[Cognomen]

Hola Juan

I'm not the best person to reply since I own a hybrid, but my feeling is, after reading many pages in this thread, that the power tubes don't affect the sound as much as the drivers. Probably someone who rolled both power and driver tubes can elaborate more on the subject.

MK2 and MK3 indeed use power tubes. You can check the current Little Dot line-up here: https://littledot.net/

Yes, as a Little Dot III owner, I agree that commonly used affordable plug and play power tubes tend to affect the sound less than driver tubes. Nonetheless, I notice differences in sound. And, I find there can be more variation in sound with power tubes that require adapters/converters. Matching can be important there because some power tubes do not have enough power for some headphones.

 

[califmike33]

Looking to find out what fuse this little dot mark ii uses ? i what fuse, but i dont know what amp fuse ?

 

[Whelkie D]

Looking to find out what fuse this little dot mark ii uses ? i what fuse, but i dont know what amp fuse ?

It is a 1 amp fuse I believe. (see page 6 of this... http://www.popular-hifi.com/projects/nad_stereo/little_dot/little_dot_mk2_manual.pdf )

 

[califmike33]

I found the correct fuse thank you amplifier still blows the fuse out every time I turn it on.

 

[TrollDragon]

I found the correct fuse thank you amplifier still blows the fuse out every time I turn it on.

Does it blow the fuse with the tubes removed?

 

[califmike33]

Yes

 

[califmike33]

I'm at work right now but you know what from reading the manual on this amp it seems like they tell you to plug in your headphones turn the volume down before you even turn it on I'm wondering if you have to have the headphones plugged in I haven't tried that it sounds stupid but I'm wondering could you test yours and tell me if it turns on without the headphones?

 

[TrollDragon]

I'm at work right now but you know what from reading the manual on this amp it seems like they tell you to plug in your headphones turn the volume down before you even turn it on I'm wondering if you have to have the headphones plugged in I haven't tried that it sounds stupid but I'm wondering could you test yours and tell me if it turns on without the headphones?

I never plug my headphones in before turning it on, it is an OTL amplifier it doesn't need a load like transformer amps do.

I power on the MK IV, let it warm up for 5 minutes then plug my headphones in. Increase the volume from zero and enjoy. When tuning the amp off I set the volume back to zero, unplug the headphones and power off.

If you're is blowing fuses without tubes installed them there is something wrong on the board.

 

[califmike33]

Found out the Transformer is fried, she is going in the trash can.

 

[Cognomen]

I never plug my headphones in before turning it on, it is an OTL amplifier it doesn't need a load like transformer amps do.

I power on the MK IV, let it warm up for 5 minutes then plug my headphones in. Increase the volume from zero and enjoy. When tuning the amp off I set the volume back to zero, unplug the headphones and power off.

If you're is blowing fuses without tubes installed them there is something wrong on the board.

I have two Little Dot MkIII's. Can I use one as just an outboard power supply for breadboards? Specifically could I use the heaters for power tubes in one unit to heat driver tubes on breadboards that require more than .4aH and not more than 1.0aH?

 

[califmike33]

Ok thanks, the transformer is fried amp is trash.

 

[TrollDragon]

I have two Little Dot MkIII's. Can I use one as just an outboard power supply for breadboards? Specifically could I use the heaters for power tubes in one unit to heat driver tubes on breadboards that require more than .4aH and not more than 1.0aH?

I don't see any problem doing that with your spare amp.

 

[zuio]

Are there good new production tubes available?. Because the NOS tube stock will be gone one day...

 

[Cognomen]

Are there good new production tubes available?. Because the NOS tube stock will be gone one day...

Yes, companies are manufacturing brand new tubes per this link:

https://www.thetubestore.com/tube-brands

I have a Little Dot mkIII and can buy a full complement of new tubes for it that are plug and play. People here mostly listen to old less expensive tubes. I don't know that anyone here has specialized in collecting new tubes and assessing their sound quality. With $10-$15 adapters there are dozens of brand new tubes that I could roll.

Technology seems either immortal or that it will live as long as our species survives. Kevin Kelly has written about how he cannot identify any technology that is no longer still being made by mankind. We are still making chert arrowheads like cave man. The other day I discovered a company that is making new 78 rpm records.

I know a nearby tube dealer that bought 6 semi trucks full of tubes a couple of years ago. He seems to list 100-200 at a time on eBay and undercuts other prices because he wants to sell them fairly quickly. I doubt he will sell all of them doing that during his lifetime. I know of another that bought 3 semi-trucks and has been working on selling them for over a decade and claims he has over 5,000 different tubes for sale. Despite almost 900 pages on this forum, I think that if one takes into account different brands and types of tubes and disparate production dates that may sound different, tube rolling ingenuity and that different combinations of tubes and/or op amps may have synergy or not that there are many more tubes that can be rolled in the little dots than discussed here. The limitation is probably not running out of supply but money and time to listen.

Closing while listening to tubes rated for 10,000 hours. I have about 100 hours on them. If I play them for 3 hours per day, they are rated to last about 10 years, unless they last longer because of probably gentler use than their initial purpose: industrial and the military. While my 12 year old little dot is still running strong, it's conceivable, the tubes would outlast the amp. If the amp outlasted them, I have a couple more sets rated for 10,000 hours.

 

[mordy]

Yes, companies are manufacturing brand new tubes per this link:

https://www.thetubestore.com/tube-brands

I have a Little Dot mkIII and can buy a full complement of new tubes for it that are plug and play. People here mostly listen to old less expensive tubes. I don't know that anyone here has specialized in collecting new tubes and assessing their sound quality. With $10-$15 adapters there are dozens of brand new tubes that I could roll.

Technology seems either immortal or that it will live as long as our species survives. Kevin Kelly has written about how he cannot identify any technology that is no longer still being made by mankind. We are still making chert arrowheads like cave man. The other day I discovered a company that is making new 78 rpm records.

I know a nearby tube dealer that bought 6 semi trucks full of tubes a couple of years ago. He seems to list 100-200 at a time on eBay and undercuts other prices because he wants to sell them fairly quickly. I doubt he will sell all of them doing that during his lifetime. I know of another that bought 3 semi-trucks and has been working on selling them for over a decade and claims he has over 5,000 different tubes for sale. Despite almost 900 pages on this forum, I think that if one takes into account different brands and types of tubes and disparate production dates that may sound different, tube rolling ingenuity and that different combinations of tubes and/or op amps may have synergy or not that there are many more tubes that can be rolled in the little dots than discussed here. The limitation is probably not running out of supply but money and time to listen.

Closing while listening to tubes rated for 10,000 hours. I have about 100 hours on them. If I play them for 3 hours per day, they are rated to last about 10 years, unless they last longer because of probably gentler use than their initial purpose: industrial and the military. While my 12 year old little dot is still running strong, it's conceivable, the tubes would outlast the amp. If the amp outlasted them, I have a couple more sets rated for 10,000 hours.

Vacuum tubes were manufactured in the millions. If you have patience even the
most rare ones will turn up sooner or later.
In the mild use these tubes see in our amps they could last for decades. Several tube amp owners report using the same tubes for 20 years and they are still good.
IMHO you are more likely to lose a tube by dropping it and breaking it than wearing it out.