[MIKELAP]

  Hey Guys...I received one of my Tung Sol (nee Rad Tel) Mouse Ears 6SN7GTs today.  I was just wondering how they came to have zero getter flash/clear glass???
 
I won't have a chance to run it for awhile...still waiting on the 2nd one and the sockets from China...but...it tests good (84) on my simple Pacific tube tester (assuming the numbers from it are legit!)...with no shorts, and good gas reading.  The black body has no markings printed on it, and the glass only has the 6SN7 over GT from what I can see.
 
-Mark 

                               

 

[gibosi]

  Hey Guys...I received one of my Tung Sol (nee Rad Tel) Mouse Ears 6SN7GTs today.  I was just wondering how they came to have zero getter flash/clear glass???

 
Getter flash ranges from shiny chrome to black to almost invisible. If the tube develops an air leak, it will turn a chalky white. Mouse ears tend to have an almost invisible flash. Have no idea why, but it is normal.

 

[buldogge]

Crappy low light photo...only place I have to plug it in is the tester socket...
 

 

[jaywillin]

  Nic Rhodes hows the MK9 coming along any comparaisons or comments. Thanks.                                                                                                                                                                       

very interested as well, i almost bought one of these, but went mk iii for now, but i may have a mk 9 yet

 

[MIKELAP]

  Crappy low light photo...only place I have to plug it in is the tester socket...
 

                                                                                                                   
  This one is a Tung Sol looks similar to yours                                                                                                              
   

 

[buldogge]

^^^Every "mouse ear" ,I have seen photos of, seems to have been made in 1952.  The other tube I ordered (marked Admiral) is a '52 as well.
 
Mike...Is that your pic?  How do you find the sound/presentation??
 
-Mark

 

[MIKELAP]

  ^^^Every "mouse ear" ,I have seen photos of, seems to have been made in 1952.  The other tube I ordered (marked Admiral) is a '52 as well.
 
Mike...Is that your pic?  How do you find the sound/presentation??
 
-Mark

Yes it is, i would have to listen to them  again my audio memory is very short lol . 

 

[gibosi]

Had some time this evening to compare the three 6463 - GE (relabeled by Sylvania), Philips (Heerlen) and Telefunken (Ulms).
 

Spoiler: GE

 

Spoiler: Amperex and Telefunken

 
Interestingly, I found the GE and Philips were quite similar. Both have a rather lush midrange, but the Philips has a bit more upper bass/lower midrange warmth whereas the GE is a bit livelier with more air. While listening to these tubes, I thought I could be happy with either one.  However, when I added the Telefunken to the mix, I changed my mind. With an LD1+ running a MUSES02 op amp and listening through Senns 700s, the Telefunken is better, to my ears.
 
I believe the lushness of the GE and Philips masks too much detail. Vocals on theTelefunken on the other hand seem cleaner, while still having good warmth and body, very similar to my reference 1975 Reflektor 6N23P. And as a result this tube has excellent transparency and detail. One of the real strengths of the 700s is imaging, and when paired with a tube as transparent as the Telefunken, I can easily pick out all the vocalists and instruments, from front to back and side to side.
 
Highly recommended.

 

[Jolfr]

Hey guys,
I have a couple questions about tube rolling. I just got my first amp (Little Dot Mk III, for my HD650's) and have heard that tube rolling can really help an amp.
How much does it help the amp in all reality? How much would I need to spend on tubes to make a noticeable/good difference? (I would prefer to not spend too much)
 
As far as the LD Mk III I see that it can take different kinds of tubes. I can't find anywhere what the difference between a 5654 tube and a 5725 tube is. And what's the difference between a 6H6PI, a 6H6n and a 6H6nN?
 
 
Thank you very much to anyone who can help me out with this!

 

[WilliamLeonhart]

   
Better?  Really? I don't think it looks nearly as good as mine! lol.
 

What are those wires for? And if I'm not wrong you're using adapters below the tubes?

 

[MIKELAP]

  Hey guys,
I have a couple questions about tube rolling. I just got my first amp (Little Dot Mk III, for my HD650's) and have heard that tube rolling can really help an amp.
How much does it help the amp in all reality? How much would I need to spend on tubes to make a noticeable/good difference? (I would prefer to not spend too much)
 
As far as the LD Mk III I see that it can take different kinds of tubes. I can't find anywhere what the difference between a 5654 tube and a 5725 tube is. And what's the difference between a 6H6PI, a 6H6n and a 6H6nN?
 
