Elekit TU-8200 DX Headphone/Speaker Amp Review

[Effusion]

JK-47,
 
Great to hear you're liking the NOS Amperex and GE, they are great NOS tubes for a very reasonable price!
 
I never really did try the stock China stamped 12au7s, except for testing, and I listened to the stock EH 6L6GCs for about a half hour or so, but I agree, much better sound can be had by changing them both out.  If I remember correctly, the stock EH 6L6GCs were very laid back and quite muddy, but with a good amount of sound-stage and presence, just less detail and a bit of a veil.  However, the NOS GE 6L6GCs are really nice tubes for the money and can really bring the music to life with great impact, but also in a smooth and silky way.
 
Congrats on the new tubes and keep us up to date on your impressions!

 

[catcherfly]

  Just got home and picked up my tubes this morning...
 
First I warmed up my amp and listened to 7 FLAC tracks that I planned on using for reference. I powered everything down, waited 15 min, and switched out the stock 12AU7's for the Amperex Orange Globe's. I let the amp warm up for 20 min and fired her up. WOW! Immediately I noticed that the sound stage opened up nicely compared to stock. The low end was cleaned up and tighter, the mids were very detailed (I could clearly hear back ground vocals, that were muddy before), and the hi end had a nice sparkle without sounding harsh. I was impressed to say the least.
 
Next I followed the same power down/up/warm-up procedure as before, and the GE 6L6GC's were in their new home. I'm on the 4th reference track as I type this sentence. I'm blown away!!! Everything is tighter and richer, it's hard to describe... The low end is still there, but way more precise and controlled, the mids sound smooth and effortless, the top end is really accurate without overpowering anything else. The sound is wonderfully balanced and has really come to life...
 
I'm in audio heaven right now. I can really crank up the music without losing any detail, simply amazing...
 
I cleaned all the tube pins with a brass brush and put a little De-Oxit on them before the install. De-Oxit did make a noticeable difference with my modded Fostex T50RP's and their stock cable, so I figured why not.
 
Sorry, gotta go... too much music to re-discover!!!

Your take on your upgrade tubes is irresistible. Can you tell me where you got them?

 

[JK-47]

Catcherfly,

I scored both sets on eBay, and I have another set of GE 6L6GC's on the way as back up.

Effusion,

You weren't missing anything with the stock 12AU7's. The change to the Amperex input tubes made more of a difference than the change to the GE power tubes. The GE's are slightly different sizes, one being a tiny bit shorter and wider, but after reading up on different size bottles. The consensus seems to be as long as they're matched its not a big deal.

 

[Effusion]

Good to know about the stock 12au7s... I was lucky enough to already have a few NOS pairs prior to plugging the amp in the first time, so I just didn't bother.
 
Not too sure about the tall bottle GE, I believe most of what I have would be considered short bottles.  It is best to try to get matched pairs though, not only in conductance, but also in make and dates when ever possible.  Small changes in the manufacturing can create slight differences in sound signature between tubes and thus, between the channels; however if they are close enough, the ears will probably compensate and the perception would probably be that they are very similar.  For resale though, in the case you didn't like them or in the future you decide to part with them, it is best to have exact matches as they'll demand a higher price.
 
I found that while variants within the same tube type had more subtle differences, changes between types yielded bigger more noticeable changes.  If you're able to score a pair of EL34s or any of the KT series, you may find that the change, when compared to the 6L6GC, in you system offers a bigger change than between 6L6GC variants.  I really like the KT-66 and even the McIntosh KT88 are nice as an every day tube, but they are not necessarily cheap.  The SED Winged "C" EL34s are cheaper and not too bad sounding, not as good as the Mullards or Amperex, but generally much cheaper.  I've also liked some of the Groove Tubes or Mesa Boogie Tubes that are new stock, but considered better quality than most new stock; they are generally used with guitar amps, but I've found them to offer a nice solid sound, if not a little less tubey than more expensive NOS.
 
Ahh, the world of tube-rolling, so many options, so little cash...

 

 

[catcherfly]

Catcherfly,

I scored both sets on eBay, and I have another set of GE 6L6GC's on the way as back up.

