had such holographic soundstaging and imaging, neither too in-your-face nor laid-back. Maybe slightly on the in-your-face side.
- In @Marvey's language, the 8600 should've committed a debatable amount of sin of tubeness commission, but no sin of omission.
- Planktons, planktons, planktons

To be continued - I'll update once the settling time has surpassed 50 hours or so.

 

The TU8600LL has passed the recommended 50 hour burn-in time.

1. Debating if burn in after 10 hours is a significant improvement may result in a fist fight.

2. The ability to appreciate the majority of your music is a privilege, not a right. It will be revoked once you upgrade your amp to a certain grade. The difference point seems to be 2K USD.

3. Debating if it's a reference amp is a valid reason to get into a fist fight.

4. Despite Moffat bass (TM), I am hearing quality controlled bass.

5. Despite Gungnir Multibit's slight warmth and tube warmth, I am hearing almost non.

6. Exotic toobs are optional.

7. Big heavy transformers are not.

8. Listening to Waltz for Debbie through this amp at 1AM while your GF is asleep is not a good idea.

 

Preliminary impressions up.

 

Further impressions up.

 

Hi there - I am new here so please forgive my ignorance. If i read you're impressions correctly, i take it you are saying that the amp doesn't have any tube warmth and even negates the warmth of your source component? (this seems consistent with WoS's review. Are we talking solid-state-y? Did the rich tube-ly warmth you reported in your 10 hr impression disappear? Also but any chance have you compared the LL against the stock transformer. I am so eager to get the tu8600 but because of where i live and the additional shipping expense and currency fees I have to pay I'd like to be sure about it. Also getting the LLs would almost double the cost for me. I have the Tu 8200 and love it. Appreciate very much your impressions on this amp, it will save me continuing to try to translate japanese coverage

 

Hi all.

This is exactly what I'm interested in as well. I have a TU-8200 and would like to upgrade to TU-8600, but I'm not sure whether the sound signature is the same. Honestly, TU-8200 has a very pleasing, warm and lush sound. Also it has an incredible soundstage.

In short, no matter how good TU-8600 is in other areas, if it doesn't deliver at least as good as TU-8200 on the things I stated above, then I see no point in upgrading. So yes, please come at us with more impressions!

 

The 8600 is not exactly like 8200. The silky smoothness is there, but more in a classical neutral tube way. If you appreciate a good tube amp (not with the warm and lush intention as 8200), then you'll know what I'm talking about. If you look specifically for that warmth and lushness, look elsewhere.

Please feel free to pm me if you prefer to communicate in Japanese.

 

You are more than welcomed. The amp doesn't have the typical tube coloration (if Woo stands for that). At 10 hour mark it had a slight bit. It has the tube smoothness. It also seems to kill the Gungnir Multibit warmth (remember what's in my whole chain). I didn't have a chance to compare stock transformer to the 2770s, unfortunately, but a hardcore member I trust had Lundahl transformer upgrade for his 8200 and said it's a significant improvement. I heard signal path caps upgrade for 8200 and it was also undeniable.

 

Hi Griffon.

Thanks for letting me know.
It would be awesome, if we had the update from you after 100 h of burning in, maybe the warmth would start manifesting, although I find it unlikely.

On the other hand, have you ever had a chance to listen anything from Woo Audio, or Viva Egoista amps?
Would you be able to give a comparison of how the TU-8600 stacks up against them?
Also, would you say that the TU-8600 is a big upgrade over TU-8200, regardless of the lack of warmth?

Oh and, yes I have been living in Japan for a while, but Japanese is not my first language.

 

I'll continue to post after maybe 100-200 hr mark. I find it unlikely to manifest warmth.

I have a profound dislike of Woo products. I heard every single Woo save for the latest WA33. I hated every single one I heard, with WA2, WA6SE, and WA7 being the less abominations. All have a wrong application of tube and all have various degree of artificially added warmth/lushness coloration, and sound muddy. They smear up macrodetails and planktons. IME even Woo WA22 can't compare to a non-upgraded TU8200. So take my opinion with however much grain of salt you want.

The TU8200 shares tube smoothness with the 8600, but theoretically the 8600 is in the same bloodline as the 8300. If you want to keep the warmth and lushness, as I said, don't consider it. If you look for a tasteful take of a slightly mid-centric neutral signature, and good tube smoothness, take the 8600. Be warned, the 8600 is uncompromising of bad recordings. It's not a polite amp in this regard. I've tried a bunch of sources with the 8600 and non sounds even half decent with bad recordings.

 

Sounds good, thanks for the detailed explanation.

I've never heard any Woo products, so I can't say, but judging by what you said, it could be the case that I wouldn't like them.
I have a feeling you understand why I like the TU-8200, so it might be a good idea for me to avoid it.

On the other hand, I will say 2 more things.

