Here is a cut/copy/paste of my weekend impressions as posted at head-fi.org:
Empirical Audio modded DAC1 vs. stock DAC1 comparison.
Okay everyone, here are the results of my comparison of my stock DAC1 vs. the Empirical Audio modded DAC1 (including opamp replacement and superturboclock3).
My setup is as follows:
Source: Marantz cd5400 digital out via coax using Cardas digital high speed cable with bnc adapter included with DAC1. I have 2 DAC1 units. A stock version and one turbomodded by Steve at Empirical Audio. I connected both DAC1's simultaneously to my dual input Singlepower MPX3 via Outlaw Audio PCA 0.5m RCA interconnects. I was therefore able to switch between sources via unhooking the Cardas cable from the stock DAC1 and hooking it up to the modded DAC1 and vice versa, and then switching from input 1 to input 2 on my MPX3. The time to switch b/n sources took approx. 15 seconds. The signal path from the Marantz to my HD650/Zu combo was identical from the cdp->Cardas->bnc adapter (included w/ DAC1)->DAC1->Outlaw PCA IC->MPX3->Zu->Senn650. The stock power cords were used with the DAC1s, ground pin lifted via adapter.
Now, although this is a work in progress, here is a summary of my experience thus far:
First, while listening to jack johnson's cd on and on I noted that the cymballs with the EA unit were more extended in frequency, more detailed such that I could hear the impact of the cymballs and the rattle of each as they were played. Midrange was much smoother and more realistic, as well as more liquid sounding. And the bass was definitely tighter and deeper.
Moving on to the Garden State Soundtrack, the shaker on Thievery Corp.'s Lebanese Blonde sounded much more "in the room with me" than the stock unit. The separation of instruments was much better and the bass lines were more well defined and better controlled.
On Iron and Wine's track, Such Great Heights, the vocal texture was much more complex and I could hear at least 3 distinctly seperate voices during harmony, while listening through my stock dac1 I was unable to differentiate the voices. Also, the analog tape hum/detail was actually much more detailed w/ the modded unit . The other thing I noted was that I could almost 'see' the guitar strings being picked with the EA DAC1, as opposed to just 'hearing' the notes through the stock unit. Almost as if the stock box sounded compressed in comparison.
Then after throwing in the remastered 1984 from Van Halen, there just is no comparison. The drum intro on Hot for Teacher just has more air, more high frequency extension, and more detail than the stock box. Not to mention the tonality and harmonics of Eddie's guitar.
Finally, I listened to the AC/DC remaster of Who Made Who. The detail,air, high frequency extension and seperation of instruments is just unequaled by the stock unit. Bass control and depth is also unmatched.
So, after comparing apples to apples, I remain extremely pleased with my modded unit. My overall impression is that the modded unit adds musicality, detail, and removes a layer or two of 'veiling' from the sound of the stock unit without sounding bright or sibilant and maintaining a high level of musical enjoyment that I have not previously experienced. Bass detail and control is improved as well, and midrange detail is much better. Are the upgrades worth it? I certainly think so. This is exactly what I was hoping would come from modding my dac1. I guess the only way to tell for sure is to compare my box to other high-end sources in the same/higher price range. Hopefully I can do this during upcoming head-fi meets. In the meantime, I certainly recommend these mods and I am definitely going to have Steve work on my transport as well. Please let me know if any of you have questions.
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