 
Thank you very much to anyone who can help me out with this!

Take a look at these power tube comparaison page 201 post # 3007

 

[MIKELAP]

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    

 

[gibosi]

  What are those wires for? And if I'm not wrong you're using adapters below the tubes?

 
I have set my LD1+ up to run double triodes as drivers using an external 9-pin breadboard socket, an external DC heater circuit and two 7-pin Vector test sockets. When I wish to run C3gs, I simply make sure there is no tube in the external 9-pin socket, and then plug the C3gs directly into the test sockets. 
 
Here pictured with the Telefunken 6463 mentioned just above.
 

 

[Nic Rhodes]

  Nic Rhodes hows the MK9 coming along any comparaisons or comments. Thanks.                                                                                                                                                                       

 
Well spent some time with the new Little Dot Mk9 now, thoughts so far:
 
Well I'll cut straight to one conclusion, this is a nice upgrade to a LD III, IV or IVse with rolled tubes (say C3Gs and 5687 / 6SN7GT premium combinations). So yes it is a far better amp than basic or rolled baby LD and one that I am very fond of now.
 
So a little more detail about the LD Mk9:
 
The amplifier has the same form factor as the a LD III, IV or IVse amps but uses a different circuit and different tubes. The amp has perhaps more in common with the MkVI+ power house but a half of it. It has a single driver tube which is 6SL7GT and two output tubes of 6080. Both of these tubes are common and cheap, this is something I think is very important as we have all seen what has happened to the cost of some tubes recently. There are also many other similar tubes that could be rolled.
 
The 6SL7GT is actually a Chinese 6N9P. The quality of this tube was average and not to my taste at all, however there are lot’s of alternative you can try.
 
Russian 6N9S / 6H9C are  widely available and come in metal or plastic bases. Most seem to prefer the metal based ones but not really what interests me. I prefer the European and US examples.
 
The 6SL7GT was released during the war years (1942?) and has been made in huge numbers ever since. The early ones were often made with round plates and were also marked VT-229.  These are not expensive at all (and this amp has the advantage of using only one!). In terms of cost they are much less than the sister tube 6SN7GT. The early example are still plentiful on the ‘bay’ so people should have no problem getting stocks. There are also some ruggedized examples. These are labelled 6SL7WGT or 6113. Then there is the ‘RCA’ red based version 5691 which is a super ruggedized ‘long life’ version. This was made in a black based version well into the 1980s by PhilipECG (Sylvania) and these late example aren’t bad at all and really well made. There is also a premium compatible version called 6SU7GT or  6188 which is my favourite. 1940s examples from Tung-sol are excellent I am a fan of all of these premium and ruggedized examples (none carry the price premium of 6SN7GT does now) but tbh there are many great examples from many great makes (usual names), especially from the 1950s and 1940s.
 
The Europeans made the ECC35 which is similar to the CV569 and close enough to be in the 6SL7GT family. The other military number to look out for is the CV1985 (Brown and Black based examples) and many examples were marked as Brimar (although actually made by STC, either at their Footscray plant, look for KB / FB marking or KB/FE for STC, Oldway ). I like these. Quality tubes but generally a little more money (still affordable however). For those wanting to use with adapters then there is 6C8G with a top cap (pre dated the 6SLGT) and the Loctal 7F7 (mostly Sylvania made). Both nice rubes. In fact there is a real wealth of quality tubes out there, they are well priced, quality is high and you only need one for this amp. It is a win everywhere.
 
The 6080 is an industrial triode and this amp uses two French Thomson CSF (very decent). This is reasonable powerful output tubes and is far easier to drive it properly than say the beefier 300b. It is ideally suited to headphone amplifiers because of it’s size and can be used in a number of configurations. Here the Little Dot Mk9 is used in SEPP (single ended push pull) OCL (output capacitor-less) design and this design means you can also use it to drive a power amplifier as well as headphones (not something I recommend with all power amps in others members of the LD range). This in itself is a departure from the LD III, IV or IVse amps and much closer to the VI+. What this means is that you will get same power into 32 ohms as you will 600 ohm phones (as opposed to the Output Transformer less Designs OTL which are best at driving >300 ohm phones despite marketing claims saying otherwise… ).
 
