AOpen AX4GE Tube-G

Review by Harry Lam on 03.01.13
Motherboard provided by AOpen

Differences between the AX4B-533 Tube and AX4GE/PE Tube:

The design differences between the AX4B-533 Tube and the AX4GE Tube-G are readily visible in the pictures below.  Both are based around a 2 channel amplification design, but there are differences in the components as well as in the circuit itself.

AX4B-533's TubeSound	AX4GE's TubeSound

The daughterboard card for the TubeSound motherboards has changed significantly from the AX4B-533 Tube to the AX4GE Tube-G, with AOpen removing the headphone and SPDIF jacks on the daughterboard.

Bracket on the AX4B-533	Bracket on the AX4GE

Differences between the AX4B-533 and AX4GE/PE Tube (ripped from AOpen's website, and formatted to fit TWL):

There is an entire segment on AOpen's R&D team that tweaked their TubeSound Amplification section of the AX4GE/PE TubeSound manual.  It made a very interesting read, although it is a bit wordy for the less technically inclined.

This is AOpen's own internal results on the audio differences between the AX4B-533 Tube and the AX4GE/PE Tube.  I for the most part agree with these results, although the audio differences weren't as drastic as between the codec outputs and the tube based outputs.  Personally, the difference I noticed the most was that the AX4GE/PE did shine a lot more during trance music (which personally is my favorite genre of music) and was a tad bit weaker at classical (but not very significantly).