Empirical Audio modded DAC1 initial impressions

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.

_______________

"Option 2: Pulse Transformer upgrade - $150"

What kind/make of pulse transformer does he use?

Steve posted on head-fi about the pulse transformer:

"BTW - the NEW pulse transformer upgrade includes a 75 ohm isolated Canare BNC rather than the 50 ohm BNC that comes on the unit. This isolates the unit and eliminates the ground-noise that you are experiencing."

http://www6.head-fi.org/forums/showthread.php?t=130714&page=3

And here are my speaker/heaphone out impressions:

Thursday I packed up my mpx3 to send back to Mikhail as I am upgrading to a Supra. Which I figured would give me plenty of time to compare the headphone outs on my stock and modded dac1's.

Well, I have had time to compare the headphone outs. And the results are quite disappointing. There definitely is a difference b/n the two headphone outs, but it is nowhere near the difference I noted using my mpx3. So I listened a bit, switching back and forth b/n the modded and stock unit via disconnecting and reconnecting the cardas coax out from my marantz cdp used as a transport. In comparison to the mpx3, I find the headphone out on the dac1 to be rather stale and uninvolving in comparison. I listened long enough to compare the headphone outs b/n the stock and modded and have come to the conclusion that while there is a small difference, this is not the intended use for this unit. Neither in stock nor in modified form.

Listening through the head-outs was actually so uninvolving that I actually stopped out of relative boredom - I felt as if though I were listening to my now sold _relatively_ low end SS head amps.

Now, after acquiring my mpx3, I had become so enamored with its sound, that I have basically neglected my speaker setup for months. But now that the mpx3 is gone, and I found myself not enjoying the head-outs on either dac1 to any significant degree, I thought, well, might as well hook up both the stock & hot-rod dac1 to the speakers and see what happens. After all, a few people here have alluded to the benefit of the modded dac1 w/ speakers.

So here's my setup:

Toshiba 4900 dvdp -> Straightwire 1.5-2.0m digital coax -> BNC adaptor -> Stock & Empirical Audio modded DAC1 (manually switched) -> Outlaw Audio 0.5m PCA IC -> NAD S100 Preamp -> Outlaw Audio 0.5m PCA IC -> NAD S200 Amplifier -> DH Labs Silver Sonic T-14 Speaker Cable -> Madisound Cygnet Mark 1 Speakers (Utilizing Peerless 8" Driver and Peerless Fabric Dome tweeter). Simultaneous output from preamp goes to NHT X-2 crossover to Rotel RB-870 BX (one channel) amplifier to Madisound NHT1259 Subwoofer and cabinet via Straighwire IC.

I sat in the sweet spot on my couch and used Feist's cd Let It Die as my source disc. I was immediately reminded of the results I obtained when using the rca outs with the Singepower. High frequency extension was much better. Sense of air surrounding instruments was much better. Textural detail of vocals was much, much better. Bass extension and control was much better. But the biggest difference I noticed with my speaker setup is that overall musical enjoyment and involvement was significantly better with the modded dac1. My speaker rig doesn't have the greatest soundstaging, so I can't comment on that too much, but overall dynamics and sense of realism/live performance-in-front-of-you were basically in a different league than the stock box. As a matter of fact, it has added such new life to my speaker setup that I'm considering having my 2nd dac1 modded as well.

In summary, I must say that the headphone output mod, while providing a slight difference, is not really worth the extra cash. At least according to my ears and my 650s.

Alternatively, utilizing the rca outs to both my Singlepower mpx3 setup and my speaker rig, there is basically no comparison and the more I listen, the more I am thrilled with my mod investment. My original plan was to sell my 2nd dac1 to pay for the mods on the 1st one, but after listening to this extent, I am seriously considering sending my 2nd dac1 in to be modded as well so I can throw it into my speaker rig, as it has really provided a kick-in-the-pants that has been missing over the last few months.