[lucidreamer]

  Glad to hear that the seller is allowing the return and making things right.  If the test ratings for the set were just "okay" on his tester, he should have never labeled the listing as NIB... crazy.
 
As far as the readings on his tester for power tubes, almost all of the vintage testers have issues with weak transformers and thus, may read certain power tubes with more inaccuracy than others.  Over time, not only use, but even by just sitting on a shelf, the transformers will eventually start to weaken.  Unfortunately there are very few, if really any, options for new transformers, since they are unique to these testers and have to be hand-wound, etc.  In general, vintage testers with weak transformers will have issues with the higher output power tubes, such as KT88s and 6550s; EL34s are generally less taxing on the transformer and thus will often provide more accurate results though.  A gas/leakage and short test shouldn't be affected by the power of the transformer though and the Hickok "Life" test can also indicate if a tube is near the end; I've had tubes with great emissions results, etc., but with an extremely poor life test, so it can be useful.
 
Let us know how the repair goes and if you ever find out from the seller if one of the tubes now tests bad; it's also smart to have a few extra FETs, just in case this happens again.  It would be helpful if all of us were able to get a better idea of what will/can happen when a tube fails in the Elekit though, if this is what happened to cause the FET to blow.  Eventually, even with the newer production batches, and sometimes even more often with them than vintage, all tubes will fail, so it will happen at some point.  I find it interesting that unlike my other experiences with tube amplifiers, the Elekit seems to have issues with dying tubes, beyond just the tubes, however I'm still wondering what the ultimate verdict may be, as the structure did not collapse/spark when the LED turned and the sound cut out.  Thus, it would be interesting to find out if it was just something wrong with one of the tubes or that their life had finally been used up.
 
I hope you're up and running again soon!

 
Thanks Effusion! I actually got the spare FETs from Amazon last Saturday and fixed my amp already by replacing both Q3 and Q4 with NDF02N60ZG FETs. It sounds the same as before (knock on wood) with my other NOS Westingate EL34 single getter tubes that I got from eBay. These are really new set of EL34 XF2 tubes that I bought for a fair price on eBay. I think from now on I will try to stay away from used tubes and sellers who have no return policy, just too much headache and risk to use your amplifier as a tube tester. I cannot hear any sound differences between EL34 double-getter and single-getter tubes, but the latter costs 1/3 less which are also easier to find NOS! I think it is a really a great deal as long as it lasts.
 
It would be great to have some additional "bad tube" electronic protection implemented in the amplifier design to prevent blowing FETs and other parts, something like small replaceable fuses or cut-off relays, etc. I have no clue what could cause the XF1 tube go bad, as mentioned before, both tubes sounded just fine for about a minute or less, then one channel died quickly and I had a red light come up. Probably over the age, some pins or leads internally started shorting out as soon as the tube heated caused by tiny expansion in the metal structure due to heat. The tube was still glowing up normally as before, no pops or sparks were visible. Depending on what specific pin may be shorting I believe that this guy's tester may still be reading this tube as good, since the tube did not explode or died completely. That is why it is really wise for professional tube sellers to invest into really good modern tube testing equipment. Based on his irate responses, plain lies and contradictory arguments there will be no surprise to see these tubes popping up for sale again in the near future only making eBay an even worse place for audiophiles. Caveat Emptor!

 

[JK-47]

lucidreamer,
 
Glad to hear everything is back to normal... or somewhat normal.
 
The world of tubes can be slippery and frustrating at times, but the reward is oh so sweet

 

[Effusion]

Good point about what can happen when getting the voltages up to operating voltages on vintage tubes.  It is always a bad idea to start up a pair that are cold as well; a sudden change in temperature will often be enough to snap something, so try to make sure they are at room temperature prior to use.  If you have any that ship over the winter it is useful to let them sit out of the packaging for a few hours at least.
 
