"PG MS amps sound like crap...
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freshkryp69
- Posts: 643
- Joined: Sat Feb 23, 2008 10:17 pm
- Location: cocoa Florida
Scott is on target with this one.
There is no way your Alpine is Class A.
When manufacturers build an amp with a Class A voltage gain stage, they slap the "Class A" label on it and deceive people into thinking they are getting a Class A amp. This is false marketing at its best. Technically the amp is Class A by their definition, but their definition is pretty useless. To be a Class A amp it needs a Class A voltage gain section, followed by a Class A current gain section. For all practice purposes there are no Class A current stage amps on the market, or ever were (aside from these very few rare ones we are referring too).
Ever hear of the Soundstream Reference Class A amps? None of them are Class A. Just bad marketing. They are actually high bias Class A/B, which means they stay in Class A mode longer, and generate more heat.
Adcom amps were not Class A either as far as I remember.
Check this out...
http://en.wikipedia.org/wiki/Class_A_amplifier#Class_A
Class A is 25% efficient when capacitive coupled (In theory). Your amp is rated at 40A fusing. P=IxV, so 40A x 14.4V = 576W. Now figure in 25% efficiency, 576 x 0.25 = 144W. Now this is a theoretical max power, not actual. Actual would probably be more like 100W. 100W total power is a lot less than the amp is rated at, so there is no way it can be Class A.
There is no way your Alpine is Class A.
When manufacturers build an amp with a Class A voltage gain stage, they slap the "Class A" label on it and deceive people into thinking they are getting a Class A amp. This is false marketing at its best. Technically the amp is Class A by their definition, but their definition is pretty useless. To be a Class A amp it needs a Class A voltage gain section, followed by a Class A current gain section. For all practice purposes there are no Class A current stage amps on the market, or ever were (aside from these very few rare ones we are referring too).
Ever hear of the Soundstream Reference Class A amps? None of them are Class A. Just bad marketing. They are actually high bias Class A/B, which means they stay in Class A mode longer, and generate more heat.
Adcom amps were not Class A either as far as I remember.
Check this out...
http://en.wikipedia.org/wiki/Class_A_amplifier#Class_A
Class A is 25% efficient when capacitive coupled (In theory). Your amp is rated at 40A fusing. P=IxV, so 40A x 14.4V = 576W. Now figure in 25% efficiency, 576 x 0.25 = 144W. Now this is a theoretical max power, not actual. Actual would probably be more like 100W. 100W total power is a lot less than the amp is rated at, so there is no way it can be Class A.
Got "schooled" by member shawn k on May 10th, 2011...
No longer really "in tune" with the audio industry, and probably have not been for some time.
Hands down the forum's most ignorant member...
Don't even know what Ohm's law is...
No longer really "in tune" with the audio industry, and probably have not been for some time.
Hands down the forum's most ignorant member...
Don't even know what Ohm's law is...
Here is an excellent read for anyone interested in what Class A is all about...
http://www.zedaudiocorp.com/Technical/A ... lasses.htm
http://www.zedaudiocorp.com/Technical/A ... lasses.htm
Got "schooled" by member shawn k on May 10th, 2011...
No longer really "in tune" with the audio industry, and probably have not been for some time.
Hands down the forum's most ignorant member...
Don't even know what Ohm's law is...
No longer really "in tune" with the audio industry, and probably have not been for some time.
Hands down the forum's most ignorant member...
Don't even know what Ohm's law is...
I once read up on this and it said everything Eric has stated above. Those old class A soundstreams only put out about 7 watts into class A. Then they switch into class B above this power output level, just like every other in car amp. So if you only power a tweeter at a very very low volume you might be listening to class A. But as soon as you turn it up to normal speech level so you might actually hear it, you are then actually listening to class B. It's a total waste of freaking time.
You'd need a bank of batteries like an SPL car to run a proper class A amp. Then you could do a quick class A "burp" in SQ
Fear not, some high end home audio digital amps have a valve like sound. You just have to wait for car audio to catch up and use digital for high end, not just a tool to achieve something compact and cheap.
You'd need a bank of batteries like an SPL car to run a proper class A amp. Then you could do a quick class A "burp" in SQ
Fear not, some high end home audio digital amps have a valve like sound. You just have to wait for car audio to catch up and use digital for high end, not just a tool to achieve something compact and cheap.