Watch Out Krell, here comes Rotel:tales of the RMB 1077

[mattburk]

What company building digital amps is based in holland?

[Feisal K]

What company building digital amps is based in holland?

Hypex

[DrJRapp]

I'm wondering what Rotel is waiting for? THere are a few 500 watters out there now. Industrial espionage?

Based on some inside information that I deem very reliable, Rotel is still tweeking the 1091 and 1092 to get them to sound similar in tonal character (timber) to the 1077 so that the three can be used together in a multi-channel setup.

That's to everyone who wrote emails and pms with their concerns about our wellbeing during Hurricane Wilma. Hopefully I'll get a chance to respond individually within the next day or so. The power is back and evrything here is fine but the trees, which are all basically gone. My office sustained fatal damage when a rooftop ac unit took of an wound up across the street leaving a 4' x 4' whole in the roof. Trying to salvage what we can right now.

[bzrk]

woehoe! ive ordered mine

rmb 1077 plus a rsx 1068

dont have much experience with other amps but ill offcourse post my findings

[PewterTA]

Jerry, Sorry to hear about the house, at least everyone is safe and okay, the house can be fixed and replaced, where the family can not.

Get some pictures of what it's like around there, I hear there's some places that look like a waste land...

[DrJRapp]

Jerry, Sorry to hear about the house, at least everyone is safe and okay, the house can be fixed and replaced, where the family can not.

Get some pictures of what it's like around there, I hear there's some places that look like a waste land...

Thanks for the concern,

Actually, it wasn't my house but my office. My house I could deal with, but finding office space around here is hell. You also have no idea how difficult it's going to be to replace all the wet paperwork from 15 projects. At least the accounting computer was backed up properly.

What happened to the CAR????? I see your scorecard, but need more details.

[DrJRapp]

woehoe! ive ordered mine

rmb 1077 plus a rsx 1068

dont have much experience with other amps but ill offcourse post my findings

That's actually a good thing, we can get a totally fresh perspective.

[mattburk]

Hypex

Thank you, Do you know anyone using this company for their systems?
I spoke to one retailer who may be using them in the future, they thought they had the best sounding configuration overall.

Aussie Geoff here - Matt, this is not really a Club Rotel question nor is it on thread topic - you will get a better result if you post it as a thread of its own in either Audio or the Home Theater forums of HTGuide....

[lvhung]

Has anyone notice a hum or buzz when 1077 running ? h:

[DrJRapp]

Has anyone notice a hum or buzz when 1077 running ? h:

The dead quiet of my 1077 is one of it's best features. I previoulsy has a slight raster buzz from my 1080 that could be heard from 1 to 2 feet of the speakers, nothing serious. I had written this off as the result of the super high efficiency of my RF7s. Now you have to stick your ear up to the horn tweeter to hear any noise at all.

[Kobus]

Jerry, you have not yet listened to the 1077 with B&W (80x).

What are the thoughts out there about the 1077 driving B&W (803 in particular).

Thanks

[DrJRapp]

Jerry, you have not yet listened to the 1077 with B&W (80x).

What are the thoughts out there about the 1077 driving B&W (803 in particular).

Thanks

I'm still waiting for my local B&W/Rotel dealers (2 of them) to get in a 1077 for demo. I'm curious about the 1077/803D combo myself.

[DrJRapp]

1077 with Classe and Wilson

This afternoon my wife and I stopped into Audio Advisors in West Palm Beach where Ron was gracious enough to let us listen to the 1077 powering Wilson Sophias and controlled by a Classe SSP 300. How sweet that was! The bottom end was absolutly outrageous! That system was pre-setup in one of their new listening rooms. Besides the totally stunning sound, the fact that a dealer as classy as Audio Advisors was using the 1077 with such high end gear as the Classe and Wilsons says a awful lot for the 1077.

[bzrk]

stop it already you make the waiting even harder :P

[DrJRapp]

stop it already you make the waiting even harder :P

Believe me it will be well worth the wait!

