[flatmap]

Am I reading the Can Jam report correctly -- the Isabella will have a headphone out???

[mateo]

The dac board is almost finished as well!

[impatient]
Any hint on what chip the DAC uses?
[/impatient]

[Bucky]

Am I reading the Can Jam report correctly -- the Isabella will have a headphone out???

umm mojo's report specifically said it didn't..

[mateo]

Mojo got it wrong because the headphone out was on the back, IIRC. It was definitely there because people listened to a pair of R10s driven by an Isabella a bunch at CanJam.

At least that's what I get from the meet impression threads, anyway.

[Vinnie R.]

All,

Stereomojo was incorrect... the prototype Isabella did have a headphone output (it was on the back  ).

Am I reading the Can Jam report correctly -- the Isabella will have a headphone out???

Hi flatmap,

This is something that we are probably going to offer as an option, but regarding timing, it will most likely be after we go into production.

Hi mateo,

Sorry, no hints on the dac chip used.

What I can say is that it is a non-oversampling, 16-bit design with a discrete output I-V stage (using discrete transistors, no opamps).  No digital filtering in the output.  The USB input converts directly to I2S to feed the dac chip (as do the SPDIF inputs).  The analog output of the dac stage is fed to the tubed preamp stage.   

Best regards,

Vinnie

[Vinnie R.]

Right now we are waiting for the latest re-spin of the preamp main board (on the way) to arrive and will carefully test it, and then order the production batch of boards.

UPDATE: The latest REV of the Isabella board has arrived!  The layout is very nice... very clean signal paths and all.  We will be building it this week and putting it through bench testing and listening testing.  We hope to have it validated within 2 weeks, and then we'll be ordering the first official production batch of boards  aa

The dac board is almost finished as well!

I'll be reporting more updates soon,

Vinnie

-- Just a quick update... the latest REV of the Isabella preamp board has been validated and is now
on order!    We should be able to start stuffing the boards in a couple of weeks.

-- Enclosures have arrived! 

-- Dac board still being finalized, but getting close.

-- We'll be working on the Isabella webpage in the next couple of weeks as well. 

We're still waiting for a few other parts, but we should be ready to rock n' roll next month (*fingers crossed*)! 

I'll be posting more updates soon.  In the meantime, here is a shot of my little princess Isabella checking out some of Daddy's vinyl:



Here is my turntable (a Scheu Analog Premier mkII, with Scheu Classic arm, SLA battery powered motor, and Dynavector 20X/L cartridge... also currently using a Sutherland Ph3d battery phonostage):




When I am asked "what reference are you using to voice and evaluate the Isabella's dac?" ...THIS IS THE ONE! 


Cheers!

Vinnie

[Afterimage]

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.

[Vinnie R.]

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

[Afterimage]

Vinnie, thanks for the response.   I really lilke your thinking about the measurements or techincal specs.  Not just in audio, but in anything measurements can be a tool, but they are not what it is really about.  When Picasso paints, he doesn't give step by step instructions with the right spec measurement for his paintings.  That kind of thing comes from within.  In audio, something may sound good, create the right emotions for ya, but it might not have the right techinal specs, whatever that means. 

[nonoise]

Vinnie:

Isabella is so precious!
She's fortunate to have a dad like you watching after her.
And, my hat's off to you for going the 16 bit, non upsampling route with no filters, etc.
It's been my experience that 16 bit, done correctly, is the way to go: it's so much more
natural sounding. I just wish I could afford to go the Isabella route after reading what
you have in store. I, myself, have the Consonance CD-120 Linear, which is built along
similar lines and I love it. Maybe, someday, I'll upgrade to the one with tubes, but right
now, it sounds pretty damn good.

nonoise

[Jerrym303]

Hello Vinnie,

I have looked around, but I have not been able to find anything about the volume control for Isabella.  Will it be a DacT unit like the 30.2?

How many steps?

I have grown to favor resistor-based stepped attenuators and that would be a major plus for the Isabella in my book.

Thanks,

Jerry

[Vinnie R.]

Hello Vinnie,

I have looked around, but I have not been able to find anything about the volume control for Isabella.  Will it be a DacT unit like the 30.2?

