AthenaZephyrian
100+ Head-Fier
Testing was done on Soundmagic HE400i headphones, carefully EQ'd to be roughly linear. I used an HRT Music Streamer Soundmagic II for this test.
Tubes:
6JI tubes (one of which burned out after 56 hours): Stiff, dry and congested in the centre-mids, and ran hot in the upper-mids/lower treble. Soundstage was not what was as expected for a $100 amp--small. Sub-par detail.
GE JAN5654W: Clear, detailed, spacious but constricted ever-so-slightly vertically, and a wee bit warm, and generally a tiny bit smooth across the midrange, great treble extension. Separates vocals from background better than other tested tubes in crowded tracks with a lot of treble, and produces a more airy sound than the Voskhods. If I had one word to describe these, it would be "laid back yet airy". Fine, four. They aren't simple tubes to describe.
Voskhod 6ZH1P-EV (1976): Clear, detailed, smooth yet detailed (more detailed than either other across all frequencies), tight bass, general fidelity of frequency response, slightly less treble extension and detail than JAN5654W. Excellent soundstage, fully 3D, rather than the slightly vertically constricted GE tubes. Mids are truly brilliant, I'd rate them a solid 10. Has a bit more edgy pop than the GE tubes, without sounding at all unnatural--in fact, I'd call it more natural.
The two aftermarket tubes sounded quite similar at first listen, and neither will serve you wrong. I'd say the 5654 felt smoother, and the Voskhod produced better detail but less separation in very crowded, treble-intensive tracks. The Voskhods are almost objectively better for classic rock, symphonic, and electronic, while 5654's fair slightly better in modern math rock/metal/other particularly hard rock.
I have a hard time choosing which to use--but the Voskhods look wicked cool, and glow more. And everyone knows the glow is what matters, when it comes to tubes...plus the Voskhods are really great all-purpose tubes.
Op-amps:
MC33078n: Veiled/congested. Smaller soundstage. Lacks details. The amp sounds good, but sounded truly hifi--not really even mid-fi--with Voskhod and the op-amps mentioned below.
AD823ANZ: Extremely detailed and analytic. Spacious, and does not let any frequency in particular down. Sounds linear to my ear, with no obvious suckouts or spikes. Very, very fast transient response, and truly superb treble detail.
LT1364: More dense and smooth than the AD823, still excellent, albeit with slightly slower transients. Does not fail to differentiate, and soundstage is still excellent. More musical.
The two aftermarket op-amps are more easily differentiated at first listen than the tubes. While the AD823 is undeniably more faithful and produces better quality in terms of clarity and resolution, the difference is, again, not particularly huge. "Which is better?" is a tossup between the two, and down to preference. That said, I find the AD823 to sound more "hifi", and it pairs brilliantly with the Voskhods.
Tubes:
6JI tubes (one of which burned out after 56 hours): Stiff, dry and congested in the centre-mids, and ran hot in the upper-mids/lower treble. Soundstage was not what was as expected for a $100 amp--small. Sub-par detail.
GE JAN5654W: Clear, detailed, spacious but constricted ever-so-slightly vertically, and a wee bit warm, and generally a tiny bit smooth across the midrange, great treble extension. Separates vocals from background better than other tested tubes in crowded tracks with a lot of treble, and produces a more airy sound than the Voskhods. If I had one word to describe these, it would be "laid back yet airy". Fine, four. They aren't simple tubes to describe.
Voskhod 6ZH1P-EV (1976): Clear, detailed, smooth yet detailed (more detailed than either other across all frequencies), tight bass, general fidelity of frequency response, slightly less treble extension and detail than JAN5654W. Excellent soundstage, fully 3D, rather than the slightly vertically constricted GE tubes. Mids are truly brilliant, I'd rate them a solid 10. Has a bit more edgy pop than the GE tubes, without sounding at all unnatural--in fact, I'd call it more natural.
The two aftermarket tubes sounded quite similar at first listen, and neither will serve you wrong. I'd say the 5654 felt smoother, and the Voskhod produced better detail but less separation in very crowded, treble-intensive tracks. The Voskhods are almost objectively better for classic rock, symphonic, and electronic, while 5654's fair slightly better in modern math rock/metal/other particularly hard rock.
I have a hard time choosing which to use--but the Voskhods look wicked cool, and glow more. And everyone knows the glow is what matters, when it comes to tubes...plus the Voskhods are really great all-purpose tubes.
Op-amps:
MC33078n: Veiled/congested. Smaller soundstage. Lacks details. The amp sounds good, but sounded truly hifi--not really even mid-fi--with Voskhod and the op-amps mentioned below.
AD823ANZ: Extremely detailed and analytic. Spacious, and does not let any frequency in particular down. Sounds linear to my ear, with no obvious suckouts or spikes. Very, very fast transient response, and truly superb treble detail.
LT1364: More dense and smooth than the AD823, still excellent, albeit with slightly slower transients. Does not fail to differentiate, and soundstage is still excellent. More musical.
The two aftermarket op-amps are more easily differentiated at first listen than the tubes. While the AD823 is undeniably more faithful and produces better quality in terms of clarity and resolution, the difference is, again, not particularly huge. "Which is better?" is a tossup between the two, and down to preference. That said, I find the AD823 to sound more "hifi", and it pairs brilliantly with the Voskhods.