If the 6080 is too dull and squat to look at, then pop in 6AS7G tubes. Often better performance again also and prettier shape but identical electrical characteristics. Both of these tubes are still cheap and plentiful (if you don’t want the best GEC models). The Russian 6N5S / 6N13S examples (of 6AS7Gs) are plentiful and cheap and have excellent performance (I like the oldest ones best). £12.50 will even get you NOS 6080 Mullard in crisp new boxes….and remember this is a big tube (Langrex by the way). Good 6080 tubes by Tung-sol, GE 5*, RCA Command, Bendix (graphite), Mullard, Thomson CSF and GEC, good 6AS7G tubes by Tung-sol, RCA, Chatham and GEC. Basically loads of good options out there including many not mentioned.
 
So this amp runs cheap tubes, has only 1x 6SL7GT and 2x 6080 / 6AS7Gs and will drive most things. So how does it perform?
 
Well considering this amp has been around for a few years now, I am amazed that more has not been written about it. I found one reference to it humming on the internet. My example is dead quiet and I mean really quiet. It does not have the romance of the OTL driving 600 ohm headphones (few do) but has a wonderful even nature. Unlike most of my amplifiers which drive one type of phone (big OTL fan), this amp has a decent stab at most of them. It won’t drive an HE6 but little does (properly) and LD have their VI+ for that anyway. So it is a great all-rounder, and when properly loaded with the quality tubes  it makes great sounds without being a power house. In fact my AKG 240DFs never have sounded better. At it’s price, I think it makes great value and I really am struck by how few people know about it. This certainly does not make any sense given it’s quality.
 
I now see this as well above the level of the LD III, IV or IVse (even fully rolled / adapters galore) and more as a baby VI+ (though I haven’t heard this yet). There is just way too much similarity in how they are designed to disniss the similarity. The big brother is now firmly on my wants list. List from David Z is $459 for the Little Dot Mk9 which puts it into an interesting area that is sparsely populated for affordable valve amp that are cheap to run. Perhaps the obvious competition will be the Elise but that is an OTL, used 2x of the more expensive 6SN7GTs and same output tubes. Both look very interesting propositions and I may be the first to own both I don’t see it as one being better than the other  but more similar priced amps aiming at different markets but similar tubes / form factor. It will make an interesting shoot off however.
 
All told, one fine performing amp, keenly priced that is cheap to run.

 

[MIKELAP]

 

  Nic Rhodes hows the MK9 coming along any comparaisons or comments. Thanks.                                                                                                                                                                       

 
Well spent some time with the new Little Dot Mk9 now, thoughts so far:
 
Well I'll cut straight to one conclusion, this is a nice upgrade to a LD III, IV or IVse with rolled tubes (say C3Gs and 5687 / 6SN7GT premium combinations). So yes it is a far better amp than basic or rolled baby LD and one that I am very fond of now.
 
So a little more detail about the LD Mk9:
 
The amplifier has the same form factor as the a LD III, IV or IVse amps but uses a different circuit and different tubes. The amp has perhaps more in common with the MkVI+ power house but a half of it. It has a single driver tube which is 6SL7GT and two output tubes of 6080. Both of these tubes are common and cheap, this is something I think is very important as we have all seen what has happened to the cost of some tubes recently. There are also many other similar tubes that could be rolled.
 
The 6SL7GT is actually a Chinese 6N9P. The quality of this tube was average and not to my taste at all, however there are lot’s of alternative you can try.
 
Russian 6N9S / 6H9C are  widely available and come in metal or plastic bases. Most seem to prefer the metal based ones but not really what interests me. I prefer the European and US examples.
 
The 6SL7GT was released during the war years (1942?) and has been made in huge numbers ever since. The early ones were often made with round plates and were also marked VT-229.  These are not expensive at all (and this amp has the advantage of using only one!). In terms of cost they are much less than the sister tube 6SN7GT. The early example are still plentiful on the ‘bay’ so people should have no problem getting stocks. There are also some ruggedized examples. These are labelled 6SL7WGT or 6113. Then there is the ‘RCA’ red based version 5691 which is a super ruggedized ‘long life’ version. This was made in a black based version well into the 1980s by PhilipECG (Sylvania) and these late example aren’t bad at all and really well made. There is also a premium compatible version called 6SU7GT or  6188 which is my favourite. 1940s examples from Tung-sol are excellent I am a fan of all of these premium and ruggedized examples (none carry the price premium of 6SN7GT does now) but tbh there are many great examples from many great makes (usual names), especially from the 1950s and 1940s.
 
