[serengetiplains]

I received an Overdrive Signature from Steve several days ago and am now prepared to give some initial impressions.  My listening setup is this:

MacBook Pro with SSD ---> Amarra ---> Lotus Polestar ---> Overdrive DAC ---> AES out to Sennheiser HD800 headphones (balanced drive)

Everything is plugged into an Accuphase power conditioner, itself plugged into an Elgar power conditioner for double-duty series conditioning.  Just the way I like it.

Upon receiving the unit, the first thing I noticed is how clearly it resolved the sound.  Interestingly, I could sense myself adjusting to the sound---a kind of mental adjustment, I think---as it was sufficiently different to require I acclimatize.  I also noticed a certain edge I assumed was due to capacitor break-in, being a lack thereof.

I then operated the unit for four days uninterrupted.  The edge disappeared, and while the unit cooked away, I couldn't resist tinkering and replaced the +18V and 12V switchers with Paul Hynes SR3 units.  Now, how did I just happen to have those sitting around my house?

Wow, this is one fine unit, Steve.  Even without the Hynes supplies, which maybe add 10%, this DAC really performs.  Most evident to me among its many qualities are clarity and transient response.  I've not heard such clarity and attack, which together combine to a kind of crystalline transparency.  It was this quality that required I mentally readjust as I mentioned above. 

Bass is wonderfully articulate, dynamic and full, though through the Sennheisers sounds a little light.  I suspect an extra few uFs output capacitance would cure this.  From other user comments I've read, light bass response is not a characteristic feature of this DAC.

Using the same setup with the same balanced-drive Sennheisers, I compared the unit to a Playback Designs MPD-5 DAC I have in my possession.  I had to listen a little carefully, but within a handful of songs, I felt a clear preference for the Overdrive: it's clearer, cleaner, more resolved, has a more delicate, engaging sound.  FWIW, I consider the difference between the two DACs less than that between Amarra and iTunes.  Going beyond mere sonics, though, the Overdrive scores with its fine volume control (good going on that one, Steve).  Volume must be controlled using Amarra for the MPD-5.  Because of this, all comparative listening between the DACs was performed at full volume for the Overdrive and at -6dB on Amarra for the MPD-5 to volume match.  Turning the volume up to 0dB on the MPD-5 didn't change the character of the sound, resolution, dynamics, etc.

Also of note, the Overdrive uses a Superclock 4.  I have a Tascam/Pace-Car/Ultraclock setup waiting to intall into this system, but Snow Leopard or something else I'm unaware of has prevented Amarra from recognizing the Tascam.  I expect a nice sonic upgrade once I'm able to solve this little glitch.

Smoking good DAC, Steve!  I am often disappointed at the appreciable oversights I see in how designers treat power supply and power delivery.  Not with the Overdrive.  Beyond the unique (non-switching!) volume control and what is likely fine digital implementation, I suspect this excellent sound I hear has much to do with Steve's attention to power supply and power delivery.  Bloody hell, someone's finally looking that direction!

[serengetiplains]

I wish to add one further characterization, that in addition to crystalline transparency, this DAC resolves harmonics exquisitely.  I often listen to Tord Gustavsen to test a unit's harmonic rightness.  With the Overdrive, the harmonic bloom I hear is as if my head is inside Tord's piano.  The subtle feeling this incites in me hints to me the universe must be made of some such stuff called harmonics.  Forget good food and good wine, give me musical harmony.

Btw, for those unfamiliar with the Playback Designs unit, read this.

[serengetiplains]

I got the Pace Car working.  The unit has an Ultraclock installed, which is the main operating clock in the system with the Pace Car installed.  An additional benefit the Pace Car adds beyond its better clock is it connects to the DAC via I2S on the Pace Car outlet, avoiding a stage of digital circuitry.

It's a little soon to give settled opinions on the Pace-Car-added sonics of this system, as I think a little more break-in (more than a single day's) is called for.  That said, I hear an extra measure of clarity, particularly in tonal definition.  An acoustic bass sounds just a little more like the woody, rosiny thing an acoustic bass is.  Sweet.

I have a few upgrades planned for Pace Car.  One is to power the clock from a 12V LiFePO4 battery, another is to separately power the remaining circuitry from a Paul Hynes supply, or possibly another battery.  I expect another upgrade in sound.

I actually feel grateful for the fine product Steve has created with this DAC.  Listening is just so consistently enjoyable, interesting, engaging and moving.  Wow.  Thanks for a great product, Steve.

[audioengr]

I got the Pace Car working.  The unit has an Ultraclock installed, which is the main operating clock in the system with the Pace Car installed.  An additional benefit the Pace Car adds beyond its better clock is it connects to the DAC via I2S on the Pace Car outlet, avoiding a stage of digital circuitry.

It's a little soon to give settled opinions on the Pace-Car-added sonics of this system, as I think a little more break-in (more than a single day's) is called for.  That said, I hear an extra measure of clarity, particularly in tonal definition.  An acoustic bass sounds just a little more like the woody, rosiny thing an acoustic bass is.  Sweet.

I have a few upgrades planned for Pace Car.  One is to power the clock from a 12V LiFePO4 battery, another is to separately power the remaining circuitry from a Paul Hynes supply, or possibly another battery.  I expect another upgrade in sound.

I actually feel grateful for the fine product Steve has created with this DAC.  Listening is just so consistently enjoyable, interesting, engaging and moving.  Wow.  Thanks for a great product, Steve.

Tom - this is what it's all about:  How it makes you feel.  Humans need music, and the better the music conveys the musical story, the better you feel.

If you are grinning ear-to-ear, so am I.

Best Regards,
Steve N.

[serengetiplains]

I was fooling with an old Elgar line conditioner today, adding some power supply bypass capacitors, changing wiring here and there, installing good low voltage supplies.  After all my fiddling I plugged it in and it worked, so I thought I'd get out my Overdrive which I haven't heard in a week or so.  Coming back to it I wondered if the impressions I posted above would seem perhaps a little overstated or hyperbolic, cuz you know I don't like misrepresenting things.  Well, the answer is I didn't overstate.

My god this is a good DAC!

    

[audioengr]

I have feedback from one customer in Europe that changing the AC polarity of only the 12VDC wall wart improves the sound, assuming that you are not using battery.  If it is opposite from the 18VDC wall warts it is evidently better.  Give this a try and let us know.

Steve N.

[kaka]

The Overdrive is here and getting underway, thanks Steve

I started with all the wallwarts but swapped across to the BPT battery supply for the 12V, and it is far smoother with that supply in the mix. Quite a change.

But there is plenty of playing-in to do before making any  permanent judgements of course.

I see serengetiplains has run with a Hynes 18v as well as a 12v, can you remember how much improvement you got from the 18 as opposed to the 12, or did you do both in one shot?

Thanks

[serengetiplains]

Hi, I installed both Hynes supplies at once.  I didn't listen very carefully for perceived differences when I installed them, though my sense with the little comparison I've done is they provide a decent upgrade.

[satfrat]

Hi, I installed both Hynes supplies at once.  I didn't listen very carefully for perceived differences when I installed them, though my sense with the little comparison I've done is they provide a decent upgrade.

I got the same impression with the Hynes SR3-12 on my Off-Ramp 3 w/Ultraclock. 
 
edit: which btw is plugged into a BPT BP2.5 maxed out Ultra. 
 
Cheers,
Robin