ASUS Essence One review -
A Look Inside - Power Section
It is said that one of the most important aspects of high end external components is the power system design. Experts suggest that bad power source and conditioning, logically equates to bad overall sound quality.
The Essence One DAC uses a Toroidal transformer. The units are usually more expensive but when speaking of power systems for audio products these are usually at the top of the list. These products dont produce large external EM fields in comparison to more tradition types so this keeps internal interference from the power system down to a minimum.
This information is here for discussion sake only and we do not recommend modifying your new Essence One DAC. You can easily damage your unit and certainly void any warranty. If you still want to modify this unit please take it to a skilled technician. If not, dont say we didnt warn you!
You could replace the external connectors with higher quality units well not so much for sound quality improvement, but they can help in keeping the device solid in the long run. That is not to say the stock units are low quality but you can always find products to pimp out your sources. Look at connectors from Cardas, Connex, Vampire, WBT and others.
Although the E1 is actually using higher grade capacitors throughout the design, you could always use higher quality units in key areas of the design such as the power section and opamp capacitors.
Look to Black Gate, Elna and others. Such modifications are much higher up the ladder though for skill level and generally done by hard core modders looking to tune every aspect of the device. We figured we would mention the option anyway.
Considering how many opamps are in this circuit and the multiple combinations possible, we decided to stick to some simple swaps for the end user. We actually spent about 2 weeks just testing opamps in the various positions and attempting to refine the signature in different ways.
To list every combination we tested for I/V, LPF and buffer would take a very large article in itself and is beyond the scope of this review.
In order to present the end user with some information they may find helpful, we decided to concentrate on the headphone buffer opamp pair only. The opamps were chosen from our lists, based on their price and availability in most cases. The OPA2111AM is a higher end unit and a bit harder to find but we wanted to put it in the list anyway.
Note: These are results found during some of our testing, please take them as opinions as opamp swapping is very subjective and what we hear depends on many factors.
These metal can opamps are a natural choice for this circuit as they are a higher end version of the stock units used. In the Essence, these chips always seem to improve the signature over the chip versions. The HA versions improve the high end extension and overall sonic signature. Although these chips are a bit pricier and require adapters over the stock version, if you are looking for a cheap upgrade, keep this model on your short list.
The OPA2107 offers an excellent bass response and a smooth high range while maintaining the overall signal clarity. Some audio enthusiasts consider this chip to be a poor mans version of the famed OPA627 modules. This unit offered a big spacious soundstage offering excellent imaging and should be tested by those looking to tune the headphone output.
The AD797 seems to be a favorite among some audio nuts and this unit seemed to improve the bass signature and give the E1 a more organic sound while adding some warmth to the overall signature. The higher range has a nice open, airy sound with great detail and extension. This unit should be put on your short list also.
The signature warmed up a bit, smoothing out the response in the high end. These amps provide excellent sense of space with, no smearing or mushing. These units add more musicality; the bass seemed to have a bit more weight without washing out. The 2111AMs offered excellent soundstage reproduction. It should be said that these opamps are a higher end unit sought after by audio enthusiasts but there are Dip8 versions also that can be used and while not quite the same grade they can still offer some of the same type of signature.
We cant list all of our choices for each position but feel free to ask or contact the leb and we can offer some suggestions. The above opamp selections should be a good start for those interested in changing the opamps in the Essence One.
A great point here is the entire signal chain of the Essence one is basically kept in dual mono mode starting from the DACs all the way to the outputs which keeps the audio pristine.
The ASUS Essence 1 is easily one of the most anticipated products to come along in the PC audio community in quite some time as many seen it as ASUS moving out of the general audio market and taking a shot at entry into the true high end audio marketplace. Can this new product offer excellent sound quality, features demanded by the external audio market and all for a reasonable price?