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Stylish new Rotel 15 series receivers / processors / power amps

mr_smidge

Active Member
It looks like Rotel have brought out a new model line, the 15 series:

Rotel RSP-1570 Surround Sound Processor

Naturally, they would do this literally moments after I bought a RSP-1098, but I'm not actually too worried about that.

Am I alone in the opinion that they're not actually that sexy? Compare the beautiful silver fascias and black heatsinks of the 10 series to this, and this new bunch looks a bit harsh and industrial.

I do, however, like that they're advertising the new range as rack-mountable, and all with RS-232 control. Looking forward to a review!
 

Mr_Orange

Well-known Member
Am I alone in the opinion that they're not actually that sexy? Compare the beautiful silver fascias and black heatsinks of the 10 series to this, and this new bunch looks a bit harsh and industrial.

I do, however, like that they're advertising the new range as rack-mountable, and all with RS-232 control. Looking forward to a review!

I tend to agree that the 10 series looks a little better, but I think the power amp looks good with that "radiator grill" on the front.

The processor looks well specified, so it will be interesting to find out the price and its performance against the competitors.
 

Welwynnick

Distinguished Member

Mr_Orange

Well-known Member
Indeed there are, but receivers, honestly, don't blaspheme ;) ;) ;)
 

cribeiro

Well-known Member
It is interesting to see that the new power amps double the power going from 8 Ohm to 4 Ohm while keeping THD equally low, which the previous line did not achieve. That's quite a good sign. I don't like their looks, though.

Another plus is that they include IR-remote capabilities.
 

idbrunt

Active Member
I don't think class D amps are digital; believe still analogue but use switch mode power supplies as used by Chord Amps (though obviously not of the same quality) - very quick response and don't run hot. Rotel used class D ICE modules in their 1077 amp which has now been superceded by these new 15 series power amps.
 

cribeiro

Well-known Member
If I understood it right, Chord amps are also Class D. This does not mean digital (see Wikipedia), but they are commonly called like that.

Actually, now that I read about it (and finally understand it), I would classify that as digital, because the output signal is either on or off. OTOH, it cannot be digital because there are no bits. The point is that the information is not binary encoded, but rather relies on the "inertia" of the system.

Definitions of "digital signal" by Wikipedia allow to call Class D "digital", IMO.
 

Mr Yakimoto

Active Member
I would be interested to find out how "audiophile" the RMB1575 actually is.

I currently use RMB1075, although very musical, I wouldnt call it audiophile.....but then again nor was the price.

I want to step up and get an AMP that really compliments my TAG and B&W set up. I was thinking Bel Canto but this really would turn out expensive.

Now for some reviews!!!:thumbsup:
 

Welwynnick

Distinguished Member
Lots of people thin class D isn't digital, and I'm always curious why. I think its' down to effective marketing by B&O, Pioneer and Rotel. They all seem to want to avoid using the dreaded digital word, for fear of undesireable sound quality connotations. ICEPower modules are invariably described as "analogue class D" amplifiers, just to avoid saying "digital".
-
Problem is, class D is digital; not because of the "D" letter, but because they are switching amplifiers. B&O have made several technical notes and papers available, and they all refer to switching amps. An amp is digital if its output state can be described with a digit - one or zero - depending on whether the output device is on or off. The output waveform is created by having this digital switching performed in the time domain, and not by having the output modulated in the amplitude domain.

Whether the control is pulse duration or pulse frequency modulated, its still modulatoin of switching.

Nick
 

cribeiro

Well-known Member
Lots of people thin class D isn't digital, and I'm always curious why. I think its' down to effective marketing by B&O, Pioneer and Rotel. They all seem to want to avoid using the dreaded digital word, for fear of undesireable sound quality connotations. ICEPower modules are invariably described as "analogue class D" amplifiers, just to avoid saying "digital".
-
Problem is, class D is digital; not because of the "D" letter, but because they are switching amplifiers. B&O have made several technical notes and papers available, and they all refer to switching amps. An amp is digital if its output state can be described with a digit - one or zero - depending on whether the output device is on or off. The output waveform is created by having this digital switching performed in the time domain, and not by having the output modulated in the amplitude domain.

Whether the control is pulse duration or pulse frequency modulated, its still modulatoin of switching.

