being a big fan of class a amps and have build a lot of them over the last years i hoped for a high biased amp/dac modul when i saw the only singelended output from the e01 treaser - and the wish was fullfield
so i ordere the module asap.
it's now in the house since around 2 weeks - well burned in. the es9038pro is a fine neutral/natural sounding dac chip, has lost the es9018 flavor for good. imo it's even more neutral as the akm4497. depends a lot of the implementation but the akm has often a tad smooth/gentle sound signature, the modul a01 is one that even increased this nature. both chips are very good even in a single chip desing. love that you can choosed your prefed dac filter setting, my preference with most dac chips from different manufacturer is the slow roll-off minimum phase filter.
the first day i was a bit puzzled about the class a setting of the e01 module. when you build a class a amp and set the bias the sound changes from (low bias) energetic/speedy to dynamic/effortless to thick/rounded (imo to high bias). the effect of a too high biased class a amp is often that the powersupply isn't stable enough for the demanding continous power. this was the effect i heard with the class a vs class ab modus, so i preferd the class ab with his better dynamic and a lot wider stage, class a stage was even a bit colapsed and 2 dimension. so i assumed the module was underpowered in class a modus.
but i was wrong, this effect is only when you use the modul in low gain and class a, as soon you change to medium/high gain and class a the amps part performs excelent. i think low gain isn't enough to drive the transistors within a good range. set to medium or high gain class a opens the stage in all 3 dimension as with class ab but adds effortless and easyness of the presentation. a good class ab amp sounds often a bit more dynamic and powerful.
cayin tuned this module very nice, class ab is more neutral and true to orginal with nice snappy dynamics, fine wide exact soundstage, solid attacks. class a is biased a tad higher as most class a amps i know but only a tad imo to get imo some gentle harmonics similar a fine tube amp. soundstage is wide, a tad rounded like in a more damped room without loosing placement, dynamics flows very effortless, attacks are more in line with the music. imo clever made, for me this is more a class a- and class a+ module, not at all dry like some other chips amps.
personally i like class a mode with m/h gain more, it sounds more real like being in the opera or a not overamped life konzert. there is a room, are people and furniture thus loosing some details which you can only hear from records with many mics and fine mixing. but of course depends on mood and gear, both options are excelent for the price.
vs my wm1z the performance is near as good, tad better resolution with the sony. price whise the cayin/e01 is the better deal.
didn't tested the module with hard to drive headphones/iem. works effortless with the tia trio, ier-z1r, lab2, zmf verite, so so with the diana phi. overall more powerful then i expected.
next module.. how about a dual pcm1702 with a nice upsampling dsp and two pga2311