Little Dot Tube Amps: Vacuum Tube Rolling Guide
Jan 6, 2015 at 3:13 PM Post #8,851 of 12,832

gibosi

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I would have owned it instead of the little dot MK2 2.0 if it had rolling,Maybe some one could some how mode it in a way to accept different vacuum tubes with a special pin slot or wired in a way to work,maybe with addition mods to the design to make it work with 8 pins.

 
http://schiit.com/products/vali
 
The 6088's heater draws only 1.2V DC and the plate is run at 60V. Unfortunately, fitting a 6.3V tube which is typically designed to operate at a significantly higher plate voltage into this circuit would be far from satisfactory. :frowning2:
 
Jan 6, 2015 at 5:55 PM Post #8,852 of 12,832

Acapella11

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Just plugged a pair of Raytheon JAN 6SN7WGT as driver tubes into the MKIVSE for the first time and firstly of course they are still not working any better with my low impedance HE500 but on the plus side they match better in signature with the MKIVSE than the MKIII. This is because the two pairs of 6SN7 I have tried tend to sound a bit warm/refined and the MKIVSE is more on the neutral side than the MKIII, which is a bit warmer.
6SN7s sound very good as power tubes with my 300 ohm HD800, they should also be good with 250 ohm Beyers. The sound is livelier than on the MKIII, very detailed, would say more than the 5687, and the perception of the stage / ambience is excellent. So, higher Z + MKIVSE + 6SN7 power tube is an equation that works nicely. Driver tubes were C3GS.
 
Jan 6, 2015 at 6:44 PM Post #8,853 of 12,832

MIKELAP

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  Just plugged a pair of Raytheon JAN 6SN7WGT as driver tubes into the MKIVSE for the first time and firstly of course they are still not working any better with my low impedance HE500 but on the plus side they match better in signature with the MKIVSE than the MKIII. This is because the two pairs of 6SN7 I have tried tend to sound a bit warm/refined and the MKIVSE is more on the neutral side than the MKIII, which is a bit warmer.
6SN7s sound very good as power tubes with my 300 ohm HD800, they should also be good with a 250 ohm Beyers. The sound is livelier than on the MKIII, very detailed, would say more than the 5687, and the perception of the stage / ambience is excellent. So, higher Z + MKIVSE + 6SN7 power tube is an equation that works nicely. Driver tubes were C3GS.

MK4SE in da house nice, congrats .Would you say sound is more solid state like compared to MK3 and would the sound be fuller than with MK3 .                                                                                               
 
Jan 6, 2015 at 7:02 PM Post #8,854 of 12,832

Acapella11

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  MK4SE in da house nice, congrats .Would you say sound is more solid state like compared to MK3 and would the sound be fuller than with MK3 .                                                                                              

 
Thanks. Again, this is from memory, and I would say, yes, more solid state like signature but the MKIII sounding fuller, in parts simply because the stage appears larger with the MKIVSE. I found that there is a MKIVSE burn in effect though, which mellowed the quite hard initial sound more to a neutral tube sound.
 
Jan 7, 2015 at 5:47 AM Post #8,855 of 12,832

ToTje

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Wow, yesterday my Little Dot had a continuous hum through both channels (left and right).
Moving the tubes a bit did change the hum a bit, but it was quite loud.
I swapped the left and the right tube, but the hum didn't change.
Pulled out all the cables and plugged them back in; no change.
I replaced the Voskhods with the French RTC 5654RT tubes that the amp originally came with, and the hum was significantly lower in volume.
Then I took new Voskhods out of their packaging and placed them in the amp; exactly the same loud hum as with the other set.
 
Then I realised: earlier that day I had placed the base of my home telephone next to the amp, and the tubes were picking up interference of it! 
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Funny to notice how much more sensitive to interference the Voskhods are than those RTC tubes. However, the sound of those Russian tubes is far superior over that of the French ones, so I keep using them for now. I still am looking around for other tubes a bit, based on what I read here.
 