The Europeans made the ECC35 which is similar to the CV569 and close enough to be in the 6SL7GT family. The other military number to look out for is the CV1985 (Brown and Black based examples) and many examples were marked as Brimar (although actually made by STC at their Footscray plant, look for KB / FB marking). I like these. Quality tubes but generally a little more money (still affordable however). For those wanting to use with adapters then there is 6C8G with a top cap (pre dated the 6SLGT) and the Loctal 7F7 (mostly Sylvania made). Both nice rubes. In fact there is a real wealth of quality tubes out there, they are well priced, quality is high and you only need one for this amp. It is a win everywhere.
 
The 6080 is an industrial triode and this amp uses two French Thomson CSF (very decent). This is reasonable powerful output tubes and is far easier to drive it properly than say the beefier 300b. It is ideally suited to headphone amplifiers because of it’s size and can be used in a number of configurations. Here the Little Dot Mk9 is used in SEPP (single ended push pull) OCL (output capacitor-less) design and this design means you can also use it to drive a power amplifier as well as headphones (not something I recommend with all power amps in others members of the LD range). This in itself is a departure from the LD III, IV or IVse amps and much closer to the VI+. What this means is that you will get same power into 32 ohms as you will 600 ohm phones (as opposed to the Output Transformer less Designs OTL which are best at driving >300 ohm phones despite marketing claims saying otherwise… ).
 
If the 6080 is too dull and squat to look at, then pop in 6AS7G tubes. Often better performance again also and prettier shape but identical electrical characteristics. Both of these tubes are still cheap and plentiful (if you don’t want the best GEC models). The Russian 6N5S / 6N13S examples (of 6AS7Gs) are plentiful and cheap and have excellent performance (I like the oldest ones best). £12.50 will even get you NOS 6080 Mullard in crisp new boxes….and remember this is a big tube (Langrex by the way). Good 6080 tubes by Tung-sol, GE 5*, RCA Command, Bendix (graphite), Mullard, Thomson CSF and GEC, good 6AS7G tubes by Tung-sol, RCA, Chatham and GEC. Basically loads of good options out there including many not mentioned.
 
So this amp runs cheap tubes, has only 1x 6SL7GT and 2x 6080 / 6AS7Gs and will drive most things. So how does it perform?
 
Well considering this amp has been around for a few years now, I am amazed that more has not been written about it. I found one reference to it humming on the internet. My example is dead quiet and I mean really quiet. It does not have the romance of the OTL driving 600 ohm headphones (few do) but has a wonderful even nature. Unlike most of my amplifiers which drive one type of phone (big OTL fan), this amp has a decent stab at most of them. It won’t drive an HE6 but little does (properly) and LD have their VI+ for that anyway. So it is a great all-rounder, and when properly loaded with the quality tubes  it makes great sounds without being a power house. In fact my AKG 240DFs never have sounded better. At it’s price, I think it makes great value and I really am struck by how few people know about it. This certainly does not make any sense given it’s quality.
 
I now see this as well above the level of the LD III, IV or IVse (even fully rolled / adapters galore) and more as a baby VI+ (though I haven’t heard this yet). There is just way too much similarity in how they are designed to disniss the similarity. The big brother is now firmly on my wants list. List from David Z is $459 for the Little Dot Mk9 which puts it into an interesting area that is sparsely populated for affordable valve amp that are cheap to run. Perhaps the obvious competition will be the Elise but that is an OTL, used 2x of the more expensive 6SN7GTs and same output tubes. Both look very interesting propositions and I may be the first to own both I don’t see it as one being better than the other  but more similar priced amps aiming at different markets but similar tubes / form factor. It will make an interesting shoot off however.
 
All told, one fine performing amp, keenly priced that is cheap to run.

To my knowledge its the first time i ear someone comment on the MK9 ,nice read thanks Nic. Last time i looked i didnt find anything on the Littledot website