Outlaw 2200 M-Block Amplifier Review

[AudioSceptic]

Good question!
Where did the term linestage or interconnect come from?
We don't talk about ampstages ... and maybe outerconnects would have been just as good a term for wires.
Edit: and while we're on the topic -- we have integrated amps -- but no one seems to refer to power amplifiers as disintegrated amps!



Good ol' Class G.

HitachiSR2004 by Mark Hardy, on Flickr

Good stuff, but it is the block bit that I don't get.

 

[pjug]

Good stuff, but it is the block bit that I don't get.

Well the transformer is a pancake, so maybe the amp should be a casserole.

 

[mhardy6647]

Well the transformer is a pancake, so maybe the amp should be a casserole.

maybe a frittata -- or is that just when the pancake's in a Class A monoblock.

On the other topic, and with some seriousness: I think perhaps the block is meant to evoke a stage in the block diagram of an electrical component or an electrical system -- there's the source block, the preamp block then the power amp block (maybe some other, discrete, blocks... e.g., an EQ block, or a buffer block, too).

You know, this kind of thing:

(from the Yamaha CA-1010 integrated amp manual)

or:

source: https://www.petervis.com/Education/...tem/block-diagram-audio-amplifier-system.html via good ol' google.

 

[Francis Vaughan]

Had a look at the schematic for the NAD C320BEE. It isn't class G. The output stage of the power amps is pretty conventional AB. Where the magic is is in the power supply. It has two windings on the transformer, two bridge rectifiers, and a very evil looking semiconductor switch arrangement that appears to deliver a higher power rail in response to large voltage swings being observed on the output of the amplifiers. Switching to the high voltage appears to be inhibited by high current draw on the +ve power rail. This is probably where the idea that the amp responds to different speaker loads comes from (it doesn't directly.) Since there is only one power supply both channels see the same changing rails, whether they need them or not.
I can't say it leaves me with much in the way of good feelings.

Proper class G OTOH is IMHO a no-brainer. Why would you not? Class G runs with two (or more) power rails feeding the output stage. The rail voltages are not switched. The output stage of the amp uses the rail(s) it needs for each output swing.

 

[peng]

Amir, did you measure the gain using XLR inputs? If not, what would be your calculated number based on the measurements?

 

[pjug]

@amirm Could you post some efficiency numbers for the 2200 similar to what you did for the AHB2?

 

[peng]

@amirm Could you post some efficiency numbers for the 2200 similar to what you did for the AHB2?

Good question, I would love to hear from Amir on this. To me, it's kind of tough to come up with a single number, by nature of the class G rail switching characteristics.

 

[Frank Dernie]

Looks like a sensible mechanical layout as well as good performance.
Don't seem to be for sale in the UK though

 

[audio_tony]

Here's a link to a post of mine about the NAD2200 which is a true class G - there is also a snippet of the output stage schematic.

https://www.audiosciencereview.com/...surements-of-nad-t758-v3-avr.8912/post-224318

 

[John Galt]

Detailed pics of the interior of the Outlaw 2200: https://forums.audioholics.com/foru...2200-mono-block-power-amp.112574/post-1368097

 

[Xyrium]

Class G just means changing the power (voltage) rails in two or more discrete steps. Lower voltage for lower power means less heat and wasted energy; then, higher voltage(s) allow greater output power when needed. The basic amplifier is usually a class AB amplifier so its low distortion is a function of good design. Class H allows the power rails to vary continuously, increasing as the signal increases and vice-versa, so again saves power. With class G one must ensure there are no artifacts induced when switching the power rails; class H moves the voltage smoothly but is generally more complex and requires greater attention to ensuring the power supply is stable as it varies. Either design can yield excellent performance.

I do not know either intrinsically lends itself to lower distortion in the core amplifier, but either would allow you to run more bias current without as much wasted energy (heat) as a conventional (fixed-rail) design, so it is possible.

It's this type of variation in topology that should require specific testing procedures to identify the potential points of weakness, IMVHO. I've been longing to pick up a slim'ish Creek integrated amp, but Class G concerns me, that switching point, if it happens frequently, what becomes of the frequency response, distortion, and other variables in performance?

Good stuff for certain...

 

[John Galt]

@amirm It looks like this review was done exclusively with the XLR inputs, and not the unbalanced RCA inputs. Would you expect a significantly different outcome with RCAs?

 

[suttondesign]

Some clever person on this site should come up with an index that shows cost-per-watt-quality. Thus, even if an amp, like this Outlaw, is not 20-bit resolution like the Benchmark, it is also a small fraction of the price for 14 or 16-bit performance. I suspect that Parasound amps, for example, would fall somewhere between, though with their little 1/2-rack things being similar to the Outlaw or not as good, but their higher-end amps being better.

 

[infinitesymphony]

Good stuff, but it is the block bit that I don't get.

Blocky enough?

Some clever person on this site should come up with an index that shows cost-per-watt-quality.

Yes, a value metric would be great. Ideally there would be a variable slider so that each person could weight the formula in favor of price or performance according to their preference. Came up with something similar when I was car shopping (power vs. mpg).

 

[TimW]

Here's some blocks.

 

[KEW]

Blocky enough?


Yes, a value metric would be great. Ideally there would be a variable slider so that each person could weight the formula in favor of price or performance according to their preference. Came up with something similar when I was car shopping (power vs. mpg).

View attachment 49697
Here's some blocks.

Right or wrong, this is where I assumed the "monoblock" moniker came from. For some reason, these tended to deviate from the more typical 17" wide dimension of audio gear and be more block-like in their shape!

 

[KEW]

Amir,
I just wanted to thank you for measuring my 2200 and the overall service you are performing for the audio community!
Advertising would call to question your impartial measurements, so I don't know where you get anything out of this aside from the "warm fuzzies" for being helpful to others!
You are a class act and I hope you are not depleting your retirement fund (or the discs in your lower back) doing this.
Hopefully others recognize this and make donations to help you out!

Cheers,
Kurt

 

[John Galt]

Amir,
I just wanted to thank you for measuring my 2200 and the overall service you are performing for the audio community!
Advertising would call to question your impartial measurements, so I don't know where you get anything out of this aside from the "warm fuzzies" for being helpful to others!
You are a class act and I hope you are not depleting your retirement fund (or the discs in your lower back) doing this.
Hopefully others recognize this and make donations to help you out!

Cheers,
Kurt

I just donated.

 

[bogart]

This is great to see. I have two of the previous revision (200 M-Block) and decided not to sell them as the residual value wasn't fantastic for what I perceived to be good performance. Glad to see it's a substantial performer to go with its substantial weight!

Other than the number of mains plugs required to have a stack of them, I see very few practical downsides for these.

 

[KEW]

Nice timing for the review because this is the best deal on these I have ever seen!
Right now, they are selling these at 3 for $799 (works out to $267/ea) with free shipping:
https://www.outlawaudio.com/mofcart/combos.html