Jan 8, 2015 at 3:18 PM Post #8,856 of 12,832

superdux

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Thx to the guys that bought the C3G's from me i was able to afford a few more tubes and i already mentioned the chinese tube a few posts back. Well now i have to say i have a very, lush and rich and mellow (and a bit dark) combination of tubes in my amp. I unplugged my C3G as the combination with the chinese 6SN7 wasn't that nice. Then i plugged back in the 6N23P Voskhod rocket factory tubes from 78 and i was fascinated with the sound that came out of my HD650s. The chinese tubes are Nankings 6SN7 from this seller:
 
http://www.ebay.de/usr/orpheus_2005?_trksid=p2047675.l2559
 
and i found a statement about these tubes after buying them, not knowing they were that precious:
 
http://forum.audiogon.com/cgi-bin/frr.pl?rprea&1188586856&openfrom&28&4
 
 The best 6SN7's I have found are a pair of Nanjing 6N8P no longer in production. This is after Sylvanias, EH's, VT231's, and even the vaunted Russky 1578's with the holes. I did my research, and then tried the Chinese tubes on a whim, due to the fact that they have metal bases and were for sale cheap. Holy Valve, Batman! they were like the Russian "Holy Grail" 6H8C's but with a cleaner lower midrange, making them very clear, dynamic, spacious, musical, and tonally accurate. I despair to think of these tubes ever wearing out - I will never find another pair.

 
This combi is nothing for you if you rather like a bright bassy presentation.But if you'd like to experience the music like sweet honey dripping in your ears then try it out. The details are also very discernable. I had Heaven or Las Vegas from the Cocteau Twins in my CD player listening to this combi. First i thought rather not say anything incase the chinese tubes get sold out but i thought about it: them having nearly a 10000 hour lifespan and me listening up to 2 hrs a day it would take more than 10 yrs for them to give up. So i won't buy a second pair and leave it to you guys to grab some.
 

 
Jan 8, 2015 at 7:06 PM Post #8,858 of 12,832

Acapella11

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Plugged today the Sylvania 6SN7WGT brown base tubes into the MKIVSE (with C3GS) and I am beginning to get sold to these as power tubes with my HD800. The feeling of the three dimensions of the stage (spatial perception) is really good, accurate instrument placement, very good imaging and great level of detail make a great experience
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Originally Posted by superdux /img/forum/go_quote.gif
 
This combi is nothing for you if you rather like a bright bassy presentation.But if you'd like to experience the music like sweet honey dripping in your ears then try it out.

 
Must be sound impression that sticks!
wink_face.gif
 
 
Was the combination of 6SN7 with HD650 in your MKIII too dark/not lively?
 
Jan 8, 2015 at 8:35 PM Post #8,859 of 12,832

superdux

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hi acapella,
 
i think this is the synthesis of 2 very good tubes and the HD650 also being dark in nature and maybe the pitch black background of the 6N23P.
 
Jan 10, 2015 at 3:16 AM Post #8,860 of 12,832

Peter_S

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I am not aware of any amp that uses the 6HM5. We stumbled across this tube when we were searching for 7-pin tubes that would work in the LD, and I suspect that the vast majority of the people who buy this tube are LD owners. So no, to my knowledge, there are no adapters to allow this tube to be used in any other amp. And very frankly, in my opinion, there is no compelling reason to use the 6HM5, as even cheap double triodes are better.
 
Edit: That said, it is very likely that the 6HM5 will work in any amp that is designed to use the 6AK5.


I just got a LD mkii v2 amplifier used with a number of tubes.  I had to re-mount the transformer, and I hope that the amp is working.  Will test it tomorrow.  One of the tubes is the EI 6HM5.  I just want to confirm that it is in fact suitable.  Can someone confirm?  Thanks, Peter
 
Jan 10, 2015 at 8:54 AM Post #8,861 of 12,832

gibosi

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I just got a LD mkii v2 amplifier used with a number of tubes.  I had to re-mount the transformer, and I hope that the amp is working.  Will test it tomorrow.  One of the tubes is the EI 6HM5.  I just want to confirm that it is in fact suitable.  Can someone confirm?  Thanks, Peter

 
I do not know if version 2 of this amp is the current model or an older model..... If your amp can run EF 95 tubes, then yes, a pair of 6HM5 are perfectly suitable when used as drivers in current versions of LD I, II, III and IV.
 
