Autoformer vs Speaker impedance Curve

Thanks again both! Was just listening to “Interstellar” sound track. Can definitely hear the fan on soft passages.  I will clean the fan filter.

@73max

You might want to clean the fan filter.

In regards to the Classe Omega Reference monoblock amps that are for sale and were purchased new in 2004. There’s no way to confirm that unless you get the serial # from the seller and contact Classe and give them the serial # and ask them what year the amps were manufactured. The Classe Omega amps are still the best sounding amps that Classe made and are superior sonically to any Classe Delta series amps.
These Omega series amps are pure class A deigns whereas the Delta series amps such as your CA-2300 are class AB designs. Those Omega series gears were very expensive more expensive than the Delta series gears.m
The Omega Reference monoblock amps original retail price was around $30k or $35k for the pair when they were still in productions.
Sometime certain Classe dealers still are able to get V stocks of these Omega series amps brand new directly from Classe.
My local Classe dealer here had a pair of these new Omega Reference monoblock amps v stock brand new form Classe 2 yrs ago.

This statement ignores just how much loop feedback is needed to fully compensate for this sort of thing. We all know what too much feedback has the reputation to sound like.

20 db is plenty. The problem area with feedback is **moderate amounts** between about 4 db up to about 15 or so. Over that and the feedback is usually sufficient to make almost any amplifier act like a voltage source.

IOW George, the quote above was completely misleading. If you doubt me, read Nelson Pass' article on distortion and feedback:
https://www.passlabs.com/press/audio-distortion-and-feedback
Any of the amps that you recommend run 20 to 30 db of feedback! In this case you're trying to play both ends- when all the amps in question run large amounts of feedback.

Consider your bubble popped.

Any of the amps that you recommend run 20 to 30 db of feedback!

Bubble still up, your having illusions, or didn’t do your homework.
Two of the amps are "local" and not sound destroying "global" feedback, and are designed to be low output impedance with resorting to global feedback, and have huge reputation for stunning bass and speaker control especially hard to drive ones like these B&W 802d3’s.

I repeat 73max OP, don’t get autoformers for your 802d3’s, unless you have an amp already that’s not right for them and want to use them as an interim band-aid fix, till you get the right amp to do the job, then autoformers are not cheap around $700, better to just put it towards getting the right amp!

Cheers George

Love this forum. The level of knowledge here is amazing!  

Any thoughts on how old is “too old” for higher end SS amps? Still have my eye on the Classé Omega Monos but it’s at least 15 years old (I have the serial numbers and will get exact age).