Wow, so you are saying your DAC is analog like? I have heard that claim before, but every time I have tried one it is never like a very good analog setup. I hope yours is, that would be great.
Hi Afterimage,
YES, and this will be described in much more detail when we get the Isabella webpage up in a few more weeks.
Your post asks a good question and I would like to add a little more detail upfront and state that THE main goal of the Isabella's optional built-in, non-oversampling dac is to recreate music from digital media as close as possible to that of a high-end analog setup. Our implementation uses a pure, non-oversampling D to A conversion without any digital filtering, and a minimalist class A discrete transistor output stage that feeds directly to the Isabella's tubed linestage. All circuitry is "off-the-grid" running on SLA battery power, including the dac board (which has its own voltage regulation and isolation). We believe the Isabella dac/linestage delivers as much of the best qualities of analog (warmth, tone, timing/pacing, dynamics, and "life") as possible with digital... and it is no easy task, but when you hear it, you'll get it.
We are NOT looking to get the best technical specs on paper that the latest, 24-bit, SOTA, X-times upsampling/oversampling d/a converters with digital filtering, etc. have to offer. We are not looking to place a microscope over the digital media that is fed in... our approach is different and sounds different.... again, as close to analog as we believe is possible.
The Isabella's dac is optional... those who believe in our approach or at least want to give it a try and listen to how it compares to others are very welcome to do so, and be prepared to get addicted!
Those who are very satisfied with their digital (CDP, external dac, etc.) will not have to buy ours if all they want is the Isabella's SLA battery powered tubed linestage. This was what we decided a while back and I believe it makes the most sense and appeals to more of our customers.
Additional Isabella information:
With both the optional dac and tubed linestage circuitry, we are doing things quite a bit differently than other manufacturers' dac and linestage designs. Our tubed linestage design is very unique and we wish to keep it proprietary. What I can say is that both the B+ and heaters of the tubes are fed via the SLA battery power, and there are NO noise-creating DC to DC converters to step up/down the voltage for the B+/heaters. To our knowledge, no one is offering this type of design and our preamp stage is one-of-a-kind and designed to work specially with our SLA battery voltage. One 6922/6DJ8 tube per channel, and BOTH sections of the tube are used per channel, and we are NOT using any form of cathode follower.
The tube heaters, relays (input and automute), and dac all get their own voltage regulation and isolation.
There is only one PIO capacitor in the signal path of the linestage.
There are NO transformers to be found anywhere (none for the input or output stages, and certainly none for the power supply section
)
The signal paths are very clean and you will not find ribbon cables and connectors for any parts of the signal path. We had to make sure that the board was small enough to fit into the same enclosure as our 30.2 (which is what we wanted so it would match our 30.2 / 70.2 line), and those who have seen pics of the inside of the 30.2 know that a large percentage of it is the two SLA batteries!
We use the same high quality hook-up wiring as found in our Signature 30.2 and 70.2 for the batteries to the board.
The Red Wine Audio SMART circuitry is present, along with a switch to allow for playing off the charger's power supply when the batteries are charging. Even when listening in this mode, it sounds great! There is extensive filtering of this input to keep things clean and enjoyable even in this mode of use.
Again, there is plenty that I need to add about the Isabella's design and features and this will be detailed on the Isabella webpage in the next few weeks as we get closer to production.
As always, thank you for all your interest and support!
Vinnie
