New to Classe

[windshear]

I have just upgraded to the CA5300. Previously i was using a Rotel Rb1090 and RMB1095 combination. I have 802D's and a HTM1D in the front. I must say the sound is quite different to the Rotel. There is certainly a lot more low level detail and in all the sound is maybe "cleaner". That said and done i enjoyed the warmer midrange from the Rotel. Maybe it needs a bit longer to run in as i only have about 30 hours on the amp.

Now i need a few ideas or different thoughts. Ultimately i want to get an 801D, however the dealer is offering me a really sweet deal on a new 800Di.

With this in mind i am considering the CA2300 to compliment my CA5300. However it will mean i need to get a CA2100 as i have 9 speakers in my surround set up.

The other option i am considering is getting is another CA5300 and it would then be same and equal power across all the speakers.

One concern i have is the CA5300 not being rated into 4Ohm's. Thus far i have not had a problem, but it may become apparent when going to the 800Di's or 801D's. I have been a little hesitant to really crank it up just in case the unit goes into protection. I did get an email from Dave Nauber via my dealer addressing these issues, but im not totally convinced as the amplifier is specifically designed to go into protect mode if the current draw gets too high into 4 ohm's.

At this stage the CAM300 or 600's are not an option.

Any ideas guys about what i may be overlooking ?

[aarsoe]

I would prioritize my front speakers any day above the rest, so a CA-2300 would be my option - even if I had to "settle" for 7 channels.
If you had the RB-1090 and the RMB-1095 then you "only" had 7 channels anyway, so why the need to go to 9 channels now?

[windshear]

I was playing around with an RB06 and used it sometimes for front effects and sometimes used it for my additional side pair. I have a second row of side speakers that are installed and wired , just need power to them, dont want to end up having them just for show.

[Srrndhound]

I did get an email from Dave Nauber via my dealer addressing these issues, but im not totally convinced as the amplifier is specifically designed to go into protect mode if the current draw gets too high into 4 ohm's.

Could you share Dave's email wrt the CA5300's capabilities? What did he advise?

I was playing around with an RB06 and used it sometimes for front effects and sometimes used it for my additional side pair. I have a second row of side speakers that are installed and wired , just need power to them, dont want to end up having them just for show.

If you choose to drive the two side speakers with the same Ls/Rs signals, you can feed them in series from one amp channel. It will work fine, but it could cause some comb filtering for certain listeners. Ideally you'd add an all-pass filter in the path of one pair to decorrelate the signals and prevent that happening. Or maybe some delay, like 3-5 ms. But those options need separate amps for each speaker again. Not necessarily Classe amps, though.

Do you have external EQs in the chain?

[rickc]

I was playing around with an RB06 and used it sometimes for front effects and sometimes used it for my additional side pair. I have a second row of side speakers that are installed and wired , just need power to them, dont want to end up having them just for show.

What brand of seating do you have? They look realy nice?

[madmac]

Gosh !! You could charge admission to see a film in there!!. NICE !!

[windshear]

Could you share Dave's email wrt the CA5300's capabilities? What did he advise?

Hi i dont think it would be appropriate to repost the contents of the email. All it amounted to was that Classe normally rate their amps all channels driven. Given that its 5 x 300W, you are looking @ 1500W into 8ohms. Which would double into 4ohms. Also mention is made of 60% efficiency meaning 5000w needed from the electrical source. They also spec it to worst case scenario ie for Japan at 100v. He says the amp is more than capable of delivering the power if you had the power to feed it, but they have a protection circuit that prevents it. At what level it cuts in and under what exact circumstances i have no idea, that wasnt answered.

I am still considering my options regarding the side speakers and hopefully will duly address the issue in time. I have no external EQ in the system at this stage and i dont use the Audyssey in my Onkyo PRSC5507 as makes the sound too bright for my liking.

So option 1. Get another CA5300 and i have enough amplification, or 2 get a CA2300 and a CA2100?

[windshear]

What brand of seating do you have? They look realy nice?

Thanks they look nicer than what they are. When they arrived i was most disappointed to see "Made in China" on the side of the packaging. Sadly the quality is not up to scratch. Unfortunately in my part of the world we dont have the options regarding seating like Europe and North America has, so we are left at the mercy of what is available. So its a no name brand as far as i can tell.

