I was lent two trial v5i opamps to test out for my honest impressions and here they are:
I used the v5i in my hattor preamp with speakers and with my lehmann headphone amp in a vinshine audio dac-r2r-ref dac/amp.
Replacing the Burson V5 opamps with v5i in my opamp didn't yield much perceptible change, they share a sound signature so sounded extremely similar with the fully discrete V5 edging out the V5i in blackness of background.
Replacing the stock TI opa2134pa opamp with the v5i in my lehmann headphone amp yielded night and day dramatic differences. The stock 2134pa has a super neutral and clinical sound, not emphasizing any particular aspect of the music and doing a good job of being a very low noise and distortion free baseline, probably making it good for pro audio applications. When I installed the v5i I immediately noticed a change in sound signature in a different direction. The v5i presents a more dynamic "fun" type of amplification. Subjectively it has a W sound signature, being the opposite of boring neutrality yet not emphasizing a single frequency range. It seems to emphasize treble, mids and bass to bring the music to you for a front row seat near the stage in a small club type experience. The 2134 was more like listening to studio monitors while the band played on the other side of a glass window. The change was definitely complementary to my HD800 headphones which while extremely detailed, especially in treble and soundstage, don't have the most impactful bass or mids.
TLDR summary: major upgrade for any headphone amp! close enough to the V5 that I'd just get v5i if they fit better
Here's a pic of a v5 and v5i in my preamp to demonstrate their size difference
equipment used to compare: Vinshine Audio Dac-r2r-ref dac and lehmann type headphone amp https://www.vinshineaudio.com/product-page/dac-r2r-ref
Hattor Small Active Balanced Preamplifier http://hattor.com/
I used the v5i in my hattor preamp with speakers and with my lehmann headphone amp in a vinshine audio dac-r2r-ref dac/amp.
Replacing the Burson V5 opamps with v5i in my opamp didn't yield much perceptible change, they share a sound signature so sounded extremely similar with the fully discrete V5 edging out the V5i in blackness of background.
Replacing the stock TI opa2134pa opamp with the v5i in my lehmann headphone amp yielded night and day dramatic differences. The stock 2134pa has a super neutral and clinical sound, not emphasizing any particular aspect of the music and doing a good job of being a very low noise and distortion free baseline, probably making it good for pro audio applications. When I installed the v5i I immediately noticed a change in sound signature in a different direction. The v5i presents a more dynamic "fun" type of amplification. Subjectively it has a W sound signature, being the opposite of boring neutrality yet not emphasizing a single frequency range. It seems to emphasize treble, mids and bass to bring the music to you for a front row seat near the stage in a small club type experience. The 2134 was more like listening to studio monitors while the band played on the other side of a glass window. The change was definitely complementary to my HD800 headphones which while extremely detailed, especially in treble and soundstage, don't have the most impactful bass or mids.
TLDR summary: major upgrade for any headphone amp! close enough to the V5 that I'd just get v5i if they fit better
Here's a pic of a v5 and v5i in my preamp to demonstrate their size difference
equipment used to compare: Vinshine Audio Dac-r2r-ref dac and lehmann type headphone amp https://www.vinshineaudio.com/product-page/dac-r2r-ref
Hattor Small Active Balanced Preamplifier http://hattor.com/
