[SonicTrance]

 

  If you don't want to do any modding, these will do the trick: http://www.amazon.com/Noctua-NF-R8-80mm-Fan-2-Pack/dp/B001QYLOA4/ref=sr_1_11?ie=UTF8&qid=1451034963&sr=8-11&keywords=noctua+80mm+fan
No need to get static pressure fans as you want high airflow, not pressure. You'll also need a 3-pin Y-splitter cable as that quote above suggests.

 
I hope you don't get sick of me thanking you, but I finally worked up the guts to unscrew the 10 flush-mount Phillips screws on the bottom of my MK VI+ and swapped in the pair of Noctua fans, complete with the necessary Y-cable ( http://www.amazon.com/gp/product/B00LPE1DDS FTW).  Took about 15 minutes of being overly cautious.  The result?  What fans??? 

 
Compared to the idling Mercedes diesel sound of the stock fans, these fans are insanely quiet.  Unless the room is perfectly quiet, I can't even hear them.  I'm absolutely amazed that Little Dot doesn't spring for the extra US $50 and install these right from the factory.
 
Thanks, yet again, for the sage words of advice, MisterX.  It's very much appreciated.
 
- Dave

Nice!
Actually, I remember powering on my mk6 for the first time and thought: What? Fans were rattling and making all kinds of noises. In short, the stock fans are terrible, lol.

 

[ViperGeek]

  OK, so it's taken me just over two weeks of evenings to get through all 150 pages of replies, but I finally did it <insert fanfare here>.  I appreciate all the time and effort everyone — especially the rock stars of the thread; and you know who you are — put into reading and responding to questions, posting their successes and funny-smelling (or shocking) failures, and providing commentary over the last 61 months.
 
Along the way, I've collected a wide and varied list of tube-rolling recommendations, specifically in my case, for the MK VI+:
 

1. 6SL7GT RCA (Driver Tubes) | TubeDepot.com
2. Tung-Sol 6SL7GT (Driver Tubes) | TubeDepot.com
3. Tung Sol 6SL7GT Cryo Treated Matched Pair (2) Vacuum Tubes
4. 6SN7-UK (Driver Tubes) | Psvane & Shuguang Treasure Audio Tubes
5. CV181-TII aka 6SN7 (Driver Tubes) | Psvane & Shuguang Treasure Audio Tubes
6. Sophia Electric™ Premium 6SN7 (Driver Tubes)
7. 6AS7G / 6520 (Power Tubes)| TubeDepot.com
8. 6N5S (black plate) (Power Tubes) - Tubes-Store.com
9. Tung Sol 5998 (Power Tubes) | Tubes Unlimited

 
I'm curious, as a way to reinvigorate this thread while at the same time provide advice to a first-time tube roller, which is the best first driver and power tubes to order?  My current setup consists of balanced LCD-2s and SE HD 650s driven by a balanced DAC (Grace Design m920).  Music tastes vary from female soloists (my favorite) all the way to metal with some pop diversions along the way to keep things interesting.  I can share my Wow! playlist if it'll help, or if there's morbid curiosity.
 

 
So I'm working down my list (can't leave success well enough alone) and started obsessing about Psvane drivers tubes.  The CV181-TII's are a bit too rich for my blood and the 6SN7-UK's have been described as "analytical" in this thread.  What I'd like to find are CV181-T's, but they're permanently sold out.  I reached out to Grant Fidelity (Psvane & Shuguang local distributor and proctor of http://psvanetube.com/wordpress/store) and they had this to say:
 

 In Little Dot the CV181-T will be used as a driver stage tube - if budget is not an issue, yes CV181-TII our best grade at $290 per pair is the best tubes. If you don't want to overkill with the budget, the Treasure CV181-Z will do just fine in this application and offer a great improvement over standard tube provided with the amp and cost almost $100 less: [url=http://psvanetube.com/wordpress/store/products/cv181-z-pair/]http://psvanetube.com/wordpress/store/products/cv181-z-pair/[/url] Hope this helps..

 
so I asked which driver tubes, the CV181-Z or 6SN7-UK, would sound more smooth and rich.  Grant Fidelity replied again (they're very responsive, BTW):
 

 The UK series is just a small step up from the regular 6SN7 but CV181-Z is a big leap....for very revealing system, I would highly recommend you to go with the CV181-Z.. it has the best bang for the buck and tons of positive reviews on internet..

 
So I'm now hovering over the PayPal button for the CV181-Z's.  The problem is:
 
"Note: this tube is taller and fatter than most other 6SN7. The widest part is 2″ diameter, and it is 4″ tall from base (not including the pins) up. Please check your amp to see if the tube will fit before you purchase. The tube base is made of ceramic which is 3.5cm (about 1 3/8″) in diameter slightly larger than an average 6SN7 tube base."
 