[Martinf]

Hi Jerry,

From what you report, the 1077 does sound promising, but I'd really like to see some professional analysis graphs on this amp. In particular, I'd like to see plots of its dynamic range / signal resolution in relation to frequency and output power. And how does it deal with clipping etc. etc. Do you know where I can find them?

Your enthusiastic descriptions of the sound remind me of the initial reactions to pulse-density-modulated SACD/DSD when it first came out. But in hindsight we now know that DSD has serious flaws, especially the high-freq noise it creates, and deteriorating dynamic range as frequency increases beyond 12kHz. ;-)

[shadow]

Well I certainly would not want to spoil my graphs by actually listening to that amp. :roll:

[Martinf]

>> Well I certainly would not want to spoil my graphs by actually listening to that amp. <<

What are you afraid of? I say bring on the measurements of dynamic range and resolution limits at high frequencies etc. . They don't lie. If the amp is as good as is being implied here, then the plots will confirm that. Maybe an independent engineer like Paul Miller can come to the rescue?

[DrJRapp]

Hi Jerry,

Your enthusiastic descriptions of the sound remind me of the initial reactions to pulse-density-modulated SACD/DSD when it first came out. But in hindsight we now know that DSD has serious flaws, especially the high-freq noise it creates, and deteriorating dynamic range as frequency increases beyond 12kHz. ;-)

Martin,

I'm sure the data you are seeking will arrive soon. The 1077 just hit the streets and dealers are having difficulty meeting initial demand, let alone finding excess stock for use as a test platform.

This situation is very different from PDM SACD in several several respects. First, the situation you are talking about was pioneering, a first for a new format and type of gear. That isn't really the case here. Bel Canto and others have been utilizing this type of technology for awhile now.

Second, unlike SACD/DSD where even the concept was new, with the 1077, multi-channel amps are not new and we have lots of conventional predicessors to sonically compare them to. On this basis, the 1077 does quite well, regardless of what the ultimate measurements show.

[Martinf]

>> Second, unlike SACD/DSD where even the concept was new <<

That's what Sony wanted us all to believe! But in fact one-bit PDM (DSD) had been around in various guises for many years before SACD came out. For a start, many CD player manufacturers in the early 1990s used basically the same technology for their one-bit DACs. The reason: They were cheaper to make than proper multibit ladder DACs. Ironically, the one-bit CD chips operated at higher internal clock rates than 64fs DSD.

Coming back to topic: I want to know much more about this ICE technology. From somebody independent.

For example, I want to know if it has an internal clock-rate limitation, and I want to see independent signal outputs plots of the entire frequency and dynamic spectrum. I also want to see what kinds of noise it generates at all conceivable frequencies and power demands.

[bzrk]

hmm :/

Wouldnt it be better to just listen to it? What if the test result are not so good (hard to believe )? The psychological effect for you will be that you think that is doenst sound as good either... That is if you have plans to buy this amp.

In case of just intrest in the icepower technology i can understand why you want to know all this.

[Martinf]

It may be no coincidence that Rotel stresses the RMB-1077's "Home Theater" credentials, rather than any pretence of music/audiophile applicability. ;-)

N.B. Home Theater is mostly low-rez & lossy MP3 quality. But then again, I've heard some people swear that MP3 is the best quality sound possible! )

[bzrk]

Because most amps sold right now are multi channel?

[sprout]

It may be no coincidence that Rotel stresses the RMB-1077's "Home Theater" credentials, rather than any pretence of music/audiophile applicability. ;-)

N.B. Home Theater is mostly low-rez & lossy MP3 quality. But then again, I've heard some people swear that MP3 is the best quality sound possible! )

Hi, what amps do you use currently?
Why did you but them?

Was it for graphs that sophisticated electronics give you a visual representation of its statistics?
OR
Good old fashion subjective listening?

If we all had oscilloscopes for ears the former may be worth it, but with normal little old lug holes, best have a listen with those.

