Am I reaching the max power / amplitude of my Rotel RB-951 power amp?


I'm currently using a Rotel RB-951 power amp to run some vintage 3.8D Fuseliers. They are pretty beefy and require a 4 ohm load, with a range of 50-125 watts as far as I can tell (information is slim on these online). 

 

However, with my Eskinsin bluetooth adaptor plugged directly into the amp, or using a Kenwood Kr3130's tuner plugged into the amp, I am only able to get up to a maximum of 70 decibels with the meter in between the speakers. The clipping indicator on the amp does not come on at any point. 

Since I seem to have such a distinct cutoff in volume, regardless of the input method, I'm thinking that I must be reaching the power limit of my amplifier. Does that sound right?

 

The Rotel does not offer power specifications on 4 ohm loads (but it can do them, per the manual). At 8 ohms it's rated at 50w/ch continuous and 100 watts in bridged mono. 

thatguyyouknow

Is the input level pot adjusted to maximum?

There are also internal jumper settings for input sensitivity.

RB-951-OM.pdf

 

@imhififan yes those level adjustments are set to maximum. I was hoping that was it when I came across those a few months back but alas. Thanks for the suggestion.

@gs5556 the levels screws do turn down the volume, but it does not go up past the limit I am at, leading me to believe that it is set to maximum.

I looked at the specs for your amp... the high level setting has an input sensitivity of 775mV. The Kenwood receiver specs show a tuner output of 160mV. That's why the amp is not playing loud, the tuner's max output is -14dB lower than the voltage required to drive the amp to max power.

I'll bet if you put a scope to the Eskinsi output to a 0dBFS test signal you will see the same thing -- an output voltage way lower than 775mV.