$1K Power Amps

I've been doing some research on the differences between the Parasound Halo A23 and A21...

I found this in a thread on audiocircle:

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I contacted Richard Schram about the difference between the A-23 and A-21. Here's an excerpt from his reply:

"A 21 and A 23 input stages are identical (same board). Driver and output topology is the same.

They don’t sound quite the same because the A 21 runs 10w/ch in class A and the A 23 runs 2.75w/ch in class A.
Although with your horns maybe you never use more than 2.75w anyway".

That's the story according to the guy who hired John Curl to design them

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http://www.audiocircle.com/index.php?topic=79637.0

depending on how efficient your speakers are you might or might not notice that since both switch over at a low wattage but if your speakers are efficient then you will notice the 21 probably sounding better at normal listening volumes. but this is all based on theory and design and real world listening would be the only way to know for sure.

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Originally Posted by harley .guy07

yeah class a does run hot and are extremely inefficient even at idle so power draw is huge and most people leave their class A amps on all the time to keep from damaging the power supply or having future problems with the unit so it will effect your electric bill. That is not the whole reason but part of what draws me to the Nuforce Amps because they are light, efficient and from everyone that has heard them sound wonderful and way past their price range.

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Just so I'm clear, which Class A is/was Ajani considering?

Originally he mention only the Monarchy SM-70 Pros as "class A". Despite some ambiguity regarding this model, the SM-70 Pro is neither Class A nor zero feedback. It is a high-bias A-AB; this was confirmed to me by C.C. Poon himself; (he didn't divulge the switch over wattage, he only told me that it would be operating Class A "most of the time"). It does not run extremely hot nor does it need to be left on all the time.

I read somewhere that direct heated tube amps like the 300b/2a3 sould not be left on as they consume three times more power at idle. Go figure?

Ajani, I would not get too caught up in the Class A, AB or D classifications. The bottom line is what sounds good in your system and to your ears.

Have you considered the Vincent SP-331 hybrid amp?

http://www.tnt-audio.com/ampli/vincent_sp331_e.html

A TAS reviewer said that the Vincent amp was the best sounding amp under $1K he has ever heard. Although it now sells for about $1100.

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Originally Posted by blackraven

Ajani, I would not get too caught up in the Class A, AB or D classifications. The bottom line is what sounds good in your system and to your ears.

Have you considered the Vincent SP-331 hybrid amp?

http://www.tnt-audio.com/ampli/vincent_sp331_e.html

A TAS reviewer said that the Vincent amp was the best sounding amp under $1K he has ever heard. Although it now sells for about $1100.

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The Vincent is too large... If I'm going for another large amp, I'd only buy one I can get locally (which would be the Halo A21 - which would require me to double the budget)...

Also, I totally agree on the notion of what sounds good... However, as I have to buy without first listening, I won't know what sounds good until I get it in my system... So I'm making educated guesses on the potential candidates based on the descriptions of their sound by reviewers and users...

Those amps are not bad:

http://www.audiogon.com/cgi-bin/cls....-M-500-ICEpowe

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Originally Posted by bluetrain

Those amps are not bad:

http://www.audiogon.com/cgi-bin/cls....-M-500-ICEpowe

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Cool, I thought the sale price on those had ended... I guess it's back again.... they do seem interesting, though I'd have to terminate my speaker wire with spades to use them... and to be honest, the cosmetics are kinda funky...

Most of Nuforces stuff is up there in price range and they seem to hold their value as their reputation is good. I got a killer deal on my preamp other most of Nuforces stuff is at least in that price range.

So of my options I've had to change the top choices:

Parasound Halo A23 - Off the list as my dealer only has access to the Classic Line...

So I'll have to order an amp from overseas, hence:

Monarchy Audio SM70 Pro - still has a sweet price if I act soon...

Wyred4Sound ST-250 - back on the list because of a load of pro and user reviews describing the sound characteristics. The description sounds much like what I'm looking for... Also I've seen some interesting comparisons between W4S and Monarchy (which are very similar to Feanor's comparison of his Class D versus Monarchy).

Odyssey Audio Khartago - off the list due to 1) lack of balanced inputs - essential given the layout of my room and how I plan to connect the DAC 1 to the amp & 2) The descriptions of the sound doesn't seem much like my cup of tea...

Van Alstine Insight + 240 - lack of balanced inputs is going to be a problem.

Red Dragon Audio M-500 - interesting alternative to the W4S ST-250, but I hate the Cardas patented binding posts (as they would require me to terminate my speaker cable with spades).


So to sum up my choices (based on description of sound quality and features) are down to either the:

1) Monarchy Audio SM70 Pro

or

2) Wyred 4 Sound ST-250

In that respect I would go with what you think would fit your speakers better and your budget. The worst thing you can do is spend more and think the you could have got more for your money if you would have spent less. But at the same time you are looking for the best for your budget so study the designs well and go with what you think will make you happy and if you get chance to listen to the gear go for it otherwise go with what makes the best sense.

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Originally Posted by Feanor

Just so I'm clear, which Class A is/was Ajani considering?

Originally he mention only the Monarchy SM-70 Pros as "class A". Despite some ambiguity regarding this model, the SM-70 Pro is neither Class A nor zero feedback. It is a high-bias A-AB; this was confirmed to me by C.C. Poon himself; (he didn't divulge the switch over wattage, he only told me that it would be operating Class A "most of the time"). It does not run extremely hot nor does it need to be left on all the time.

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Yep, the Class A I am considering is the SM-70... Since it doesn't run extremely hot then it's still an option...

However, I'm really getting more and more interested in Class D (specifically Wyred 4 Sound) as I've read some reviews comparing W4S to Monarchy (SE100) and the descriptions are very similar to how you described the Class D audio amp VS the SM70...

Ajani, if you are interested in the Insight amp then you should consider giving Frank VA a call or email him to see if he can upgrade the amp to balanced inputs. He is now offering balanced connections on his DAC's and Preamps.