Little Dot I+ Tube Rolling
Oct 29, 2020 at 3:11 AM Post #3,122 of 3,129

GotNoRice

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I decided to try a Burson V6 Classic in my Little-Dot I+. My goal is to put them in my DAC but I don't have three of them yet, so I figured I might as well give it a whirl in my Little-Dot I+. I was happy with the results. Here is my little mini-review:

History:

A while back, when deciding which Opamp to use in my Little-Dot I+ Headphone amplifier, I had narrowed down my favorite opamps to the LM4562 (dual opamp) and the OPA627 (two single OPA627 opamps on an adapter board). The LM4562 had a texture to the sound that I enjoyed, but was also just a little bit harsh. The OPA627 was very smooth, but almost too smooth, and lacking texture. I generally preferred the LM4562. The Burson V6 Classic Dual seemed to be the next step up, but I was not actually sure what to expect.

My system:
-Maverick Audio TubeMagic D2 DAC (Sylvania 5654W tube & 3x LM4562 Opamp)
-Little-Dot I+ (Sylvania "Gold Brand" 408A tubes)
-Beyerdynamic DT770-Pro 80ohm / Sony MDR-XB700 24ohm headphones.

First impressions:

The Burson V6 Classic Opamps come in wonderful packaging, also containing an optional riser. The riser was very helpful in keeping the Burson Opamp up above the other components on the circuitry on the Little-Dot I+ (at least with my PCB version).

Case with one Opamp and one riser removed:


When playing the first song after installing the Burson V6 Classic, what I noticed immediately was that the sound just seemed a bit more energetic, especially vocals, and making for some very punchy midbass. Thinking back to my previous comparison between opamps, this Burson seems to have both the smoothness of the OPA627 while having even more texture than the LM4562; truly a best of both worlds, and more.

Unfortunately, the V6 Opamp is so large that the bottom of the case for the Little-Dot I+ won’t close with it installed (and the riser only makes it worse). As I have seen in other reviews, some have simply cut a hole in the bottom of the case, others have used custom extensions/adapters to use the Opamp at an angle. I will have to decide which route I want to take, but for now, I will simply use my Little-Dot I+ on its side.







Extended listening:

First, I went through some Hard Rock and Metal using my Beyerdynamic DT770-Pro 80ohm headphones. I use many of these songs as my benchmark to test vocals, to see if the vocals can retain their clarity and energy even in the middle of a very “busy” song. The Burson V6 Classic had no problems passing this test. There was no accentuated treble either, and listening fatigue was not an issue even after a long session.

Next, I swapped over to my Sony MDR-XB700 24ohm headphones. These have very large drivers, and at 24 ohms the Little-Dot I+ can put out almost a full watt. I use this for listening to music with very deep bass, including some Pop, Hard Rock, EDM and Dubstep. Bass can have a texture of its own, and I have observed differences between Opamps in this regard before. Using the Burson V6 Classic, I did not notice anything special about the deep bass. But at least, it didn’t seem to be doing anything worse than past Opamps that I have tried, and even bass-heavy songs still have plenty of midrange and midbass that clearly does benefit.

Conclusion:

My experience with this Burson V6 Classic Dual Opamp has been fantastic. Everything about my listening experience was either equal to, or better than, every past opamp that I have tried.

The tall size does make installation in devices such as a Little-Dot I+ a challenge without getting creative, but in my opinion, It’s worth it.

Ultimately, I really look forward to trying these in my DAC also and seeing if they make a noticeable change there as well.
 
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Oct 30, 2020 at 6:02 PM Post #3,123 of 3,129

Onik

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Just had chance to take picture of these two revs of Ld i+ before I'm going to sell the old ones, and as you can see the older(v_2.0) models have smaller transformer than the latest models(rev 4.0).

Not really an expert with tube amps I can say this for sure that the new model is an improved version of LD i+ but why Little dot choosed to change the size of this amps transformer?

I only used the new ones rev 4.0 because it didn't have any buzzing noise/gnd loop issues at high gain mode like the old ones, but I didn't really hear significant SQ difference between this two when using same tubes.

20201030_214331.jpg
 
Nov 9, 2020 at 10:55 AM Post #3,124 of 3,129

brucew268

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I just received an LD1+ with Mullard M8161's from someone who probably bought it off of Drop, since it only has 40 hours on it and is a v4.0 board. Nice and quiet and so far not overly bothered about by LCD monitor inches away or my smartphone about 18 inches away.

Here is what I'm noticing and wonder which direction will gain more benefits:
In intimate musical settings, simple jazz trios, etc. it presents with a little bit of depth and space around the instruments and voices, though not especially obvious. But it doesn't scale up very well. When the music gets complex and/or loud the sense of space between the instruments is lost and it gets slightly muddy. In upper mids it sometimes gets a little strained.

These are mostly noticeable by comparison to the ifi Zen amp (Class A) I was just listening through, and I'm listening on M1060 planars 50Ω, 96dB sens.

So I could get any of the following to see how much each will address what I'm hearing:
  • Silicone o-ring dampers
  • Damping feet or base below the amp
  • Change opamp to OPA2107
  • Try other tubes, like 6HM5 Yugoslavian

...or I might be asking too much of a $100 hybrid.
 