Personally if I want to listen to music or get a friend to give me an opinion, I turn the system on rather than show them a load of graphs

[Martinf]

>> Good old fashion subjective listening? If we all had oscilloscopes for ears the former may be worth it, but with normal little old lug holes, best have a listen with those. <<

It may come as some surprise to you, but the very engineers, who designed that amp in the first place, certainly do not rely on old-fashioned "subjective listening" when verifying whether or not the product meets their initial design spec goals. ;-)

[sprout]

>> Good old fashion subjective listening? If we all had oscilloscopes for ears the former may be worth it, but with normal little old lug holes, best have a listen with those. <<

It may come as some surprise to you, but the very engineers, who designed that amp in the first place, certainly do not rely on old-fashioned "subjective listening" when verifying whether or not the product meets their initial design spec goals. ;-)

No surprise at all, but they are designing it, but if you think good HiFi is about figures only :E
I think you will find the engineers, Engineer, and then they too have their good old fashion listeners

[RobP]

I dont think that Martin is out of line on this point, you should do your homework completely before making a purchase. Information is key to that decision so you dont end up with something that you will be trying to get rid of a year down the road.

[DrJRapp]

I don't think Martin is out of line either. But, as an engineer and I don't place all my confidence in what specs and tests reveal or don't reveal, I know better, it's never a black and white situation. There is a flip side to this whole thing. I've recently experienced amps with wonderful specs and great test results that at the end of the day came up very short when it came to actual sound quality in a real room with real speaker loads.

I think your insinuation that Rotel's stressing the home theater aspect of the 1077 is something sinister is way off base. I seriously doubt that Rotel was trying to hide anything by making their first digital entry a multi-channel (read that theater) amp. I think they saw the opportunity to accomplish the extraordinary in a 7 channel amp and decided to go for it. I also think they decided to establish the sound quality of the multi-chaanel first, then match the mono and 2 channel to it. This makes far more sense from marketing aspect. Rotel probably sells 90% of their gear for home theater use nowadays (including 2 channel amps that ultimatly find their home driving the front channels of a 7.1 system). There was also the opportunity to fill a market niche that Rotel was missing...a 7 channel amp.


Martin, there is a lot of data available on B&Os IcePower site. I also belive you can find some design whitepapers there also.

[Martinf]

It seems that the "Home Theater" application is certainly appropriate, since the target bandwidth is 0Hz-20kHz (according to para 4.1.2 on PDF page 12 of the AES paper preprint 5039).

http://www.icepower.bang-olufsen.com/graphics/powerhouse/user_graphics/Library/AES_Publications/5039.pdf

. . . "The audioband is defined as to the range of frequencies within 0kHz to 20kHz." . . . and . . . "Worst case in terms of harmonic dostortion is present when modulating a 6.66kHz signal as 3rd harmonic lies just within the audio audioband at 20kHz."

Moreover, on the previous page it seems they are making some worrying excuses: "In real life however, the precision does not need to be 16bit accuracy since exact LPWM pulse-edge placement leads to harmonic distortion anyway." . . .

In summary, from what I deduce from that paper, the target "box" for this technology is <16bit accuracy in the amplitude domain, and <20kHz in the frequency domain. Whilst the 1077 amp may go beyond 20kHz, I suspect there’s all sorts of HF noise-shaping required to combat noise artefacts, as well as loss of dynamic resolution, much as is the case for SACD/DSD (which I inherently dislike for this very reason).

Now for me, if my above assumption is correct, this technology would not be acceptable to me, especially since I have about 100 high-resolution DVD-Audios, and most of these are 96kHz/24bit recordings. Of course, for DVD film soundtracks, a 16bit/20kHz amplifier bandwidth is right-on spec (but it would certainly defeat the object of having a high resolution DVD-Audio source).

[csuzor]

In summary, from what I deduce from that paper, the target "box" for this technology is <16bit accuracy in the amplitude domain, and <20kHz in the frequency domain. Whilst the 1077 amp may go beyond 20kHz, I suspect there’s all sorts of HF noise-shaping required to combat noise artefacts, as well as loss of dynamic resolution, much as is the case for SACD/DSD (which I inherently dislike for this very reason).