I used a caliper to measure the MK VI+ gold ring and it's 3.25cm which means the penultimate tubes (CV181-Z's) won't fit.
 
I noticed some of you have used socket savers to install wider driver and power tubes in the past.  Does anyone have a recommendation for brand and source?  I found these on Amazon:
 
http://www.amazon.com/gp/product/B005IYPLH0
 
but can't say for sure if they're any thinner than the 3.5cm CV181-Z's.
 
Thanks!
 
- Dave
 
UPDATE: I just impulse-bought a pair of these: http://www.ebay.com/itm/150688246271 .  The stated girth is 1.3" which is pretty darned close to the ring size for the front driver tube sockets.  Fnigers Crsosed.

 

[SonicTrance]

@ViperGeek
Those socket savers will work fine. I've used similar myself, though I'm now using some higher quality socket savers, http://www.ebay.com/itm/191109289479?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
Mostly because they look nice Socket savers are great as they "saves" the sockets and elevates the tubes so the amp doesn't get as hot.
 
I've no experience with the Shuguang CV181-Z, though I've had both the UK-6SN7 and the CV181-T. The CV181-T's are much warmer than the UK-6SN7's and sound OK, but wont compete with the "average" NOS tube IMO. 

 

[ViperGeek]

  @ViperGeek
Those socket savers will work fine. I've used similar myself, though I'm now using some higher quality socket savers, http://www.ebay.com/itm/191109289479?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
Mostly because they look nice Socket savers are great as they "saves" the sockets and elevates the tubes so the amp doesn't get as hot.

 
Wow.  Those socket savers are gorgeous.  Damn.  Now I've got four coming from eBay.
 
Oddly, Grant Fidelity wasn't too keen on socket savers:
 

 You can simply remove the gold ring from inside of the amp and check the chassis opening diameter to see if the tube socket will fit through without the ring.. Usually we don't recommend to use socket saver - which is often made inexpensively and some even cause current leak... If you prefer to keep the ring on, you may have to look at the CV181-TII which has a smaller tube base..

 

  I've no experience with the Shuguang CV181-Z, though I've had both the UK-6SN7 and the CV181-T. The CV181-T's are much warmer than the UK-6SN7's and sound OK, but wont compete with the "average" NOS tube IMO. 
 

 
Interesting!  So, you're not a big fan of the Psvane & Shuguang tubes at all, or only not a fan of the 6SN7-UK's?  I'm actually looking to take the "hard edge" off my LCD-2s.  The Tung Sol 6SL7GT's really opened up the presence and tightened the bass, but now my orthos are being very critical of nothing but the best-recorded FLACs (in fact, it's not even the encoding, but rather the mastering where I notice flaws).
 
- Dave

 

[ViperGeek]

I didn't mean to limit responses to my new best friend and mentor.  Does anyone subscribed to this thread have any strong opinions for or against Psvane & Shuguang tubes?  Now that I have Mister X's pretty gold socket savers being shipped to me from Hong Kong, I'd like to order the CV181-Z driver tubes soon so they all arrive at about the same time.
 
- Dave

 

[ViperGeek]

I'm happy to report that my Shuguang CV181-Z driver tubes made it from Shenzhen, Guangdong, China, to New Hampshire, USA, and are currently in their first hour of 100-200 of burn-in.  So far, they sound deeper, tighter, and crisper than the Tung-Sol 6SL7GT driver tubes, but that could just be observer bias.
 
I have a question for the avid tube-rollers on the thread/forum.  How do you store all your displaced vacuum tubes?  So far, I've been replacing tubes on the MK III and MK VI+ with same-sized tubes, and repurposing the new tube boxes as storage for the old[er] tubes, but now I've gone from smaller round tubes to Coke bottle-shaped tubes and my logical shift left of boxes and tubes won't quite work.
 
Do you have some Tupperware container for all your old/spare tubes, or keep them in their original boxes when possible, or have some other clever storage method?  Between the two Little Dots amps, I'm amassing quite a collection of unused vacuum tubes and would like to store them in such a way as to not damage them, especially long term.
 
Thanks!
 
- Dave

 

[ViperGeek]

I feel like I "broke" this thread, since I've been the only one posting here for almost a month. 

 
So, I was curious how the MK VI+ would pair up with the recently uber-popular Fostex/Massdrop TH-X00 headphones.  Being only 25 ohms, I had concerns that anything more than a Grace Design 0.1-1.2 ohm output impedance may not be able to drive them.  I dropped a note to David on LittleDot.net and he had this to say:
 

The output impedance will be around 32 ohms on the SE and <100 ohms overall. While not technically ideal, if there is a return policy on the TH-X00 you may want to evaluate the pairing for your own ears.

