To be honest, I didn't know whether to put this review in the Burson V6 Vivid or Little Dot LD-1+ sections or simply treat it as an ode to tube/opamp rolling. I ended up putting it here because Burson was the driver that made me write it (DISCLAIMER: Burson provided me with a Burson v6 Vivid free sample in exchange for my honest feedback).
So here goes.
Since I was a kid, I've always been interested in collections. I don't quite know how to explain why, maybe because it's a way of learning from everyday things that pass through our hands, or because I like to scrutinize and catalog everything. Pocket calendars, stickers, stamps, coins, cans, beer coasters—I collected everything. As I entered adulthood, my collecting interests shifted to things I could use and not just collect: watches, fountain pens, and music, lots of music. I grew up surrounded by music. My father had an enviable collection (there's the word again) of vinyl, and, naturally, the taste for various styles of music grew, such as vinyl, cassettes, CDs, and, later, all kinds of digital formats on the computer.
When I was looking for an amplifier for my headphones, I guess my relationship with collections, unconsciously, came to the surface. I knew I wanted a tube amp to experience the richness, depth, and smoothness that are normally associated with this type of equipment. But which one?
After some research, I found the Little Dot LD 1+. According to the manufacturer, "The Little Dot 1+ is a hybrid transistor-vacuum tube headphone amplifier, which combines the smooth, musical sound of tubes with the high output current of transistors. The vacuum tube stage is run in Class-A, the MC33078 operational amplifier (socketed) provides voltage amplification, and BD139/BD140 transistors serve as output buffers."
Wait a minute, is it a hybrid? Is it possible to change the opamp in addition to the tubes? And on top of that, they say it plays well? Furthermore, I found a thread here on Head-Fi, still alive today, about tube rolling in Little Dot (https://www.head-fi.org/threads/little-dot-tube-amps-vacuum-tube-rolling-guide.563884/). There are more than 800 pages of experimentation with every conceivable tubes. This is what I need!
The Little Dot did not disappoint. I bought it with 408A and 6AK5 tubes and immediately started experimenting with some opamps I had at home. The sound matched to what I had read: the tube warmth was there, but the original opamp was boring. As the LD 1+ is a hybrid amplifier, either changing opamps or tubes brought new sounds, and I quickly learned that not all opamps match well with certain tubes and vice versa. Of all the combinations I had tried so far, the one I liked the most was the National Semiconductor LME49720NA with the Soviet Voskhod 6Zh1P-ЕV tubes. With this combo, the soundstage changed radically for the better and effortlessly took my HE4XX to a sound quality that I hadn't experienced yet.
And then there was this invitation from Burson to review one of their opamps. I had never tried a discrete opamp (for those unfamiliar with the concept check this link: https://www.bursonaudio.com/about-us/discrete-opamp/) and the expectations were high. I was asked which one I would like to try, and after seeing a comparison on their website, I ended up choosing the v6 Vivid because "Color & Texture" are characteristics that tubes easily bring to the table. It would be more interesting to understand what we can get from their opamps in terms of "Transparency", "Details" and "Dynamic & Soundstage".
Since the Vivid is significantly larger than a traditional opamp, I asked Burson to send me an extension that would allow me to close the Little Dot box after installing it. It worked like a charm.
Countless reviews have already been made of both the LD 1+ and the V6 Vivid, so I did something different. Bearing in mind that the quality of both products has already been duly scalped, how about finding the best pair (spoiler alert: it wasn't a pair) of tubes for this opamp? But before that, nothing like test the Vivid with my favorite tubes so far, the Voskhod 6Zh1P-ЕV.
These tubes were manufactured in March 1988 by the Voskhod Tube Factory in Kaluga, Russia. The company still exists today, but apparently no longer manufactures tubes. Compared to the original tubes of the LD 1+, these Soviet ones brought much more spectacular dynamics, capable of covering all frequencies effortlessly with clarity and a vastly improved soundstage. The only thing to point out is some aggressiveness in the highs, especially with regard to female voices. All this with the LME49720. How would Vivid cope with these tubes?
I'd say it was anticlimactic. Yes, the sound had improved slightly. A sense of bigger depth and greater detail in the highs. The bass remained powerful, but some of the attack the LME provided was lost, especially in Mombassa from the excellent Inception soundtrack. For an opamp that costs 20x more, I was expecting a more significant change. But experience dictates that one opamp doesn't always goes with a particular tube. The first time I heard the Voskhods was with a Linear LT1364 and I didn't like the combination at all.
