Monoblock Aegirs

Any amp that is mono'd including these Aegir's have bridged output stages. And when that's done they DON"T drive the bass when it has low impedance as good as the same amp in stereo mode.

As a bridged output stage as in the mono'd Aegir,
Is higher in output impedance (bad)
Lower in damping factor (bad)
Lower current ability(bad)
Higher in distortion(bad)  
Less stable in to low impedances (very bad).
But you have higher wattage?
  
You make what was a good stereo amp into "almost" a higher wattage PA amp. Good for easy >8ohm load speakers, just to get higher dB's and go loud.

Cheers George  

But, when the midrange driver is being driven by a different amplifier than the woofer, (and in these cases by amplifiers not chosen for the similarity in their sounds, but rather for the difference in their sounds), the blending between the drivers is compromised and the sonic consistency of the speaker is inhibited.

It not, suggest you study the close ups of both. Same topology, just different rail volts, and the amount of Class-A bias.
They have the same DNA, by adding more Class-A to one amp is not! going to change the phase integrity from bass to mids. Not that it matters that much anyway, so long as they have the same gain.
I’ve heard magic from Class-D on the bass and tubes on the mids and highs.

He recommends vertical bi-amping with two of the same amps.

I do too if they have the "quality in the mids and highs of the Class-A Aegir", but the Vidar doesn’t. That’s why if the Schiits are used the Aegir is better on the mids and highs for it’s sweet class-A sound and the Vidar on the bass for it’s dynamic impact and bass drivability.



Cheers George

That’s a really bad idea. Particularly for a Vandersteen which has been phase aligned with such care in it’s design.

Impossible, if gains of both the amps are adjusted with the Sys to be the same, Vadersteen’s phase alignment will be unaffected as the original Vandersteen xover is still used.
  
Yes different story if an external active xover is used.
  
BTW: He wouldn’t have done bi-amp or bi-wire terminals, and his level controls will screw up any phase alignment anyway once taken off the 0db position.
https://www.stereophile.com/images/archivesart/107vandy2.jpg

Cheers George

Vidar is not a Lin topology. When used as a monoblock, it is simply amplifying a differential signal. It is not bridged."

This only applies to the input stage, output stage’s negative speaker terminal is still at ground potential therefore will only degrade in many parameters when the amp is "bridged", but gain more wattage.
Only amps that are are "fully balanced amps from input to output stage" with no earth ref will apply, like many Class-D’s. .
And here’s what Schiit told Stereophile As I said the output is "bridged"

" In mono output mode, Schiit says that the Aegir will deliver 80W into 8 ohms (19dBW). With a balanced, "bridged output"

As for the OP he will only be using one Vidar in stereo mode anyway only for the bass of both speakers, in the way I suggested he do it.

395garrison OP

A simple way for the OP to find out, is to ask Schiit if a mono’d "bridged" Vidar will be more or less stable into low impedances than a stereo Vidar, also a tell tale is which one has the "lowest output impedance" and "highest damping factor". This will settle it once and for all.

Cheers George

395garrison OP
Thanks, appreciate the info on the sound quality issues caused by bridging, I had never looked in to it. Using both had crossed my mind but I had always read that when bi-amping the amps should be of the same type.

They are very much the same amp, very similar circuit topology. Study the closeup photos.
Just the Aegir has much low rail voltage and higher Class-A bias than the Vidar.

Cheers George

395garrison OP

This will be the best as the Class-A Aegir is for the mids and highs where it’s best at doing.

Aegir will will have plenty for the mids and highs and a Vidar great for the the bass.

Just horizontal bi-amp as I outlined.
The Sys goes on whichever amp has the higher gain in this diagram I made, it's assumed the Vidar has the higher gain, it could be the Aegir.  https://ibb.co/qjZmGsZ


Cheers George

Curious if anyone has hooked up a pair of monoblock Aegirs to the Sig II’s and how well they drove them on the bottom end?

Never bridge amps, you turn a "good" stereo amp into a more powerful "mediocre" amp

By bridging stereo amps you gain wattage, but you loose low impedance drivability, stability, and increase distortion.

If the Vandersteen’s go down in impedance with low’ish -phase angle in the bass then things "could" be worse not better.

Your better to use the Aegir on the mids and highs and the Vidar on the bass and if they are different gains use a Schiit Sys on the louder of the amps to reduce it to the others level then use your Schiit Freya + preamp as the master still.

Cheers George