About me: I am not a professional reviewer by any means, I am just a part-time audiophile slowly accumulating gear and sharing some thoughts.

Gear Used: Burson FUN, connected to Creative X7 Amp/Dac combo which is using 2x Dual Sparkos op-amps and 2x Single Sparkos Op-amps.

Headphones used: Ether Flow 1.1, LCD-2C Classic, Hifiman Sundara, AKG K 712 Pro, Sennheiser HD 6XX

Packaging, Build Quality and extras
The unit showed up at my door in perfect condition. The packaging job wasn't to warrant a single complaint, you could tell it wasn't moving around in there. The box is minimalistic but gets the point across of what lies within.
The unit itself is of a solid build, emits minimal heat and my only niggles would be my preference to a switch on the front of the device isn't met here (hard to access the rearward switch, so many cables) and the volume knob is a little hard to get a good hold on.

Capability:



The FUN headphone amplifier puts out enough power to drive all of my headphones, a little easier than the Creative X7. The Hifiman Sundara seem to be my hardest to power headphones and I had no issue powering these with the FUN, though my volume crept towards 12:30 on the dial.
Sound:
This is a pure Class-A headphone amp, the first that I've used. I can't comment on the difference in sound that alone makes, but it has enough juice to make for an impactful sound no matter the headphones I've tried.
I'm not going to go into decay, mids or any of that too much but I will say that in comparison to the Creative X7 which has upgraded op-amps, the FUN keeps up close in terms of detail. I'd say the FUN leans a little more neutral, laid back, less bright. Solid low-end, sounds no less impactful than any other amp I've used. Highs are clear without piercing my ears, mid-range is smooth without sounding recessed.

I haven't detected a noticable difference in soundstage, or imaging. I do tend to use the FUN instead of the X7 while gaming now, which could be in-part to sounding less bright.
Listening to older tracks from 90s, back to 70s seems to present less harshness of the recording with the FUN than it does with the X7's amp section.


So far, can't say anything bad about the FUN. It's at a good price, and with the options of op-amp rolling it can really be your "do it all" amp if you don't want to accumulate multiple amps, instead switching the characteristics of one instead.

V6 Classics Installed
V6 Classic op-amps arrived from Burson and I ran the FUN with its stock configuration with many songs before unboxing the Classics.


Within the first moments of using the V6 Classics, I could clearly hear a difference.

Words that came to my mind instantly were "body" and "musical". These op-amps opened up a new realm of sound from an already solid amp, bringing with it an increase of detail, warmth, punch and musicality without question.

I'd even say that the bass and mids seemed to become more present, which aligns right to my tastes in sound signature.


V6 Vivids installed
After using the V6 Classics for awhile I cannot hear as much of a change as I did going from the stock op-amps, to the Classics.
That being said, the changes are there and I really do not have a clear favorite.
The V6 Vivid op-amps seem to mellow out the mid-range a little, less forward than with the Classics. I wouldn't say it brings up the low-end or treble per say, but it does seem to strike a more balanced sound signature which can pair well with certain headphones, amps, music or moods.
I can't help but feel that there is more body to the low-end with the Classics, while some extra sparkle, clarity and dynamics with the Vivids while the Classics provide a closer sound to a tube amp in all the right ways.
I do not believe you can go wrong with either, as both the types of V6 op-amps are audio bliss and a clear upgrade from what comes stock.
I believe this would be the same for something like the Burson Swing DAC and I could only imagine if this type of sound upgrading/personalizing will be possibly on the new monster Conductor that it would absolutely be worth it.
I love swapping the op-amps so much now as they both have benefits, that I wish for a toggle switch between the op-amps

THX AAA 789 comparison
Prior to the V6 Classic op-amps coming in, I've spent a few weeks with the highly sought-after THX AAA 789 amplifier. The 789 immediately brought forward a different sound compared to the other amplifiers in my stable, one which I can only describe as clear, neutral and accurate.

This seems to be a highly reference amplifier for its price range, one which I'm glad to have in my collection.

Though, it is not my favorite amplifier. It is accurate, clear, detailed and dare I say sterile.

It does give a different dimension to music, which at times is the sound I want - so it definitely does get its use.


If I could only have one amplifier from my collection it wouldn't be the 789, it would be the FUN with the V6 Classics. I haven't heard the V6 Vivids and I haven't heard either amp with a dac different than my op-amps rolled Creative X7, but at this point in time the musicality that the FUN w/Classics brings is right up there with my tube-rolled DarkVoice/HD6xx pairing, but with all of my headphones.


I will update this review with any new findings once my Airist Audio R2R dac comes in and yes, I would recommend Burson Fun w/V6 to a friend.



Great Fun and Bang for the buck!





