3 Channel vs. 7 Channel Amps

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sbcgroup1

re:
« Reply #20 on: 16 Jun 2004, 08:09 pm »
George-

Did you buy your Rowlands used?

If you're advice indicates the fact of not getting involved with "WPC" ratings...you mean to tell me a McIntosh MC206 (200x6) would be equal in power to your 6 Rolands at 500 WPC? I want to push these speakers to drive them to their full potential!

-Ed

Marbles

3 Channel vs. 7 Channel Amps
« Reply #21 on: 16 Jun 2004, 08:27 pm »
I think what he's saying is watts aren't necessarily watts and that all other things being equal the difference of 3 decibels difference of a 600 watt at 4 ohm amp and a 300 watt at 4 ohm amp might not make as much difference as the first 300 watts sounding better.

It takes roughly twice the wattage to make a 3 db increase, so a 400 watt at 8 Ohm amp will only give you 3 db increase over a 200 watt at 8 ohm amp.

Unless that last 3 db's really makes a difference to you, I wouldn't worry too much about it as long as you get an amp that delivers high current and at least 150 watts at 8 ohms.

As mentioned before, the 7 channel Cinanova cannot do 600 watts with all 7 channels at the same time.

ScottMayo

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3 Channel vs. 7 Channel Amps
« Reply #22 on: 16 Jun 2004, 08:34 pm »
Quote from: ctviggen
This has completely separate power supplies per channel. However, I don't know whether it's better to have multiple small transformers (0.25 kVA in the Bryston, for a total of 1.25kVA) or one HUGE transformer (3.6kVA in the case of the 5-channel Cinenova) with individual windings for each channel.
Quote


Having separate transformers for each channel is almost certanly less efficient, but that's rarely important to anyone. With everything on one transformer... I suppose someone could make an argument that if one channel hits a really loud and sustained peak, that it will suck power that much harder from its transformer secondary. That would presumably make the whole transformer field lopsided (briefly) and affect available power, however slightly, to the other channels. Whether you could ever possibly hear such a power variation is a question I can't answer. Probably not, though. Amps of that size tend to have deep reserves.

Bryston tends to take a "if it could possibly make a difference, we'll do something about it" approach to design, AFAICT. That might have driven the design decision to use separate coils But there's another angle as well: it has to be possible to easily take Bryston stuff apart and fix it, quickly and easily, no matter which part broke. If the one huge transformer in the 'nova cooks, your whole amp is dead and the whole amp will probably need service. If part of a Bryston dies, you slide out that one part and get it fixed, and in the meantime the other parts still work. When you supply to music studios and muscians on the road, that sort of "drop me, pour beer on me, mis-wire me, kill me if you can - I will survive" reliability becomes important.

Having once killed a channel on a Bryston amp, and having had them fix it, free, in under 72 hours (I paid $6 in one-way shipping on the broken subunit - total), I really, really like the way they think. And sound.

John Casler

Re: re
« Reply #23 on: 16 Jun 2004, 08:49 pm »
Quote from: sbcgroup1
This is turning into a good debate. I was going to write out a check this Friday for two of the Cinenova 3's. Let's get to the bottom of this!!

Whats John Casler's opinion on this?:)

-Ed


Hi Ed,

Just sent this in an e-mail to you but I'll post here too.

1st the 7 channel is not available yet and is probably 30-60 days out

2nd I am a fan of Big transformers and power supplies and I would recomend Monoblocs if you could afford the AMPZillas.

Spreading the channels over more power cords and powersupplies is almost always a good idea.

For the power requirements of the RM40s and RM30 the CineNova is excellent with very low S/N and distortion numbers.

jgubman

3 Channel vs. 7 Channel Amps
« Reply #24 on: 16 Jun 2004, 09:00 pm »
Ed,

have you seen that MC206 in person? First time I've ever heard of it, but it looks weird. The photo of the back panel only shows 3 inputs, but 6 outputs. I tried to decipher the PDF on their website, but it only really talks about using the MC206 in some proprietary way w/ a McIntosh pre/amp and some other McIntosh component.

