Little Dot Tube Amps: Vacuum Tube Rolling Guide
Jan 15, 2021 at 9:57 AM Post #12,496 of 12,832

lupoal

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are you going to experiment with fuses?

I use to have exactly the same feeling/position you have (about cables I mean)... then because of these Covid boring days I decided to build one... and I changed my opinion about it... but I can understand, playing with tubes, that glows and are thousand all different each other, that are nice in the picture... ok, it is more fun then braid a cable

to keep it simple I'm doing both... you know curiosity is a powerful engine some times bringing unespcted surprises

I discovered that LDII is quite cable sensible ... you know, those misterious things called electrical pollution that could require shielded cable (LD one from factory isn't)... anyway, you will decide to play with fuses or not I'm happy in any case
 
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Jan 21, 2021 at 4:20 PM Post #12,497 of 12,832

Geo70

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Hi everyone. I wanted to give a warmer sound to my chain as follows: Pc-usb -> DAC-toppinge30 -> pre-ampTube-03 -> ampli-Icepower-classD final without potentiometer. Which tubes should I upgrade my Tube-03 with that can give me deep bass, not too dry bass.? I had thought of the Mullards.
Maybe there is someone here who knows the sound of the ICEpowe 125asx2 amps. Ty:)
 
Jan 22, 2021 at 10:37 AM Post #12,498 of 12,832

TrollDragon

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Hi everyone. I wanted to give a warmer sound to my chain as follows: Pc-usb -> DAC-toppinge30 -> pre-ampTube-03 -> ampli-Icepower-classD final without potentiometer. Which tubes should I upgrade my Tube-03 with that can give me deep bass, not too dry bass.? I had thought of the Mullards.
Maybe there is someone here who knows the sound of the ICEpowe 125asx2 amps. Ty:)
Very few of us here would use those cheap tube buffer amps. IMHO they are a novelty and the tubes are just a selling feature, they run with just enough voltage to get the tube to conduct and alter the sound.

The Little Dot MK 2/3/4 amps used in this thread are all tube OTL amplifiers that run at the proper voltage for optimal operation. How these tubes sound in our amps will not relate to your "tube buffer" amp as the use of tubes in those amps is mostly a gimmick.

There is a large FX-Audio thread over on Audiokarma, they would probably have better suggestions for replacement tubes.
 
Jan 23, 2021 at 3:15 PM Post #12,499 of 12,832

dtbach

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Been lurking here for awhile after getting my little dot mk3 ( not that I ever made it through all 834 pages) and have gotten a variety of driver tubes from the suggestions on the first few pages (voskod, Millard 8100 and 8161, tung sol and GE JAN). Just love what the amp can do. The one thing I will state is I just can’t hear much difference between the various tubes. I think I like the Tung Sol best but no way in heck could I ever tell what is what in a blind test. Perhaps by the time I listen to one tube, let it cool down, replace with the next one, let that one warm up I have lost all memory of the nuances of the first. Anyway my regards to you Golden Ear audiophiles! Is there a method to your techniques? On the other hand I will be saving money on tubes.
However I can readily hear differences between headphones so guess will be spending my bucks there.
 
Jan 29, 2021 at 7:21 PM Post #12,500 of 12,832

triod750

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I am happy to report very good result with 12AU7 as input tube via adapter from @Deyan to, for example, General Electric 6BX7GT, RCA 'bisquit' 6BX7GT (impressively and unexpectedly clean sound) and GEC A2293 (four of them - two per channel in adapters from @Deyan) as output tubes. Both input and output tubes get their filament feeding from external psu via adapters , all of it made by @Deyan.

I have had C3g as favourite input tubes for quite some time but they are more 'strident' in the higher registers than 12AU7/ECC82. So far I have tried one Telefunken and two Philips I already had on hand. 12AU7 gives a more relaxed listening without any impression of that something is missing.

I have something else on its way from @Deyan that might provide an alternative to C3g, also without use of external psu. I have high hopes for this, inspired by @gibosi .

Mind you, these are early impressions so don't make too much of it. I want to listen to more music before saying too much. But to me, this seems to possibly be a giant leap in sound quality to my ears. But...we are all different.