Nov 19, 2020 at 11:20 AM Post #3,125 of 3,129

brucew268

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Perhaps everyone has lost interest in LD1+… or another newbie, can’t be bothered. Anyway, No, it’s not asking too much of a $100 hybrid.



At first I played a little with putting a board under the amp with soft footers beneath that, which helped but weren’t soft enough for a component this light in weight.

Then I tried silicone o-rings as tub dampers which really made the details pop across the frequency spectrum, lows, mids, and highs, but it came at the loss of some air and sense of natural space around the instruments. Impressive but unnatural. And of course, where one places the o-ring on the tube makes a difference.

Vibration control in general is an art as much as a science and so I’m not finished with experimenting, including thinner o-rings on the tube, or an o-ring on the tube socket (ceramic base).

But replace the stock opamp MC33078 with an OPA2107, and this just became a much better amplifier giving me a lot more time to experiment while enjoying this amp... and scales well with better DACs.

Of course RFI can present as audible noise or just as slightly degraded sound, so it’s worth experimenting with whether you stack this on top of a DAC or other component or separate by a few inches, and how near is it to the mobile phone, cordless home phone, LED or CLR lightbulb, its cables mingling with other cables behind the desk, etc.

I found that when I moved the amp to the other side of the desk from the phone and desk lamp, things improved. But life, presence and bass definition were not quite as good as they had been at some points in the trials. So, I put a bamboo board between the amp and the DAC and ultrasoft silicone bumpers underneath the board. Bingo, that all came back.

If you get swish or hash noise sometimes even when the volume is down, and it gets worse when touching or adjusting the tubes, what about those pins on the NOS tubes? I cleaned the pins and socket holes well with alcohol and then even Deoxit, let it dry and then pushed in and out of the socket a few times, which quieted things right up.

Of course those who have used tube amplifiers before know all this, but with the new waves of users through Drop and ChiFi, I thought it might be worth my summary of the last week’s efforts.
 

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Nov 25, 2020 at 8:55 AM Post #3,126 of 3,129

johanchandy

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I have a LD1+ on the way as well as some Mullard M8100 tubes, I am trying to decide between the burson v6 classic and vivid op amp, which do you all think would serve me better? I plan to use it with my Grado Hemps and a modi 3 dac. I'm leaning towards the v6 classics but I'm worried if it would sound slightly congested?
 
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Dec 6, 2020 at 12:31 AM Post #3,127 of 3,129

johanchandy

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So I got the LD1+, installed the burson v6 classic opamp and the mullard m8100 tubes, and it sounds pretty decent but I find it fatiguing with my Grado hemp, I was hoping for a smoother more relaxed sound. I even find the stock tubes better in this regard. What is a nice warm bassy tube that would work for my setup? I'm using the modi 3 as a dac and the schiit heresy is amazing with the hemp for a live sound, I was hoping the LD1+ would give me a more relaxed alternative. Could this also be because it probably needs more burn-in as well?

Edit: I'm really loving the stock tubes soo much more paired with the burson v6c, really smooth and musical, but they're a tad noisy, what would be an upgrade to the stock tubes that share a similar sound?
 
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Dec 18, 2020 at 2:02 PM Post #3,128 of 3,129

brucew268

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These tube damping experiments were all with Mullard M8161 which I quite like overall, good dynamics, detail, soundstaging, air, mids and frequency extremes. Natural sounding with richness but not bloomy.

Adding the following silicone o-rings had the following results for me:

17mm (ID) x 2mm – on tubes by the upper mica spacer. Makes details pop and is dynamic but is a bit hyped and unnatural. (A good fit without being tight so one can add or remove with power on. These tubes don’t run hot.)

17mm x 1mm – same place on tube as above. Takes the above and backs of to more realistic levels. It still felt slightly unnatural to me in an absolute sense but many might like it.

14mm x 2mm – fitted to porcelain socket base, have to open up and get at the back side of the PCB. Better than the effects of the 17mm x 2mm above but not quite as much as the 1mm – not entirely natural.

10mm x 1mm – Put around the tube’s pins not the glass. At only 1mm does not get in the way of a good fit with pins and socket. This kept most of the musical details about the same as no o-ring but reduced the sense of air that goes with plate reverb or fill mics. If you feel like the air and space is a bit overdone in most recordings or suffers from a bit of electronic overshoot, then this tames that nicely. The vocals and music felt very real and present so that when I removed these o-rings, the HF stuff mentioned above felt a little distracting for a bit. Which is most realistic I’m not prepared to judge at this moment. I could even see switching these in or out like tube rolling based on mood or music.

Of course one has a loss of at least 10-15 minutes minutes for turning off amp and letting capacitors drain before making the change and then getting back to "optimal temperature".

In the end I prefer the amp mostly with just the extra soft silicone bumpers pictured in post #3,125 and no o-rings, though I could see occasionally ‘rolling’ in the 10mm rings on the pins.

#orings
 
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Mar 8, 2021 at 12:13 PM Post #3,129 of 3,129

Onik

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Hi maybe not the best place to ask but maybe someone can help me:

I wanna know if its possible to add pre amp option(rca phono sockets) at the back by drilling holes on my Ld I+, by increasing the output impedance(say 15k registor) and with a switch for changing the output from headphone out to preamp?
 

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