So I went ahead with the plan of finding the best tube for the Vivid. Since (so far
) I have 41 different tubes, I did the "highly scientific" experience of trying them all for a few minutes with the Burson and choosing the ones that sounded best to me so that I could, with more calm and time, see if we had a winner. Here's the 6 ones that qualified for the next stage:
I started with other Soviet tubes, this time the Novosibirsk 6S2S, manufactured in the factory with the same name in Russia in May 1974.
As you may have noticed, these tubes are completely different from the "normal" ones used in the LD 1+. The beauty of this amp is that, with all the tube rolling experimentation (the first post on the thread I told you about is almost 12 years old!) and knowledge sharing, many adapters were made (or if they don't exist, they can be made) for countless types of tubes. In this case, I used two adapters: one that allows the use of double triodes from the 12AU7 family and another that allows the use of octal-based triodes from the 6J5G family. The sound has improved compared to Voskhods. The highs were even more detailed, especially with female voices. The cymbals on People Ain't no Good were tremendous. However, some strength was lost in bass. It looks like we were on the right track.
I left the adapter for double triodes (this time in the position compatible with the 6DJ8 family) in Little Dot and placed the next tube. This time it really is just one tube, as the adapter "transforms" the double triode into two isolated triodes.
After the Soviets, we moved to the United States with RCA. Well, actually, we moved to England, as this 6ES8 was manufactured by Mullard at their Blackburn factory, in the first week of March 1965 (if you are curious about this exactness, see here how to determine these dates: https://mullard.org/blogs/news/mullard-valve-etched-codes-how-to-interpret-them). And here, everything has changed. I stopped recognizing the Little Dot. The airy entrance of the strings of Albeniz's Asturias immediately made it clear that we were facing something different. Immediately afterwards, when the brass section enters, the attack is just breathtaking. With To Die Among Strangers, acoustic guitars, Jérôme Reuter's voice and the percussion were perfectly combined in a phenomenal soundstage. In addition, the whole texture felt like a real tube sound: full, rich and enveloping. I had read a lot about the qualities of Mullards, but I had never experienced such a thing with other opamps.
Could it be improved with other tubes?
The next ones to test were the Elektronska Industrija 6HM5 tubes, manufactured in Yugoslavia, more precisely in Niš, present-day Serbia. Once again, these are highly recommended tubes in the tube rolling thread. They had a great time with Vivid, doing what they do best: bringing female voices to shine. Lisa Gerrard's voice on Sanvean was simply superb, as natural as you can have it. However, as I've noticed with other opamps, some bass punch is lacking, and the highs can be slightly sibilant.
I was very curious about the next tubes, the Mazda 6CB6, manufactured in France by Compagnie des Lampes, probably in the 60s. They had been the ones who had so far held their own with the LME49720 when it came to bass extension. They turned out to be a disappointment. A very large predominance in the mids with muddy highs. The soundstage also left something to be desired. In short, little finesse.
The ones that followed were the Mullard M8083, this time manufactured in another factory, in Mitcham, in the 3rd week of May 1977. The sound ended up, curiously, not being very different from the RCA also manufactured by Mullard. Engaging and warm, it made an excellent impression on the imaging with Juan del Enzina's Renaissance song. I ended up liking the RCA better because of a slight too forward highs.
Finally, the Hitachi 6AV6, double diode-triodes whose some pins have to be cut so that they can play in the Little Dot (no tubes were harmed in the making of this review. I use tube savers with the pins cut instead).
They turned out to be the biggest disappointment. Very opaque, with a weak attack, all very edgy and culminating in the female voices of Hedningarna sounding with enormous stridency.
In short, the RCA (or should I say Mullard) was the winner of the match. It managed to transform the Little Dot into an amplifier comparable to models several times more expensive. I am, however, aware that this would not be possible without Vivid. The soundstage and imaging, as well as the full, velvety sound, didn't just come from the tube, as I had heard it before with other opamps. For that reason, I can't help but highly recommend the Burson V6 Vivid.
Gear used in the review:
Foobar2000 -> Topping E30 II -> Little Dot LD 1+ -> Hifiman HE4XX
My opamp/tube rolling test playlist:
Isaac Albéniz - Asturias (from Suite Española) - First Impression Music FIM XR24 068
Rome - To Die Among Strangers (from To Die Among Strangers) - Trisol TRI 361 CD
Nick Cave & The Bad Seeds - People Ain't No Good (from The Boatman's Call) - Mute CD Stumm 142
Hans Zimmer - Mombasa (from Inception) - Reprise 524667-2
Juan del Enzina - Una Sañosa Porfía (from Romances & Villancicos) - Astrée Auvidis E 8707
Dead Can Dance - Sanvean (from Toward the Within) - 4AD DAD 4015CD
Hedningarna - Joupolle Joutunut (from Kaksi!) - Xource XOUCD 101
So here goes.