(GEC A2293 is supposed to be half a 6AS7g so two of them is a real powerhouse. Compared to the Soviet version of 6AS7g - 6H13C/6N13S - they sound a lot better. I use Sennheiser HD650 with a Mobius cable. I don't know how well these tubes mentioned would cater for the needs of more power hungry headphones. They could easily blow my brains out without sounding distorted).
 
Jan 30, 2021 at 7:21 PM Post #12,501 of 12,832

triod750

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Today , or tonight, I am trying a Ken-Rad 6N7 as input tube via adapter for external psu to cater for the filaments (and to split the dual triodes to 6AK5). The tube is totally NOS and probably needs time to show its colours but it is very promising. For this I was inspired by @mordy . @Deyan provided the neccessary adapters and I found the tube in Portugal. I have shown the adapters and psu in a previous post. The photo is taken by @Deyan.

When listening to a jazz tune a few minutes ago I could not sit still. I found myself dancing around, making all sorts of weird moves. My dog looked both disturbed and disgusted. If you had seen what she saw, you might have looked the same way. Thank you, @mordy, for the inspiration.

(This just might be a first in Dotty. One 6N7 to four A2293. Very versatile amplifier, my LD MKIVSE. I really enjoy the ride). Thank you, @Deyan, for the hardware.
 
Jan 30, 2021 at 7:27 PM Post #12,502 of 12,832

mordy

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Today , or tonight, I am trying a Ken-Rad 6N7 as input tube via adapter for external psu to cater for the filaments (and to split the dual triodes to 6AK5). The tube is totally NOS and probably needs time to show its colours but it is very promising. For this I was inspired by @mordy . @Deyan provided the neccessary adapters and I found the tube in Portugal. I have shown the adapters and psu in a previous post. The photo is taken by @Deyan.

When listening to a jazz tune a few minutes ago I could not sit still. I found myself dancing around, making all sorts of weird moves. My dog looked both disturbed and disgusted. If you had seen what she saw, you might have looked the same way. Thank you, @mordy, for the inspiration.

(This just might be a first in Dotty. One 6N7 to four A2293. Very versatile amplifier, my LD MKIVSE. I really enjoy the ride). Thank you, @Deyan, for the hardware.
In these days of quarantine exercise is very important lol!
 
Jan 31, 2021 at 4:07 AM Post #12,503 of 12,832

carrots99

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Hi, I was planning on trying either some EF91, EF92 or 6AH6 tubes on my FX Audio Tube 03, but will it make a difference (considering the fxaudio has 2-7 and 5-6 straps, hence they'll be in triode mode)? Just wanted to try something different, other then the regular Ef93 or Ef95 tubes (I've just tried a Brimar 6BE6W -and like it a lot)
Thanks
 
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Jan 31, 2021 at 2:18 PM Post #12,504 of 12,832

triod750

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Tonight I changed output tubes from A2293 with external psu to Melz 6N12S with Dotty's own transformer. While not as powerful I think this combination is truer to tone. It is a different flavour that is very transparent with more space between instruments. Ken-Rad 6N7 still used as input. Worth to remember that my A2293 has not seen much use yet. They might open up eventually. But this combination gives great twang to the strings of upright bass and great piano tones.

I will try the same setup with external psu eventually.
 
Feb 1, 2021 at 12:54 PM Post #12,505 of 12,832

triod750

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Today I have tried Melz 6N12S with Dotty's own transformer after having used the external psu for a while. Using the internal transformer gives a truer tone and more relaxed sound. I am using the 6N7 for input. This tube needs external psu but is very rewarding. I believe it to be a better match for these output tubes than C3g is. I really want to find something to better this but expect that quest to be difficult. I find myself more involved in the music - it is much easier for me to follow what is happening. I give most of the credit for this to the Melz 6N12S. I will keep on trying to find the ultimate input tube for them. I have a pair of adapters on its way to try a pair of tubes that need no external psu.
But remember, as @gibosi always reminds you, my ears and my gear.

(I have a 6N7G on its way too).

Just wanted to add that the 6N12S needs the same adapter that 6SN7 does. It has the same pinout. You can't just use it in Dotty's own sockets.
 
