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

Volume isn’t my problem :)

Using 4ohm 84db speakers, I never go past 11 o’clock on the dial :)

@russ69 -- I know the Saga has no gain (that's what "unity gain" means.) And I was using a DAC with the typical 2 volt output, so nothing amiss there. While most of the time I got the desired playback volume, the problem was when the recording itself was recorded at lower than normal volume. Certainly not a problem with most pop/rock material, but there are some recordings out there where this can be an issue.  Its not an issue limited to certain turntables/phono preamps.

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.

Watts per channel are only the out put measurement ( horse power). There is so much more (torque) inside the an amp that produces the watts per channel. They did not name the company “First Watt” because it was catchy!

gain and input sensitivity ...man, how about my conrad johnson preamp:

Gain:

Phono stage 47dB

Line Stage 31dB

is is sometimes too loud at 9 o clock. i use inline attenuators on amplifiers that dont have a volume knob. man this thing has a lot of gain.