I’ve been comparing the Senn ie600 and the original Campfire Vega using the iBasso DX320, which is the most resolving and technically capable DAP I’ve ever heard. Most of the music is from a micro SD card, although there’s been a little streaming from Roon, Qobuz, and Apple Music. Both IEMs are using the Campfire Audio black foam tips. I ordered new pairs direct from CFA so I could compare them both with fresh tips. The Vega sound best to me with the smallest tips and the most shallow insertion possible that still gives a solid seal. The ie600 sounded best with the deepest insertion I could get. The ie600 comes with two stock cables, a 3.5mm SE and a 4.4mm pentaconn balanced. The stock cables are quite nice. I hear some slight microphonics with them only when there is no music playing, but never once it’s plugged in. The cable is lightweight and seems to be tangle-proof. The ear hooks are bendable so you can adjust them, and frankly I’m a fan of these cables to the point where if one broke I’d just buy another stock one. The sleeve for the MMCX connectors on the Senn cable are pulled back in comparison to most MMCX cables because they need to accommodate the extra depth of the connector on the IEMs themselves. This means that only cables designed to work with the latest ie-series IEMs can fit them, and if using the Senn cable with other MMCX IEMs, there will be a bit of the connector exposed to the open air, which shouldn’t affect performance but don’t try and jam the connector all the way down. For the Vega I ordered a Linsoul Kinera Ace cable from Amazon, mostly because it seemed flexible, had modular terminations, and was under $50. Both IEMs are tiny, although the ie600 with its 3D printed metal body feels lighter and less substantial than Vega body. They easily fit into my ears and I can listen to either for hours, but the combo of the more shallow insertion and heavier shell of the Vega did result in some irritation if worn for very long periods. While both are single DDs, and provide excellent timbre, the two presentations could hardly be more different. The Vega is thick, full bodied, and constantly dynamic. It has an elevated midbass that propels the sound forward. Drums and electric bass have exceptional slam and drive. Male vocals and instruments like electric guitars are rich and inviting. The treble is solid but not the star of the show. The reason I have to go for a shallow insertion with the Vegas is because they become bassy to the point of drowning out the mids with a deep insertion. Even with the most shallow insertion that still gets a seal, the bass of the Vegas is so prominent that it can obscure fine details in the mix. As I mentioned in my previous post, tip selection with the ie600 is absolutely crucial. The stock silicone tips can’t seal for shit and the stock foams put such an emphasis on the high end that they overpower the presentation. That’s why I’m using the Campfire tips, as they tame that eager treble while bringing the rest of the FR into focus. Using the Campfire tips, the ie600s blossom. With a sub bass emphasis instead of mid bass, the low end is taut and well defined. The mids have a clarity that I have rarely heard in a dynamic driver, and the highs are still well extended with notable sparkle. The extended highs and overall clarity combine to present a soundstage that is nearly panoramic, although not with significant depth. With a highly resolving DAP like the 320, the amount of detail, texture, and sheer resolution can feel overwhelming. The ie600s truly feel like a DD version of Andromeda, able to dissect the mix so each individual element is plain to hear. I’ve heard details in songs I’ve listened to for decades that I’ve never noticed before with the ie600/320 combo. All of this is with DD timbre that sounds natural and authentic to the tonality of each instrument. If there are any nitpicks, the head stage could use more depth, the sub bass emphasis means that at times while the bass lacks the impact one expects (although when the sub bass wakes up the rumble does feel visceral), especially in comparison to Vega, and the presentation feels at times like it lacks macrodynamics, again especially in comparison to the Vega. The Vegas however, despite also being resolving and fast for a DD, absolutely obscure finer details because of its mid bass emphasis and their headstage is claustrophobic in comparison to the ie600. If you had a gun to my head, I’d be forced to go with the ie600. It is simply one of the best IEMs I’ve ever heard, even with the criticisms I listed above. For all their attempts to recreate the HD800 in an IEM by goosing the treble, Sennheiser finally managed to create an IEM that retains the best qualities of the 800–highly resolving, wide soundstage, comfortable to wear for hours—with a balanced FR and the result is often intoxicating. The Vegas are “fun” IEMs, more colored, less detail and soundstage, but with bass impact that will rattle your teeth and macrodynamic swings that are simply thrilling. It’s not an IEM I could recommend as a main driver but with used prices in the low $300 range, certainly are worthy of consideration as an alternate. I highly recommend the ie600. With the Campfire Audio foam tips, their performance is so impressive that I’d take them over many full size headphones within the same price range.