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Class A bias, speaker sensitivity, watts...?

Hello

Please help me understand the relationship between Class A bias and wattage output. I recently bought a used Vincent Audio SV236MK used for a great price. The specs state 150 watts into 8 ohms, 250 into 4 ohms, and the first 10 watts being Class A @ 8 ohms.

My speakers are Sonus Faber Lumina II which are rated as 4 Ohm with 86db sensitivity. Everything is set up in my small cube shaped office. I used a DB meter on my iPhone and found that when I turn the volume up to what I consider to be "loud" the peak measurement I get is 80db and under.

 

Given the specs above, am I hearing mostly/all Class A watts while listening?

craigvmn
tomcy6's avatar
tomcy6
2,605 posts
 

@richardbrand

There is only one number given for Class A watts that I’ve seen, which is why it stuck with me when the guy said they dropped into 4 ohms. It’s nothing to spend your time on, If someone who knows for sure comes across this thread maybe we’ll find out, but until then, forget I mentioned it.

richardbrand's avatar
richardbrand
274 posts
 

@tomcy6 

What was it you mentioned?

invalid
1,245 posts
 

Most solid state amplifiers can double the output power when impedance is halved if well under the max power spec. Not one amplifier I have seen measured by a third party has the ability to double max power when impedance is halved (not even the big Krell amps) the 8ohm spec is usually underrated to give this illusion. 

richardbrand's avatar
richardbrand
274 posts
 

@invalid

True.  Even the electron has its spin!

agwca
130 posts
 

Would like to try a really accomplished class A someday but don't want to deal with heat.  Same with tubes I suppose.  Purportedly, some class D can sound very class A like and that could be the best option.

But if space suffers, instrument sep. and stage depth isn't there, I wouldn't like it overall regardless if how smooth it sounded.

If you have 10 watts of class A, it should perform well at both low to moderate SPLs including dynamic swings.  The occasion peaks into class AB, etc probably wouldn't be audible until you turn it up to louder levels and at that point, its hard to listen too for longer periods of time and without risk to hearing.

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