Quick question: There is little stated on the internet about it that I could find. Is it fully tube amplified? Or hybrid SS and tube?
While Iām not fully sure, it looks like itās tube drive not hybrid. It is a solid state power supply so not tube rectified, but the tubes drive the headphones, believe itās transformer coupled
I do seem to remember reading about it being DC coupled to the transformer, yes. Thanks!
I remember the original fireflies were true transformer coupled tube amps (sans tube rectification), Iād say itās pretty safe to assume the gen 3 is as well given the changes from 1-2 and 2-3. I just wish they would offer a version without the dac, as from my experience the internal dac on the gen 1 and gen 2 was pretty lackluster. Would have just rather pocketed the savings from not having a dac and gotten a nicer standalone dac. But could be better in the gen 3, wonāt know until I try them lol
I couldnāt agree more. Supplement the dac with some XLR inputs instead. Then I can run my Ares II balanced into it.
I can sort of understand why they didnāt bother with xlr inputs, likely because the internal design of the amp isnāt balanced, and they just create a balanced out with taps on the output transformer. For a fully balanced design they would need 4 12au7 instead of two, otherwise in order to accommodate a balanced signal as it is now, they would need to add input transformers to convert to single ended internally, which would add unnecessary cost and complexity (also likely make the unit larger lol). Unless Iām misunderstanding how a balanced tube design actually works lol, the older firefiles werenāt balanced, so Iād be surprised if they redid the entire thing to make it balanced
If you wanted a balanced design from them, youād have to step up to the WA22 as I believe that is fully balanced iirc (and also pretty great, nice step over the fireflies at least from gen 2)
Huh. Somehow I thought it was truly balanced. Isnāt the 12AU7 a dual triode? You could send plus to one side and negative to the otherā¦
The marketing on the website indicates it is a Class-A balanced amp and DAC.
In theory yes, although it would depend on the overall topology of the amp, the amp could use both sides of the triode as push pull in opposite polarity, then add the signals back together when it reaches the transformer which acts as the common ground. Which wouldnāt be balanced (no separate ground for each channel at the end). Using the tubes in parallel would allow for more current overall, using both sides of each triode, but wouldnāt really be balanced either with a transformer coupled design. Iām not really the most educated on circuit design, but I do know there are tube designs which despite using a pair of double triodes, arenāt actually balanced for one reason or another. Youād really have to ask woo what parts of the amp are actually balanced to really know
Amps can be balanced on the output stage, but not balanced on the input stage, or vice versa, and also be balanced in the amplification stage, generally if something is balanced from start to finish throughout that would fall under fully balanced (or differential?), although I guess something only balanced on the output stage could also count as balanced, but not fully balanced. Can be confusing lol
Itās just weird that itās noted as balanced, but not fully balanced like the wa22 or wa33.
Can be confusing lol, I guess if woo says itās balanced then thereās a high chance of it being internally balanced lol, I just would have figured theyād give you a 4.4mm input if that were the case. Either way, not like it matters all too much as long as it sounds good
Yeah, thereās a subtle note in the marketing text that suggests it has a balanced output stage, and doesnāt indicate fully balanced, or otherwise balanced anywhere else. This is disappointing.
It could be fully balanced only if youāre using the built in dac, but Iām really not sure to be honest. Would really be a question for woo. Iām sure it sounds great regardless. A lot of this technical stuff goes over my head so just making guesses
Yeah. Thatās the thing, I am betting they are sending the negative to one side of the tube and positive to the other, and balancing the output at the DAC. Still, I would like a fully balanced option for input, too. And at $1500, it doesnāt seem like a lot to ask for.
This is a beautiful thing! I love mind 
1 Like
Some genuine first impressions after only about an hour of listening.
My only previous experience with tubes has been the Dark Voice and a few cheaper hybrid amps.
So far Iāve only listened with the Focal Clears, listening to a mix of pop, dance, and electronic music on YouTube and Spotify, not super clinical stuff. Single-ended for the time-being, as Iām waiting for a longer 2m 4.4 cable to come in the mail.
So how does it sound?
-The difference in the low-end is the most immediate thing that you notice. It definitely loosens things up a noticeable bit. I think that does resolve in less direct, sharp bass impact, but you trade it for a low-end (and mid-range) that feels more filled out and a bit ābloomyā. It still manages to sound very punchy and dynamic overall, as class-a amps typically do. Itās a nice balanced affect, imo!
-Iāve seen people describe an āexpanded sound stageā, I believe the affects Iām describing are what contribute to that perception, as each hit of any heavy note feels like it reverberates and has a softer fall off compared to listening directly from the Aune X1sGTās built-in headphone amp. Gives the effect of everything just feeling like it has more space.
-My one negative, at least off the bat, I think the ESS Sabre dac is a bit of a boring and odd choice to pair with this amp, but you can feed it an external line-in and bypass the DAC altogether. Itās nice to have it as convenience, but even now Iām opting to feed it the line out from the Aune X1S GT, I just prefer the softer custom filters that roll off the treble a bit on it a lot more. Pairing it with an R2R Dac that adds a bit of ācolorā might be worth looking into, I might look into picking up the Bifrost or Ares now at this point.
