Which amp to buy. ATI or Anthem or something else? (1 Viewer)

[Dan Driscoll]

Greg,
I'll be using my Yamaha RX-V596 as a pre/pro for the time being. I want to see how the dust settles on the next gen of pre/pros.
The Sherbourn will be driving Monitor 90Ps, CC-350 and ADP-370s.
Jody,
I had looked at the Outlaw 750 and decided I prefered the Sherbourn, especially the design of the Sherbourn's power supply. That alone was worth a few hundred $ more to me. I did look into the 755 when it was announced and it definitely is a nice improvement to the 750, but I still preferred the Sherbourn. Then AVS offered the Sherbourn demo units for immediate delivery for the same price as the yet to be shipped 755. Even if the demo units hadn't been available I still would have gone with the Sherbourn.
I am a big believer in power supply design and IMO the Sherbourn has far and away the best power supply of any 5 channel power amp in its price range. Throw in a very clean, neutral sound quality and I was sold.

 

[Gregg Hart]

Jody,

I agree with Driscoll. The Outlaw is a scaled down version of the ATI amps. ATI still does not have the sound quality as the Sherbourne IMO, let alone the Outlaw. The Sherbourne is built off the same design concepts as the Bryston Amps, but for half the cost. There is no comparison in build quality and the fact that the Sherbourne has separate power supplies for all 5 channels. I would call Ron Fone at Sherbourn. He's the owner and main person who answers their phone and let him talk to you about the amp. He was also the previous president of Macintosh. I am sold on these units. They sound fantastic.

Gregg

 

[Brian Corr]

Have you guys listened to the Sherbourne/ATI/Outlaw side by side or at least in your own system where you could swap them out? Just curious.

 

[Dan Driscoll]

Have you guys listened to the Sherbourne/ATI/Outlaw side by side or at least in your own system where you could swap them out? Just curious.

Here's a link to a list of which and how I demoed and auditioned a number of amps, including the ATI. My post is the second one. I was not able to find an Outlaw 750 to demo and the 755 hasn't shipped yet.
Unfortunately, I was not able to do direct A>B comparisons in a common system, but I did try to take into account the characteristics of the speakers and sources when forming my opinions.

 

[RAF]

The Outlaw is a scaled down version of the ATI amps.

This may or may not have been true in the past but it is my understanding that this is not the case with the new 755/770 series. And the new Outlaw amps have separate power supplies for each amp.

 

[Dan Driscoll]

This may or may not have been true in the past but it is my understanding that this is not the case with the new 755/770 series. And the new Outlaw amps have separate power supplies for each amp.

The 750 did look very much like the ATI, with similar specs, and I had assumed they were almost the same design and from the same manufacturer. But I agree with RAF that the 755/770 is not the same design as the 750 or ATI.
However, because there are only 2 toroids, I disagree that the 755 has separate power supplies for each channel. It does appear to have separate power regulation for each channel, but not complete power supplies. Also I can't tell from the Outlaw website if there is any other shared circuitry. Maybe RAF could look inside his and let us know?
Did you know that you could actually pull each channel out of the Sherbourn 5/1500A chassis, attach an A/C power cord, and have 5 fully fuctional monoblocks? In fact, that's exactly what the Sherbourn 1/300MB is, one channel out of the 5/1500A. However, on most other 5 channel power amps under $4K, (including the 755) this is not possible because of shared toroids, capacitor banks or other common circuitry.
It is typically only in much more expensive amps, like Bryston, that you see truly independent channels, with complete power supplies. That's what sets the Sherbourn apart from all the other 5 channel amps in the under $2K range, IMO. Well, that plus some damn fine sound!

 

[Brian Corr]

Dan (or anyone else),

any idea what characteristics of the ATI would make it sound harsh or be lacking in the lower ranges (capacitors, transformers, etc) compared to the other amps you listened to?

 

[Dan Driscoll]

Dan (or anyone else),
any idea what characteristics of the ATI would make it sound harsh or be lacking in the lower ranges (capacitors, transformers, etc) compared to the other amps you listened to?

