As an example crown does not list voltage gain , though that may be because it as gain controls and a pro would set them with proper equipment (speculation).
Hi Richard, I thought I will chime in on the subject a little bit. I am an electrical engineer by trade and my company deal with IC design on daily basis so I understand the varies fundamental approach to amp design. To me the move away from discrete components to IC carries multiple advantages, not just cost and weight saving. Without bored everyone to death here, let me just say the Crown drivecore IC (from Texas Instrument) is really a bless and move in the right direction. Much like your mobile phone now the day, we are doing things that we dreamed about only ten years ago all thanks for advancement in IC design and manufacturing process. Anyway, I choice Crown XLS not because that's all I can afford. But rather to reward them for make such of wonderful product. Is it perfect? I doubt it, but it's a step in the right direction. It's only going to get better as time progress and other companies following suit.
As for the gain calculation, I quote Avi from Crown
An amp with a voltage gain of X40 will output 40 times it's input sensitivity spec to reach full power on the output, on the XLS series the input sensitivity is 1.4V.
That means that if we put 1.4V on the amps input we get at 8 ohm for the XLS 1000 215W per channel. So we'll calculate the maximum output voltage:
V out max = SQR(P max X R) = SQR(215 X 8) = SQR(1720) = 41.473V
The amps voltage gain is the ratio between the input sensitivity and the amps maximum output voltage. So we take the two figures (Voltage sensitivity=1.4V and Maximum output voltage=41.473V) and find the ratio between them, that's:
R = V1 / V2 = 41.473 / 1.4 = 29.625
Let's redo it for 4 ohm load:
V out max = SQR(P max X R)=SQR(350 X 4) = SQR(1400) = 37.417V
R = V1 / V2 = 37.417 / 1.4 = 26.726"http://www.crownaudio.com/forums/index.php?showtopic=4459&#entry16750
I will be testing the XLS series soon and will give you guys an honest feedback on what I think of it.