Spatial Audio Raven Preamp

@downtheline Thanks for your thoughts. The LS 36.5 isn’t balanced throughout. I am using the Xlrs for my dac and the SEs for my analog rig. I was wondering what a fully balanced preamp could offer in perception of increased sound quality, which is what I believe you are referring to with respect to the Raven preamp. 

I was wondering what a fully balanced preamp could offer in perception of increased sound quality

@iamsportsdoc  It really 'depends'. 

A fully balanced preamp presents a constant load to its power supply. If that preamp is also fully differential, then it also has a fair amount of noise immunity from the power supply (which a single-ended preamp does not). 

In a fully balanced differential circuit, even ordered harmonics are canceled from one stage to the next. The overall result is less distortion compounded from stage to stage. Since distortion obscures detail (in addition to altering tonality) the result is greater detail and neutrality. 

AFAIK, we've been building balanced tube preamps longer than anyone worldwide so this is coming not just from theory but experience as well. 

One other thing to keep in mind when shopping balanced preamps whether tube or solid state:

In the old days before exotic interconnect cables, record labels and the broadcast industry had no problems moving a signal from the microphones to the mic preamps even if they were 100 feet away. This was made possible by the balanced line system, which has a couple of standards which, when observed, prevent interconnect cables having a 'sound'. This is why they were able to make regular microphone cables work at a world class standard. 

One of those standards is AES48, which defines how the connection works. Ground is ignored and the signal is carried on a twisted pair within the interconnect. Because ground is only a shield, this practice prevents ground loops and goes a good way towards eliminated interconnect cable artifacts (their 'sound'). 

The other standard of sorts it to spec the output of the preamp in dBm. 0dBm is 1 milliWatt into a 600 Ohm load (the 600 Ohms being the old school termination standard for line level interconnections). As an example, our MP-1 can make 10dBm. -4dBm and 0dbM are commonly used. The ability to put out a bit of power into a low impedance is used to swamp noise and interconnect cable issues like capacitance and the like, causing them to be inaudible. 

On this account such a preamp is immune to interconnect cables so they need not be expensive. 

If your preamp supports these aspects the simple answer to your question is things sound a lot more lifelike. Its usually not subtle either. 

@atmasphere Thanks for chiming in. The information helps. I guess now the question is about the merits of a tube preamp vs SS pre given I have a Class D amplifier. Since you manufacture  both. Thoughts?

I am hoping a Raven user or 3 with more electrical engineering knowledge than I — a very low bar, that — can offer some guidance on XLR cables to connect the Raven to an amp.

In the first instance, the amp will be the integrated CODA CSiB v2, but other amps are possible in the future.  I need only about 5 feet.  
 

The cable I have on hand that is not otherwise being used is described by its maker (Signal Cables) as follows: 

CABLE DESIGN

2 conductors, 5N Silver/Copper Alloy strands (each channel)

Insulation for each conductor - thin wall Extruded Teflon

Effective gauge size per channel - 22awg

Shield - braided 5N Silver Plated OFC

Outer Jacket - Extruded Teflon

Geometry - Internal Twisted

ELECTRICAL CHARACTERISTICS

Nom. Capacitance - 18.1 pF/ft

Nom. Conductor DC Resistance - 20.1 Ω/1000 ft

Nom. Inductance - 0.12 µH/ft

that would seem to be low enough capacitance to be good with the Raven, but I wonder what you all think? 
Thanks.