Autoformer vs Speaker impedance Curve

73max OP14 posts08-27-2018 3:48amAny thoughts on Pass Labs XA-160.8 with 802D3s?

While great amps and very nice sounding, it's bit of 6 of one 1/2 dozen of the other for your speakers though, they are Mosfet and when done in complimentary n and p channel push pull, can't really supply the current like BJT's (bi-polars) can, there are a one or two Mosfet amps that are push pull, but they only use an N channel for both top and bottom which may do the job (much higher current), but I can't remember what is was.    This if you read will give you the gist, of not being able to do your speakers justice "maybe" not worth the chance in my opinion.
https://www.stereophile.com/content/pass-labs-xa160-monoblock-power-amplifier-measurements

Cheers George

Thanks for the link. Doesn’t look like a good match.  There is a Classé Omega for sale for that is tempting, but I just can’t bring myself to part with that kind of coin for a 15 year old amp.  Too close to a recap.  Not sure I could find a local tech willing to hoist these monsters on the bench... never mind sourcing parts.  The hunt continues. 

73max OP

Just look at amp reviews on Stereophile and in the bench tests you see they test them into 8 4 and some times 2ohms if they can handle it. Doubling the watts from 8 to 4 to 2ohms is good current, but no amp can double exactly without losses, so instead of 2 x the wattage 1.8 is fine.

Look at the watts they get of of it EG
at 8ohms (eg 100w),
4ohms should be at least say 1.8 x higher (180w)
2ohms at least 1.8 x higher again ( 324w)

This is the sort of amp you should look for, one that almost doubles it’s wattage for each halving of ohms, with those loads that your speaker gives to get 100% of of them.

Your Classe ones look good, maybe yours just has noisy fan bearings or your filters are blocked?

Cheers George

I I agree with Georgehifi. Your noisy fan on your Classe CA-2300 was probably caused by dirty filters on the fan. You might want to check your filter. Cause the fans on all my Classe CAM-600, CAM-300 & two CA-2300 amps that I have in my dedicated HT room are silent and barely barely audible. My dedicated HT room is very well treated and get dead quiet when there’s nothing being played, and while it’s true that I have a very large dedicated HT room.

Which Classe Omega amp is it that you saw for sale? Was it the Omega stereo amp, Omega monoblock amps or the Omega Omnicron monoblock amps, which are lower end series of the regular Omega monoblock amps.
The Omega stereo amps are even older than the Omega monoblocks or the Omega Omnicron monoblocks.
I believed that the Omega stereo amps were first introduced in the late 90’s, whereas the Omega monoblock amps and the Omega Omnicron monoblock amps came out in early 2000s if my memory served me well maybe between 2001 to 2004 I think and remained in production until late 2000s around 2008 or 2009 or maybe even 2010.
Make sure you get the one from late production around 2008 or 2009. You can ask the seller for its serial # of the amp and once you have it, I would suggest you contact Classe give them the serial # of that Omega amp and ask them what year it was being manufactured.

Omega Mono Refrence purchased new in 2004