Spatial Audio Raven Preamp

I would be really interested to hear any reactions/reviews of anyone using the Raven preamp with the praised Class D monoblock amps such as the Atma-Spheres or the AGDs. 

@donsachs Yahsureyoubetcha I'm using Hijiri XLR's from a LuminX1 streamer into the Raven PRE and Cardas Clear Beyond XLR's from the pre into the Blackbird Monoblocks. 

I boosted the base a bit more w/ the roon parametric equalizer at 20 and 40 hertz.

Rather than take the pre and monoblocks 200 feet or so to the other speakers up and over hill and dale, I used the Lumin AMP w/ X1 streamer and compared that to the Blackbird Monoblocks and the Raven Preamplifier. Apples to apples; heck no. The Lumin AMP is 160W per side into 8Ω. It's a class A amp. The tubes vs solid state sounded too close to call. Take that SS.

@atmasphereI was just thinking sub(s) and your post said it better. I'm not sure how to attach a sub(s) to the Raven Pre? Must be an easy way? 

T H A N K you both.

was just thinking sub(s) and your post said it better. I'm not sure how to attach a sub(s) to the Raven Pre? Must be an easy way? 

@wsrrsw It appears there is a single-ended output in parallel with the balanced output. You'll have to check to see how this works but it might be quite simple- the main amps on the balanced outputs and the subs connected to the RCA outputs. I would expect to see a switch that grounds pin 3 to pin 1 so the RCA connections will work properly but they may not be connected to the output transformer driving the XLRs, negating the need for a switch.

The Raven has split windings on the output transformer so both RCA and XLR’s can be used at the same time (the RCA output uses one-half of the secondary winding). So feel free to use to use the RCA output to power the active subs.

However ... the added cable capacitance on one-half of the winding, might, in principle, unbalance the XLR output a little bit. Maybe. Most likely not. Use low capacitance cable for the sub output, if possible.

Mostly, try it and see. The Blackbird power amps have pretty good common-mode rejection, so unbalance gets washed out in the input stage.

I keep hearing good things about the Rhythmik servo subwoofers, so you might check out getting a pair (using stereo bass, with the lowpass filter set to 40 Hz).

Although horn speakers have gratifyingly low IM distortion, they drop off very fast below cutoff. It's basically a brickwall cutoff, so "pushing" them below cutoff has limited utility.

The degree of overlap between the horns and the subs (at least two) will be entirely subjective. Unlike closed and vented boxes, horns do not have a smooth, predictable cutoff region (which is 12 dB/octave for all closed boxes, and 24 dB/octave for vented boxes). Instead, they drop like a stone, and the octave just above cutoff can be pretty rough as well.

Combining the horn with the subwoofer will require judicious use of the "phase" control on the subwoofer plate amplifier, and messing around with the lowpass filter. The magic spot might be anywhere from 30 to 60 Hz.