Asus Essence ST - cheapest upgrade

[abraxalito]

I've just upgraded my Asus Essence ST with a change to 4 caps in the balanced I/V stages. Originally, I think these caps were the values in TI/BB's recommended output stage, but they got destroyed as I was removing them, so I couldn't check their value. However by replacing them with 100pF NP0s, I've made a worthwhile improvement to the sound. Specifically, much deeper sound stage and better resolution of low-level details. Total cost of the upgrade - less than 1 yuan.

More details to follow if anyone's interested in trying this.

 

[phizen]

I am interested ;-)
Have already modded my STX to a certain degree.
Did you choose specific opamps for IV stage?
I am using LME 49990 @ the moment. Very low distortion, but the sttling time discussion got me interested in say the AD8066.
Thanks!

 

[zman01]

Abraxalito,

Got the Xonar STX - would the same mods apply? Anyways would be interesting to knw more about your experiment!

 

[abraxalito]

@zman01 - I reckon the STX is just the ST with an extra bus interface chip tacked on. So I reckon the same mods would apply.

I put more details of this mod up on Head-Fi here: HELP! Need opinions for upgrading to Benchmark DAC1 HELP!

 

[zman01]

Thanks for sharing the link. Look forward to more listening impressions going fwd. Do you see any difference in bass articulation and energy in mid-bass/upper mid bass?

My soldering skills are non-existent, so don't dare to touch the PCB w/o help of someone more experienced.

 

[abraxalito]

Ironically, I've abandoned all sigma-delta based chips in my search for sonic nirvana. The future is definitely multibit as far as I'm concerned. (See my blog if you'd like to learn more).

 

[zman01]

Abraxalito,

Just curious, before performing surgery on the Xonar , did you try the opamp swap discussed here:

ASUS Xonar Essence STX soundcard review

 

[abraxalito]

Nope, I came to this card having tried out various I/V opamps on my AD1955 DAC and had already decided LM6172 sounded best (with the cap mods). I did try a few JFET opamps but didn't much like the sound compared to bipolars, with the exception (if I recall correctly) of the AD845.

 

[zman01]

Abraxalito,

Got some LM6172 opamps to try out in my Xonar STX. Did a swap to OPA2134 from the default JRC ones few weeks back - like the results a lot, so ready to explore more choices.

Referring to your earlier thread:

HELP! Need opinions for upgrading to Benchmark DAC1 HELP!

One of the posters suggest soldering the required capacitor(s) to the legs of the LM6172 opamp directly.

Just to clarify, if I do so, no need to take out the capacitors on the PCB, right?

 

[abraxalito]

If you leave the original caps on the PCB they'll be in parallel with the caps on the opamp, rather defeating the mod. So yeah you do need to remove the PCB caps to get the benefit of this.

 

[zman01]

If I were to go back to OPA2134

If you leave the original caps on the PCB they'll be in parallel with the caps on the opamp, rather defeating the mod. So yeah you do need to remove the PCB caps to get the benefit of this.

Ready to take the dive with the LM6172 and do away with the caps on the PCB, but worried if I would be able to revert to the OPA2134 in case I do not like the LM6172 on my system.

Since this mod calls for caps to be soldered to the legs of the ompamp(s), so would it be a case of soldering the caps (2x2200 uf/opamp) and then installing the OPA2134?

 

[abraxalito]

Yes once you've removed those four caps from the PCB, if you need to go back to OPA2134 just solder the 2n2s (use 0805 C0G dielectric) between pins 1&2 and 6&7 of the 2134.