I too would be very much interested to hear something about the basic design (and sound) differences between these two models (which are several thousand dollars far away from each other). I have Lavry Blues, they already sound stellar to me ... so I wonder how much further can the quality od AD DA conversion still reach. Dan, could you please qive us few basic thoughts ? Anyone having both and able to compare ? Thank you.
I am told I should answer direct questions about my gear on the forum. I’ll try to stay as technical as I can, within the spirit of the forum. But before I answer your question I feel compelled to give some technical background.
Why is there such a difference between converters based on the same IC?
The IC makers work with a very restricted and limited boundaries. They try to fit as much as possible into a chip the size of a “pin head”. They must “limit the activity” to say l watt or so of power, or else the IC will overheat. They can not use inductors, and all the capacitors tiny (a few pF)… IC based on say a 5V supply, is not going to accommodate say +/-15V for good analog… no poly caps, no specialty items…
It is true that IC designers also have some advantages. Good matching and tracking is due to the fact that all components are “curved out of” the same materials and operate at the same environment of that tiny silicon chip. But all things considered, it is a “wonder” how well the IC makers do within their limitations!
Almost all AD and DA’s today are made around a ready made IC. In other words, some designers of your gear often do not really have much understanding of the theory behind the conversion process. Often they lack knowledge about the difficult issue regarding circuits such as the sample hold, resistor stability for PCM, the math behind high order noise shaping for sigma delta… I only recently came to realize how much of the gear on the market is the fruit of the “glue that IC on the printed circuit board and put it in a nice looking chassis” mentality. While protesting the use of 192KHz for audio, I came across EE’s that did not understand Nyquist theorem. There are EE’s out there who don’t know that impulse response and signal bandwidth are one and the same. There are a many more EE’s today, but fewer than ever analog types. Not surprising in this computer age…
I am not saying that the AD or DA equipment designer has no challenges. One can and should go beyond a simple copy the manufacturers “typical application” on the data sheet. The AD front end analog circuit, DA output stage, clocks circuits and more are the business of the gear designer, less so of the IC maker. The good designer will not hesitate to bypass parts of an IC, such as up sampling or down sampling filter with external hardware driven by external coefficients. Coefficients from where? Again, you can “buy a ready solution” (software to generate coefficients) or even better, do the math yourself… But you have to know math… There is a lot that can be done to make an IC based solution work well.
The above comments apply to the LavryBlue. What about the Gold series?
Say you want to go beyond what you can find in an IC. Say you want to push new frontiers, what is called state of the art. New concepts, system architecture and ideas not found on an IC (some even incompatible with IC technology) will force you to make a converter from “basic building blocks”. Such “from the ground up” approach requires years of product development. The Lavry Gold converters are such products. They are designed from the ground up. You start with quality resistors and go from there. The design is not the old design with better parts. It is a better design aimed at overcoming the limitations of the old design.
Obviously I was very familiar with PCM DA’s. I made my first audio DA while still employed at Analog Solutions – the first segmented architecture type DA. That design was later repackaged by Ultra Analog, and found it’s way to Mark Levinson, Wadia, and Pacific Microsonics. Not a bad design, but PCM had a number of flaws. So I decided to list the flaws and solve ALL of them in my next DA.
Here are some examples:
Problem: Resistors change with temperature
Solution: Put them in an constant temperature linearly controlled oven
Problem: Resistors age
Solution: An elaborate automatic calibration scheme.
Problem: PCM performs worst at digital black (Pointed out in a paper By Dr. Lipshitz)
Solution: Create a network with “digital DC” shift
Problem: DA’s are susceptible to small jitter
Solution: Processor based re clocking scheme CrystalLock (TM) provides over 200 times improvement….
Obviously, the Gold series (from the ground up) product is a difficult way to go!
The Gold AD is great, but I made changes to allow the unit to run cooler. The upgraded MKII+ dissipates 19 Watts (MKII was 30 Watts) and a complete AD module repackaging job with 6 heat sinks plus air vents, and a new potting material ( which allows heat to dissipate more evenly) is a dramatic improvement.
The Gold DA is my favorite design.
BR
Dan Lavry