Is it really a 6 channel amp, or is it a 3 channel amp w/ 6 outputs?

ctviggen

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3 Channel vs. 7 Channel Amps
« Reply #25 on: 16 Jun 2004, 09:15 pm »
Hey Scott,

I was originally going to buy an Outlaw 5-channel amp for my surround duties, but it had one large transformer and five channels (so it's designed similarly to the Cinenova).  I went instead with a Lexicon NT512, which was made by Bryston for Lexicon.  My amp is basically the Bryston 9B SST, only I don't get the Bryston 20-year warranty.  One of the reasons I went with Lexicon/Bryston is because the "independent transformer" design makes more logical sense to me.  Another reason is that Lexicon was transferring design to another amp manufacturer (one they own -- don't they pretty much own everybody now?) and the NT512 was "cheap" -- only a little more than the Outlaw.  So, I'm a fan of independent transformers, but I can see that each design probably has benefits and detriments.

zybar

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3 Channel vs. 7 Channel Amps
« Reply #26 on: 16 Jun 2004, 09:21 pm »
if you want a very good true mono bloc design in a single chasis at a good price check out the Sherbourn line of amps.

I use a 5/1500A 5 channel amp for my 4 surrounds.

You can get one of these for around $1K on Audiogon.

George

Sedona Sky Sound

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3 Channel vs. 7 Channel Amps
« Reply #27 on: 17 Jun 2004, 05:37 pm »
Just like in cars, if you want to go fast quickly, it is hard to make up for the lack of displacement. As John mentioned, the Ampzillas are one of the real hotrods (2.4 kVA per channel). It makes me cringe sometimes when people talk about their "super high current stereo amps" that are "350W into 8 ohms", powered by a "massive .5 kVA transformer"  :shake:  

Personally, I would not worry about the potential power differences between dual 3-channel amps and a single 7 channel. If Solution A works, the Solution B will work just as well. That being said, you just have to decide for yourself if Solution A is good enough. As everyone realizes, VMPS speakers like lots of current. Based upon my own testing, here is what I view as the optimal and minimum required current for each of the models I have:  

RM/X: Optimal = Ampzilla + Son of Ampzilla, Minimum = Ampzilla
RM40: Optimal = Ampzilla, Minimum = Classe + Marsh
626R: Optimal = Son of Ampzilla?, Minimum = Marsh
New Original Sub: Optimal = Ampzilla, Minimum = Classe (bridge mode)

Ampzilla = 2.4 kVA Mono
Son of Ampzilla = 2.4 kVA Stereo
Classe = .6 kVA Stereo
Marsh = .5? kVA Stereeo

Even with its large transformer, I can still bottom out the single pair of Ampzillas when playing Blue Man Group on the RM/Xs. I have tried just using the Classe or Marsh with the RM40s and they could not control the bass at all (even the Classe + Marsh is marginal from a current perspective). For the 626Rs, the Ampzilla was overkill but the Marsh is just a tad light on the bass (so the SoA should be just about perfect). I have tried other combinations and amps as well and so far kVA tracks pretty well with performance at least with the larger VMPS speakers.

The amp that works best for you is strictly a personal matter based on your ears and pocketbook. However, hopefully the above can give you a starting reference just from a current perspective (wattage ratings for most amps tend to be less than worthless IMHO).    

Best of luck.  

Julian
www.sedonaskysound.com

sbcgroup1

re:
« Reply #28 on: 18 Jun 2004, 05:38 pm »
Quote from: jgubman
Ed,

have you seen that MC206 in person? First time I've ever heard of it, but it looks weird. The photo of the back panel only shows 3 inputs, but 6 outputs. I tried to decipher the PDF on their website, but it only really talks about using the MC206 in some proprietary way w/ a McIntosh pre/amp and some other McIntosh component.

Is it really a 6 channel amp, or is it a 3 channel amp w/ 6 outputs?


Usually the Mac stuff is connected with a proprietary DB25 port which will hook up to their MX series pre's. It makes everything much neater and friendlier. I don't know if it improves connectivity sonic ratios.

Anyways, the 206 does 6 channels at 200wpc @ 4 ohms. If you look closely at the back panel, you will notice 3 pairs of RCA input jacks = 6 channels.

I wonder if this would be able to push a pair of RM40's & RM30C if you bi-amped. Wouldn't it make sense if you biamped that the speaker load would then turn into 8 ohms per channel?

-Ed

jgubman

3 Channel vs. 7 Channel Amps
« Reply #29 on: 18 Jun 2004, 05:51 pm »
Jeez, I should have my head examined.... I don't know what I was thinking, when I looked at the photo of the rear panel, for some reason I only saw 3 inputs :oops:

I think I had a brain fart bcs they colored them red and white, like a stereo input, but obviously it's an amplifier... I must be going senile.

