RB 1090 vs RB 1092

[Roteller]

Hi, I am looking for some advice on the differences between the two amps. I currently have an RB 1090 and love it to death, but I am becomming more and more curious about these new D class amps.

How much of a difference would a person notice power wise with the extra 120 Watts per channel?

How stable are these new amps with lower ohm loads on them. We all know how well the RB 1090 can handle this.

Also I noticed the damping factor is much lower on the RB 1092(400), compared to the RB 1090(1000). How much of en effect would this have on speaker control?

I would like to upgrade, but want to educate myself before making the big jump. Also it is quite the hike to my nearest dealer, so any insight on this subject, be it positive or negative would be greatly appreciated before heading to a dealer.

Thanks.

[gianni]

Hi, I am looking for some advice on the differences between the two amps. I currently have an RB 1090 and love it to death, but I am becomming more and more curious about these new D class amps.

How much of a difference would a person notice power wise with the extra 120 Watts per channel?

How stable are these new amps with lower ohm loads on them. We all know how well the RB 1090 can handle this

Also I noticed the damping factor is much lower on the RB 1092(400), compared to the RB 1090(1000). How much of en effect would this have on speaker control?

I would like to upgrade, but want to educate myself before making the big jump. Also it is quite the hike to my nearest dealer, so any insight on this subject, be it positive or negative would be greatly appreciated before heading to a dealer.

Thanks.

Depends on speakers and room but in the vast majority of cases the extra power will make no difference.

Rotel's class D amps track low impedance loads quite well - better than most traditional amps.

A damping factor of 400 is more than adequate. Anything more just pads the specs and won't make much difference for most speakers. In fact, there are many good amps with factors under 400.

While gaining a basic understanding is good, don't select your amps on specs alone. Take your time and do some comparative listening tests.

[Mig17]

damping factor 1000 is needed for very big speakers like BW 802 or 801
or Dynaauio Audience 82

[BassThatHz]

Unless you need to save space, weight and electrical bill... I would say don't bother. Digital amps have some residual switching noise above 7khz... how much of that you hear really depends on your ears and speakers. ~1%THD above 16khz @ 100watts

[Ferres]

I agree. If you already have an rb1090 and have no space/weight/electricity bill issues with it...

[gianni]

damping factor 1000 is needed for very big speakers like BW 802 or 801
or Dynaauio Audience 82

Oh really? I guess that means that most of the Bryston line, Krell, Pass and other quality amplifiers are incapable of driving these B&W speakers.

I would suggest you take another look at this topic. No sense in making statements that may not be accurate.

[Roteller]

Thanks to all that responded, and if anyone else has any other input or information I would greatly appreciate it.

[Roteller]

Unless you need to save space, weight and electrical bill... I would say don't bother. Digital amps have some residual switching noise above 7khz... how much of that you hear really depends on your ears and speakers. ~1%THD above 16khz @ 100watts

So are you saying that these amps are not as clean as the RB 1090?

[mjb]

Unless you need to save space, weight and electrical bill... I would say don't bother. Digital amps have some residual switching noise above 7khz... how much of that you hear really depends on your ears and speakers. ~1%THD above 16khz @ 100watts

Can you qualify that?

http://www.icepower.bang-olufsen.com/files/solutions/icepower1000aspdata.pdf

Says on the data sheet:
1000W @ 0.01% THD+N, 100 Hz, 4Ω
1175W @ 1% THD+N, 1kHz, 4Ω

THD+N < 0.2%, 0.1W – 1100W, 4Ω

I agree the THD is a little higher than a linear amp, but I can't hear it. I don't think I can hear any "residual switching noise" either.

At the end of the day, either people like the Rotel D amps, or they don't (probably due to a pre-conceived prejudice). Personally, I'm more than happy with my RB-1092. The power is virtually bottomless, it tracks any load, runs cool, its light, and it takes up minimal room. Very high WAF factor!

If you're interested in a D amp, then try to listen to one (without prejudice) and let your ears decide.

[Alaric]

Having heard both , I vote for the RB1090. YMMV.

[JRachwalski]

The Rotel Class D amps use Analog Controlled Oscillation Modulation rather than Digital. This helps to reduce audible switching noise. I have auditioned both the 1092 and 1085 - and neither have audible HF distortion, (the 1092 measured close to 1% above 5Khz at 300 watts).

My listening tests with the 1092 was done with B&W 804s.
My listening tests with the 1085 was done RAW Acoustics OB3 (Open baffle midrange and ribbon tweeters).

Measurments:
http://www.hometheaterhifi.com/ampli...plifier_3.html

[style]

Hy,

I do not use anything when I have to choose between one or the other ...

I use "only" my ears! ops:

I had all two hours and now my set is RB1092 to front, RB1091 to center, RB1092 to rear.

I like very much the sound from the new D class.

Only point for RB1090 was XLR I/O but the Rotel pre/pro don't understand this
point.......

Omar

[miner]

I have compared the two; the owner of the RB-1090 and I both came to the same conclusion: RB-1092.

[BassThatHz]

http://www.hometheaterhifi.com/image...ct-reviews.gif

According to this image: 20v @ 4ohm's is 1% THD+N above 5khz
and >0.1THD+N above 3khz

I = V/R
P = I * V
So:
20 volts / 4 ohm = 5 amps
5 amps * 20 volts = 100 watts (or 50watts for 8ohm)

http://www.hometheaterhifi.com/image...ct-reviews.gif

At the 312 watt sweep:
The Min THD+N is ~0.018% and Max is 5% at 18-20khz

At the 496 watt sweep:
Min THD+N is 0.22% and Max is > 1% above 5khz
Between 11khz and 35khz ~2-11% THD+N

This isn't apples to apples, but the rb-1090 was measured at 4watts and never rose above 0.05% even when >20khz; and at >407W it clips.

Now to throw a monkey wrench into this whole thing, check out the real-world watts/ohms/THD on this amp, and then check its price tag ~$350:

http://i21.photobucket.com/albums/b297/chasw98/amp%20testing/EP2500/EP2500-8ohm-061007.jpg

http://i21.photobucket.com/albums/b297/chasw98/amp%20testing/EP2500/EP2500-4ohm-061007.jpg

http://i21.photobucket.com/albums/b297/chasw98/amp%20testing/EP2500/EP2500-2ohm-061007.jpg

Power the woofers with this, and the mids +Tweets with your trusty RB-1090; problem solved. :P

[DL86]

I recon you would be hard pressed to hear a difference. Spend your money on something with guaranteed improvements like room treatment or a nice sub. I recently got my SVS PB-13 Ultra and it has provided me with the greatest improvement in my sound over any other electronic peice of equipment I have bought or upgraded from.

[thezone]

I second that, all the guys at my local specialist hi-end hi-fi shop are saying that they prefer the sound of older bigger rotel amp models to the new ice stuff. I f you really want to improve your sound get a couple of active subs with internal crossovers and run a second send of L & R pre-outs to them whilst listening to stereo. Doesn't matter how good your speakers are this will improve the overall sound. Don't need to be loud just a nice bottom end presence.

[style]

Hi thezone,

You have reason but is a personal taste.

I prefer the 1092 (I was also 1075/1090) but also depends on the room and other factors.

It is not only with the power amplifier you get the best sound.

Greetings from Switzerland
Omar