Effusion,

You weren't missing anything with the stock 12AU7's. The change to the Amperex input tubes made more of a difference than the change to the GE power tubes. The GE's are slightly different sizes, one being a tiny bit shorter and wider, but after reading up on different size bottles. The consensus seems to be as long as they're matched its not a big deal.

Thanks JK-47!

 

[JK-47]

Effusion,
 
Well, I decided to return the GE 6L6GC's to the seller... He was a little sour, but it appears that one of the tubes is actually a Groove Tube, slight traces of  Orange/Red paint (Groove Tube logo) and the font for "6L6GC made in the USA" were different between the 2 tubes (the suspect tube's font looked thicker, like a Groove Tube reissue). I'm not accusing him of rubbing the logo off, but I feel slightly misled. He says he will measure them when they get to him, but I said that's not the point. They were advertised as being 1959 GE tubes... Ah, the wonderful world of ebay.
 
The switch back to the Electro Harmonix 6L6's was noticeable. I definitely noticed the loss of detail and punch in the mids and lows.

 

[Effusion]

So sorry to hear about that... seems everyone is only trying to make a buck nowadays on the Internet and that you can't really trust everyone anymore.  At least he is accepting the return, he almost has to as the description of the items was not correct, which is a direct violation with eBay, so not much he can do and if he resists, you can just start a claim.  Over the years, eBay has been much tougher on sellers and even negative or below 5 star service can really hurt them in the long-run; one thing to watch out for is if the seller has changed names recently, as it clears their rating, but this is usually because it got too bad for the volume they sell.
 
Sometimes it's hard to tell with the older GE's as the labels tend to rub-off easily, same with the EL34s, and they sometimes didn't print the bases on the older batches.  One thing though, on pretty much all GE tubes (regardless of type), they will have a "dot pattern" near the GE/date label, even on re-brands.  Not really sure what the pattern means, as it is a little strange, but it is one way to distinguish between what is GE and what is not.
 
I haven't tried the Groove Tube 6L6GC, but the other types of Groove Tubes I have tried weren't horrible for new stock, but definitely not the best.  You did the right thing by returning them and I hope the backup spares you ordered will work out for you better.
 
Keep us tuned!

 

[JK-47]

Effusion,
 
I had already gave him positive feedback before I really looked closely at the tubes ( I was more worried about them being broken). When I tried to contact him, I used the listing and chose item not as described as reason I wanted to return them. Apparently it opened a case against him (I didn't know ebay worked like that), I didn't mean to, I merely wanted to contact him. He took it to heart and said all kinds of things, like I personally attacked him. I explained several times that I just wanted a refund and that was it. He said I called him a liar, which I didn't, and explained I wasn't going to get in a pissing contest with him. I live 7 hrs from him and was almost considering paying him a visit, just to straighten things out, he was really starting to act childish. Oh well, I hope cooler heads will prevail and he keeps our agreement, and pays me back within 24hrs of receiving the tubes.
 
Geez, the stock EH 6L6 tubes are not even in the same league as the GE's ( lack of detail to say the least)
 
The back ups should be here tomorrow... now I need to find backups for the backups, lol
 
Effusion, did you ever start the thread regarding your tube journey?

 

[Effusion]

Crazy, sorry that all happened.  I agree, it's hard to just contact the seller after the sale, seems like eBay wants everyone to start a case; understandably so that the buyers are protected and they can track, but I've also had issues with this when I just wanted to ask a simple question after a sale, without having to go to all that trouble.  If the seller sells a lot of tubes, than they really should have known that these were only matched in conductance and not the same tube type/manufacturer.  The description of a potential sale is everything, so as a seller you really need to be as thorough as possible in your examination; mistakes do happen and no one is perfect, but the biggest mistake sometimes is just being in denial of the initial mistake, regardless of taking it out on others, especially when the whole reason for selling a matched pair is that they are actually truly matched... anyone could find two of the same type of tubes that have similar tests results, but are of different makes/manufacturers, and call them matched, but this is not what the term "matched" implies and no one in their right mind wants to pay a higher price for a pair of matched tubes that are in fact very different from each other.
 
