Distortion on mono amp at low (1/4) gain

[sparten576]

Hello,
I have an MRV-500 from alpine that ive had for a few years decided today i wanted to retune my amp since I haven't done it for a while and it was sounding odd.
I set head unit to max volume (doesn't clip I checked with oscilloscope) and played a -5db 40hz tone. I was amazed how much disortion and clipping there was as I was measuring the outputs with scope. I had to turn the gain down to 1/4 to get rid of all visible distortion to the sin wave.
This seems really low to me... Could the amp be damaged? Input preamp was 6V. Didn't remember the output voltage.

Thanks for the help!

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[1aespinoza Premium Member]

This seems really low to me...

That is the best you will get out of the amp. Another user told me that one can reach full gain even at 1/8 of the way because the input signal could be quite strong. Most audio companies suggest radio volume 3/4 up regardless. I guess that is for better headroom, but that is beyond my knowledge. I just apply what others have succeded with.

 

[tommydh 10+ year member]

If your sending 6V to the amp yur gain will generally be low. Gain is not a volume its an adjustment to match input signal to output so higher in lower gain will be. Gains are set high usually with lower preamp voltage head units.

 

[Jeffdachef 5,000+ posts]

the alpine is like 5 volts so i'm surprised you arent at zero gain. The gain is not a volume knob, where the input sensitivity rests is the level of pre out your head unit is putting out.

 

[sparten576]

Thanks for the tips. I read the scope wrong It was 6v pk-pk so 3v peak. I ended up getting a 600 watt version of basically the same amp and I'm getting decent volume now.