Now for me, if my above assumption is correct, this technology would not be acceptable to me, especially since I have about 100 high-resolution DVD-Audios, and most of these are 96kHz/24bit recordings. Of course, for DVD film soundtracks, a 16bit/20kHz amplifier bandwidth is right-on spec (but it would certainly defeat the object of having a high resolution DVD-Audio source).

Martin, I suspect you don't know much more than most of us on this topic, and by comparing a technical document you don't fully understand, which presents several methods of which you don't know which is actually implemented in the 1077 (if any), and claiming that is a good reason not to like the 1077, is ridiculous.

As for the noise above 20kHz on SACD, seriously, you don't like SACD because of this ultra-frequency noise? Are you looking at charts, or listening to the music? Have you heard a good SACD player playing a DSD recorded source, and can you honestly say it sounded worst than the DVD-A you have? (let us know which models / albums if you can).

You've got to move beyond the charts, go and listen, and then come back with your analysis on the sound. Isn't that what it's all about?

[sprout]

20KHz, can someone remind us of the peak of human hearing at say 40 years of age

Perhaps SACD was meant for Dogs :rofl:

sprout

[Martinf]

>> As for the noise above 20kHz on SACD, seriously, you don't like SACD because of this ultra-frequency noise? <<

That's just one symptom of the flawed PDM technology. b.t.w. The loss of HF resolution & dynamics with SACD actually starts well below 20kHz! Moreover, it is audible, and I don't like it. (OTOH, other people do like this effect which SACD has on 'smoothing' the treble. It doesn't make it right, though.)

>> Have you heard a good SACD player playing a DSD recorded source, and can you honestly say it sounded worst than the DVD-A you have? <<

Absolutely.

>> (let us know which models / albums if you can). <<

Mozart Requiem, Harnoncourt, on Harmonia Mundi SACD. An all DSD five-channel recording.

Compare with the same orchestra, conductor, and artists on St Matthaus Passion, Teldec/Warner DVD-A, 96kHz/24bit 5.1 recording.

My machine: Denon -A11 (-5900 in the US) running in "pure-direct" mode.

[csuzor]

20KHz, can someone remind us of the peak of human hearing at say 40 years of age

No one can reliably hear music beyond 20kHz, and at 40y old hearing stops well below that.

Perhaps SACD was meant for Dogs :rofl:

No, but equipment that pretends to play music above 20kHz was!

Seriously, some claim very high frequency adds life to the music, more realistic. But most music is recorded and played back with filters to remove such high frequencies, if the encoding media even allows it. It's well beyond TT and CD capability anyway.

Hmm, Martin... 2 different recordings? And Denon is far from being among the best SACD sources. But OK, it's your opinion. Care to share it in http://www.audioasylum.com/forums/hirez/bbs.html and talk to some real experts?

PS. The sound on this SACD is not highly rated... a bad recording? http://www.geocities.com/jmserre/ENMozartRequiem.html

Anyway, back to the topic: Anyone else actually heard the 1077?

[Martinf]

>> And Denon is far from being among the best SACD sources.<<

Off topic, I know, but . . .
The -5900 in source direct mode sends SACD/DSD data straight to the DACs with no PCM conversion. It also allows you to apply time alignment without converting to PCM. Not many other SACD players can do that.
(Only if you want bass management, it converts DSD to 176kHz LPCM so that the two 32bit floating-point SHARC DSPs in the Denon can apply the appropriate bass filtering. Again, not many SACD players can do that either!)


>> But OK, it's your opinion. <<

And also that of Mark Knopfler’s record producer whom I chatted with last week. But hey, what would he know? ;-)

Care to share it in http://www.audioasylum.com/forums/hirez/bbs.html and talk to some real experts? <<

"Real experts"? Are you serious??!

