[lostspyder]

I just got a little dot II - It's amazing. I used a PIMETA before this and it was nice, but the LDII is so smooth and lucid. Anyhow, to the point, I have a few generic questions:

1) It gets really hot (as in I can touch parts of the enclosure for only a few seconds, and I'm a 'chef'). Is that perfectly ok, or should I attempt to cool it (e.g. put a small fan blowing on it) or use it for only short periods of time?

2) Where should I get started with some tubes to roll - what kinds of tubes can I use and what kinds can't I? A link with reviews of tubes would be great too.

3) Like how long does a tube last?

4) What's the diffrence between the two big tubes and the two little ones? Is one like a buffer tube?

5) Does it need to 'warm up' before sounding its best?

 

[Penchum]

Quote:

Originally Posted by lostspyder /img/forum/go_quote.gif I just got a little dot II - It's amazing. I used a PIMETA before this and it was nice, but the LDII is so smooth and lucid. Anyhow, to the point, I have a few generic questions: 1) It gets really hot (as in I can touch parts of the enclosure for only a few seconds, and I'm a 'chef'). Is that perfectly ok, or should I attempt to cool it (e.g. put a small fan blowing on it) or use it for only short periods of time? 2) Where should I get started with some tubes to roll - what kinds of tubes can I use and what kinds can't I? A link with reviews of tubes would be great too. 3) Like how long does a tube last? 4) What's the diffrence between the two big tubes and the two little ones? Is one like a buffer tube? 5) Does it need to 'warm up' before sounding its best?

Hi! The heat is a normal byproduct, so don't worry. Make sure it has room around it for air circulation, and you'll be ok.

There is a bunch of information about tube rolling the MKII and MKIII (they use the same tubes) in the MKIII tube rolling thread here: http://www.head-fi.org/forums/f5/lit...olling-276757/

Most tubes will last for years and years.

The big ones in the back are power tubes, the ones in the front are driver tubes. More info in the MKIII tube rolling thread.

Most folks will turn on their tube amp, wait maybe 30-45 seconds, then play away.

 

[Dept_of_Alchemy]

Quote:

Originally Posted by lostspyder /img/forum/go_quote.gif 2) Where should I get started with some tubes to roll - what kinds of tubes can I use and what kinds can't I? A link with reviews of tubes would be great too.

Welcome to the little dot family, I'm glad that the word about little dot's performance is getting out to new people.

As to where to find quality tubes, I'd recommend looking here eBay Store - Yen Audio: Little Dot, Upgrade Tubes, Little Dot headphone amp, I've gotten some very nice sounding tubes from them and their service is amazing, I think that's probably where most LD owners get their upgrade tubes.

Tube life depends on the specific tube you're using, some Mullard tubes (like M8161 and M8100) are rated at 5000+ hours, Joint Army-Navy (JAN) tubes are also rated at 5000+ hours, expect normal tubes like the stock GE 6AK5 to last about half as long. The power tubes have considerably shorter life than the driver tubes and you should expect the stock Chinese 6H6 to fail in one to two years under normal-heavy use (which probably isn't a bad thing considering the 6H6 is quite poor sounding compared to the premium Russian 6H30PI tubes and having the stocks fail just gives the impetus to upgrade).

 

[lostspyder]

Its not a little dot MK II, its just a "little dot II+" - does that make a diffrence?

Quote:

Originally Posted by Penchum /img/forum/go_quote.gif Hi! The heat is a normal byproduct, so don't worry. Make sure it has room around it for air circulation, and you'll be ok. There is a bunch of information about tube rolling the MKII and MKIII (they use the same tubes) in the MKIII tube rolling thread here: http://www.head-fi.org/forums/f5/lit...olling-276757/ Most tubes will last for years and years. The big ones in the back are power tubes, the ones in the front are driver tubes. More info in the MKIII tube rolling thread. Most folks will turn on their tube amp, wait maybe 30-45 seconds, then play away.

 

[Tech2]

Nevermind.

I posted a response thinking you had an original Little Dot II, not a "+" model.

 

[Penchum]

Quote:

Originally Posted by lostspyder /img/forum/go_quote.gif Its not a little dot MK II, its just a "little dot II+" - does that make a diffrence?

Yes, but only in the tube rolling possibilities. Better ask DoA or Negatron about what is possible. They know the most from that model amp.
Good luck!!!

 

[Dept_of_Alchemy]

Quote:

Originally Posted by lostspyder /img/forum/go_quote.gif Its not a little dot MK II, its just a "little dot II+" - does that make a diffrence?