Iāve re-purchased an HD 6xx which should be here in a couple weeks, and Iām still waiting on a pair of ZMF Atriums & Bokeh that I ordered a few weeks ago. Also ordered 4.4mm cables for everything so I can test this amp to itās full potential.
To summarize these early first impressions, I really like this thing a lot. I definitely wouldnāt describe it as āhigh-fidelityā as I believe you are technically losing detail, but it does add some nice coloration thatās really pleasing, IMO. I think you could probably technically approximate SOME of the effect with some reverb and EQ, but it would probably take a lot of work to get it close, and even then, I doubt it would be quite the same thing as there are a lot of little subtle things happening with distortion and the like. This also goes well beyond the Dark Voice in offering up that āeuphonicā tube sound that so many have described, and Iāve been craving to hear for myself.
One super interesting note, I believe I remember reading that this originally came with Russian Tubes. That doesnāt seem to be the case anymore, as mine came with tubes made by RCA in the US. Ukraine war might have something to do with that. That being said, the sound is still great, and while I am curious to try some alternative tubes, I donāt feel the need for that for the moment. And I can respect Woo Audios decision on that part. Going to set this up as a line out to my desktop speaker setup next, and later will hook this up to my turntable. =)
Update: Just tried things a bit my short 4.4mm cable and just leaned in for a bit and itās nice. That extra power makes a difference! Maybe higher output impedance too? Feels like the bass got emphasized a bit more.
Update 2: Oh yeah, balanced output takes things up a notch for sure!
Update 3: double pre-amping from the Aune X1s into the WA7, out to the Emotiva BassX, which is amping a pair of RB42s on my deskā¦ SUPER nice
Update 4: Added my RNHP to the end of the chain, from the Emotiva amps passthrough. Result is also very fantastic. The amount of āplayā you get out of this thing using it as a pre-amp is a lot of fun.
Update 5: I have to force myself to stop, but damn it is a fun little amp. ultimately fell back into listening from it directly with the Clears. It definitely settles in really nicely after it warms up. Just based on first impressions, a lot of what people say is accurate. Worth it if you crave the ātubeā sound and you can reasonably afford it. Might even say itās worth saving up for as it ACTUALLY makes an appreciable sound difference, unlike just buying a bunch of SS amps. pre-amping from it is also REALLY cool.
Update 6: I got the tripowin 4.4 cable. Listening to it after a short nap. I really enjoy the sound of this amp. Iāll end initial impressions here. Iāll upload new impressions when I get some more headphones in for testing.
Nice overall impressions. I have the Denafrips Ares II hooked up to mine, and it is indeed a nice improvement over the internal ESS chip.
Additionallly, and they are pricy, Telefunken 12AU7s bring back much of the detail you feel youāve been lacking from the RCAs. Amperex is a good detail match as well, more balanced than the Telefunken. RCA has a reputation for being more tubey and euphoric than other tubes. Followed by Mullard then Amperex and Telefunken.
The other thing you will notice is that this amp does exceptionally well at driving reasonably easy to drive Planar Magnetic headphones. I have mine paired with the Abyss Diana V2 I got on warehouse sale from Abyss last year. No loss of detail there! I love my Focal clears with it as well.
You will notice one thing for sure: more liquidity in midrange will happen as you burn in the tube. Iād let them run in overnight and try them out again after the burnin time.
Welcome to the Foreflies club!
1 Like
Nice, Iāve been thinking about picking up the DCA E3s. Also, I was never hugely interested in the HD800s, but now with the WA7 the concept of driving a headphone with an already large sound stage through this sounds like it could be a lot of fun. Dianaās are definitely on the bucket list too. Really, really looking forward to the ZMFs coming in and giving them some rounds with this little tube amp too. But man, I did not expect to like it so much pre-amping my desktop speakers. Lol
Iāve been binging videos on the subject of distortion, tube amps, etc and came across this video. I think for anyone who had doubts about how good tube amps can sound (as i did, basically gaslighting myself, despite being pleased with tube amps Iāve heard in the past, like the Schiit Val), this video explains really well how distortion can add some nice āmusicalityā to your audio chain from a really well explained and purely objective point of view (with clearly defined audible examples). IMO, the WA7 is really well engineered in how it basically adds a nice amount of saturation to your sound. Iām still loving it to death.
1 Like
I picked up a pair of the Amperex Orange Globes. First Iāll say A/Bing tubes is a bit difficult given the process of replacing them doesnāt allow for any reasonable quick A/Bing to compare. So feel free to take anything I say with a massive helping of salt.
With that disclaimer out of the way, Amperex Orange Globes definitely brings back some of that high end detail, while still maintaining a moderate level of ātubeyā distortion. You do lose some of that tubey-ness compared to the RCA tubes, though. I still lean towards the RCAs, personally, but Iām going to put the Amperex back in and give them some time to warm up and give myself a bit more time to get used to them. I also found a pair of mullards for around $50, so plan to give them a go as well. Also these are tested with both the HD6xx and Focal Clears. In both cases I lean more towards the slightly smoother RCAs.
Ooohhhā¦Mullard for $50? A pair of them? That sounds a little too good to be true, unless they are used and not matched. Iāve heard it said that matched pairs are overrated. But I never go for unmatched pairs.