So one fine day last September, I was approached by Charles of
@SS-Audio. He asked if I would be willing to try out the Burson V5i in return for my honest review.
At that time, I’d just received my XD-05 and was just about to pull the trigger on the V5i so I took him up on his offer. Fast forward a few weeks, the V5i arrived.
As everyone has observed, the capacitorss right beside the IC mount need to be bent out slightly. I just pushed the V5i down and it displaced the caps on the way down.
This makes future op amp rolling easier as well.
To be perfectly frank, I had significant difficulty in quantifying the difference between the opamps. I could tell that something was different but couldn’t quite put my finger on what.
My first impression of XD-05 (stock) was not unlike that of the Fiio X7 with AM1: extremely clean and polite sounding, but not lacking in detail. Afterwards I saw that the X7 uses the same OPA1612 opamp so that might explain it.
Swapping to the V5i, the first thing I noticed was that the bass punch (speed?) had increased, big drums like the wadaiko (traditional Japanese drum) had a THUMP that was more felt than before. The overall sound became *slightly* more spacious just perceptibly more musical.
I repeated this swap several times over the period of a few months, sometimes letting others listen as well. Each time, the response was the same: the V5i tweaks the sound ever so slightly towards musicality and punchiness of bass. However, it must be emphasised that this is more of a sidegrade than a significant upgrade; a subtly different flavour, if you will, than another animal entirely.
To try to pinpoint and verify if there is indeed a difference, I enlisted the help of
@earfonia (thanks Bram!) and his advanced measurement equipment. We used his QuantAsylum QA401 to directly measure of the output signal of the amp, rather than using a calibrated mic. Results are below:
OPA1612 and V5i at 1kHz, 33 Ohm load, 50mV. There is some slight channel imbalance.
OPA1612 and V5i at 1kHz, 33 Ohm load, 1V. Channel imbalance has all but disappeared.
As it turns out, the V5i actually measures slightly worse than the stock OPA1612 in terms of SNR at lower levels (thereby demonstrating that the stock 1612 is indeed the ‘cleaner’ sounding of the two), but at higher levels they measure exactly the same. Harmonics behave slightly differently though, and may account for the perceptual differences between the two.
Later on, I had a thought that my low-mid-fi gear may not have the level of resolution needed, so I went to Stereo Singapore (many thanks!) and borrowed their UM Miracle V2 to repeat the experiment. Finally, a substantiable difference could be perceived. Using the Yuko Suzuhana’s song Yuki Tokei (jp: 雪時計) from her Cradle of Eternity album, there is a twinkling sort of sound at the start of the song that is quite 3d, and it seems to reach the limits of the soundstage. With the V5i, the XD-05 clearly produced a significantly wider and deeper soundstage than with the stock opamp (twinkling sounded further away).
@timorinolee, who also has the XD-05 and V5i, had a similar experience:
“I actually find it much warmer and musical compared to the stock opamp. Definitely can hear the difference in tonality.
Besides that, it's more balanced/natural sounding, love the mid bump it brings, soundstage has increased as well.
Better bass, although sometimes I wish there was more (thankfully for the bass boost).“
These are my impressions up till now, I will update if I discover anything new.
Many thanks to
@SS-Audio again for the opportunity!