I doubt that it is any one thing, but rather a combination of little things. For example, I wouldn't be surprised to learn that the Sherbourn, Rotel and Parasound amps are actually biased at least a little into class A operation. The ATI and Anthem might be fully biased as class AB. The farther into class A the output devices are biased, the less crossover distortion there is. It could also be the output devices themselves. Different manufacturers use different parts and that is part of what contributes to differences in sound. Another factor is the type, size, number and quality of the capacitors, the number of output devices, etc., etc., etc.
Also, keep in mind that we are talking about what are actually fairly small differences among amps in a comparable price range and that a lot of the differences are personal preference. My comments about the ATI don't necessarily mean that it is a bad amp, just that I prefer the sound of the Rotel, Sherbourn and Parsound amps. In fact, I think the ATI does sound pretty good, just not as good as those other amps. But that is my personal preference and it won't be the same for everyone. Remember, ATI has sold a lot of amps and has quite a few satisfied customers, so clearly a lot of people do like the way it sounds.
Something else to consider is that any of these amps, including the ATI, will be an improvement over all but perhaps the best flagship receivers. And those few receivers that might be able to match these amps probably cost considerably more. So if you are upgrading from a receiver, then most likely whichever amp you decide on will provide you with a significant improvement in sound quality. Like everything else in this hobby (read - fanatical obsession) which amp you should choose is really a matter of personal preference.

 

[Sankar]

I have the ATI and a friend of mine across town has the Sherbourn 5/1500. Admittedly we cannot do a swap and try test, but I see/hear no evidence that either one dominates the other. They are both extremely well built amps and handle music and HT effortlessly. At the time that I was buying my amp, I did a survey and found the following review that put the ATI above the Sherbourn ... I'm sure that there are others who rank these two differently, but at the end of the day, I doubt that you can confidently say that one dominates the other. The ATI is slightly heavier probably due to either a heavier power transformer (or maybe heavier guage steel for the cabinet, I do not know), but performance-wise I doubt that there will be much difference (across a spectrum of music) between amps in this category (AT1505, Outlaw 750, Anthem MCA-5, Sherbourn 5/1500 etc). Of course, if you compare a Bryston or Krell to these, you may end up having some clearer rankings, but IMO the differences between the amps being discussed are highly personal and not "universal" .. just my opinion ...
One more thing that I have noticed over the years --- at various points in time, different amps are considered to be the "best" in the various forums (and we always find reasons as to why that is the case!) ... at the time that I was on the market, I got multiple recommendations for the ATI, somewhat later I noticed that the MCA-5 was considered as the best, now its the Sherbourn. Not too long ago, folks insisted that differences between the Outlaw and ATI were irrelevant for all practical purposes (now I see folks ranking them more explicitly) ... who knows what the future will bring? Amp technology is not changing by leaps and bounds and so the crop of good amps from a few years ago are probably at the same position of the heap even today (and will be in a few years) .. the only change is us.
Finally,

For example, I wouldn't be surprised to learn that the Sherbourn, Rotel and Parasound amps are actually biased at least a little into class A operation. The ATI and Anthem might be fully biased as class AB.

.. is this a conjecture or is it based on published statistics?

 

[BruceD]

According to John Curl who designed the Parasound amps, they do use quite a bit of Class A biasing, as is his trademark. I don't know about the others.
A few specs about the Parasound:

• ->Conservatively rated at 45 amps peak current on each channel.
  ->Direct Coupled -- no capacitors or inductors in signal path
  ->High bias Class A/AB operation
  ->1.6 kVA Toroid power transformer with independent secondary windings for each channel, 100,000 µF power supply filter capacitance
  ->Independent power supplies for each channel
  ->Input stages use hand matched complementary JFETs
  ->30 beta-matched 15 amp, 50 MHz bipolar output transistor

 

[Justin Doring]

Aren't the Sherbourns made in China?

