[I.Greyhound Fan]

Today I picked up my Ultra DAC from Frank that I had modded with the upgraded Mosfets.  I can honestly say that I am truly stunned at the improvement in sound.  The best way to describe it is that there is more emotion to the music. Every aspect of the sound has improved.  It is more dynamic, the treble is smoother with more resolution. There is no fatigue at all.  Bass is punchier, faster and deeper.  The overall sound has more depth and power without being forward.  The sound stage and transparency improved as well.  Even my 20yr old son was impressed and commented on how much better the sound was.  Whats even more impressive to me is the fact that I gave the DAC to Frank with the stock Electro-Harmonix tubes which I normally don't use because they are way too bright in my system, but when I got the unit back it sounded great. I may just leave the EH's in place but there is some tube rolling in my future.

[martyo]

Okay okay, I'm sending in my DAC.

Thanks Larry, glad it worked out, in spades, too.

[Wally King]

Today I picked up my Ultra DAC from Frank that I had modded with the upgraded Mosfets.  I can honestly say that I am truly stunned at the improvement in sound.  The best way to describe it is that there is more emotion to the music. Every aspect of the sound has improved.  It is more dynamic, the treble is smoother with more resolution. There is no fatigue at all.  Bass is punchier, faster and deeper.  The overall sound has more depth and power without being forward.  The sound stage and transparency improved as well.  Even my 20yr old son was impressed and commented on how much better the sound was.  Whats even more impressive to me is the fact that I gave the DAC to Frank with the stock Electro-Harmonix tubes which I normally don't use because they are way too bright in my system, but when I got the unit back it sounded great. I may just leave the EH's in place but there is some tube rolling in my future.

Did the change made to your Ultra DAC essentially make it a Vision hybrid?

[I.Greyhound Fan]

Did the change made to your Ultra DAC essentially make it a Vision hybrid?

It is not quite a Vision Hybrid.  The Vision uses new circuitry.  Maybe Frank can elaborate?

Martyo, this was the best $300's that I have spent on my system.  The DAC upgrade made a much greater improvement in the sound compared to the upgrade to my Ultra preamp but maybe it is because of the synergy between th DAC and preamp upgrades.

[avahifi]

The Ultra Series DACs use our original Philips 16 bit x 4 digital chip set, followed by a very very fast and linear solid state current amplifier and then by the Fet Valve hybrid (triode and power mps-fet) analog filter and output section.  The Ultra series made major improvements to the solid state current amp section, the Ultra II does the same for the hybrid tube section, replacing the original J79 Hitachi mos-fet with a Exicon 10P20 devices along with some circuit changes to make this work best.  6CG7 tubes cannot be used in this unit without running the unit with the cover off.  The hybrid filter board cannot be lowered enough in the chassis to provide cover clearance.  Larry's unit has the cover raised on small stand-offs to provide clearance for the 6CG7 tubes.  However, with the Exicons, both 6N1P and 12AT7 tubes work really really well (not interchangeable without heater supply revisions!)

The Vision series DACs use the more modern Wolfson 8742 chip set allowing high bit rate capability.  The hybrid board in the Vision Hybrid DAC has a distinctly different topography as the output of the Wolfson itself is a voltage, not a current.  It too uses our patented hybrid transimpedance amplifier with a 6CG7 followed by the Exicon 10P20.  Both versions are great, only the Vision is capable of 96/24 and 192/24 performance.

Regards,

Frank Van Alstine

[srb]

Both versions are great, only the Vision is capable of 96/24 and 192/24 performance.

Based on your website, I was under the impression that beyond its high resolution capability, that the sound quality of the Vision is much improved over any of the other earlier models:
 
"It sounds more musical than our best previous solid state, vacuum tube, and vacuum tube hybrid DAC designs! It makes them all sound pale and flat in comparison. We did not expect that. The Vision DAC is so amazingly musical, dynamic, transparent, and easy to listen to long term that we must sadly discontinue our current Ultra+, Transcendence Eight, and Insight+ series DACs. They can no longer stand up as the best we can do."

 
Steve

[avahifi]

That information was true at the time, but we never stopped working on making the Ultra DAC better because a major sonic improvement to that would be much less expensive for our clients that owned one than the cost of a brand new Vision DAC.

We hate to obsolete the equipment our long term clients own, not a good way to say thank you for their long term support.

So we went back to work on the Ultra DAC, even though it is a discontinued model, to see just how much better we could still make it, working within the context of the Philips digital chip set.  We were able to improve it much more than anticipated, and we are pleased that we can offer the Ultra II upgrade at a rational price and come close to our Vision DAC performance.

The Vision DAC is better, but not day and night better than an Ultra II, and it is suited for high bit rate material that the Ultra II cannot deal with.  There is no point keeping two really good DACs in production at near the same price point, so the Ultra II DAC upgrade is only available as an upgrade, not as a new production unit.

Regards,

Frank Van Alstine

[Tone Depth]

Martyo,

Let us know what you think of it when you get your Ultra2 DAC back! 

Okay okay, I'm sending in my DAC.

Thanks Larry, glad it worked out, in spades, too.