Elekit TU8200DX

I think I've been long overdue on this one. The Elekit TU8200DX has been an amp I've been longing for for some 5 years, and I finally decided to pull the trigger. Unfortunately I was not able to find the extremely special smooth sound signature I heard five (or two) years ago, which was with Brimar 12AU7s and Shuguang Treasure KT88s. This combination of tubes made HD650s sound like STAXs to me. To put it brutally, what the 007 mk2 should have sounded like. With all the tubes I tried, I was not able to replicate such a sound. It was a massive disappointment to me. Yet still the 8200DX has a lot to offer, and it's not a shy head amp against the bigger 8600.

Notes: I paid for the amp kit and upgrades. I soldered and assembled the kit. The upgrade parts include 2% resistors, 4 x 180uf Sanyo OS-CON organic caps, and 4 x Mundorf 0.1uf Supreme silver/gold/oil caps. EH 6L6GCs and Shuguang 12AU7s come default with the kit. Other than these tubes, all tubes I'll mention are loaner units from VK.

The TU8200 itself can be had for relatively cheap, and there are many ways to meaningfully tweak this kit. The output tube types are many, including 6L6s, 5881s, KT66s, KT88s, and EL34s. This with the 12AU7s create a massive amount of possible tube combinations, and it's impossible to be exhaustive here.

At the time of writing this amp has passed 100 hours of running time and is probably sitting more than 200.

Oh, and I still don't have speakers.

Non-stock tubes used:
Brand new EH KT88s, nearly unused original RCA 6L6GC unicorns (the base on these tubes felt loose), near unused unknown type of Russian 6550Cs, unknown Russian 5881s (maybe Tung Sols?). I don't know if these tubes are matched but they sounded fine. I limited my listenings with EH KT88s and RCA unicorns. Keep in mind I did not have much time with these tubes, and I did not warrant them the same level of attention.
Operation mode: ultra-linear
Source: Sony UDA-1, Coaxial in

The difficulty of the build is similar to the 8600. Maybe the 8200 was even slightly more difficult for me.

- Just in terms of the headamp section, the TU8200DX is highly powerful. Possibly more powerful than its big brother, the TU8600. This level of power reminded me almost of the Mjolnir 2...
- With high power comes great slams (in general).
- The catch is that there are not much volume granularity for even moderately efficient headphones.
- No matter of tube choice, with HD650M it delivers a blackground.
- Overall sound signature is on the slightly warmer and more energetic side of neutral.
- Bass quantity is correct (just slightly on the bassier side) and up to my preference, but texture will depend upon tube choice.
- Average air. Wide, deep, but not necessarily high soundstage. The width itself is remarkable.
- The TU8200's performance depends greatly upon tubes used. I felt the original RCA 6L6GC unicorns were obviously bright and aggressive sounding, but these tubes otherwise deliver the best technicalities. Holographic imaging reaching nearly to my neck. Great separation and rendering of macrodynamics. Not so much planktons, which is kinda surprising. However, the brightness remains a somewhat annoying issue, preventing me from fully appreciating neither the amp nor the tubes.
- Stock 6L6GCs: surprisingly good, given they came with the kit. They are one to two inferior to the original RCA unicorns on all fronts, except that they got rid of the damn brightness.
- EH KT88s: they're new production and the price is OKish. Compared with 6L6GCs, they deliver a certain tube sweetness/euphoria, which I take as a typical Japanese "tubey" sound. In-your-face kind of vocal presentation and a somewhat holographic imaging. A tad more bassy than 6L6GCs.
- Unknown Russian 6550Cs: now these are less holographic than the EH KT88s. These are also on the brighter side. However, these 6550Cs extract the most planktons, and deliver even slightly more sweetness than the EH KT88s, particularly in the vocals. They also have the strongest reverb. Otherwise they're kinda similar. I think these are my favourite tubes.
- Unknown Russian 5881s: they're shit boring tubes.

 

Brimar 12au7 was my favorite in the tu-8200 before but I like E80CC even more. (You have to upgrade the rectifiers to use these)
For power tubes I also recommend 807 tubes. The bass is not as tight as the Philips 7581a or RCA but they have a nice soundstage and sweet vocals and you can find them cheap. I also love how they look. (My favorite is the Toshiba UY-807 because of the somewhat forwardish vocals similar to the Jotunheim but sweeter.)
Also with the 807s (and socket savers) the amp runs much cooler, only lukewarm to the touch after hours of listening.

 

I've got to try some RCA 807s. These are some f'ing awesome tubes! I'd totally sacrifice those last bit of planktons for these added sweetness and smoothness. This is nearly the same to the unicorn sound I've been chasing after!