 

[Gregg Hart]

Sherbourn amps are made in Korea I believe because the co-owner of the company is Korean. It was cheaper for them to build the units there than here. That is what the other owner, Ron Fone told me anyways. It's still a US design, just made over there.

 

[Dan Driscoll]

Aren't the Sherbourns made in China?

Taiwan, I believe. I think the Parasound and Rotel might also made in Asia. IIRC, the Outlaw 755 & 770 are made in the US. I don't know about the ATI or Anthem.

 

[RAF]

However, because there are only 2 toroids, I disagree that the 755 has separate power supplies for each channel. It does appear to have separate power regulation for each channel, but not complete power supplies. Also I can't tell from the Outlaw website if there is any other shared circuitry. Maybe RAF could look inside his and let us know?

Dan,
I spoke to an engineer (I think he designed the 755/770) because I had a question about the 755. As you might know if you've read my comments elsewhere, I'm using the 755 to power my front three channels (L/C/R) and two of the surrounds (with my Marantz MA700 monoblocks powering the two rear surrounds.) I had tried a bunch of different configuration options and found no discernable difference in which amps I used where.
My concern (and the reason for having Outlaw hook me up with the engineer) was the realization that the two toroids are split in a 3/2 configuration. I wanted to know for sure (I could probably figure it out by looking in the case) which 3 amps shared the slightly larger transformer because I wanted to use them for the front channels. My reasoning was that in shared designs I know there's a bit of power steering and I was hoping to use these three amps in the L/C/R so that in two channel mode there would be a little more freedom, if I'm making any sense here. During the discussion I mentioned "shared power supplies" and he stated that the amps in the 755 have separate power supplies, which surprised me a bit. But I don't feel qualified to argue with the designer. Perhaps it's a matter of semantics, or perhaps it is something else. He might have meant separate power regulation since I always thought the transformers were part of the power supply. But he specifically said, "separate power supplies."
Granted, with common transformers, you'd be hard pressed (I think) to have each module stand on its own (like some of the modular combo amps I've seen) but I'm not sure that's critical with the design of the 755. The engineer assured me that it wouldn't matter which of the 5 amps that I used for the front soundstage since power steering would never enter into the equation. For one thing, the 755 toroids were designed so that the one supporting three amps has additional windings (or whatever) to compensate for the greater demands of three modules. And he also mentioned that the 755 was so overspec'ed compared to previous Outlaw offerings that it was not even in the same league and that I'd never be in a position to drive this amp in a Home Theater beyond its capabilities. He sounded quite convincing and this didn't appear to be a sales pitch by any means.
Even though I've looked inside the 755 it's now firmly seated in my rack (this sucker was about 80 pounds and took quite a bit of effort to install) so I'm not real anxious to rip everything apart again. Hope you understand.
All in all, I'm very impressed with the build quality and the performance of the 755. Also, I understand that the 770 is actually a 755 with two more channels of power. Slightly bigger toriods (in a 4/3 configuration with 4 and 3 secondary windings respectively) but fit in the same case. Because of this I would suspect that there is very little, if any additional shared components.
Hope some of this makes sense. This is one time I wish the circuit board pictures on the Outlaw site were as good as the Lexicon circuit board pix over on SMR!

 

[BruceD]

RAF,

I believe it's the same issue with the Parasound, a common Toroid power transformer with independent secondary windings for each channel, that qualifies for the separate power supply designation.

Is that still an absolutely accurate description of a separate power supply? I'm not sure.

 

[Brian Corr]

Dan - thanks for your explanation. I agree the differences are minor and subjective at this level.

I think only by having the amps (or any other piece of equipment) in your own system at the same time can you make a semi-accurate comparison of the attributes of each amp.

I've thought about popping the lid off my ATI and possibly experimenting with swapping parts to see if any noticeable changes/improvements can be made. Probably be so minor that it's not worth messing with, but I love to tinker so who knows.

