Class d vs Class a/b amps? RSX-1550 vs RSX-1560

[grit]

I'm demoing a RSX-1550 (class a/b) vs a RSX 1560 (class d). Speakers are Era Design 14s. What I've come to decide is that the class d amp has more power (duh) and is more precise or detailed perhaps? However, when i'm listening to the 1560, I feel like it's obvious that I'm listening through speakers. The best way to describe it is to say the sound stage feels like it has no depth. When I switch to the 1550, I lose a little bit of detail, but the sound stage feels 3-dimensional again.

Can anyone else verify this? Is this a common issue between class a/b amps and class d amps? And finally, which one is putting out the more accurate sound? I know which *I* prefer, but I'm curious if what I'm preferring is the most accurate.

I'm considering an RSP-1570 with either a class d or class a/b amp, so any general input on this effect will be VERY helpful.

Thanks!

[mjb]

Well, people say switching amps are very precise, but have limited bandwidth, and the necessary filtering will remove most if not all of the harmonics. Generally we prefer a warmer sound, full of harmonics. Thats why valve amps sound so good. So, a/b is probably more accurate, but whats the source material? Chances are its been digitally processed, you just can't get away from digital these days. At the end of the day, you just have to go with what you like. There are just too many excellent products for broad generalisations.

[sal1k]

Having just recently purchased and set up an RSX-1550 (my first rotel) at home, I can say that I am thoroughly satisfied. I did audition the 1560 at the store along with a 1550, and although I couldn't detect any difference in sound, my wife who is a trained musician felt the 1560 was colder, more "surgical" in tone. She also preferred the 1550, sonicall and financially, as it's less expensive than the 1560 as well.

After having it set up for just over a week, I do notice that it does generate heat. I don't know if the 1560 with the class D amps would generate as much as the 1550.

Sal

[grit]

I can vouch for the heat, as I have both... the 1560 is much cooler.

And Sal1k, I think your wife articulated what I'm hearing - the 1560 is more "surgical". Definitely more detailed, but it loses the harmonics, as mjb posted. And true, the sources (CD, SACD, etc.) are all digital, but the class d amp just doesn't work for me. Basically, I lose my involvement in the music. With the 1550, i found I was swinging my foot with the music. With the 1560, it felt like listening to speakers.

So, no generalizations, but for me, the current class d amp technology isn't what I prefer. And I feel better hashing out what differences cause that. Thanks for your input guys!

[MickeyVee]

Don't underestimate the 1560. It take a good two months to break in. When I ordered my black 1560, I was using the store demo and was seriously regretting my decision. Luckily Rotel was back ordered and I had the demo unit for 6 weeks. It started off weak an uninvolving so I got a Parasound amp to drive my Martin Logan speakers. Ahhh... the sound again (I came from a 1067). Switching back and forth, the 1560 amp began to break in and smooth out. After the 6 weeks, I preferred the Rotel. When I got my black 1560, I went through the same scenario.. now, after 3 months, it is so good, I ordered a 1572 for the extra juice to drive the Logans (not the the 1560 is doing a bad job.. just prepping to move up the line).

In the end, I prefer the Rotel Class D to Rotel's and Parasound's Class A/B.

[gianni]

I'm demoing a RSX-1550 (class a/b) vs a RSX 1560 (class d). Speakers are Era Design 14s. What I've come to decide is that the class d amp has more power (duh)...

Thanks!

According to the specs. HomeTheater Mag did a bench test on the RSX-1550 and the 1560. There is on a practical level little difference in power between the two. In some areas the 1550 actually beat the 1560. The main advantage of the 1560 is the 2 extra channels and low heat output if you don't have adequate space for cooling.