Since I was a kid, I've always been interested in collections. I don't quite know how to explain why, maybe because it's a way of learning from everyday things that pass through our hands, or because I like to scrutinize and catalog everything. Pocket calendars, stickers, stamps, coins, cans, beer coasters—I collected everything. As I entered adulthood, my collecting interests shifted to things I could use and not just collect: watches, fountain pens, and music, lots of music. I grew up surrounded by music. My father had an enviable collection (there's the word again) of vinyl, and, naturally, the taste for various styles of music grew, such as vinyl, cassettes, CDs, and, later, all kinds of digital formats on the computer.
When I was looking for an amplifier for my headphones, I guess my relationship with collections, unconsciously, came to the surface. I knew I wanted a tube amp to experience the richness, depth, and smoothness that are normally associated with this type of equipment. But which one?
After some research, I found the Little Dot LD 1+. According to the manufacturer, "The Little Dot 1+ is a hybrid transistor-vacuum tube headphone amplifier, which combines the smooth, musical sound of tubes with the high output current of transistors. The vacuum tube stage is run in Class-A, the MC33078 operational amplifier (socketed) provides voltage amplification, and BD139/BD140 transistors serve as output buffers."
Wait a minute, is it a hybrid? Is it possible to change the opamp in addition to the tubes? And on top of that, they say it plays well? Furthermore, I found a thread here on Head-Fi, still alive today, about tube rolling in Little Dot (https://www.head-fi.org/threads/little-dot-tube-amps-vacuum-tube-rolling-guide.563884/). There are more than 800 pages of experimentation with every conceivable tubes. This is what I need!
The Little Dot did not disappoint. I bought it with 408A and 6AK5 tubes and immediately started experimenting with some opamps I had at home. The sound matched to what I had read: the tube warmth was there, but the original opamp was boring. As the LD 1+ is a hybrid amplifier, either changing opamps or tubes brought new sounds, and I quickly learned that not all opamps match well with certain tubes and vice versa. Of all the combinations I had tried so far, the one I liked the most was the National Semiconductor LME49720NA with the Soviet Voskhod 6Zh1P-ЕV tubes. With this combo, the soundstage changed radically for the better and effortlessly took my HE4XX to a sound quality that I hadn't experienced yet.
And then there was this invitation from Burson to review one of their opamps. I had never tried a discrete opamp (for those unfamiliar with the concept check this link: https://www.bursonaudio.com/about-us/discrete-opamp/) and the expectations were high. I was asked which one I would like to try, and after seeing a comparison on their website, I ended up choosing the v6 Vivid because "Color & Texture" are characteristics that tubes easily bring to the table. It would be more interesting to understand what we can get from their opamps in terms of "Transparency", "Details" and "Dynamic & Soundstage".
Since the Vivid is significantly larger than a traditional opamp, I asked Burson to send me an extension that would allow me to close the Little Dot box after installing it. It worked like a charm.
Countless reviews have already been made of both the LD 1+ and the V6 Vivid, so I did something different. Bearing in mind that the quality of both products has already been duly scalped, how about finding the best pair (spoiler alert: it wasn't a pair) of tubes for this opamp? But before that, nothing like test the Vivid with my favorite tubes so far, the Voskhod 6Zh1P-ЕV.
These tubes were manufactured in March 1988 by the Voskhod Tube Factory in Kaluga, Russia. The company still exists today, but apparently no longer manufactures tubes. Compared to the original tubes of the LD 1+, these Soviet ones brought much more spectacular dynamics, capable of covering all frequencies effortlessly with clarity and a vastly improved soundstage. The only thing to point out is some aggressiveness in the highs, especially with regard to female voices. All this with the LME49720. How would Vivid cope with these tubes?
I'd say it was anticlimactic. Yes, the sound had improved slightly. A sense of bigger depth and greater detail in the highs. The bass remained powerful, but some of the attack the LME provided was lost, especially in Mombassa from the excellent Inception soundtrack. For an opamp that costs 20x more, I was expecting a more significant change. But experience dictates that one opamp doesn't always goes with a particular tube. The first time I heard the Voskhods was with a Linear LT1364 and I didn't like the combination at all.
So I went ahead with the plan of finding the best tube for the Vivid. Since (so far
) I have 41 different tubes, I did the "highly scientific" experience of trying them all for a few minutes with the Burson and choosing the ones that sounded best to me so that I could, with more calm and time, see if we had a winner. Here's the 6 ones that qualified for the next stage:
I started with other Soviet tubes, this time the Novosibirsk 6S2S, manufactured in the factory with the same name in Russia in May 1974.