A few modern testers will and do test at close to full power output, for which they claim gives a truer emissions test, I also agree that it would and does.  Unfortunately, most modern testers aren't as versatile as many vintage ones, often requiring multiple testers, and they're also not really any good cheaper options.  Many, if not most, tube resellers also still use all vintage equipment for their results, so trying to file claims if you are not satisfied with the results can be a little tougher sometimes.  It all makes me think why there isn't something to fill this demand niche, such as modern tester with better features (maybe even a "Hickok" measurement mode that's close), more versatility, and all at a reasonable price point... too much to ask I guess, but with the amount of tubes being tested and traded even on eBay, I think there may be a pretty good market out there for one.
 
As far as eBay, it's usually cheaper and definitely more plentiful then other vendors, but most listed are used to just slightly used and very few are actually true NOS.  You can get lucky from time to time and the pictures are key, but there is more risk and headache if something goes awry than maybe at other places.  Generally for a price, going with a more established vendor can be the way to go to avoid dishonesty and unnecessary headaches, giving the assurance that it would be taken care of if needed.  This isn't always the case though, as even a few of them I wouldn't recommend due to pairs I paid too much for, thinking they would be different and that also showed signs of use/wear, plus very few have a return policy if you just don't like the sound, etc.
 
Several of the folks here have experiences with a few testers as well as research/issues surrounding them, so make sure to let us know if you are ever interested.
 
I find it quite interesting and actually a little funny about your take on the different versions of the Mullards; sometimes rarity plays a bigger factor than we realize and hype can often cloud judgment.  You may find that in general, many prefer the older and militarized versions often the best, where many claim that the sound is generally both cleaner and with better/enhanced characteristics.  This is obviously not always the case, so rarity plays a role sometimes were it agreeably probably shouldn't.  However there are dozens of types that I have multiple versions of that do, in fact, sound a bit to even a lot better than my commercial pairs.  I have found that the sound of the militarized versions can be more detailed, but also sound a bit more solid state at times; they were often the cream of the crop and are known for being more rugged and having better lifespans, in addition to going through military grade testing before the original sale.  Whereas both the age of the tube and the resulting sonic superiority generally is more specific to the manufacturer/type and over the span of production.  During the late 70's and 80's, the quality of many manufacturers everywhere went down a bit, but those in Russia were actually not too bad during that time.  Like most things, it's a mixed bag of complexity.  I do actually like the later production, 1980's Japanese Mullard EL34s, which can be found cheaper, but they just don't have the tube like tone of the originals, nor the sound-stage.
 
Welcome to the interesting, but often very complex and frustrating world of tubes! 

 

 

[jamespineapple]

Hello fellow TU-8200 owners!
 
I wanted to chime in at Victor’s recommendation with my experience building this amplifier.
 
As I live in Vancouver, Victor suggested I visit his home to check out the kit before I purchased it.  He was so helpful in explaining the process and even gave me a few additional upgrade components!  We spent plenty of time at his place rolling through some different tubes as well – I got to listen to some Tung-Sol 5881s, PSVane KT88s, and even the holy grail RCA 6L6GCs.  The RCAs blew me away with bass extension and treble clarity – they sounded perfectly flat, very smooth, very responsive.  I felt a bit like I had gone back in time.  It was an incredible experience. 
 
I was originally planning to use a set of Winged C 6L6GCs in my build, but after the comparison at Victors place I knew I had to go another way. 
 
The kit came together quite easily – Instructions were easy to follow and I had the whole thing assembled after about 8 hours of work.  I’ve spent the past 3 weeks burning it in and it sounds better every day!
 
The tubes I ended up settling on in my amp are a pair of PhilipsEGC 6L6GCs and a pair of RCA cleartop 12AU7s.  I find the Philips a little thicker sounding than Victor’s RCAs, but very similar in terms of bass extension, midrange detail, and responsiveness.  The brightness of the cleartops seems to balance them out and adds a little bit of clarity and tightness to the equation.  I tried some Sylvania 12AU7As as well as the Shuguangs that come with, and found that both sets tended to double up the low-mids from the power tubes.  With the Winged Cs, which reminded me of Victor’s Tung-Sol 5881s in their mid-forward response, the Sylvania preamp tubes were a fair compliment but overall I liked the Philips/RCA combination better.  
 