 

[RAF]

Is that still an absolutely accurate description of a separate power supply? I'm not sure.

Bruce,
Exactly my question. I would think that as long as there is a sharing of transformers you can't just swap out amps as though they were totally modular (like some expensive designs I've seen where you buy the case and as many amps as you want - adding more amps as needed.)
However, my understanding of the shared power supply issue when comparing the performance of monoblocks with amps in a combined case is that a common power supply can lead to "power steering" if that's the correct terminology. In other words, if all amps are being called upon at the same time to provide some serious power (not a usual occurance but, I guess, possible) then there can be some loss in performance due to sharing the load. If the only thing the amps have in common is the toroid, with all other power functions (regulation, etc.) separate, I wonder if this somehow circumvents any "problems" either real or perceieved. In other words, is the compromise (if in fact it is one) something that shows up in performance or is it something that never makes it to that stage if the amp is designed to be able to deal with this.
Hopefully, someone with more information regarding this will chime in here.

 

[Dan Driscoll]

quote:
Is that still an absolutely accurate description of a separate power supply? I'm not sure.
Bruce,
Exactly my question. I would think that as long as there is a sharing of transformers you can't just swap out amps as though they were totally modular (like some expensive designs I've seen where you buy the case and as many amps as you want - adding more amps as needed.)

Robert, Bruce,
The secondary windings of shared toroids (transformers) are physically very close to each other and they share the primary winding. While the risk is small, especially with good rectification and filtering, there does exist some minor potential that signals from one channel could be coupled into one of the other channels that share that toroid at a level that could be audible. With completely independent power supplies that potential doesn't exist. But again, the risk that it would be audible is very small.
However, I believe that because that risk does exist is why more expensive amps often have competely separate and independent power supplies, including toroids.

 

[Randy G]

Thanks for the explanations Dan and Robert.

Maybe I can add something?

As far as I'M concerned, torroids IS power supply, and 2 of 'em sure as heck ain't five. Ahhh, but that isn't necessarily a bad thing, otherwise, ALL manufacturers would be using the monoblock design. As has been pointed out, whenever you have shared power supplies, your chances of interchannel crosstalk goes up, but a good designer can pretty much alleviate that thru good design(sounds kinda redundant, no?).

The advantage that the 2 torroid Outlaw COULD have is that if a single channel is pushed into what would normally be its clipping point, well, one of those big ol' torroids probably has more current carrying ability than the one in the Sherbourn. Which kinda brings me to a point: If you aren't NORMALLY pushing all 5 channels to their limit SIMULTANEOUSLY, a single(or dual) torroid MIGHT have an advantage if you're only stressing a single channel(ie..center channel) at a time, because it's got a larger torroid to draw from. Now if you're an earbleeder(which NONE of you folks are, except for maybe a 30 second demo), then MAYBE the Sherbourn might serve you better, but for all practical purposes, there is no inherent "BETTER" between the two of them. One thing IS for sure though; the Sherbourn WILL be easier to service if a single channel goes out. Also, I can guarantee you that the monoblock design is more expensive to manufacture...whether that's important is your call. Also, the number of output devices per channel can make a difference in sound quality. One of the differences between the ATI and Outlaw was in the number of bipolar output devices...the Outlaw had 6/channel while the ATI had 8. Both were manufactured in the same plant, though.

Oh yeah, I forgot to mention that the protection fuses in the Sherbourn are supposed to be in a somewhat difficult location to reach inside the amp. Some nice extras about the Sherbourn include auto-on sensing and "balanced" inputs.

Between a similarly priced Outlaw/ATI and Sherbourn, I'd go with the Sherbourn. Between the 7 channel Outlaw and 7 channel Sherbourn, it'd be a tough call without taking price into consideration($1800 vs. $2750). Due to price, I'd probably go with the Outlaw.

my .02

 

[Frank Frandsen]

The seven channel Outlaw will sell for $1800. The Sherbourn can probably be had for 75% of the msrp which puts them at similar price points.