With the LDII your tube rolling option is limited to 4P1S power tube and EF92 driver tubes. Both are rollerable and there are plenty of choices from the link I provided above. MY new favorite(ish) is the United Electron EF92, it offers a more neutral sense of balance across the spectrum than the Mullards (which tend to have an emphasis on bass in comparison) in my opinion.

EDIT: The LDII+ uses the 4P1S power tube, my bad.

 

[strangedaze39]

Glad it found a good home

1) It gets really hot (as in I can touch parts of the enclosure for only a few seconds, and I'm a 'chef'). Is that perfectly ok, or should I attempt to cool it (e.g. put a small fan blowing on it) or use it for only short periods of time?

Thats normal, just make sure to keep it out of really small shelving units with no back on them while it's turned on.

2) Where should I get started with some tubes to roll - what kinds of tubes can I use and what kinds can't I? A link with reviews of tubes would be great too.
Not to keen on where to pick them up but the other users mentioned the Little Dot MK II tube rolling forums thats probably the best place for info on that. Also I would recommend for current use, you use the Russian Tubes. IMO they sound much better then the stock tubes.

3) Like how long does a tube last?
Something like 3,000 to 5,000 hours ? Correct me if I'm wrong. The tubes I sent it with probably only have around 300 hours on them right now.

4) What's the diffrence between the two big tubes and the two little ones? Is one like a buffer tube?
Big ones= Power Tubes/Little ones= Driver Tubes

5) Does it need to 'warm up' before sounding its best?

Normally I would turn it on with the volume down let it warm up for 10-20 seconds and turn up the volume.

 

[GotNoRice]

I see the potential for confusion in this thread.

First, let’s clear up the model history of the Little-Dot II Amps (Focusing on the “II” series and successors)

Little-Dot II - Used 4P1S Directly Heated Pentodes as Triodes for power tubes and Chinese 1B2 or 1K2 driver tubes depending on reversion. Known tube rolling options for this model are to swap the Chinese 4P1S power tubes with Russian 4P1L Power Tubes and there are perhaps replacements for the 1B2 and 1K2 tubes. I know they aren’t interchangeable with each other without a jumper or soldier switch but I unfortunately don’t know anything more about that.

Little-Dot II+ - Used 4P1S Directly Heated Pentodes as Triodes for power tubes but switched to using EF92 tubes as driver tubes. Known tube rolling options for this model are to swap the Chinese 4P1S power tubes with 4P1L power tubes. Driver tubes can be swapped with any EF92 equivalent and there are many available. For more information on my comparison between 4P1S and 4P1L tubes on this model see my post in this thread: http://www.head-fi.org/forums/3714271-post10.html

Little-Dot II++ - This unit constituted a rather large design change from previous models. Rather than using directly heated pentodes as triodes, it uses indirectly-heated triodes; 6C19 Power tubes. It uses EF92 Driver tubes. Tube rolling options are to use Russian 6S19P-V (looks like 6C19n-B in crylic) for power tubes and any EF92 tube for the driver tubes.

The little Dot MKII used another model of power tube as well, but I’m not familiar with it. It can use both EF92 as well has EF95 driver tubes via jumpers.

My main point here is that not all Little-Dot II units used the same power tubes, it’s important to be careful before giving advice to someone to upgrade their power tubes. Telling someone with a Little-Dot II+ to go out and buy a pair of 6C19 tubes is obviously bad advice as those won’t even fit. If a II+ is the model you indeed have then your only upgrade option is the 4P1L.

As far as temperatures go, I wouldn’t worry about it too much, but at the same time I wouldn’t run the unit without at least some air circulation in the room such as a desk or ceiling fan and probably not on a hot summer day without A/C. I've run my II+ for about 2 years and haven't had a single tube fail yet, though I swap tubes around fairly often. I notice the Directly heated units such as II+ produce sound instantly while the Indirectly heated such as the II++ units require 5-10 seconds of warm-up before they begin to produce sounds

 

[tjohnusa]

I have a model II and love it. I recieved 3 sets of tubes with my amp and recently swapped out all 4 tubes with another set and man what a difference. They are all the same numbers as the stock tubes but they sound much more detailed and a little louder. I also had some wood sides and top for the transformer cover made up out of maple and picked up a pair of tube guards for the driver tubes. Makes the amp look expensive! I will try to posts some pix saturday. I can imagine many amps sound better than this one but I am happy with my $110 investment. I don't have the heat issues with ny amp that I have read about.

 

[Dannygillis]

I have a LD II with the 1K2 drivers.    Do you know whether these driver tubes should glow or get warm?   The amp seems to work well, runs very hot, but the drivers do not get warm at all.    The power tubes run very hot as they should and the entire case also.     If the drivers weren't working should the amp function at all.      I am puzzled.