[spykids777]

Hi i dont think it would be appropriate to repost the contents of the email. All it amounted to was that Classe normally rate their amps all channels driven. Given that its 5 x 300W, you are looking @ 1500W into 8ohms. Which would double into 4ohms. Also mention is made of 60% efficiency meaning 5000w needed from the electrical source. They also spec it to worst case scenario ie for Japan at 100v. He says the amp is more than capable of delivering the power if you had the power to feed it, but they have a protection circuit that prevents it. At what level it cuts in and under what exact circumstances i have no idea, that wasnt answered.

I am still considering my options regarding the side speakers and hopefully will duly address the issue in time. I have no external EQ in the system at this stage and i dont use the Audyssey in my Onkyo PRSC5507 as makes the sound too bright for my liking.

So option 1. Get another CA5300 and i have enough amplification, or 2 get a CA2300 and a CA2100?

Hi,

I have the CA5300. As per my talk with the tech support at Classe - the 5300 is designed to NOT increase output for 4ohms. THe explanation given was that if it were to double, the power needed would trip a 15amp fuse. Unlike the CA5300, the other amps do not have that limitation and double their output when the resistance falls.

[Kal Rubinson]

That's why I was hoping for a CA3300.

[ShadowZA]

Congratulatons on your new CA5300! Fantastic setup you have there too!

I'd like to try to answer your question but firstly I'd like to share my experiences with driving the amazing 802D's. Previously I was using a Krell KAV amplifier (250w into 8 ohms; 500w into 4 ohms) and although they did the job, they were simply not the best match for the difficult-to-drive 802D's. When I'd push it, the amps struggled and distortions were noticeable. The sound that I'm getting out of the 802D's now that I'm using the Krell 403e (400w into 8 ohms; 800w into 4 ohms; 1400w into 2 ohms), is clean, accurate, detailed, distortion-free and simply bliss (imho, of course). The point that I'm making here is that to sound at their very best, the 802D's need to be driven by a beast of an amp, preferably high-current. If I was going the Classe route, I'd be looking at nothing less than a CA-M400 (maybe 2nd hand, if you can find some) to drive the 802D's and maybe even the HTM1D. If finances were a problem, my strategy would be to concentrate on 2 channel primarily (using Rotel for surrounds), until I could afford to upgrade further.

Now, back to your question ...

I humbly apologise if it seems that I am throwing a spanner in the works ... but having experienced what I have ... my path, given your setup, would be as follows:

1. I'd keep the 802D & HTM1D front end. If driven adequalely, they would perform fantastically imho.
2. Seeing as you have 12 speakers in total (including the front end) excluding the sub and assuming that your goal would be to drive them all, my goal would be to drive the front end with 3 x mono's (at least CA-M400) & then have 2 x CA5300's to drive the other 9 surrounds. You would end up with one unused CA5300 channel of course.

Achieving this goal would be the main challenge for me if finances were the weakest link & I would probably start off with one CA5300 (driving only front end + 2 surrounds) then try to get mono's for the front end and then lastly get the 2nd CA5300 for the remaining surrounds.

Of course these are simply my thouights.

Good luck & whatever you do please keep us posted.

[ShadowZA]

Regarding your goal to get some 801D's or even 800Di's an idea might be for you firstly compare your present 802D's driven by some high-current amplification (to 801D's and 800Di's also driven by said amplification) before you finalize your thoughts.

In this regard, you are most welcome to fly down to Cape Town for a day, bringing some of your own music/movie discs with you & test them on my system. This exercise could prove to be cheaper than making a decision that you could regret later on. Remember that it is to the supplier's advantage to create insecurities and sell you new speakers - their primary objective is profit driven - gotta keep that in mind at all times.

[Srrndhound]

Hi i dont think it would be appropriate to repost the contents of the email. All it amounted to was that Classe normally rate their amps all channels driven.

He says the amp is more than capable of delivering the power if you had the power to feed it, but they have a protection circuit that prevents it. At what level it cuts in and under what exact circumstances i have no idea, that wasnt answered.

The answer that I was looking for had to do with whether the 5300 would somehow automatically sense the 4-ohm load and shut down, and based on the reply, that is clearly not the case. That means you can drive 4 ohm loads with impunity. The 5300 will control the load just as well as any other 300 wpc Classe amp.

