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The main Isabella question is immortalized by Oh Brother, Where Art Thou: Is she is or is she ain't?
At $4,000 for the preamp, $5,500 for the DAC/pre and $500 extra for the headphone buffer*, Vinnie Rossi plays in a different league now than he did when the Sig 30 first bowed. That had precious little competition for its concept then. Now Isabella faces countless competitors keen on cutting her back to size. And let's be honest. Many $4K preamps of the tubed persuasion are more gussied up. They might add numeric volume displays. They might arrive with snazzy backlit remotes. Chrome. Visible tubes. A full-size chassis. And they might bundle more material worship to reflect a more easily justified parts density for your precious coins. Though hard-core 'philes claim not to be impressed by any of that -- only the sound matters -- I predict that Isabella will face precisely those perceptional hurdles.

* About the headphone module, I guessed that the 6922s provided sufficient gain and that all Vinnie needed was an impedance/current-converting op-amp buffer. "You nailed it! We are using the 6922s for the gain (remember, you have the 0dB or 12dB gain switch on the back and this applies to headphones as well) and essentially feed the preamp output to the headphone module on the inside. This module is a zero-gain buffer using what we believe to be the best sounding op-amp for this application biased heavily into class A and configured such as to drive loads as low as 4 ohms. Of course there is not enough voltage swing to get regular speakers loud enough (though I'm sure it would do quite well with ultra-efficient speakers like the Avantgardes) but with headphones, it's magic!

Headphone buffer module

"The headphone module has its own linear voltage regulation on board and plenty of power supply capacitance and filtering. This module is extremely transparent. It allows the true character of the Isabellina DAC and Isabella tube linestage to emerge with your favorite headphones. We tried it with so many models (AKG 701s, Senn 650s, Grados, Audio Technicas, Ultrasones, Denons and my favorite, the discontinued Sony MDR-R10s, which are now selling used for around $5,000). The 1/4" stereo headphone jack is mounted directly to the board (no additional wires or ribbon cables here) and this assembly attaches to the upper-left portion of the rear panel next to the AC/BATT switch. It was a tight fit but we made it work and kept the signal paths short and sweet. Depending on the output voltage of your source and the sensitivity of your headphones, either the 0dB or 12dB gain setting will give you a nice usable range on the volume control.

"At CanJam '08, I heard some of the finest headphone amps around. While you know that I am biased, my favorite was the Isabella's headphone stage using the internal Isabellina DAC as the source. There is the battery silence, the richness of tone, the dimensionality and the ability to drive everything to more than adequate levels (well, except for the K1000s perhaps as those really require a speaker amp like the 30.2). While it's no secret that I prefer home audio to headphone listening, the Isabella headphone stage with exceptional headphones such as those Sony MDR-R10s definitely offers me a very satisfying listening experience!"

Back to claim jumpers. Even though Mr. Rossi remains tight-lipped about the identity of his no-longer-made (NOS) DAC chip with zero oversampling (NOS again for squared NOS perhaps), it's not hard to guess what he's using. If so and starting with Scott Nixon, 47 lab and Peachtree Audio to the Opera Audio Linear players, AMR, Audio Note and Zanden (the latter four all with tubes), that type of DAC on both the affordable and heavy-duty end of the scale isn't exactly scarce anymore. And even though they take up most the space and mass, neither are the SLA batteries at the heart of Red Wine Audio designs expensive. In fact, they're cheaper than many quality transformers Mr. Rossi's competitors rely on. So the Isabella concept at its final asking price has its work cut out. Lastly, there's the truly priceless. Experience. Think Art Audio, Audio Research, BAT, CJ, Manley, Rogue, VTL. Those are just a few of the valve audio brands on Vinnie's home turf whose designers have proven themselves in this sector many times over. Who ever heard of Vinnie Rossi, tube designer wunderkind? Even batteries + 6922s in preamps enjoy at least one precedent in the less costly Dodd Audio machine now. Yet the Vinnster would convince us that his Isabella is a groundbreaking, perhaps even revolutionary product...

Even his most ardent admirers and supporters will wonder. What exactly makes it so? And what references did the man test to make such bold claims? How many $5,000+ statement preamps did he evaluate for context to know that his goes beyond in ways not attempted before? Remember that just three short years ago, Vinnie still sang the song electric over passive linestages. And the need-no-stinking-active-preamp Blues. Then, his Signature 30.2 based on the Signature 30 platform proved quite the sonic upgrade. It demonstrated how a first concept implementation did not deliver the full potential which more experience eventually squeezed from it. So experience takes time - as a designer and as a listener. Are we to believe now that somehow, Vinnie has progressed from passive preamps to a statement-level tube preamp in one leapfrogging evolution? It's possible. But likely? Not really.

As someone who appreciates Mr. Rossi's entire approach and contributions to the hifi business very much, I'll merely add that having owned Audiopax, Bel Canto, Eastern Electric, VTL and Wytech Labs preamps and as someone who considers his present ModWright LS/PS 36.5 and Supratek Cabernet Dual special treasures, I was rooting for Vinnie but just couldn't believe that he'd truly authored a giant killer which hard-core audiophiles would consider high value at $4 to 5.5K despite the Plain Jane half-size packaging. I was quite prepared that Isabella might well be the best product Red Wine Audio had launched thus far. That'd be nothing whatever to sneeze at considering my honest enthusiasm over their Sig 30.2 integrated. But global dominatrix status for Isabella dearest? This now sets the background, technical and emotional, against which the Isabella (trimmed out in DAC and headphone finery and accompanied by a Signature 30.2 amp without attenuator and a MacBook as transport) would have to prevail. A number of fine preamps stood by to take the measure and no prisoners. [Photos courtesy of Steve Marsh's Red Wine Audio factory tour.]

But first, the obligatory "can I help you; just looking" routine.

RWA goods these days are packaged for bear and surrounded on all sides by 2-inch foam. They seem ready for a sky dive without a chute. Comprehensive owner's manuals are included as are universal hi-speed battery chargers with umbilicals, AC cords for the chargers and, in the case of the Signature 30.2 with volume control or the Isabella, a simple but functional remote control now adorned with the Red Wine Audio logo.

Vinnie wasn't joking about the bare space left to fit the headphone jack. Even its board had to mount on edge.

When fitted with the Isabellina DAC board, a silver-mesh USB cable with BNC/RCA adaptor is included.

A close-up of the DAC board.

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Here's a look underneath the green board behind the inputs.

Finally, the infra-red actuated volume control solution.