DNA Stratus 2A3 amplifier - first impressions

Discussion in 'High-end Audio Forum' started by budx3385, May 12, 2012.
  1. mysticstryk
    Low. IEC is 120ohm output. Way too much for Utopia (can make an argument it's too much for anything, but some like using it with 300-600ohm headphones so it's a cool option to have).
    DMck2000 likes this.
  2. DMck2000
    Yeah after some more listening, I would have to agree. With Utopias it just feels too bloated with the IEC output option, I think the low is more balanced.
  3. Sorrodje
    Low. The iec setting means the output impedance will be 120ohms. It will affect a lot the sound and will make sound your utopia much bassier. Mud galore as well :)
    DMck2000 likes this.
  4. CoLdAsSauLt
    Low for sure. IEC is 120Ohm. This not only gives a bass boost at the headphone's (usually primary driver resonance) impedance peak, but also a looser sound due to lesser electrical damping of the driver.

    It just got mentionned in Tyll's latest review of the Focal Clear at https://www.innerfidelity.com/content/focal-clear-over-ear-open-headphones.

    DMck2000 likes this.
  5. DMck2000
    Thanks guys for the help! The IEC option does sound extremely muddy to me as well after going back and forth between the two options.
  6. auricgoldfinger
    IEC only works with the 1/4" jack
  7. DMck2000
    I'm using the 1/4 in. jack with my Utopias. Haven't gotten a balanced cable yet for the Utopias, though it would be nice to have as the current cable is pretty heavy.
  8. auricgoldfinger
    Actually, what I meant to say is that switch only works with the 1/4" jack. The XLR jacks are unaffected by the IEC/Low toggle.
  9. DMck2000
    Oh got ya! Thanks for the info.
  10. Sorrodje
    Where's @ogodei ? :)

    I'm curious to read his impressions about the upgraded Stratus vs Stellaris . I own the first one and heard the second but never compared directly.
    DMck2000 and sheldaze like this.
  11. DMck2000
    This amp is just too good. I'm listening to some Charles Mingus (if you haven't heard of him and you like jazz, then listen to him right now haha) right now on Vinyl and it is insane. The dynamic range, the separation, the dynamism, the space, the tonality, everything is amazing about this experience. I just want to thank Donald for making such a beautiful amp! Happy New Year to you all!
    Last edited: Dec 31, 2017
    808cityill likes this.
  12. ogodei

    I’ve had just over two weeks to compare my Stellaris head-to-head with a Stratus with the latest updates. I did some critical listening sessions during the holiday time off, some casual listening sessions, and invited some people with better ears than mine over to hang out and give some opinions. Jump to the findings section for conclusions.

    Critical listening was done with matched sets of tubes in both amps. I used two sets of rectifiers, either Western Electric 422A grey plates or Mullard/Philips Miniwatt metal-base 5AR4s. Power tubes were Shuguang Nature Sound 2A3C-T s and drivers were matched Voskhod 6N1P-EV for all sessions, the only double sets I had. I flipped tubes back and forth between the amps to make sure I wasn’t just hearing tubes.

    Hardware chain was PC, playing either Tidal via Roon or DSD & FLAC via JRiver, streaming to an SOtM SMS-200 (W4S PS-1 PSU) > iFi USB > Singxer SU-1 > HDMI i2S > HoloSpringDAC > goldpoint balanced level controls > Balanced Splitter > Balanced cables to the amps. For the Stratus I converted balanced to RCA using either a Jensen ISO-MAX PI-2XR or Sescom SC15XJR. I tested only against the balanced input on the Stellaris cause that’s what I bought it for.

    Amps were level matched, headphones used were the Audeze LCD-MX4, SE cable; stock Senn HD-800s with stock balanced cables; Utopia with a custom balanced cable, and a ZMF Auteur Blackwood with the neutral pads, balanced and SE cables. I did a lot of casual listening with other tubes and headphones.


    Both amps are end-game territory. The differences noted here all at the hypercritical edge.

    Bass was very slightly extended and pushed on Stellaris in the 10 to 30dB region on some tracks but I didn’t find this to matter with most material. More importantly, low bass was better controlled on Stellaris which helped with clarity and timbre in the mid-range, especially in orchestral or very busy material. This was probably the most noticeable difference between the amps and it became very clear on the comparatively bass-pushed headphones (e.g., Audeze, ZMF, Denon). Stellaris was also faster, with speedier attack and decay on most headphones. I found the difference reduced when using the Philips vs. the WE422A, with the Stratus almost reaching up to the level of the Stellaris. Another listener didn’t hear that change though, so, grain of salt.

    Treble extension, dynamics and noise floor seemed identical. Openness and imaging were essentially the same except when heavy or persistent bass was involved. Another listener stated that the Stratus seemed ‘almost congested’ compared to Stellaris on one track, then we laughed our heads off at the idea of the Stratus ever being called congested.

    Other comments were that Stellaris consistently had better ‘layering’ of sound, was faster, was clearer in overall presentation. The consensus, which I totally agree with, is that the Stellaris sounds slightly better but the Stratus is the better value.
    Last edited: Jan 8, 2018
  13. mysticstryk
    How do you think the EC camp fairs against the DNA camp? ZDS vs Stratus, AF vs Stellaris.

    I own the ZDS now and had an extended demo with the Stratus last year, but not at the same time and not with my current main headphone (Auteur with a side of HD800).
  14. Donald North Contributor
    I recommend also trying a directly heated rectifier, like the EML 5U4G, in the amps.
  15. ogodei
    Lots of ways to compare these amps. Without having rolled many tubes through the Aficionado yet, and based only on sound, my personal preference runs in line of ZDS < Aficionado < Stratus < Stellaris.

    ZDS is a lower price point than all the others and has its own signature sound: its kind of 'one of these things is not like the others', so I hesitate to put in this line up. I got my first ZD and Stratus simultaneously but the ZD never got time since I much prefered the Stratus sound signature.

    Aficionado v. Stratus may be the most interesting comparison for buyers right now. Without having rolled much through the Aficionado, I still prefer the Stratus sound signature. I fnd it more airy, dynamic,fast and exciting overall. Several other listeners I've had over are finding the same. I may dedicate some time to a better comparison this week.

    I've only got one of those so I couldn't do head-to-head listening. Probably i should pick up another one and try it out.

Share This Page