My <US$40
Fosi Audio P1 tube preamp/buffer with bass, treble and volume dials has two
TI NE5532Ps.
The device is between a
Topping E30 and
L30, so I have plenty of clean, low noise, linear, etc. signal.
More photos in the
album.
Two dual
Burson V6 Vivid fully discrete opamps arrived from Hong Kong courtesy of a generous offer from
@John Burson at Burson Audio who asked only for "honest feedback and pictures of the upgrade posted in your frequent forums".
Since I am just starting my planned testing, I plan to split my review across multiple posts here, but first a photo of the V6 Vivids showing their neat packaging and how they might be a challenge to fit in the P1.
Caveats
To properly review an opamp swap usually involves making the swap in an amplifier where the difference can be directly experienced, whereas I am swapping opamps in not only a pre-amp, but a tube pre-amp with stock tubes in which the two opamps operate across tone controls and volume in a way which I don't understand. Testing will involve twiddling bass, treble and volume dials on the pre-amp in order to try to discern the difference between the
TI NE5532Ps and the
Burson V6 Vivid. To make this harder, I am unable to effectively A/B test, so will rely on memory of impressions, approximate volume matching and comparable twiddling.
The Plan
My test plan has three stages:
- The Truth
- Create a demo playlist
- Choose review components excluding the pre-amp
- Listen to the playlist
- The Tubeth
- Connect the Fosi Audio P1 between the DAC and amp
- Listen to the playlist
- The Vivid
- Replace the two TI NE5532Ps with the Burson V6 Vivids
- Listen to the playlist
The Playlist
A mix of aw-dee-oh-file demorific and familiar tunes to enable a suitable test of the highs, lows, wides, deeps and details with a mix of natural and synthetic sounds. Most files are 96 or 48 kHz 24 bit or 44.1 kHz 16 bit FLAC with a couple of 48 kHz Opus/Ogg. The fist uncontroversial choice.
- Yosi Horikawa - Spaces - Timbres
- Hans Zimmer - Dune Original Motion Picture Soundtrack - Dream of Arrakis
- Pink Floyd - The Dark Side of the Moon - Time
- How to Destroy Angels - Welcome Oblivion - Ice Age
- NIN - Hesitation Marks "Audiophile Mastered Version" - Came Back Haunted
- Daft Punk - TRON Legacy (The Complete Edition) - Solar Sailer
- GUNSHIP - Dark All Day - Black Blood Red Kiss (feat. Kat Von D)
- Public Service Broadcasting - The War Room - Spitfire
- Steven Wilson - THE FUTURE BITES - KING GHOST
- King Crimson - Radical Action to Unseat the Hold of Monkey Mind - Starless
- Dire Straits - Brothers in Arms - Brothers in Arms
The Gear
Files on the PC played with
Audacious go to
EasyEffects where a
full parametric EQ for Crinacle's Harman over-ear 2018 is applied with no further modification resulting in a 96 kHz PCM signal from
PipeWire going to the
Topping E30, which sends line level output to the
L30 which powers my unmodified
Sivga SV021. The intention here is accurate reproduction with a familiar sound signature in which the most components are neutral, i.e. do not significantly limit or colour the sound, leaving the colouring for the pre-amp stage. The second uncontroversial choice.
While an objective description of my hearing is impractical, mine has no noticeable damage and tops out somewhere around 14.5 kHz.
Impressions
The Truth
Neutral is far from boring. With the naturally bassy-V SV021 EQ'ed to the gently warm curve, all the available details of the tracks appear in their intended places. Low, high, loud and quiet and everything in between appear without great emphasis or evidence of distortion or limitation.
Since this is the reference listen, volume on the L30 stayed at a comfortably loud one o'clock for two playthroughs.