>> PS. The sound on this SACD is not highly rated... a bad recording? http://www.geocities.com/jmserre/ENMozartRequiem.html <<

Or just a bad format? Note that with long play times, they need to compress (reduce dynamics) to keep within disc capacity of a Hybrid SACD.

Hey, I like this bit of the review you linked to:-

"Some passages are so bad that I first believed that something was broken in my sound system. But a comparison with a recording of similar musical formations (DVD-A ARTS 45007-6 Messiah of Handel) shows that there are ways to make a really better recording of a choir and an orchestra."

I agree. FYI, I wrote a review of that same Arts Music Messiah recording a while ago. Here it is:-

http://www.highfidelityreview.com/reviews/review.asp?reviewnumber=10400465

[Sim reality]

. . . "The audioband is defined as to the range of frequencies within 0kHz to 20kHz." . . . and . . . "Worst case in terms of harmonic dostortion is present when modulating a 6.66kHz signal as 3rd harmonic lies just within the audio audioband at 20kHz."

Moreover, on the previous page it seems they are making some worrying excuses: "In real life however, the precision does not need to be 16bit accuracy since exact LPWM pulse-edge placement leads to harmonic distortion anyway." . . .

I think you missed one of the more important comments of the article where the THD of the 3rd harmonic of WPWM is lower then the Max THD. The article was exploring the weakenesses of LPWM and at a carrier frequency of 352.8 KHz the one place where there is non-linear theoretical THD is the harmonics of the carrier frequency.

I would be rather surprised if anyone would hear pulse edge placement errors given at the carrier of 352.8 KHz at the "theoretical limit" of human hearing that would equate to less then 1/10th of a wavelength... Given that you would have to accelerate the mass of the speaker driver you would have to be running remarkably effecient speakers if you are worried about the phase of 1/10th of a wavelength...

Also anyone know if they are using a carrier of 352.8 KHz, 512.9 KHz or 705.4 KHz?

[Martinf]

This is telling:-

According to Rotel, the RMB-1075 (not even their top-of-the-range model) has a pretty respectable 116dB S/N ratio, whereas the RMB-1077 only goes up to 105dB (and it probably deteriorates above 20kHz)

But then also realise that the RMB-1077's 100 watts, all channels driven, is with a 20KHz filter engaged.

Then look at the max frequency-response:-
RMB-1075: 100kHz +0.5; -3dB
RMB-1077: (only) 80kHz +- 3db (presumably without the 20kHz filter)

In short: the RMB-1077 is not a hirez amplifier.

[Sim reality]

I think from an absolute theoretical sense, you are correct that a Class D amp will not match a class AB for accuracy (at least not until freqencies reach 1MHz which would require a major re-think of how speakers are connected to amplifiers). And the RMB-1077 will never be used to recording studios (or probably any class D amplifier for that matter)...

But given the largest distortion in most home settings is actually the room acousitics and not a limitation of the equipment I think you would be hard pressed to say it's not a High-Res amplifier unless you have a dedicated listening room...

I also noticed that the frequecy response in the specs go to 80KHz... I think that would mean that that is a 6db decrease at that frequency, which would be 20 KHz filter with a very gentle slope to the curve...

[DrJRapp]

This is telling:-

In short: the RMB-1077 is not a hirez amplifier.

OK, then I guess I should sell this piece of crap and go back to listening with my "hirez" 1075 and 1080 which don't hold a candle to the 1077 in real world listening.

[RobP]

Ok Jerry, Ill take it off your hands, now knowing all of these facts I can only offer you a couple of hundred dollars. :B

[Aussie Geoff]

MartinF,

The language in some parts of a number of your posts above is in the sarcastic / semi-insulting category. The Moderators in the HTGuide (including me) discourage that from anyone as it tends to create emotional responses back and leads to a deteriorating general tone of the thread and the forum if allowed to continue. Look at your posts, consider the tone carefully and please think again and rephrase any future posts if your tone could be interpreted as an insult.

Thanks in advance...