Not sure whether you've had the experience of listening to the Goldmund Telos HDA, but this is a solid state amp, which is incredibly euphonic, and personally, based on my short listen only, I consider it the best amp I ever heard. Again, not a tube amp, but the experience was amazing.

Also, I've heard the AirTight ATM-300, which is a 300B amp as well, and would without a doubt say that this is the best speaker amp I've heard, and no, I'm not even into speakers. What I heard was very enjoyable. So assuming this 300B AirTight amp has any semblance to TU-8600, it just might be to my liking.

In any case, yes please do update us as the time goes on. I'll post my impressios when I'll listen to the amp at the next Fujiya Avic show in November.

 

Further adventures:

Again VK has been kind enough to encourage me to venture into more tube rolling options and loaned me a pair of Psvane 300B TII. The tubes are supposedly cooked. Thank you VK!!!

I have also went through lengthy discussions with the guru @Jh4db536 about this TU8600LL, and with his truly wonderful advice I did a bit of unsuccessful tweaks... and would also like to share. This part should be treated as more of out joint stupid adventure.

First thing first, the Psvane TII 300B vs EH 300B:
- I think one should not settle on 300Bs until the transducers used are settled.
- The Psvanes are obviously bassier and have better bass texture. It does not mean the Psvanes sacrifice air.
- The Psvanes sound more full-bodied. In comparison, the EHs are slightly bright and lean.
- With things bassier than HD650 I would not want the Psvanes.
- If I had any higher end Audio Technicas I will not hesitate to jump to the Psvanes.
- Psvanes definitely win on blackness.
- Both have a similar performance of macrodetail and plankton extraction.

Second thing: headphone jumper test
- The TU8600 has 8 headphone output z settings. The lower range is 4-6.3, and the higher is 8-16. Low/high is controlled by the toggle on the back of the unit. The jumper further has 4 positions, with 1 being the lowest and 4 being the highest. I do not know the exact values of position 2s and 3s. I previously had the setting on the higher, position "2". Now after experiments, I settle on lower position 1.
- This is all relative, not changing that essentially this amp is on the slightly leaner, "SS-like", neutral side. As the output z goes up, the sound gets more full-bodied, but planktons get muddied up. Bass quantity also seem to rise as output z goes up. Whether one would opt for which z setting should be a purely subjective thing. I find clarity and planktons a necessity and settle for lower 1. With a screw driver the hp out z change is in a minute.

Third: trying no Negative Feedback
- @Jh4db536 suggested the possibility of the 8600 utilizing NFB to eliminate the conventional tubeness.
- It can't hurt much by removing the cables controlling NFB...
- I opened the chassis, removed the white cables, plugged in the 650s, and shit sounded BAD.
- I put back the cables and everything went back to normal.
- This amp may not be designed to operate with no NFB.

 

Thanks both for this excellent discussion, all invaluable info (you cant really get this info from anywhere else on the net yet). Please continue to post impressions. On the fence at the moment. i have a tu8200 and a good soild state amp that i am happy with that i use for speakers, and i enjoy the difference between the two. My ears are not super sensitive so im currently thinking the tu8600 might be close to my ss amp, which i find nice and smooth. Any thoughts on how the tu8600 might compare with the ank kit 1? I might save up to get that instead of the tu8600 to replace my tu8200 (and promote tu8200 to headphone only use.

 

I'm afraid the Lundahls are probably no longer available. From the mouth of the horse, the 8600 is 400 kits worldwide, and 150 of them are with VK. In total VK has 50 LL modified kits and what I got was the last 3rd. The 8200 is a very versatile headphone amp and that signature is really something so unique you can't find anywhere else.

Sorry that I have no experience with any ANK products. I have a limited exposure to speaker gear.

 

I heard of (not heard!) this Goldmund Telos HDA, and had a glance of their webpage. They seem to claim they don't design bullshit unless it gets a measurable improvement. But I don't see a lot of specs published. This makes me naturally suspecting of this brand.

I have no idea of the ATM-300. I generally don't care about uber expensive gear.

 

Noted! Elekit gear is in my opinion an excellent value for money you won't find that easy with other brands. That's why I'm having such a hard time replacing my TU-8200, it's sound is very specific and I feel like I'm not being offered that by many other brands. But when I am offered exceptional sound quality out comes with also am exceptional price.

Elekit gear is quite fairly priced to say the least.

 

Hey Griffon, was introduced to this thread by ho lee and I must say your impressions of the TU-8600 has piqued my interest. I currently own a Utopia and was told it would make a fine pairing with this amp. Problem is as you said the Lundahl's are no longer available for purchase so this begs the question, would this in stock mode still be better than something like a TU-8200?

 

TU-8200 sounds great with HE-1000, I'll also get to listen to them on TU-8600 at the next Fujiya Avic show in Tokyo. So if they sound much better on TU-8600, the Utopia should too.