The only downside is that I had to pull my Philips tubes from my guitar amp, a vintage Magnatone 460, which sounds nice with the Winged Cs but some of that magic warmth is gone. 
 
I’ve been using my TU-8200 in pentode operation, primarily with my Technics 1300 through a Boozhound Labs Phono pre that I also built.  Speakers are yet to come for me, as I’m in a tiny Vancouver apartment!  I have a set of AKG K702s that make me happy – as someone with a background in audio engineering I prefer a more clinical sound, and as someone who is more into jazz I also appreciate the mellow bass response so many people dislike about these cans. 
 
I have to commend and thank Victor again for all his help!  I was blown away by his hospitality and his suggestions really helped me with the build.  

 

[Effusion]

Hi jamespineapple,
 
Thank you for sharing your experiences with Victor and I completely agree about his interest, helpfulness, and customer service regarding these kits; absolutely world-class guy all around.  I'm also glad the build went well and that you are enjoying the sound from the Elekit!  It is truly a great DIY amplifier.
 
I think you'll find that this amplifier has amazing versatility and will match to many different headphones and tastes.  The type/make of tubes you choose can/will also make significant changes to the sound signature.  Many of the posters here have had a ton of experience with different types of tubes in this amplifier, so please don't hesitate to ask if you find you want something more out of the Elekit.  Since you like a more clinical sound without a whole lot of bass emphasis, I think the 6L6GCs are a pretty good choice.  Ultimately a good pair of RCA "black-plate" 6L6GCs may sound the best to your ears, but you may also want to try some GE 6L6GCs, as I've found them to be a little warmer and fuller in sound, plus they can be found pretty cheap.
 
Other than the 6L6GCs, the KT88s may also work well for you, however they are a little, to a lot, more expensive and generally have more low-end weight.  A pair of Telefunken EL34s may also be a good choice, but they are hard to find and can be very expensive.
 
Congrats on the build and welcome to the club! 

 

 

[JK-47]

Welcome jamespineapple !!!
 
I also picked up my kit directly from Victor at his house last December. He was awesome to deal with, and has always been very helpful  responding to questions very very quickly.
 
Some of my favorite power tubes are the Philips 7581A or the GE 7581A (both militarized versions of the 6L6GC). I took Effusions advice and tried vintage GEC KT66's and they are extremely nice, but pricey.
 
Input tubes... I'm a fan of Amperex.I have a pair of 7316's in right now, and they are sweet. Different power and input tube combo's yield some really amazing results. Some pair beautifully with each other, and not so much with others.
 
I was born and raised in Vancouver, but the dreaded "Vancouver apartment" pricing and the endless rain drove me to the eastern foothills of the Rocky Mountains... I still think Vancouver is one of the most beautiful cities in the world during summer...
 
Keep us all posted on how things progress

 

[lucidreamer]

Welcome to the Elekit club Jamespineapple!!! Hope you enjoy your new Elekit TU8200DX amplifier for a long time and thanks for sharing your experiences with us.
 
As for power tubes - I would suggest NOS EL34 Mullard XF2 (with either dual or single getter "O" rings, they all sound the same to me). If you like sweet mellow tubey sound with great bass and detailed smooth highs - Mullard EL34 is the way to go. Those true Mullard vintage tubes are fantastic and are by far my favorite tubes for all kinds of music. They can still be found NOS on eBay at great prices if you are patient or from reputable sellers online (costing more $$$ than eBay). I have Psvane MKII KT-88 too but prefer Mullards for both headphone and speaker setups.
 
For input pre-amp tubes - consider Westinghouse black plate 12AU7. They sell on eBay under CONN or other label and are real secret audiophile gems for a low price. I prefer them to a $100 Psvane MKII 12AU7 anytime. Westinghouse tubes sound more open and cleaner with more bass.
 