Geoff

[Kobus]

A lot is being said in this thread which is of such a technical nature that I wish I understood. I know that a lot of the mentioned stats are extremely marginal and unlikely to be audible in the average listening room. One stat that looks like it needs to be understood by more of us average people is the following:

Then look at the max frequency-response:-
RMB-1075: 100kHz +0.5; -3dB
RMB-1077: (only) 80kHz +- 3db (presumably without the 20kHz filter)

Would anyone please care to explain that to me/us.

Thank you

PS: WHEN IS ANYBODY ELSE GOING TO GIVE SOME REAL COMMENT ON THE 1077 AND JERRY, WHEN WILL YOUR DAMN STOCKIST AFFORD YOU A LISTEN OF THE 1077 WITH THE B&W803.

[Feisal K]

Soundgravy, if the numbers aren't good enough for you, I'll be happy to take over...

[bigburner]

I would really like Victor to comment here, but Victor does not respond to threads on commercial amps because he does not have a first hand practical knowledge about the circuit topology, component quality and overall performance of those amps.

So, I would like to take the liberty of including a few of Victor’s opinions here…


You see, electronics is not an art form. It is not like the painting by your favorite artist or like the food you happen to favor. Electronics is not subject to an emotional response.

Electronics is all about application of laws of physics as we know them. This is why we characterize amplifiers by a set of well defined parameters, like the THD+N for example. We do not characterize amplifiers by their warmth or transparency or harshness or whatever other terms you may find that are more applicable to your sense of color or taste.

This is why Blind Testing is used to show that our senses betray us all the time. Blind test introduces a Control Group that is necessary to make an informed opinion.

Let me get a bit technical here in an effort to show why all transistor driven power amps must sound the same, regardless of what you think you may be hearing. Amplifiers are by definition linear circuits and as such they are designed to accomplish one task only and it is to amplify an input signal. They must do nothing else.

Indeed Rotel engineers understand what I just said. They know that if they build the amp to be only linear then there will not be any Rotel-perceived sound! So, their amps do not just amplify, but also add a bit of distortion and/or frequency-dependant amplitude variations, - which is commonly known as voicing. Do we want that? I know that I do not. Do you?

The purpose of this great hobby of ours is to reproduce the sound as it was recorded on a CD or DVD. Sound reproduction is all about having a zero-distortion signal processing chain. That would mean that any signal, other then the one that recording engineer has intended for you to hear, represents a distortion of the original soundtrack. Again, I must ask, - do you want that? Because if you do, and it is perfectly fine with me, then you will in fact spend your time listening to different power amps and rightfully expecting them to sound different.

On the other hand, if a distortion-free sound is what you are after, then you must look at the parameter such as the THD.

What does this THD mean? It is a measurement of how spectrally different the output signal is from the input signal in a given power amp. Only a wire will in theory give you a zero THD. However, it has been decisively shown that a human hearing is capable of distinguishing between signals with a THD on the order of not lower then about 1%. Meaning, that you will hear difference between two amps if one of them has high THD and the other does not.

Look at the Bryston product specs and you will see the published THD numbers on the order of 0.05% or lower. Do you really think you can hear that? Do you really think you can hear difference between two amps when both have THD specifications lower then even 0.1%? If you can, then you are more unique then Lucian Pavarotti!

Now, why do people claim to hear differences? It is simple really, - what you hear are the amplitude variations, not spectral differences. This is why you must properly set-up a Blind Test, so that the playing field is fair to all participants, - otherwise the amp that is set to be a little louder will win the context, - just ask an experienced salesman at your local Hi End store. Human hearing, you know, is capable to distinguishing a 0.1 dB of difference in a volume level.

The THD measurement is a classic evaluation technique. It gives us a measure by which we can say if the signal that went in, is the same as the signal that came out. When I say the same, I do not mean the amplitude or how big the signal is. After all an amplifier must amplify. I mean the frequency of the input signal is still the same as the frequency of the output signal. A gross example perhaps might be this, - let’s say we have an amplifier with very high THD like 1% or so. You plug this amp in and you play your favorite selection that you have heard many times before. The sound that you will hear will be very different from what you expect it to be. Why? Because it is distorted.