Good luck! :)
 
Jan 10, 2015 at 2:59 PM Post #8,862 of 12,832

Acapella11

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Re MKIVSE and 6SN7 powertubes: I have kept on listening to the two pairs of 6SN7 tubes and just wanted to share a few impressions.
Both are 6SN7WGT brown base tubes and both fit very well with the MKIVSE (for MKIII, I prefer the more vibrtantly sounding 5687) and HD800. Both sound more refined, darker and detailed than the 5687.
The Sylvanias present more bass and treble than the Raytheon, sound is more V-shaped and exciting. Treble is a bit harder, bass more "visceral", mids are a bit sharper, stage representation is more forward.
The Raytheons sound a bit more linear/mid centered and wetter with a resulting larger stage. The mids are to die for, the treble is refined and very detailed. This is probably the most detailed sound I have ever heard on the MKIII & MKIVSE. Instruments have a good volume and presence, imaging is a bit better than with the Sylvanias.
In summary, I will probably stick with the 6SN7s as driver tubes and the HD800 as my preferred setup and keep the Raytheons in for now. Driver tubes were C3GS.
 
Jan 10, 2015 at 3:33 PM Post #8,863 of 12,832

MIKELAP

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Re MKIVSE and 6SN7 powertubes: I have kept on listening to the two pairs of 6SN7 tubes and just wanted to share a few impressions.
Both are 6SN7WGT brown base tubes and both fit very well with the MKIVSE (for MKIII, I prefer the more vibrtantly sounding 5687) and HD800. Both sound more refined, darker and detailed than the 5687.
The Sylvanias present more bass and treble than the Raytheon, sound is more V-shaped and exciting. Treble is a bit harder, bass more "visceral", mids are a bit sharper, stage representation is more forward.
The Raytheons sound a bit more linear/mid centered and wetter with a resulting larger stage. The mids are to die for, the treble is refined and very detailed. This is probably the most detailed sound I have ever heard on the MKIII & MKIVSE. Instruments have a good volume and presence, imaging is a bit better than with the Sylvanias.
In summary, I will probably stick with the 6SN7s as driver tubes and the HD800 as my preferred setup and keep the Raytheons in for now. Driver tubes were C3GS.

Do you mean stick with 6SN7 as POWER tubes not drivers .Can you say so far if your upgrading to the MK4SE is a big jump or moderate in sound quality .Also  do parts used seem to be of a better quality to explain the difference in price .I use the HD800 with my MK3 i think you said the MK4 SE was more neutral then the MK3 meaning ,a cleaner more detailed sound ?  does it loose warmt., or is it just a different sounding altogether .Thanks 
 
Jan 10, 2015 at 4:55 PM Post #8,864 of 12,832

gibosi

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I have been curious about 6F8Gs for some time so when I recently stumbled on a pair, an RCA and a Ken-Rad, for $15, I couldn't resist. For those who are new to the 6F8G, it is considered the direct predecessor of the 6SN7.
 
A picture of the Ken-Rad 6F8G, dated 1942, and a Ken-Rad 6SN7, dated 1945. The staggered plates and micas appear almost identical, but of course, the 6F8G bottle is significantly larger and there is a top cap connected to the grid of the first section. 
 

 
Assuming one already has adapters to allow the use of 6SN7s, it is then necessary to purchase an additional adapter to allow a 6F8G to be used in a 6SN7 socket, like so:
 

 
I haven't taken the time to compare these tubes, but going from memory, used as a driver in my LD 1+, the 6F8G has the same big bass, smooth midrange and highs as the 6SN7. A terrific tube. For about $8, I am real pleased. :)
 
Jan 10, 2015 at 5:05 PM Post #8,865 of 12,832

Acapella11

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  Do you mean stick with 6SN7 as POWER tubes not drivers .Can you say so far if your upgrading to the MK4SE is a big jump or moderate in sound quality .Also  do parts used seem to be of a better quality to explain the difference in price .I use the HD800 with my MK3 i think you said the MK4 SE was more neutral then the MK3 meaning ,a cleaner more detailed sound ?  does it loose warmt., or is it just a different sounding altogether .Thanks 


Yes, powers, not drivers. Loses warmth, some more details and stage. Moderate jump but noticeable and because the synergy with 6SN7 is better, I'd  say the jump just got bigger. For me now, it was worth the money.
 

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