Nick
According to Wikipedia:
"The term "Class-D" is sometimes misunderstood as meaning a "digital" amplifier. The quantization of the output signal at the power stage can be controlled by either an analog signal or a digital signal. Only in the latter case would an amplifier be using fully digital amplification"

It is not my field, so I am not sure, and I guess it depends on how you define "digital". Again following Wikipedia, and as I previously pointed out, there are two different definitions of "digital", so it is unclear (according to this) as long as there is no agreement on the definition.

I don't care if digital or not. they could be "quantum amplifiers" as well :rotfl:(someday...). The main point is if they sound good :D

They should call them "Class G" instead of D. "G" stands for "green", of course. They are definately the answer to global warming.
 

Welwynnick

Distinguished Member
According to Wikipedia:
"The term "Class-D" is sometimes misunderstood as meaning a "digital" amplifier. The quantization of the output signal at the power stage can be controlled by either an analog signal or a digital signal. Only in the latter case would an amplifier be using fully digital amplification".
I think we agree on one thing in common, that it doesn't really matter whether its digital or not. I haven't heard these amps of course, but Rotel have, and they seem to be keen for class D amps to take over the Class A/B amps they used to use. I don't think its because they sound grim. Certainly the current generation 1077, 1085, 1091 & 1092 amps seem to perform pretty well.

As to what class D really means, it depends on what the primary process is - whether the output devices are switched or linear or wether the control of those switching output devices is linear or digital.

Nick
 

eaglemmoomin

Well-known Member
I think we agree on one thing in common, that it doesn't really matter whether its digital or not. I haven't heard these amps of course, but Rotel have, and they seem to be keen for class D amps to take over the Class A/B amps they used to use. I don't think its because they sound grim. Certainly the current generation 1077, 1085, 1091 & 1092 amps seem to perform pretty well.

As to what class D really means, it depends on what the primary process is - whether the output devices are switched or linear or wether the control of those switching output devices is linear or digital.

Nick

Weeell I may be being cynical but it might be down to cost and being simpler to construct perhaps? I was talking to one of the hardware engineers a while back at work and to say he was a bit dismissive over the idea was a bit of an understatement. Mind you he was getting a bit misty eyed talking about valves and I was flogging him an amp at the time.
 

Welwynnick

Distinguished Member
Weeell I may be being cynical but it might be down to cost and being simpler to construct perhaps? I was talking to one of the hardware engineers a while back at work and to say he was a bit dismissive over the idea was a bit of an understatement. Mind you he was getting a bit misty eyed talking about valves and I was flogging him an amp at the time.
Dismissive about what idea?
 

eaglemmoomin

Well-known Member
Dismissive about what idea?

Current implementations of digital amps. He seemed to think that there was great potential for high frequency ringing or somesuch. If I remember to ask him next week I will.
 

JohnWH

Active Member
My understanding is that all class D amps operate the output stage in either off or fully on state (this is where the efficiency comes from). However the modulation (typically PWM) is driven by an anlaogue stage so the amps are still strictly analogue in what they are doing, not sure if there are any available commercially that do this digitally at this time...

Not sure why any truly knowledgable person would be so dismissive of the technology, guess its the same as some folks still insisting that valve amps are better ;)

John.
 

cribeiro

Well-known Member
My understanding is that all class D amps operate the output stage in either off or fully on state (this is where the efficiency comes from). However the modulation (typically PWM) is driven by an anlaogue stage so the amps are still strictly analogue in what they are doing, not sure if there are any available commercially that do this digitally at this time...

Not sure why any truly knowledgable person would be so dismissive of the technology, guess its the same as some folks still insisting that valve amps are better ;)

John.
So you agree with Wikipedia´s definition.
I don´t know what I should think. Nick´s argument is also a valid one )it really amplifies the analog signal in a digital way), and I think it is only a matter of definition. I am not versed enough as to discuss which definition is the most appropriate, though, so I leave it to the experts :) and care only about their sound :D
 

eaglemmoomin

Well-known Member
My understanding is that all class D amps operate the output stage in either off or fully on state (this is where the efficiency comes from). However the modulation (typically PWM) is driven by an anlaogue stage so the amps are still strictly analogue in what they are doing, not sure if there are any available commercially that do this digitally at this time...

Not sure why any truly knowledgable person would be so dismissive of the technology, guess its the same as some folks still insisting that valve amps are better ;)

John.

All I will say is that he did used to build amps and speakers...........plus is an electronics engineer.
 

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