RB-1080 or RB-1070 power amp to purchase?

[soundhound]

Congrats thyname, you will not regret it. Also as Azeke say's, it will mellow after a little run time on it. I have noticed all of my new Rotel components are a little clinical out of the wrapper, they relax very nicely.

[benny]

Congrats on the 1080. Just wondering how you managed to swap a 1070 for a 1080 at no extra charge. That's a trick I need to learn!

[Parsonsk]

I hear ya Benny!
Thyname, you'll have to fill us in on the details, what did you do so you could do a straight trade?

[Taito]

Amplifier distortion

Very interesting!!! I don't know how it applies in my case. My speakers have a 250 Watts max power handling. Anybody can elaborate on the above?? Andrew Pratt maybe???

Amplifiers distort more as they approach their power limits (compression and harmonic distortion mainly). At low power, the noise floor of the amplifer is much larger relative to the signal output. This means the the amp will measure as having higher distortion at low levels, but the measurement is actually being influenced by the background noise in the amp.

Hope this helps, Ben

[thyname]

Hey Ben, a little difficult for me to understand the above, probably too technical for me.

I agree with you guys, I think my RB1080 will sound better in a couple of weeks. I am also happy that this amp will serve me well in the future (with RSp 1068 in mind and 1080 to power my fronts and a surround amp to power the rest).

As for swapping, this dealer (Myer-Emco) in DC area has this 90 days upgrade policy on Rotel. I purchased 1070 a few weeks ago, just brought it back, got 1080 and paid the difference. As their customer, I got a decent discount as well (considering Rotel).

[Taito]

Hi thyname, any amplifier will have a noise floor. This is the background noise that it produces. Let's take the extreme case. If an amplifier has no input, then the only output is this noise. So, by directly comparing the amplifier's input to its output, you would say that there is a lot of distortion (distortion being a change from the original signal). If there is an input to the amplifier(say very low volume), then the output consists of the (amplified input + noise). As the input gets larger, the amplified input at the output gets larger, but the noise level stays the same. So, as a percentage, as power increases from no power, noise makes less and less of a contribution to the overall distortion of the amplifier.

Therefore, at very low power, we have a higher % THD + noise than we do at middle power.

As the power amp approaches its power limits (a large input signal), other distortions set in such as compression and harmonics. This is because of stress on the power supply as well as other factors (wont go into detail here...). The closer the amp gets to its limits, the greater these distortions become.

So we now have a higher % THD + noise at low power than at middle power (due to noise floor/background noise). And also a higher (much higher) % THD + noise as the amplifier approaches its power limits.

As long as you can't hear the background noise from your amplifer with no input from your listening position, the higer % THD + noise measurement at low power is not an issue. The amount of distortion as an amplifer reaches its power limits is an issue.

Conclusion: The best case is to have a high powered amplifier with a low noise floor.

I hope this clears it up a bit, I am used to discussing this sort of thing with people who have learnt the same things I have (Electrical Engineering student). Also, I have had a 1080 for about 15 months, and it mellowed out a lot. It really is a fantastic amplifier. Good choice.

-Ben

[benny]

swapped at no extra cost = paid the difference?

[thyname]

swapped at no extra cost = paid the difference?

Yes, of course, no extra cost meaning got full purchase price back for RB-1070... Sorry if it sounded different!

[benny]

cool, man. i thought you had "the force" with you or something! :T

[thyname]

Very funny Benny!! I watched the new Star Wars yesterday, the best of all series by far!! at least for me.

[jltrdavis]

I'm in the same situation. I've got the RC-1070 and am trying to deciede between the RB-1070, RB-991, and RB-1080 to drive my new B&W 804's.

Thyname,
Any further insight on differences between the 1070 and 1080 now that you've had a little time with each? Anyone else have any opinions on which way to go considering my setup? I'm interested in quality over quantity.

Thanks,

Jason

[thyname]

There are not huge differences between 1070 and 1080, at least for me. With my 1080, I can notice some crisper highs in some of my CDs as well a better "feeling" overall for the music, it feels and sounds kinda deeper. It also plays louder, but I can hardly crank it up in my apt. builduing where I live. Other than that, they are both just as good and I suspect I could not tell the difference if I had to do a blind test. However, I am happy since there are no buyer's regrets for me in that field. I also think that if you have higher wattage and better quality speakers than my Axioms, you would probably hear more difference with 1080. One thing I can tell you for sure: switching from a receiver (rx 1052) to separates, was the biggest improvement in my system!