How many steps?

I have grown to favor resistor-based stepped attenuators and that would be a major plus for the Isabella in my book.

Thanks,

Jerry

Hi Jerry,

Welcome to the RWA forum!

We have decided to use a motorized pot (Alps... just like what is found in the Modwright and other high end preamps) for the Isabella instead of the DACT/Goldpoint stepped attenuator. 

We decided that for the Isabella preamp, we wanted the volume control to offer the following features:

-- A continous adjustment range (instead of only 24 steps that the DACT/Goldpoint offers)
-- An "all on one board" remote volume control solution for better reliability and more ease of manufacturability.
-- Something that was more quiet (the motor)
-- Something that consumes less power.
-- A smoother feel when adjusting the volume manually.

Once again, John Chapman of Bent Audio has designed the remote volume control board for us.  We have been carefully testing it in the last month and we are very pleased with the results of his efforts. 

Best regards,

Vinnie

[Jerrym303]

Thanks Vinnie.   I did notice that both Modwright and Dodd used the motorized Alps.  I am currently running a Placette Active, but need some gain in the system (it is unity gain).

[Vinnie R.]

Thanks Vinnie.   I did notice that both Modwright and Dodd used the motorized Alps.  I am currently running a Placette Active, but need some gain in the system (it is unity gain).

Hi Jerrym303,

The Isabella has a switch on the back to run the preamp stage at two different gain settings... 0dB and 12dB. 

For those with low voltage sources (e.g. the output of my phonostage using my low output MC cartridge), less efficient speakers, or amps with low gain -- the 12dB setting would be ideal.

For those with higher voltages sources, more efficient speakers, and/or amps with higher gain -- the 0dB setting would be more ideal.

The idea is to use the gain setting that gives you the most usable range out of the Isabella's volume control -- in YOUR system 

Best regards,

Vinnie

[Afterimage]

In my opinion, good move.  I can't stand stepped Attenuators.  Sometimes there is to much volume betweeen the steps so I can never find the right level. It is very frustating.

[Vinnie R.]

In my opinion, good move.  I can't stand stepped Attenuators.  Sometimes there is to much volume betweeen the steps so I can never find the right level. It is very frustating.

Between using the Alps and having the 0db / 12dB gain select switch for the Isabella, we believe just about everyone will be able to get the the most usable range of volume level.... no matter if they are adjusting manually or with the remote control. 

[Vinnie R.]

Just a quick update:

-- Isabella preamp boards should be here by the end of next week!  We will then immediately begin "stuffing" them with components and getting them installed and tested in the units!

-- The latest REV board layout for the Isabella dac board has been sent out.  We will get the samples to test and verify that everything is perfect.  We hope to have this all tested by the end of next week, and then the batch of dac boards will be ordered.

-- We are aiming to have the official Isabella webpage up in about 2 weeks

-- Once we have all the parts, we will begin taking orders.  This will be announced here on the RWA forum.  It is likely to happen this month 

Thanks for all your interest and patience!

Vinnie

[Vinnie R.]

-- Isabella preamp boards should be here by the end of next week!  We will then immediately begin "stuffing" them with components and getting them installed and tested in the units!

Well, they are here and we're moving into production!       

Dac boards should be ready in approx. 2 weeks and we'll install them into units as this option is ordered.

Regarding placing orders, we should be all set to start taking orders in approx. 2 weeks.  This will be for the first batch of units and they
are going to go quick (BIG dealer demand to get the first ones, as well as demand from many loyal RWA customers... thanks, guys!).

I will post more details, links, etc. as we get closer -- and we ARE getting close  aa

Thank you,

Vinnie

[Afterimage]

Just to clarify, you are only taking preorders from dealers at this time?

[Vinnie R.]

Just to clarify, you are only taking preorders from dealers at this time?

Hi Afterimage,

We are not taking any pre-orders at this time, but will be taking orders as soon as we receive the dac boards.  At that time, we'll have ALL the parts in hand and will be able to quote very accurate lead-times.

I am estimating that within 2 weeks, we'll have the Isabella webpage up (the official one with all the details) along with the Isabella User's Manual, and should be ready to begin taking orders.

Thanks,

Vinnie