 
Now, I'm delighted with the balanced performance of the MK VI+ with my LCD-2s which are rated at 50 ohms, but given the gross violation of the 8:1 inpututput impedance rule, how could this be?
 
- Dave

 

[coinmaster]

I feel like I "broke" this thread, since I've been the only one posting here for almost a month. 

Most of the action is over in the mod thread now. This one has been dead ever since it was created.

 

[ViperGeek]

 

I feel like I "broke" this thread, since I've been the only one posting here for almost a month. 

Most of the action is over in the mod thread now. This one has been dead ever since it was created.

 
Thanks coinmaster!  So it's copacetic to post random n00b questions over in the mod thread?
 
- Dave

 

[coinmaster]

Probably not unless it's related to the mods. You could technically mod your amp to accept low impedance headphones though.

 

[Maxx134]

So, I was curious how the MK VI+ would pair up with the recently uber-popular Fostex/Massdrop TH-X00 headphones. Being only 25 ohms, I had concerns ...

I owned the Fostex th600.
It supposedly has the same or similar driver.

They are very efficient.

Furthermore, I recently heard a friends THX00 at home.

Furthermore, that friend also has a tube amp.

So from my experience, you have nothing to worry about as it plays just fine.

Personally, I still feel the TH600 is superior to the THX00, because of the larger soundstage, and ability for it to be easily moded from "U" shaped to a balanced signature, as I posted in the th600 thread long ago..

Yet the alure of the THX00 cannot be denied,
which is a slimmer form factor and the absolutely gorgeous looking wood grain cups...

Believe me, I owned a few woodie cans, and so know just how beautiful wood cups can be...

 

[Sam-Fi]

I'm selling one of these amps over in the marketplace section. It's been modded and upgraded by little dot, I'm sure someone here would love this.

 

[baronbeehive]

Just taken a trip down memory lane, nice to see the thread still live...... just!
 
Quote:

  OK, so it's taken me just over two weeks of evenings to get through all 150 pages of replies, but I finally did it <insert fanfare here>.  ..........
........

 
What kind of hifi nerd are you........I thought it was just me that did that kind of thing....joking

.
 
Quote:

.........
 
Along the way, I've collected a wide and varied list of tube-rolling recommendations, specifically in my case, for the MK VI+:
 

1. 6SL7GT RCA (Driver Tubes) | TubeDepot.com
2. Tung-Sol 6SL7GT (Driver Tubes) | TubeDepot.com
3. Tung Sol 6SL7GT Cryo Treated Matched Pair (2) Vacuum Tubes
4. 6SN7-UK (Driver Tubes) | Psvane & Shuguang Treasure Audio Tubes
5. CV181-TII aka 6SN7 (Driver Tubes) | Psvane & Shuguang Treasure Audio Tubes
6. Sophia Electric™ Premium 6SN7 (Driver Tubes)
7. 6AS7G / 6520 (Power Tubes)| TubeDepot.com
8. 6N5S (black plate) (Power Tubes) - Tubes-Store.com
9. Tung Sol 5998 (Power Tubes) | Tubes Unlimited

 
I'm curious, as a way to reinvigorate this thread while at the same time provide advice to a first-time tube roller, which is the best first driver and power tubes to order? My current setup consists of balanced LCD-2s and SE HD 650s driven by a balanced DAC (Grace Design m920). Music tastes vary from female soloists (my favorite) all the way to metal with some pop diversions along the way to keep things interesting. I can share my Wow! playlist if it'll help, or if there's morbid curiosity.
 
Thanks for the past, present, and future advice!

 
I would go with SonicTrance's advice, the TS6SL7BGRP is a great, detailed tube with beautiful smooth and silky sound that you can't really get anywhere else, except perhaps the RCA's but they aren't quite so good though I like them, good, cheap, entry level tubes.
 
I agree again I wouldn't go with the new issue tubes such as the Psvanes, although they are probably the best new issues , but all new issues to me don't have that depth of sound of NOS tubes.
 
Re: the power tubes, the 5998 family are undoubtedly the best, most musical and detailed, however the cheap and nice RCA 6AS7G's are very widely used and respected, giving a warm sound but not as detailed. Bendix 6080WB graphite plate are one of the best for detail and separation while still sounding musical but like all the best tubes are getting expensive.
 