For speakers - you may also consider a DIY kit with full range drivers such as Fostex, Audio Nirvana, etc. I believe that the full range drivers are the best for tube amplifiers because they sound more natural and no energy is lost on crossover resistors, coils, capacitors, etc. I just put together a small set of speakers from Madisound Speaker store consisting of two 4" full range Fostex  FE103-SOL Limited Edition Drivers and am pretty happy with the overall setup (see the picture). It really sounds very natural and sweet at moderate levels especially for acoustic music but still a little harsh when pushing the volume up a little bit. That should resolve with more break-in time, those drivers take a long time to break-in but it is worth it! A small subwoofer helps with low notes tremendously, since those speaker cabinets are tuned to 100Hz, noone can bypass the laws of physics. I also put more damping material inside the speaker cabinets(it lacked some of that stuff) and did small tweaks to the drivers too to reduce the sound reflections inside speakers, the difference was huge! Because I had to choose small speaker size cabinets to fit everything on the A/V cart for my audio setup it did need a subwoofer but a bigger folded horn cabinet can be considered for standalone setups without subs. There are great reviews about  Fostex FE206En full range speakers that rival the speaker sound costing tens of thousands!!!  Fostex FE206En full range speaker is considered as one of the best full range drivers and should work great with Elekit in UL or Pentode mode. I may create another setup later in the living room using bigger Fostex speakers with folded horn cabinet designs. They should not need any subwoofer and the price tag would be around $600-700 for everything.
 

 

[JK-47]

Here's a re-post of my Fostex 168EZ 's in madisound folded horn enclosure's. They sound fantastic, and can play loud and accurate when I choose to pump up the volume. For the most part the volume rarely climbs past 10 o'clock and they are very nice and smooth sounding. I originally had the Fostex FE166En (slightly lacking in the treble, and I was considering a Fostex super tweeter), then decided to upgrade the whole driver (on another forum, a fellow had the same drivers then upgraded to the EZ sigma's, and felt the super tweeter wasn't necessary). I would say the Fostex EZ Sigma drivers are worth the extra expense. The angled stands are almost a necessity if you want to hear the low end with any authority. They truly came alive when angled up to ear level.
 
 
 

 

[lucidreamer]

... there will be no surprise to see these tubes popping up for sale again in the near future only making eBay an even worse place for audiophiles. Caveat Emptor!

Just like I thought these tubes are up for sale again on eBay and the seller mentions me as a "recent scammer" only because I returned the tubes that blew my amplifier:
 
http://www.ebay.com/itm/6CA7-EL34-Mullard-xf1-Matched-Pair-Dynaco-Marantz-HH-Scott-EICO-Fisher-/252027501568?pt=LH_DefaultDomain_0&hash=item3aae027c00
 
Just wanted to advise everyone to think twice before purchasing anything from this eBay seller anthonybrian23

 

[430011]

I've been absolutely loving my TU-8200 with Sennheiser HD-650's lately. Listening back to back I prefer the more "full" sound of the 650's over my 600's with the Elekit. I've found my preference is for EL-34 tubes, just a pair of Electro Harmonix. I don't have the budget to try the NOS tubes.

I've also been pretty happy with the amp driving less sensitive bookshelf speakers. I had a pair of Paul Carmody Speedster speakers that played loudly enough for me in a smaller apartment. But I listen quietly. If I need more volume I switch to headphones. Haven't tried the amp with any single driver speakers. I'm sure that pairing is nice.

 

[lucidreamer]

I've also been pretty happy with the amp driving less sensitive bookshelf speakers. I had a pair of Paul Carmody Speedster speakers that played loudly enough for me in a smaller apartment. But I listen quietly. If I need more volume I switch to headphones. Haven't tried the amp with any single driver speakers. I'm sure that pairing is nice.

 
Just wondering how would Speedster speakers compare against MartinLogan Motion LX16. They are basically in the same price range, since Speedster kit is over $300 plus cabinets and LX16 are the older model of MartinLogan 15 (only cosmetic difference) and sell for much less these days:
 
http://www.crutchfield.com/S-y6BOb1JX57p/p_839MLX16GB/MartinLogan-Motion-LX16.html?o=undefined&tp=186&nvpair=FFBrand%7cMartinLogan&#customer-reviews-tab
 
I believe LX16 should probably be an overall better sounding factory speaker since they have a bigger woofer (5.25" vs 4") and more frills and gimmicks like motion folded tweeter, precision crossover and so on. I have not listened to them yet, probably will stop by some BestBuy who carry them one day. 
 