Anyway, I hope everything gets sorted out.  No worries and no need to feel bad, it's not the buyers responsibility if the listing was described wrong; if the seller had stated that the sale was for one GE and one Groove Tube, than it would have been a buyer mistake if this is not what was expected, but that wasn't the case.  Also, sometimes it's hard to wait a little before leaving feedback, especially if the seller starts to inquire about the feedback soon after the sale, but sometimes it is best to wait just a few extra days, as this is ultimately the buyer's chip if something goes awry.  I guess one way to look at it is that it may have been a good learning experience for both parties in the end, sort of a silver lining to the headache endured, in order to help avoid the same issue in the future.
 
Unfortunately, I haven't been able to really document all my experiences with tube-rolling the Elekit yet; I've tried so many types and haven't really had the time lately to sit down and focus.  Seems the more I try, the more I want to try, then the more I buy, and suddenly the amount/variety starts to snowball, which can be a little overbearing.  Really the only experiences I've shared so far have been in this thread; I just hope that with all the various types I've tried over the past year or so, I haven't mixed things up badly or given any wrong impressions.  I'll admit that sometimes I've commented on a tube that I haven't really listened to in a few months, however most have left me with enough of an impression that I feel confident that I'm not totally misleading anyone, at least not intentionally.  As always though, the best thing to do is to take my suggestions as just that, a suggestion from my system/ears, and let your own ears make the final decision/verdict for you, in your system.  Many factors can influence the sound of a tube, as every system is different, not even to mention that every headphone is also different.
 
If you ever have any questions or concerns regarding a type of tube up for sale before you purchase, let me know and I'll try to help as much as I can; I really don't mind.

 

[JK-47]

  Crazy, sorry that all happened.  I agree, it's hard to just contact the seller after the sale, seems like eBay wants everyone to start a case; understandably so that the buyers are protected and they can track, but I've also had issues with this when I just wanted to ask a simple question after a sale, without having to go to all that trouble.  If the seller sells a lot of tubes, than they really should have known that these were only matched in conductance and not the same tube type/manufacturer.  The description of a potential sale is everything, so as a seller you really need to be as thorough as possible in your examination; mistakes do happen and no one is perfect, but the biggest mistake sometimes is just being in denial of the initial mistake, regardless of taking it out on others, especially when the whole reason for selling a matched pair is that they are actually truly matched... anyone could find two of the same type of tubes that have similar tests results, but are of different makes/manufacturers, and call them matched, but this is not what the term "matched" implies and no one in their right mind wants to pay a higher price for a pair of matched tubes that are in fact very different from each other.
 
Anyway, I hope everything gets sorted out.  No worries and no need to feel bad, it's not the buyers responsibility if the listing was described wrong; if the seller had stated that the sale was for one GE and one Groove Tube, than it would have been a buyer mistake if this is not what was expected, but that wasn't the case.  Also, sometimes it's hard to wait a little before leaving feedback, especially if the seller starts to inquire about the feedback soon after the sale, but sometimes it is best to wait just a few extra days, as this is ultimately the buyer's chip if something goes awry.  I guess one way to look at it is that it may have been a good learning experience for both parties in the end, sort of a silver lining to the headache endured, in order to help avoid the same issue in the future.
 
Unfortunately, I haven't been able to really document all my experiences with tube-rolling the Elekit yet; I've tried so many types and haven't really had the time lately to sit down and focus.  Seems the more I try, the more I want to try, then the more I buy, and suddenly the amount/variety starts to snowball, which can be a little overbearing.  Really the only experiences I've shared so far have been in this thread; I just hope that with all the various types I've tried over the past year or so, I haven't mixed things up badly or given any wrong impressions.  I'll admit that sometimes I've commented on a tube that I haven't really listened to in a few months, however most have left me with enough of an impression that I feel confident that I'm not totally misleading anyone, at least not intentionally.  As always though, the best thing to do is to take my suggestions as just that, a suggestion from my system/ears, and let your own ears make the final decision/verdict for you, in your system.  Many factors can influence the sound of a tube, as every system is different, not even to mention that every headphone is also different.
 
