"Volume" difference between amps with same preamp?

[borgetc]

I recently was fortunate enough to acquire an NAD preamp (C162) and amplifier (C272) in excellent condition at "friends and family rate."

I also have, and was previously using, a vintage Pioneer SA-8100 in near mint condition and professionally serviced. I have the 8100 tuner as well - a lovely set of vintage gear. All servicing a museum quality Pioneer PL-61.

I first started using just the NAD preamp and found I really liked the sound. When I added the amp, while different, I also found the sound pleasing. My question is this: when I started using the NAD amp, I noticed a significant change in power. The power ratings suggested I might experience the opposite if anything. It isn't a problem with sound quality, just that the overall range available for phono seems to be quite different. The amount of headroom left on my Pioneer when the NAD would be at 3/4 is like having the Pioneer's volume at 1/4 - any explanations? I'm guessing this is about my relatively modest understanding of how these things work despite my lifelong love of music and vinyl etc. Any insights most appreciated!

 

[shelly_d]

To further complicate the issue there are also the specific sensitivities of each of the devices. For example, if you take two amps of similar output by two different manufacturers, you could easily see one going to full output with a 1 volt signal, while the other might need 2 or 3 volts. There will lead to very different volume dial positions, leading some less technical folks to the erroneous conclusion that one amp is more powerful then the other.

Please be more specific with your question and we will try to address it. Also let those of us not familiar with the equipment know which unit is preamp, power amp, integrated amp, receiver etc. That too may make a difference in our answers.

Shelly_D

 

[whoaru99]

Yes, as Shelly_D eludes to, the difference is almost certainly that the two different amps have different gain. That basically means when you put the same amount in, the two produce different amounts coming out.

Different input sensitivity isn't really the culprit but different gain is.

 

[rothwellaudio]

Different input sensitivity isn't really the culprit but different gain is.

This is absolutely spot on. Thinking in terms of power is less useful than thinking of power amps simply as voltage amplifiers just like any other voltage amplifier. Voltage amplifiers have gain. The power rating is simply a measure of how high the voltage will go before hitting the "end stops".

 

[George W]

the Nad preamp has 2 sets of outputs. I'd like to think the variable pair, if set to max level, would approximately equal the fixed output. are you using these to feed your two amps?