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89lbs but only 150 wpc, what is the catch ?

The truth of the matter is that is very little difference between 150 watts and 380 watts. The majority of the general use is near the first watt.
 
qguy said:
Looking at an Usher R1.5, it is 89 lbs, 150 watts per channel at 8 ohm, guessing the first 25 watts is in class A as the R2.5 is 250 wpc AB/50 wpc Class A. Idle current is at 250 watts for the R1.5. From what I read, the amp is based on Nelson Pass' Stasis design. My Rotel RB-1090 is around 85 lbs but delivers 380 wpc in AB, 0.0000001 wpc in class A :) The question is, why build an amp that weighs a ton, idles at 250 watts, but only delivers 150 wpc in Class AB?
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Likely for reasons similar to why my Levinson No. 23 (200wpc @ 8) weighs ~100lbs. It doesn't weigh 100lb because it's 200w @ 8, rather, because it's 700+ @ 2 ohms and capable of 2 ohms bridged operation (equivalent to 1 ohm per channel).
 
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My old 333.5 factory modded Levinson weighed around 150lbs IIRC. Bonus was you could cook hotdogs on it. Bad thing was if you blew anything in it, it was a 150lb doorstop because most folks could not afford the cost to repair if it was possible which is why I sold it before I or something else hurt it
 
Now you guys are onto something. The power supply ... Joules. Power Factor. Rail compression (or lack thereof).

That's where the rubber meets the road in solid state.
 
mad shadows said:
The catch - it's derived from a Nelons Pass amp. Hence it's big, inefficient and probably sounds very nice.
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Yes.., it is. And yes, it does. I happen to own an Usher R1.5, and it is a very capable and superb sounding piece of gear. It handles my big Infinity speakers and their infamous low-impedance dips with aplomb, all thanks to that big power supply.

The large heat sinks also contribute to the weight.
 
Do you have the service manual for this unit? Need to bias my amp

Tedrick said:
Yes.., it is. And yes, it does. I happen to own an Usher R1.5, and it is a very capable and superb sounding piece of gear. It handles my big Infinity speakers and their infamous low-impedance dips with aplomb, all thanks to that big power supply.

The large heat sinks also contribute to the weight.
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Northwinds said:
My old 333.5 factory modded Levinson weighed around 150lbs IIRC. Bonus was you could cook hotdogs on it. Bad thing was if you blew anything in it, it was a 150lb doorstop because most folks could not afford the cost to repair if it was possible which is why I sold it before I or something else hurt it
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Despite than my No. 23 is still plugging away. I kick myself for not sending it in for Levinson-authorized checkout/tune up/reconditioning when it was $1200 flat rate.
 
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