If you ever have any questions or concerns regarding a type of tube up for sale before you purchase, let me know and I'll try to help as much as I can; I really don't mind.

The thing that bothered me the most was that I repeatedly told him the tubes were not the same as the listing, maybe one was, but not the other. I needed a pair, NOT A SPARE! He kept on saying they tested the same and asked what kind of tester I had to verify the readings. I didn't fall into his trap, and stuck to my guns, the listing was not what I received.
 
I'm not going to belittle him or post his ebay tag, as he has 100% feedback with a considerable history. He said he tested them 10 years ago, and knew not retesting them would bite him in the ass. I told him the listing was the problem, plain and simple.
 
 A tube NOS learning experience for sure, I"m happy it didn't blow my amp!!!!!!!!!

 

[JK-47]

  Time to join the TU-8200 club.  I finished up my TU-8200DX build last week.
 
I went with all of the upgrade options Victor offers, including Amtrans oil caps for coupling. I also replaced the plastic 9-pin tube sockets with ceramic gold pin sockets, and the included volume pot with an Alps RK27 Blue Velvet (the section of the board where the volume pot mounts is designed to break away to accommodate the RK27 - one tip - if you go with the Amtrans oil coupling caps, the gold plated leads that get clipped off when the caps are soldered in make good bridge leads from the main board to the volume pot board if going with the larger pot)
 
I'll reserve any in depth comments on the sound until it's had time to fully break in, but my initial impressions are very good.  I'm primarily using it as a headphone amp to drive my LCD-X, running in Triode mode.
 
One minor annoyance - I do wish there was a better system to switch modes other than having to remove the entire top cover and change jumpers. I understand wanting to prevent someone from switching while the amp is running, but even if it was a switch under a small access panel that required a couple of screws to be removed it would be more convenient.
 
Otherwise, the kit itself is top-notch. Quality parts, nice construction (if a bit plain) on the casework, well-packaged. This is far from my first kit, DIY or electronics project but it was one of the most fun kits I've built. I was almost sorry that it was finished.
 
As for difficulty, I don't know if I'd recommend it to someone that has never tackled any DIY or kits before, mainly due to some of the soldering required and the voltages involved, but for anyone that has a good handle on soldering basics and has some previous kit or DIY experience, it shouldn't be a difficult build. It took me 4 nights of a few hours a night, partially because I was waiting for the RK27 to come in and partially because I've got a habit of measuring/matching every part before I install it.
 
Communication with Victor before, during and after the sale was also great. He's patient with questions, responds quickly and has been a pleasure to do business with.
 
Meanwhile, as it burns in, I'm enjoying it and will post more impressions of the sound later.
 
It's also given me a chance to dig through my tubes plus pick up a few new pairs to roll, which I'm looking forward to.
 
Pre Tubes:

1. New:
   1. Gold Lion B749
   2. EH 12BH7
2. NOS:
   1. Several different RCA and Sylvania 12BH7/12BH7A
   2. 1950s Sylvania 12AU7a
   3. 1960s RCA "Cleartop" 12AU7a
   4. 1952 Raytheon JAN-CRP 5814
   5. 1962 RCA JRC 5814A
   6. 1956 RCA 5963

 
Power Tubes:

1. New:
   1. Gold Lion KT88
   2. Gold Lion KT66
   3. Tung Sol Tall Bottle 6L6G (6L6GC spec)
   4. EH KT88EH
   5. EH 6550EH
   6. Mullard EL34
2. NOS:
   1. 1960 RCA 6L6GC

 
 
   -Mike

 
 
Any updates on the tube rolling adventures?