There are of course other great brands, such as Monitor Audio (I have bronze-II floorstands which are great), KEF, B&W, etc.... But it looks like there are people like me who just prefer full-range drivers to any ###-way design for speakers.

 

[430011]

Lucidreamer-
 
I'd be interested to listen to them side by side. I've only heard the Motion 15's for a brief amount of time, but I thought they sounded nice. The cabinets are definitely very attractive and hard to match easily with DIY. I'd probably snatch up a pair of the Martin Logans if there was a smoking deal on them.
 
That said, I did really love my Speedsters. They produced more bass than I was expecting and it sounded tight. I actually sold them though to help fund my build of Carmody's Carreras. I really like the way he voices his speakers, and I'm thinking the Carreras will be a good long term speaker for me. Although for all of us into DIY it is hard to say any one thing we build will stick around very long. I'm about to wrap up that particular build. I'm worried the TU-8200 won't quite have the drive for them, but I really do listen to my speakers fairly quietly. Small apartment life.

 

[lucidreamer]

Thanks Evan99. Please keep us posted on the Carreras progress and how these speakers pair with the Elekit amp. I think if you switch the jumpers to Pentode mode and use KT88 tubes in this amplifier it should suffice driving them with 10 watts of pure Class A output. Should be plenty of wattage to drive any smaller speaker at decent level. I should also try to hook up my Monitor Audio bronze ones (rated 100w) to Elekit someday, but they are pretty heavy with sand-filled cabinets standing on the 1st floor.

 

[Effusion]

Welcome to the club Evan99!  I'm glad things have gone well and that you are enjoying the sound of the Elekit!  The EL34 tubes are very nice indeed, however you are correct, the older/NOS versions can be quite expensive.  You may like the SED Winged "C" EL34, which can be found a little cheaper, but are also becoming rarer every day.  Other than those I really like the Mullard and Tesla EL34s old stock the best.
 
Thanks for sharing some info regarding different types of speakers you've used with the Elekit (lucidreamer as well).  It would be beneficial to get more one-on-one accounts of this amplifier with different speakers as well as to see how well it pushes them all.  I agree, single-driver speakers, when implemented right, can sound absolutely amazing and are probably the closet thing to headphones as far as speakers go, since the sound originates from a single source/point.  However, they can be quite more finicky about placement and amplification than most crossover designs.  Single drivers is where I'll go eventually, but my speaker listening is still just a little limited right now.
 
Keep us up to date on how things progress! 

 

 

[lucidreamer]

NOS Mullard EL34 are very sweet-sounding tubes indeed and cost more than the new ones. The more recent single-getter XF2 or XF3 can still be found NOS for much less than XF1s or XF2 double-getters. I have a pair of used double-getters (my current use) and another pair of NOS single-getters Westinghouse-labeled XF2 which I got for a great deal on eBay recently (grabbed last pair from the seller). They both sound the same to me, I would not be able to tell the difference between them in the blind test, but double-getters are considered to be older and better-made, therefore more valuable to collectors driving the prices higher. Would be also great to compare XF3 and some Holland-made XF4 with DD-getters, some consider them to sound more dynamic and interesting than Mullards.
Probably =C= EL34 and Groove Tubes EL34 are the best closing match for NOS EL34 as some people recommend those. I originally ordered the pair of new Svetlana =C= EL34 for around $100 and then cancelled the order considering the NOS route instead. For a serious listener it may be worth paying twice more for a pair of NOS EL34 if a deal is available, I think $400 for a pair of NOS EL34 is a lot. But all the new production tubes that I purchased earlier are resting in their boxes at the moment.
I just won a pair or used but still great GE 6L6GC on eBay today and am looking forward to compare them with EL34 on the Elekit. Maybe GE 6L6GC will be my next favorite ones.