As you may have noticed, these tubes are completely different from the "normal" ones used in the LD 1+. The beauty of this amp is that, with all the tube rolling experimentation (the first post on the thread I told you about is almost 12 years old!) and knowledge sharing, many adapters were made (or if they don't exist, they can be made) for countless types of tubes. In this case, I used two adapters: one that allows the use of double triodes from the 12AU7 family and another that allows the use of octal-based triodes from the 6J5G family. The sound has improved compared to Voskhods. The highs were even more detailed, especially with female voices. The cymbals on People Ain't no Good were tremendous. However, some strength was lost in bass. It looks like we were on the right track.
I left the adapter for double triodes (this time in the position compatible with the 6DJ8 family) in Little Dot and placed the next tube. This time it really is just one tube, as the adapter "transforms" the double triode into two isolated triodes.
After the Soviets, we moved to the United States with RCA. Well, actually, we moved to England, as this 6ES8 was manufactured by Mullard at their Blackburn factory, in the first week of March 1965 (if you are curious about this exactness, see here how to determine these dates: https://mullard.org/blogs/news/mullard-valve-etched-codes-how-to-interpret-them). And here, everything has changed. I stopped recognizing the Little Dot. The airy entrance of the strings of Albeniz's Asturias immediately made it clear that we were facing something different. Immediately afterwards, when the brass section enters, the attack is just breathtaking. With To Die Among Strangers, acoustic guitars, Jérôme Reuter's voice and the percussion were perfectly combined in a phenomenal soundstage. In addition, the whole texture felt like a real tube sound: full, rich and enveloping. I had read a lot about the qualities of Mullards, but I had never experienced such a thing with other opamps.
Could it be improved with other tubes?
The next ones to test were the Elektronska Industrija 6HM5 tubes, manufactured in Yugoslavia, more precisely in Niš, present-day Serbia. Once again, these are highly recommended tubes in the tube rolling thread. They had a great time with Vivid, doing what they do best: bringing female voices to shine. Lisa Gerrard's voice on Sanvean was simply superb, as natural as you can have it. However, as I've noticed with other opamps, some bass punch is lacking, and the highs can be slightly sibilant.
I was very curious about the next tubes, the Mazda 6CB6, manufactured in France by Compagnie des Lampes, probably in the 60s. They had been the ones who had so far held their own with the LME49720 when it came to bass extension. They turned out to be a disappointment. A very large predominance in the mids with muddy highs. The soundstage also left something to be desired. In short, little finesse.
The ones that followed were the Mullard M8083, this time manufactured in another factory, in Mitcham, in the 3rd week of May 1977. The sound ended up, curiously, not being very different from the RCA also manufactured by Mullard. Engaging and warm, it made an excellent impression on the imaging with Juan del Enzina's Renaissance song. I ended up liking the RCA better because of a slight too forward highs.
Finally, the Hitachi 6AV6, double diode-triodes whose some pins have to be cut so that they can play in the Little Dot (no tubes were harmed in the making of this review. I use tube savers with the pins cut instead).
They turned out to be the biggest disappointment. Very opaque, with a weak attack, all very edgy and culminating in the female voices of Hedningarna sounding with enormous stridency.
In short, the RCA (or should I say Mullard) was the winner of the match. It managed to transform the Little Dot into an amplifier comparable to models several times more expensive. I am, however, aware that this would not be possible without Vivid. The soundstage and imaging, as well as the full, velvety sound, didn't just come from the tube, as I had heard it before with other opamps. For that reason, I can't help but highly recommend the Burson V6 Vivid.
Gear used in the review:
Foobar2000 -> Topping E30 II -> Little Dot LD 1+ -> Hifiman HE4XX
My opamp/tube rolling test playlist:
Isaac Albéniz - Asturias (from Suite Española) - First Impression Music FIM XR24 068
Rome - To Die Among Strangers (from To Die Among Strangers) - Trisol TRI 361 CD
Nick Cave & The Bad Seeds - People Ain't No Good (from The Boatman's Call) - Mute CD Stumm 142
Hans Zimmer - Mombasa (from Inception) - Reprise 524667-2
Juan del Enzina - Una Sañosa Porfía (from Romances & Villancicos) - Astrée Auvidis E 8707
Dead Can Dance - Sanvean (from Toward the Within) - 4AD DAD 4015CD
Hedningarna - Joupolle Joutunut (from Kaksi!) - Xource XOUCD 101