As to the rated power output issue, it does not matter in real life. No real audio has the crest factor of a sine wave. Certainly not for more than a few cycles and certainly not in every channel at the same time for any sustained period at full scale. Never happens. This is a non-issue. Just enjoy the amp. No need to baby it.

[windshear]

The answer that I was looking for had to do with whether the 5300 would somehow automatically sense the 4-ohm load and shut down, and based on the reply, that is clearly not the case. That means you can drive 4 ohm loads with impunity. The 5300 will control the load just as well as any other 300 wpc Classe amp.

As to the rated power output issue, it does not matter in real life. No real audio has the crest factor of a sine wave. Certainly not for more than a few cycles and certainly not in every channel at the same time for any sustained period at full scale. Never happens. This is a non-issue. Just enjoy the amp. No need to baby it.

What i would like to know is if the protection is on total current draw or on a by channel basis?

[windshear]

Regarding your goal to get some 801D's or even 800Di's an idea might be for you firstly compare your present 802D's driven by some high-current amplification (to 801D's and 800Di's also driven by said amplification) before you finalize your thoughts.

In this regard, you are most welcome to fly down to Cape Town for a day, bringing some of your own music/movie discs with you & test them on my system. This exercise could prove to be cheaper than making a decision that you could regret later on. Remember that it is to the supplier's advantage to create insecurities and sell you new speakers - their primary objective is profit driven - gotta keep that in mind at all times.

Thanks for the offer, at this stage im leaning towards a CA2300 as im not convinced going to the monobloc's will be that noticeable except the CAM 600's. Maybe i can convince the dealer to let me do a side by side comparison, he has been very accommodation in terms of loaning me equipment.

One thing that has me a little disappointed in the CA5300 is a minor noise related click on all the channels at switch on( occurs 2x). Also i can hear HF noise from my Lutron Graphic eye bleeding through into all the speakers(at extremely low level, you have to have your ear next to the speaker to hear it). Strangely the CA5200 i tested before this did not do this at all. It seems something may have been compromised in the name of cost.

[Srrndhound]

What i would like to know is if the protection is on total current draw or on a by channel basis?

Good question for Classe.

I have not seen much test data. The Home Theater test with 4-ohm is so brief it's hard to know what to make of it. They say it puts out 190w, but was that with 1, 2, or 5 channels driven? Did they try a tone burst?

Has anyone reported the amp limiting/protecting in actual use? That would be more useful than any test data.

Just wondering. Since B&W speakers are rated as 8Ω (minimum 3.1Ω), why worry about 4 ohm capabilities?

[Kal Rubinson]

Good question for Classe.

I have not seen much test data. The Home Theater test with 4-ohm is so brief it's hard to know what to make of it. They say it puts out 190w, but was that with 1, 2, or 5 channels driven? Did they try a tone burst?

Has anyone reported the amp limiting/protecting in actual use? That would be more useful than any test data.

Just wondering. Since B&W speakers are rated as 8Ω (minimum 3.1Ω), why worry about 4 ohm capabilities?

Oh, yeah? Look at the impedance vs. frequency. Most of the demanding part of the spectrum is 4ohms or lower.

[Srrndhound]

Oh, yeah? Look at the impedance vs. frequency. Most of the demanding part of the spectrum is 4ohms or lower.

So you're saying B&W has mis-characterized their speaker? If they lied, they lied. I just went by the published specs.

BTW, where do they publish the impedance curves? I have it in the manual from their in-walls, but the 800 lit does not have it, manual, brochure, nor info sheet.

[Kal Rubinson]

See the current issue of Stereophile for the impedance curve of the 800Di. If you do not have access to it, it is very similar to the curve for the 802D seen here: http://www.stereophile.com/content/b...r-measurements

[windshear]

I have been using the CA5300 on the 802D and HTM1 with no problem so far, but thats with a 220V supply. However it has been foremost in my mind and have thus not cranked it up to the extremes i would maybe like as the idea of something going "click", followed by silence abhors me, comming from an electronics background. To clarify, the 10 days i have had my unit, it has been running flawlessly never having shut down, the only issue i have is the noise sensistivity of the unit as mentioned in one of my above posts.

[windshear]

Good question for Classe.