Quote:

  @ViperGeek
Aha, that's great regarding the DAC and cables for the HD650
 
I don't know how the TS flat plate 6SL7's sound, never heard one. I have the 6SL7, 6C8G, 6F8G and 6SU7GTY TS BGRP and they all sound very similar. Good allround tubes IMO.
 
 
Edit: And then, when you've listened to your mk6 for a few months, check out what we're doing in this thread: http://www.head-fi.org/t/782183/little-dot-mk8se-mk6-super-mods
You wont regret it

 
Yes, the mods thread is keeping interest in the LD, the problem with the LD's is the lack of reviews so its difficult. I have heard a flat plate TS and they're very ordinary and to be avoided.
 

   
Just wanted to give my tube mentor an update that I picked up a pair of:
 
http://www.ebay.com/itm/Tung-Sol-6SL7GT-Cryo-Treated-Matched-Pair-2-Vacuum-Tubes-/381147818356?hash=item58be2e2974
 
and have been loving them.  Even before they've burned in, I noticed quite a bit more bottom end and sparkly highs.  My balanced LCD-2s are even more mind-expanded than ever before.  I'll wait a little while before working down my Chrome bookmarks and picking up a quad of power tubes.
 
Thanks again for the advice!
 
- Dave

 
Your new issue TS's will sound reasonably good but not a patch on the NOS RP TS's. Also I see llittle point in cryoing new issue tubes really.
 
Enjoy your LD, good to see continued interest in these fantastic amps!

 

[ViperGeek]

  Just taken a trip down memory lane, nice to see the thread still live...... just!
 
Quote:

  OK, so it's taken me just over two weeks of evenings to get through all 150 pages of replies, but I finally did it <insert fanfare here>.  ..........
........

 
What kind of hifi nerd are you........I thought it was just me that did that kind of thing....joking

.
 
 

 
The best kind: a Head-Fi fanatic.  Love this site and love the Little Dots.  The MK VI+ sits proudly right next to my "gateway" Little Dot: the MK III.
 

I would go with SonicTrance's advice, the TS6SL7BGRP is a great, detailed tube with beautiful smooth and silky sound that you can't really get anywhere else, except perhaps the RCA's but they aren't quite so good though I like them, good, cheap, entry level tubes.
 
I agree again I wouldn't go with the new issue tubes such as the Psvanes, although they are probably the best new issues , but all new issues to me don't have that depth of sound of NOS tubes.
 
Re: the power tubes, the 5998 family are undoubtedly the best, most musical and detailed, however the cheap and nice RCA 6AS7G's are very widely used and respected, giving a warm sound but not as detailed. Bendix 6080WB graphite plate are one of the best for detail and separation while still sounding musical but like all the best tubes are getting expensive.
 
Quote:

   
Just wanted to give my tube mentor an update that I picked up a pair of:
 
http://www.ebay.com/itm/Tung-Sol-6SL7GT-Cryo-Treated-Matched-Pair-2-Vacuum-Tubes-/381147818356?hash=item58be2e2974
 
and have been loving them.  Even before they've burned in, I noticed quite a bit more bottom end and sparkly highs.  My balanced LCD-2s are even more mind-expanded than ever before.  I'll wait a little while before working down my Chrome bookmarks and picking up a quad of power tubes.

 
Your new issue TS's will sound reasonably good but not a patch on the NOS RP TS's. Also I see llittle point in cryoing new issue tubes really.
 
Enjoy your LD, good to see continued interest in these fantastic amps!

 
Thanks for the seconded opinion on the Tung-Sol 6SL7.  One of the nuances that continues to escape this n00b is the modifier letters at the end of a tube designation.  For example, what's the difference between a TS 6SL7GT and 6SL7BGRP?  Is there a decoder ring website I can reference to determine the differences?  Also, descriptions like "black plate" and "flat plate" confuse me, but perhaps that's a stupid question for a different post.
 
Since my last post, I've also picked up a quad of NOS RCA 6AS7G from the mid 50's.  Initially (to my ear), the difference in power tubes was much more subtle than the difference from rolling driver tubes.  But what I've notice over a dozen hours of listening is that I'm more willing to crank up the volume than I was with the stock power tubes.  I've been told that the brain confuses harshness with loudness, and if that's true, then the 6AS7G's are much, much smoother and "analog" than the stock tubes, which IMO is an awesome improvement.
 
Thanks again for taking the time to swing by this old thread and help a new LD fan.
 
- Dave

 

[SonicTrance]

Hi Dave,
 
When we write BGRP, we mean "black glass round plates". Meaning the tubes glass is black and the plates (anodes) are round.
You can see it in this pic:

You see those two round grey plates above.
 
Down below you see the 6C8G version of TS BGRP.