 

[catcherfly]

I have a couple questions I'm hoping some of you might have answers for.
First off, I purchased a matched pair of Amperex 12AU7 Orange Globe tubes on eBay. I did not test the tubes before putting in the amp but everything is fine and I now understand the importance of testing first. I have been doing some research about testers and I'm wondering I could get some recommendations. Should I spend the money on a mutual conductance tester that reads Gm? The TU-8200 certainly won't be my last tube amp.
And secondly, one of the Amperex tubes makes a sound through the speaker it is on the side of, when I tap it with my finger. I can't hear anything unusual at any other time. Is this anything to be concerned with?
I need to do some more A-B testing with the stock ECC82 before I can speak to the difference in sound. I do think it is a subtle difference, however.

 

[JK-47]

I have a couple questions I'm hoping some of you might have answers for.
First off, I purchased a matched pair of Amperex 12AU7 Orange Globe tubes on eBay. I did not test the tubes before putting in the amp but everything is fine and I now understand the importance of testing first. I have been doing some research about testers and I'm wondering I could get some recommendations. Should I spend the money on a mutual conductance tester that reads Gm? The TU-8200 certainly won't be my last tube amp.
And secondly, one of the Amperex tubes makes a sound through the speaker it is on the side of, when I tap it with my finger. I can't hear anything unusual at any other time. Is this anything to be concerned with?
I need to do some more A-B testing with the stock ECC82 before I can speak to the difference in sound. I do think it is a subtle difference, however.

I noticed a considerable difference with the Amperex orange globes when listening through my headphones, more than through the speakers (I have sensitive Fostex FE168EZ's in folded horn enclosures) that the TU8200DX drives very nicely. Mainly in the mid's and hi's, with a vastly wider soundstage on my Fostex T50RastaPants 2's.
 
I have also been considering a tester/testers. I think rather than buying a vintage tester that most likely needs to be rebuilt then calibrated, I will purchase something more modern... An Amplitrex AT1000 being the ultimate but some what pricey at $2700, the Maxi matcher II $700 (power tubes only), Maxi Pre Amp II $989 (preamp tubes only), Orange VT1000 $400-$500 (more of a go/no go tester). I'm leaning towards the two Max units at the moment. I figure in the long run they will save me $$$, time, and frustration. I could always sell them fairly easily in the future as well.
 
A couple of great 6L6 and family reviews from 1998 and 2005. They are done in guitar amps though...
https://www.watfordvalves.com/cgi-bin/documents/testreport_34.pdf
https://www.watfordvalves.com/cgi-bin/documents/testreport_44.pdf
 
here's their full page of different reports:
http://watfordvalves.com/reports.asp

 

[mhamel]

   
 
Any updates on the tube rolling adventures?

 
Still burning things in, but so far the combo of 1950s Sylvania black plate 12BH7 and reissue Gold Lion KT-88 is my favorite.  I need to put some more hours on some of the other tubes before doing any sort of meaningful comparison.
 
  -Mike

 

[mhamel]

 
I noticed a considerable difference with the Amperex orange globes when listening through my headphones, more than through the speakers (I have sensitive Fostex FE168EZ's in folded horn enclosures) that the TU8200DX drives very nicely. Mainly in the mid's and hi's, with a vastly wider soundstage on my Fostex T50RastaPants 2's.
 
I have also been considering a tester/testers. I think rather than buying a vintage tester that most likely needs to be rebuilt then calibrated, I will purchase something more modern... An Amplitrex AT1000 being the ultimate but some what pricey at $2700, the Maxi matcher II $700 (power tubes only), Maxi Pre Amp II $989 (preamp tubes only), Orange VT1000 $400-$500 (more of a go/no go tester). I'm leaning towards the two Max units at the moment. I figure in the long run they will save me $$$, time, and frustration. I could always sell them fairly easily in the future as well.

 
I've got the Maxi Preamp II.  I've been very happy with it so far.  It's an additional $180 for adapters if you want to test 6DJ8-family tubes.  Another small preamp tube tester I've heard good things about is the Tube Imp.  It needs to be ordered from the UK and works out to around $500.   I came to the same conclusion about vintage testers. I really didn't want to have to go through restoring and re-calibrating a vintage tester.  I'd love an AT1000 but just couldn't justify spending that much on it.
 
Up until the TU-8200DX, I didn't have a need to test power tubes, so I may end up picking up a Maxi Matcher II at some point.
 
   -Mike