My 30 Watt class A is louder than my 100 Watt Class AB?


Curious observation…

I had just done some work on my DIY Hiraga 30 Watt Class A amp, and decided I would do an A/B comparison with my Adcom GFA 545.

To my great surprise, when I switched from the Hiraga to the Adcom, leaving everything else in the set up the same, and when I turned the music back on, it needed to be turned up to play at the same volume.

Input impedance is different, and I’m wondering if this is what could be causing this counter intuitive finding? Hiraga is around 33K and the Adcom around 100K.

Wondering if anyone has any thoughts as to why this is what I’m experiencing.

Thanks

 

perkri

Showing 1 response by mwood

I went from a tube preamp with 3-5 db of gain into a ZMA and always had the preamp up more than half way to get reasonable volume from 96db sensitive speakers. When I got a Backert preamp with 9db of gain now all of the sudden the ZMA is a  power house and never needs the pre up nearly as much to reach very robust listening levels. Gain staging is crucial and of course component synergy.