2. amps-preamps
  3. 129598-4158

How to measure the preamp output?

Can someone please tell me how to measure the output of a preamp. I am feeding  the output of a Bryston BP-25 to a First Watt F5 and I'd like to know just how much voltage I am feeding to the amp in order to ovoid driving the amp beyond a safe point. I am using the First Watt F5 to drive a pair of Opera Quintas (89 db sensitivity) in a small room (10 x 16 ft). Any help would be very much appreciated! 
tiofelon
erik_squires
16,152 posts
 
What you really need is a power meter on the amp outputs. I think you can find them on ebay.

Best,

E
erik_squires
16,152 posts
 


Usually you will hear the amps distort long before you can damage them. :)
kalali's avatar
kalali
1,977 posts
 
I would have thought the combination of the preamp maximum output voltage, amp's input voltage sensitivity and to some extent the speakers sensitivity, serve as good guidelines in terms of how "stressed" the amp is under certain volume conditions. Just as an aside, I suppose one could also measure the (A/C) voltage at the amp's speaker taps and calculate the power (in Watts) coming out of the amp. The challenge is the voltage will fluctuate constantly according to the amplitude of the music being played.
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