I've auditioned and compared the two models at home. There is a huge difference IMHO.
To resume both have a great definition and quite same sounding in the high but with the INT60 you will have much deeper and more define bass and a wider soundstage.
I've also found the Int25 a little bit "agressive" when you turn up the volume. I've always preferred to keep it under 30.
This could be explained by its limitations in the bass register.
I've kept the INT60 for these reasons.
Gear: AvantGarde Uno Xd, Audiomat Maestro 3 Réf, Esprit Structura loudspeaker cables, D4 XLR ZenWave Audio, Pass Labs INT-60
To resume both have a great definition and quite same sounding in the high but with the INT60 you will have much deeper and more define bass and a wider soundstage.
I've also found the Int25 a little bit "agressive" when you turn up the volume. I've always preferred to keep it under 30.
This could be explained by its limitations in the bass register.
I've kept the INT60 for these reasons.
Gear: AvantGarde Uno Xd, Audiomat Maestro 3 Réf, Esprit Structura loudspeaker cables, D4 XLR ZenWave Audio, Pass Labs INT-60