[leeperry]

Quote:

Hey guys I'm trying to improve the details on this DAC and make it a tad more laid back.  Are there any op-amps I can switch to achieve this?

 
I believe Asus made a PDF on this subject, but OPA2132P would be a safe bet 

 

[winged creature]

Would i be replacing all of the opamps with that particular one, or would I choose a particular opamp.  Im new this whole mod stuff

 

 

[daws0n]

I'm still awaiting the rest of the chips to complete the upgrade, but so far I have replaced the RCA output stage and low pass filter chips with LME9720HAs (3 altogether). The change was not subtle - the "edgy" treble/brightness has gone and the DAC's sound signature has more midrange weight and a noticeable increase in bass output.
 
I plan to to replace the NE5532PE chips in the I/V stage with the same once they arrive. So far I am pleased with the change.
 
I considered using the more expensive single LME49990s (See above) but decided against it - they require good PSU decoupling caps and I am not sure the E1's layout is sufficient (people who have tried this combo have reported the chips run very hot, suggesting oscillation). In contrast, the LME49720s only has half the gain bandwidth, and is a less/fussy more stable chip to "drop in" to an existing circuit.
 
Good luck
 
Dawson

 

[mwindham08]

I've ran the E1 with the dt 990s 600 ohm and the T1 and it runs them both great. Should be no reason to go past 12, let alone turn volume all the way up. If I did that with any of my Beyers I would go deaf!

 

[daws0n]

Hmm interesting development... Asus are releasing a special "MUSE" edition using 6 x NJRC MUSE 01 opamps for the I/V and LPF stages:

http://www.6moons.com/audioreviews/asus/1.html

It's considerably more expensive, so I checked out these chips are they're $50 each on digikey?! Wow, I sure hope they're worth the money - strange how Asus have gone for this seemingly little known estoric chip and not something reputable from Texas Instruments, Burr Brown et al.


 

 

[midnightfox]

Quote:

Hmm interesting development... Asus are releasing a special "MUSE" edition using 6 x NJRC MUSE 01 opamps for the I/V and LPF stages:

http://www.6moons.com/audioreviews/asus/1.html

It's considerably more expensive, so I checked out these chips are they're $50 each on digikey?! Wow, I sure hope they're worth the money - strange how Asus have gone for this seemingly little known estoric chip and not something reputable from Texas Instruments, Burr Brown et al.


 

 
Quite an interesting article as you get to read a little about the development team behind the Essence One and there future outlook. I will be interested to read a full review on the Muses Edition and how well it sounds with MUSES 01 Op-Amps.

 

[daws0n]

Yes I thought so too. I've completed the upgrade on mine (67xLM9720HA metal tin op amps on I/V and LPF stage, plus another for the RCA output) and am pleased with the results - the fact that there are now 3 editions of the E1 (original, PLUS and now MUSE) goes to show that the NE5532 configuration was hardly optimal and chosen for cost reasons rather than absolute performance.... I am looking forward to hearing how it sounds with these MUSE opamps also, but given the price of them I doubt I'll take the plunge!

 

[nosemanny]

I just got my Beyerdynamic T1 and I was suprised that the ASUS drives them easy, I have the volume at 9 o'clock and I find it quite good, but I dont have any experience with other more expensive amps, but I'm thinking to get Bottlehead crack or Woo audio wa2 later I'm not sure yet.

 

[daws0n]

New drivers and firmware have been released - well worth checking out IME, fixes all the issues I had regarding the bit perfect LED misbehaviour and ASIO pops/clicks.
 
I have to say with the recent opamp upgrade and these new improvements this is a top DAC!

 

[DMarasovic]

Quote:

New drivers and firmware have been released - well worth checking out IME, fixes all the issues I had regarding the bit perfect LED misbehaviour and ASIO pops/clicks.
 
I have to say with the recent opamp upgrade and these new improvements this is a top DAC!

Agree with you, ASIO pops/clicks are removed

.
Sounds top class and stable with AD797 BR on I/V, LME 49720 HA on buffer and headamp buffer.
Excellent is LT 1028 on I/V with dry bass, but very analytical and detailed.

 

[Suopermanni]

I've got one of these and from the discussion here, some of the respondents here know how to mod it. I've just got two main questions I need to ask you guys.
 
1. Is there a method to change OPamps in relative safety? I've had nightmare experiences with OPamp swapping before, mostly causing my devices to stop working.
 
2. How do I know what goes where? I'm a newbie at this sort of thing so I don't know what type of OPamp goes in what slot. I've read the OPamp guide done by Asus and I understand that but if I want to do more, what do I have to know?

 

[daws0n]

Here's a low down of my experience with op-amp installation/best tools for the job etc...
 
http://rockgrotto.proboards.com/index.cgi?board=talk&action=display&thread=7599&page=3

 

[leeperry]

Quote:

Sounds top class and stable with AD797 BR [..] LT 1028 on I/V

 
Did you manage to stabilize them? AD797BR was wooshing IME from time to time, and I can't imagine what the super cranky LT1028ACN8 would do 

 

[daws0n]

I am interested in hearing your comments too DM - how do the AD797 sound on the I/V?
 
In my experience the biggest leap was when I swapped the RCA output and LPF to LME49720HAs, that really transformed the DAC's character in my system... When I eventually bought more to upgrade the stock I/V I did not hear that much of an improvement in comparison.
 
@ Suopermanni
 
You need to swap all opamps from a given section in one go.... Going from front to back - the I/V opamps are the row of 4 chips, the LPF is next row (just 2 chips) and the remaining 3 nearest the output jacks at the back are for the output stage(s). The top right hand chip effects the RCA output, and the two left of that one are for the XLRs (one for each channel).

 

[DMarasovic]

Quote:

 
Did you manage to stabilize them? AD797BR was wooshing IME from time to time, and I can't imagine what the super cranky LT1028ACN8 would do 

AD797BR and LT1028 (on 2x mono to dual adapters) work stable on I/V stage when followed by LME49720 HA or LME49720 DIP or LME 4562 or LME 49860 on Filter/Buffer.
I/V stage uses high amplification rate and uncompensated IC's are stable. At all other stages there is mainly buffering and low amplification rate so there is the need for compensated IC's.
 
Quote:

I am interested in hearing your comments too DM - how do the AD797 sound on the I/V?
 
In my experience the biggest leap was when I swapped the RCA output and LPF to LME49720HAs, that really transformed the DAC's character in my system... When I eventually bought more to upgrade the stock I/V I did not hear that much of an improvement in comparison.

AD797 sounds like listening to live performance, not emhasizing anything but with lots of bass, midrange and highs. It is not easy to explain. You can concentrate on any instrument and take attention to it's line. Soundstage is very 3D. I can listen to them long time with no fatigue. LME 49720 HA's are very transparent and pass all the AD797's goods to outputs.
LME 49720 HA's compared to LME 4562 has clearer and more detailed highs, smoother midrange, bass is the same. LME 49860 has more pronounced highs, less bottom end.