Other gear used for reference: DarkVoice 336SE with 5998 and GTB tubes, LD1+ with Mullard 8100 Tubes and Burson V5i op-amp, Hifiman HE-400i, Fidelio X2, Fostex TH-x00, Beyer-Dynamic DT 1990, Sennheiser HD 598

Little Dot 1+ op-amp upgrade with the Burson V5i
Gear used
Creative Soundblaster X7 as DAC with 2x Sparkos SS3601 single op-amps, 2x Sparkos SS3602 dual op-amps, Hifiman HE400i, AKG K712 Pro, Fostex TH-x00 PH, Fidelio X2, Little Dot 1+ with Mullard M8100 tubes and of course the Burson V5i op-amp.



Impressions
The LD1+ was already using a different op-amp, the dual op-amp that I swapped out of the Creative X7 was being used which already made for a clear upgrade from stock. The X7 op-amp upgrade seemed to give the sound a more neutral signature, while also lowering the noise floor with the LD1+.
Because of this, I wasn't expecting to have as noticable of an improvement with swapping in the Burson V5i, but I was happily mistaken.
The differences aren't as large as swapping all for out of my X7, but they were immediate. The LD1+ is not by any means an expensive tube-amp (well, maybe to those who don't use these forums!) However, the sound didn't improve in one area - it was improved all around, while retaining the neutrality I noticed with the X7 op-amp upgrade.
Details, transparency, cleanliness, soundstage, imaging, and a blacker background were all improvements I could notice on all of my headphones. Some more than others, such as the K712 Pro and HE400i seeing as these are harder to drive headphones I could only assume.
The Fidelio X2 still had some background fuzz when the volumes were at pub-style band performance levels but this is a reasonably low impedance, easy to drive headphone.
I'd also like to point out exactly what I mean by "cleanliness" because this was a very appreciated change.
I like to EQ, some are are against this, I am not. For example: for the X2 or TH-x00 I will EQ in a little bit of mids, and I will EQ some low-end into all of my headphones.
The LD1+ with the warm, buttery mullard M8100 tubes would become syrupy sounding while running high levels of bass (only as high as what the X7 as my amp would reproduce cleanly).
Now with the V5i op-amp, the bass was no longer thick and syrupy sounding, so creds for this.
Overall, this is an upgrade I could easily recommend if you are a owner of the Little Dot 1+ and want to go a little farther with your amp, without shelling out for a whole new tube amp.
I have not used the V5 to compare, but the V5i having a smaller footprint is a positive in this case as closing the LD1+ with the backplate remains possible.

First, a little about me. Skip this if you want to get right to the meat and potatos.
I've only really been getting into audio since August 2016, with my purchase of the Sennheisher HD 598 paired with my (at the time) Asus ROG Phoebus sound card.
My eyes were opened to just how good sound could.. sound.
I've always had an interest in audio, being a guitarist and gamer, but this being said - I am not a well experienced audiophile, but I am a hobbyist with a bit of an obsession.
Also, thank you Andrew Sparks! He was an absolute pleasure to deal with, would reply quickly and answer any questions I had. I will note that I received a slight dicount for this purchase, as it was of 2X single and 2x dual op-amps.

Gear used 

Creative Soundblaster X7 (which these op-amps are in), 2x Sparkos SS3601 single op-amps, 2x Sparkos SS3602 dual op-amps,  Hifiman HE400i, AKG K712 Pro, Fidelio X2, Little Dot 1+ (with Mullard M8100 tubes and original X7 dual op-amp), Klipsch RP-160M bookshelf speakers.
 
Impressions
The Creative X7 was already a completely satisfactory amp/dac, in which I could find no faults. I was debating buying another amp/dac such as the JDS Element, but decided first after reading some reviews that I would squeeze the most that I can out of the X7.
Well, I'm glad I did. The differences aren't going to be like going from on-board to the X7, or like going from the HD 598 to the HE400i. However, the sound didn't improve in one area - it was improved all around, in a seemingly even way. Sound became louder, more transparent, details were a touch easier to pick up on (some new details in songs were brought to light), I could turn up my volume higher with the X2 before I would hear the noise floor and overall it helped for gaming, as imaging seemed to pick up a touch of accuracy.
I've been leaving the X7 exclusively in high-gain mode, I don't have the ears to notice an improvement apparently, as some say there is a fuller sound to high gain, but any of my headphones are powered easily though they are all sub-100ohm.
I received my Klipsch speakers only a week before the Sparkos op-amps, and I broke them in with pink noise and media for around 50 hours. Switching the op-amps was noticable with the speakers, as well as while using the LD1+ tube amp and X7 only as a DAC.
I have not used any other op-amps to compare to aside from the stock ones.
 My overall impressions are that if you like the Creative X7, and you want as much as you can get out of it - this is worth it. It's like the stock op-amps had the X7 at 85%, while this upgrade brought it up to 100.
 

 
 
 


I ended up making little feet after this photo, so the X7 now sits higher