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Feb 1, 2021 at 3:52 PM Post #12,506 of 12,832

triod750

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I have now compared the 6N7 to the 12AU7/ECC82 as input tubes to the 6N12S. Preliminary impressions, they couldn't be anything else, is that they both sound very good. With the 12AU7 I am able to enjoy a very clean and relaxed presentation of the music. I could go on listening like forever.
With the 6N7, on the other hand, I am within the music. It's so involving and engaging that I become overwhelmed, in a good way. It's not as relaxing as the first one since it makes me really concentrate on what is going on.
In my opinion they complement each other. If I had to choose between them I would take both, since I can. If I couldn't, I would probably take the 6N7. Or...
Too early to say. But if I had to choose only one pair of output tubes, I would take the Melz 6H12C/6N12S. I haven't listened to all tubes that could be made to work in Dotty and am aware of that I can change my mind in the future but this is where I am today.

My only other experience of tube amps is Audion Silver Night 300B SET, my main amp Triod 750 Push-Pull (4x6B4G with 6922/6DJ8/ECC88 as input) and an EL84 PP. I enjoy listening to Dotty as much as listening to them. It's all about the music.
 
Feb 2, 2021 at 10:29 AM Post #12,507 of 12,832

triod750

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Right now I am listening to the same jazz recording as before, using 6N12S with internal transformer as output and a good Brimar 6SN7GT with external transformer for input. While sounding very good it's interesting to notice that the tone of the piano now comes closer to when using 6N7 and the external psu for the 6N12S. When comparing that setup with and without external psu I found the piano tone more natural without external psu for the 6N12S. This is another proof of that it is all about synergy. The piano tone in this setup is less natural. The difference isn't between bad and good, more between good and better. (I hear the same difference when concentrating on the trumpet).

I don't believe that there is one tube combination that is best for all kinds of music or for all recordings of one kind of music. Too many factors involved.
 
Feb 2, 2021 at 12:33 PM Post #12,508 of 12,832

triod750

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I'm in no way trying to give a masterclass on tubes or on Little Dot, I'm only sharing my impressions. When I first visited this topic/ thread there was an awful lot of pages written, with lots of valuable information. I read it from the beginning, a couple of hundred pages, and then decided to instead read it from the end. By doing this I could jump a lot of tubes and start with so-called end game tubes. So I haven't tried all tubes present in this thread (thanks heaven) and saved some money by doing this. That way I have some money left to spend on tubes that, to my ears, surpass those end game tubes. To my ears.

I have made these posts aiming at people new to tubes. Main message is that it is all about synergy and to trust one's ears and there is no combination that is good for everything. At least this is my conclusion. And never stop experimenting. It can be very rewarding.
_______________________

I can add that a few hours later this combination sounds a lot better; Brimar 6SN7GT as input and Melz 6N12S as output. I always find that Little Dot (MKIVSE) performs a lot better after several hours of warming up. (It might all be in my head).
 
Feb 2, 2021 at 2:00 PM Post #12,509 of 12,832

dtbach

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I'm in no way trying to give a masterclass on tubes or on Little Dot, I'm only sharing my impressions. When I first visited this topic/ thread there was an awful lot of pages written, with lots of valuable information. I read it from the beginning, a couple of hundred pages, and then decided to instead read it from the end. By doing this I could jump a lot of tubes and start with so-called end game tubes. So I haven't tried all tubes present in this thread (thanks heaven) and saved some money by doing this. That way I have some money left to spend on tubes that, to my ears, surpass those end game tubes. To my ears.

I have made these posts aiming at people new to tubes. Main message is that it is all about synergy and to trust one's ears and there is no combination that is good for everything. At least this is my conclusion. And never stop experimenting. It can be very rewarding.
_______________________

I can add that a few hours later this combination sounds a lot better; Brimar 6SN7GT as input and Melz 6N12S as output. I always find that Little Dot (MKIVSE) performs a lot better after several hours of warming up. (It might all be in my head).
I’ve had my little dot now for a couple of months and have tried mullards, voshkods, tung sol, GE, and others. I can’t tell any difference between any of them. The main reason is that there is no way to do good A/B comparisons. By the time you let the first tubes cool down, take them out, put different ones in, power on, let warm up you have at least 5-10 minutes of elapsed time. A/B comparisons need to b done in less than.2 seconds to be reliable. Have fun with tube rolling, I’ll spend my money on headphones.
 
Feb 2, 2021 at 2:29 PM Post #12,510 of 12,832

MIKELAP

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The guy having fun and sharing is findings like we all did at one point or another .Nothing wrong with that in my book .its being part of a group and trying stuff
 

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