Fosi Audio ZA3 upgrade with Burson Discrete V7 Classic opamp

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Post Info

On my Fosi ZA3 amp, I changed two original Dual Opamps (1 per channel) for a Burson Dual Opamp V7 Classic Kit.
The original sound was lively/dynamic and the soundstage was well balanced.
From bass to treble, the sound was good too but a little harsh in the treble on some recordings.
The V7 Classic adds more depth, opens up the soundstage and adds silky smooth mids.
Jazz trios and quartets are therefore surprisingly good as well as the voice with piano and acoustic guitar.
On the other hand, the lively/dynamic sound has disappeared and the bass and treble are less resolved.
I think my V7 Classic kit has a problem because one of them is about +3 dB louder than the other one.
And one of them is always hotter to the touch than the other one too.
I’m going to buy a new V7 Vivid kit to test the sound and see if I have the same problems.

The System

Listening with

Fosi Audio ZA3 · Power amp: balanced Class-D stereo / mono power amp (TPA3255)
  • Frequency response: 20 Hz – 20 kHz (±0.1 dB)
  • Power: 8 Ω: not published · 4 Ω: 155 x2 stereo (48 V PSU); 95 x2 (32 V PSU); mono 235 (48 V) / 110 (32 V)
  • Inputs: RCA; XLR; 6.35 mm TRS; 12 V trigger
  • Input impedance: not published
  • Outputs: speaker terminals (2-8 Ω); subwoofer out
  • Other: SINAD 89 dB; SNR >=106 dB; THD <0.006%; 24-48 V DC in; five swappable DIP8 opamps; 1.78 kg

[1] [2]

Burson

Burson V7 Classic Opamp

Specs from manufacturer data unless a source below says otherwise. “calc.” values are worked out from those figures (V = √(P × R); 110 dB SPL used as a loud reference level). Gear listed without specs is not in our spec library yet.

  1. Fosi Audio ZA3: fosiaudio.com (fosi-audio-za3-balanced-dual-mode-class-d-amplifier page)
  2. Fosi Audio ZA3: fosiaudio.com (user-instruction-za3 page)