Voicing comes to us as a result of many studies conducted on human hearing. Those studies indicate that humans prefer to hear a particular set of frequencies with particular amplitudes. For instance, high even order distortion does sounds very warm to many people, while high odd order distortion products sound harsh. Furthermore, a slight low-pass effect of frequencies past 3 kHz results in less bright and more neutral sound. Again those preferences are statistical in nature and they come to us as a result of studies conducted on many individuals.

Another good example here is tube-base amplifiers that many audiophiles like so much. It is a common knowledge that the use of tubes results in “majestic” sound, although the specs are terrible. Look at the classic Cary 300 single-ended triode amp. It is a distortion city, but there is a religious following with people going to the barricades in defense of that obsolete technology. Why? Because they say it sounds good. What sounds good? People really do not know that they are listening to the grossly distorted sound with high content of even order distortion which is by the trick of nature sounds pleasing to humans.

Personally I prefer undistorted and therefore unvoiced electronics. However, even Zigfrid Linkwitz thinks that a minor voicing is a good idea. And he advocated compensation “…to account for differences in the ear's free-field and diffuse-field response and differences between sound pressure pickup in recording and playback environments…” Nothing wrong with that. Rotel engineers may have their own ideas and therefore their own voicing preferences. Bryston amps are not voiced at all.

Well, where does it leave us? It seems to me that any amp with low THD can be thought of as a completely transparent for the purposes of human hearing. With this in mind, if you use such amp within its design envelope, i.e. you do not demand more power from it then it can give without excessive distortion, then the output signal will be spectrally identical to the input signal. Therefore, it is irrelevant what is written on the faceplate of such amp. It can be $5000 Krell or $2500 Bryston, or $800 Rotel (providing no voicing is used) - no differences due to the amp characteristics can ever be heard. To say that you can hear differences is to defy logic.

These days you can have a transparent 200 Watt (8 Ohm) amp for about $600-800US. For more money you will get a better sheet metal box, better warrantee, better cosmetics, perhaps even better connectors, perhaps better ergonomics, more accessories like a 12 Volt trigger, etc, etc., but you will never get a better sound.

[DrJRapp]

PS: WHEN IS ANYBODY ELSE GOING TO GIVE SOME REAL COMMENT ON THE 1077 AND JERRY, WHEN WILL YOUR DAMN STOCKIST AFFORD YOU A LISTEN OF THE 1077 WITH THE B&W803.

Sooner or later I guess. Soon I'll be able to comment what the 1077 sounds like with the new B&W XT4 since I just ordered some.

Trying to explain a frequency response curve to you on a thread like this could be difficult, but I'll give it a shot and take it in small bits.

We refer to an amplifier as "linear" when any input comes out the other end at the same level of amplification. ie: if we input a 20hz signal at 20db and it comes out the other end at 50 db, and then input a 20khz signal at the same level and it comes out at 50db then we could say that the amp is linear because a plot of the frequency response would be a straight line. In reality with real amps there will be some variations due to the characteristics of the chain of parts that exists between input and output. At 1kz that amp may output 51db and at 10khz it may output 47db with all sorts of variations along the way. The more the variations the less "linear" the amp. That theoretical amp would then spec out as 20hz-20khz +1, -3 db. OR the manufacturer may chose to spec it at 20hz-20khz +or-3db, which would indicate on paper at least a less linear amp. Usually the variations in frequency response occur at the extreme ends of the frequency spectrum. They are rarely spikes, but more a general trend in the overall frequency response. If I could draw a frequency chart here I could make this much clearer, but as is I've probably just clouded the situation in your mind.

[Martinf]

Hi Geoff, I can see several examples on this thread where people have replied with denigrating sarcasm to my posts which I have, with my best intentions, endeavoured to keep objective. In short, if there's a rule for me, then it should apply to all.
Best, Martin.

Aussie Geoff - You're right and it should apply to all... Hence my post a little later on, trying to get everyone to lighten up.