I have not seen much test data. The Home Theater test with 4-ohm is so brief it's hard to know what to make of it. They say it puts out 190w, but was that with 1, 2, or 5 channels driven? Did they try a tone burst?

Has anyone reported the amp limiting/protecting in actual use? That would be more useful than any test data.

Just wondering. Since B&W speakers are rated as 8Ω (minimum 3.1Ω), why worry about 4 ohm capabilities?

Having just read the review and test again. It says with 2 channels driven and it seems its not a hard protection, but merely output limiting.

[Srrndhound]

See the current issue of Stereophile for the impedance curve of the 800Di. If you do not have access to it, it is very similar to the curve for the 802D seen here: http://www.stereophile.com/content/b...r-measurements

Thanks. Not easy to integrate the curve by eye to come to a single value. Would have been very easy to apply a pink noise signal (either bandlimited to the speaker's range or weighted to mirror typical music spectral balance if that's preferred), measure the RMS voltage and current, then compute the wideband total impedance. That would tell us something about how an amp will perceive the load under actual use.

[Srrndhound]

Having just read the review and test again. It says with 2 channels driven and it seems its not a hard protection, but merely output limiting.

You're right. So it appears that it will not react like so many AVRs that go click/mute when faced with a stressful load. If the limiting is done well, without clipping the audio and with a fast release, its onset may be very benign--the first and only indication being an LED on the front panel. (Assuming it has such an indicator.)

[Kal Rubinson]

Thanks. Not easy to integrate the curve by eye to come to a single value. Would have been very easy to apply a pink noise signal (either bandlimited to the speaker's range or weighted to mirror typical music spectral balance if that's preferred), measure the RMS voltage and current, then compute the wideband total impedance. That would tell us something about how an amp will perceive the load under actual use.

I do not see how that is any more useful than a measurement vs. frequency. For example, if you use band-limited pink noise or, even, weighted to mirror the power distribution of "typical" music, I would find that less useful than what JA shows. Unweighted pink noise would not be relevant to general use and to what "typical" music would the weighted signal be matched. To me it is clear that the impedance is below 4ohms for most of the band from 70Hz to 900Hz and, given the power distribution of my non-rock/non-rap music, it tells me that an amp's performance with a 4ohm load is relevant. Anyone else can assess that curve as it applies to the music he listens to.

[Srrndhound]

I do not see how that is any more useful than a measurement vs. frequency. For example, if you use band-limited pink noise or, even, weighted to mirror the power distribution of "typical" music, I would find that less useful than what JA shows. Unweighted pink noise would not be relevant to general use and to what "typical" music would the weighted signal be matched. To me it is clear that the impedance is below 4ohms for most of the band from 70Hz to 900Hz and, given the power distribution of my non-rock/non-rap music, it tells me that an amp's performance with a 4ohm load is relevant. Anyone else can assess that curve as it applies to the music he listens to.

I would just like to know what the total aggregate impedance of the speaker is, so as to compare that with B&W's claim of 8 ohms. How did they come up with that figure?

ETA: Just for fun, I calculated the area under the curve from 20 Hz to 20 kHz, and the impedance comes out to 7.1 ohms.

[Kal Rubinson]

Either they did what you did or they accepted the rating at 1KHz.

Kal

[Srrndhound]

Either they did what you did or they accepted the rating at 1KHz.

At 1kHz it is 6 ohms. That might have been a more meaningful figure to quote, in retrospect, but only by accident. It could have easily been 20 ohms.

[Kal Rubinson]

At 1kHz it is 6 ohms. That might have been a more meaningful figure to quote, in retrospect, but only by accident. It could have easily been 20 ohms.

All the more reason why the graph vs. frequency is needed.

[mjb]

At 1kHz it is 6 ohms. That might have been a more meaningful figure to quote, in retrospect, but only by accident. It could have easily been 20 ohms.

Isn't this rather meaningless when driven from a solid state amp? The power supply is the limiting factor, not the speaker impeadance (at 1 frequency)... The amps output impeadance is close to zero, maximum transfer will occur when the speakers impeadance is also close to zero - BUT can the power supply handle it, and for how many concurrent channels? This is the information that Classe needs to provide.

[stuofsci02]

Not just the powers supply, but can the output stage of amp handle the current requirements.