But, to answer your question, no when bi-amped I believe the RM-40 still presents 2 4-ohm loads to the amplifier. It would still be a good way to go though, since then the woofers would have their own 200watt amplifier pushing them. I'm sure you'd get better bass response.

You could also resurrect your original idea of biamping w/ tubes and ss amps. You could power the RM-40s and 30s' mids/trebles w/ tube amplifiers (I believe you can get nice results w/ as few ad 40w tube amps) and use the Cinenovas on the bass. You'd have to be careful to match up the levels (which is hard w/ no gain controls on the Cinenova), however.

ctviggen

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3 Channel vs. 7 Channel Amps
« Reply #30 on: 18 Jun 2004, 06:05 pm »
I'm going to try and biamp my RM40s.  I have ordered (relatively cheap) cable to do so and will initially biamp my Linns to see what happens (the Linns can be triamped!).  However, I also have a version of the same speaker cable and interconnects for not biamping the RM40s.  If the 3db difference between my two amps can be made up by the controls on the RM40s, I think biamping will help.  I'll have 150 W (8 ohms) on the uppers and 120 W (8 ohms -- although this tested at 160W) on the lowers.  Plus, this will allow me to put all 7 channels to use -- I hate wasting perfectly good equipment!

sbcgroup1

re:
« Reply #31 on: 18 Jun 2004, 06:44 pm »
Jon-

There's only a variable hi-pass and low pass filter dial? No gain control? Can't that be dangerous? Oh well, I always run my poweramps full out anyways.....

Anyways, with that filter on each channel, I could tailor each channel how I wanted. That's really cool! And in effect, I wouldn't need to biamp to get more punch (even though it would sound better sonically).

How do you think the Ampzilla would compare to the Cinenova? I think the Cinenova will put out more juice....and give me more bass!!!

-Ed

ctviggen

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3 Channel vs. 7 Channel Amps
« Reply #32 on: 18 Jun 2004, 06:48 pm »
I would think that the Ampzilla would be better, simply because the transformer is much larger.  The Ampzilla = 2.4 kVA Mono, whereas the Cine has 3.6kVA for five channels.  Certainly, the Ampzilla has the capability to put out more power (whether it actually does that is a different story).

sbcgroup1

re
« Reply #33 on: 18 Jun 2004, 07:03 pm »
Bob-

The amp I am comparing it to is a Cinenova3 = 3 channels. I'm not sure how large the torodial transformer is....3.6 you say? I thought it was bigger....

-Ed

jgubman

3 Channel vs. 7 Channel Amps
« Reply #34 on: 18 Jun 2004, 07:04 pm »
Ed,

I've only heard the ampzilla at Brian's house and at CES. The Cinenova can't hold a candle to the ampzilla, unfortunately. Now, I'm sure Brian's LEDE room w/ bass trap aplenty had tons to do w/ this, but I've never heard the RM-40s so controlled, pure and w/ bass SLAM as at Brian's house. In fact, I wasn't sure I'd ever heard a speaker sound as good as the first time I ever heard RM-40s at Big B's (this was right after 2002 CES and they were powered by a big Plinius amp). That was until I went for one last audition in 2003 right before placing my order. Big B had the mono ampzilla's hooked up (single amp, no biamping or anything). The bass response just blew me away.

That said, I'm listening to Casler's favorite right now (Flight of the Cosmic Hippo), and I can't believe how good the bass sounds. The minute I turned it on, I had to get up and make sure the subs weren't on (they weren't). The Cinenova and RM-40s are a winning combo in my book. If I can create a budget to upgrade my amp in the future it'll probably be to a pair of ampzillas, but I'm in no hurry.

Also, as to the high-pass/low-pass filter on the Cinenovas, I wouldn't bother w/ it. If you do wind up biamping w/ the novas, just feed them full range signals to both binding posts and let the crossover deal w/ the filtering. That's why it's there! I think the filter on the nova is a neat idea, but more of a gimmick than anything, of course YMMV.

ctviggen,

Actually Ed's amp is a 3-channel (I think), so the available current should be equal. But you're right, the Ampzilla is a better amp.

Your biamping exeriment sounds like a good plan. Let us how it works out and if you have any problems level matching.

YoungDave

Amp power ratings
« Reply #35 on: 19 Jun 2004, 05:02 am »
1.  600W x7 = 4200W.  Since power = current squared x resistance (assuming a resistive load for simplicity & best-case power transfer), 4200 W is 32.4 amps of current going from the amp through the speakers.  That current has to come from the power line feeding the amp.  You can't make 32 amps of current come out of an amplifier on a 20-amp line.  Power ratings are steady-state, not transient, and so that rating is terribly exagerrated.  Shame on that company...

2.  The reason for high power is to maintain output reserve for transients.  If you think you are going to need 600W to be loud enough, you are quite wrong.  You get about 90dB, measured at 1 meter from the speaker, with 1 watt of input.  You will get about 105 dB on 32 watts.  Again, the high power is to be able to make those 1 or 2-millisecond-long transients without clipping, and thereby sound clean & real.  But when an amp manufacturer lies about his power output, the whole rating thing is meaningless.  In the end, you just have to play it & see how it sounds.  Why 7 channels?  Left and right are the ones that count...

Speaking of lying, check out the review of the $350,000 amp in this month's Stereophile.  It didn't come close to its power spec, and distorted like hell, too.  They tried to be polite -- you had to read between the lines to see them say it sounded like crap.  Nonetheless, I could envision John Atkinson shaking his head in dismay.  I guess there are charlatans in all walks of life, what?

John Casler

Re: re
« Reply #36 on: 19 Jun 2004, 04:28 pm »
Quote from: sbcgroup1
Bob-

The amp I am comparing it to is a Cinenova3 = 3 channels. I'm not sure how large the torodial transformer is....3.6 you say? I thought it was bigger....

-Ed


According to my owners manual the transformer is 4KVA for 3 channels.  (Although I have seen the 3.6KVA figure also) Either way, that is very sufficient for most purposes.

The adjustable filters on the channels work well and are excellent for biamping.

I have my bass channel set to about 100Hz with my NHT X-2 crossover filter set at 50Hz

I should mention that anyone who has the CineNova should check and make sure that the filter set control is dialed to "full range" or you may be missing a bit of the music.

How does the CineNova compare to the AMPzilla?  Well spec wise it certainly has the numbers, but the AMPzilla is one of the best sounding amps you can buy without a 2nd mortgage ($5500 for a pair of monoblocs) and it can be compared favorably with Halcros and all the rest of "megabuck contenders".

6 channels of Ampzilla would list for $16,500 the CineNova lists for $7000 for 6 channels (two $3500 three channels)

Little argument from me if price were no object which I would get, but it is hard not to recognize the quality, and sound perfromance of the CineNova for the price.

As far as bass, it is a champ for quality bass.  I have "raved" over the "quality' of bass I get from the amp with my 626Rs and LARGER all powered by a single 3 channel.

I have never heard bass of this quality on my system.  I have only heard it on Big B's system with a pair of A2K in his LEDE room which is a Bass Haven.

I agree that numbers mean nothing and the truth is in the listening.

While there are some who may have opinions without ever hearing an amp, I do not.  There are also some who have heard the amp and have opinions which are valid to the point of the system the amp was heard in and the room.  

I read sometime ago about a shoot out between a CineNova and another very respectable amp and the comments were "totally" the opposite of what I suggest.

My best guess is the "outing" parties either had a damaged amp, or they did not check the filters and were not listening to the blocs full range, for I have heard the other amp and at best, it would "sound" the same to the untrained ear.

And to address the use of two three channels in Ed's system:

While the surround channels "may" be slightly over powered, the surround speakers are a pair of LRCs.  These can use lots of power.  The third speaker on that amp will be the LARGER sub.  This then means that we will have a LARGER and two LRCs on one amp.

I really can't think of a cleaner, more balanced, and more cost effective way to power those three speakers.

The frontal array will also have a 3 channel CineNova.  It will power a pair of RM40s and an RM30C.  600wpc into each.

During Stereo duties only two channels will be used to the RM40s w/ the sub only on the other amp.

Now while the list price for these amps is $7000, I can assure you that in a package, the pricing is much better than anthing comparable on the used market and with full factory (10 year) warranty.

So in essensce, I would say that it would be "very" hard to assemble a system with this much sonic potential and balance at any where near the package.

Possibly the newly re-designed ADCOMs (re-designed by some of the CAL Audio guys) might be close in power, performance and price.