[roscoeiii]

Higher db is more efficient.

[srb]

There is no strict definition of low vs. high efficiency loudspeakers, but if one were to make some approximate classifications, one might say that 82dB - 86dB is low sensitivity, 87dB - 91dB is medium sensitivity, 92dB - 96dB is high sensitivity and 97dB and up is very high sensitivity.
 
A speaker that is 3dB less sensitive requires twice the power to produce the same volume level, and one that is 3dB more sensitive requires half the power to produce the same volume level.
 
Average listening levels often don't require more than a handful of watts, but when the music encounters large dynamic peaks, they could require 20 or 30 times the instantaneous power.  It depends upon the recording, as many recordings are compressed to limit dynamic range so that they will sound decent on a large variety of systems.
 
But if the amplifier can't supply the power required for the peaks, the top of the waveforms are cut off or "clipped" in most solid state amps (NAD has a circuit that reduces power and they call it "soft clipping") which results in distortion and harshness, and can potentially damage speakers, particularly tweeters.
 
Tube amplifiers by nature have "soft clipping" and although they may have higher distortion specifications than solid state amps, the harmonics produced by overdriving are not as unpleasant or damaging.
 
Your 88dB sensitive speakers are medium efficiency and as mentioned, wouldn't require enormous amounts of power, but their maximum sound level capability will also be ultimately governed by the physics of the 3" woofers, cabinet size, voice coil power handling capability and maximum cone excursion.
 
But I still think you can realize an improvement with a quality amp of higher power than what you currently have.
 
Steve

[Wind Chaser]

My speakers claim 101 db with just 1 watt making 25 watts feels like 1000.  In terms of sheer volume and clean output, this combination easily rivals 200 watts into 87 db speakers with staggering dynamics.  Very, very life like!

[poseidonsvoice]

There is no strict definition of low vs. high efficiency loudspeakers, but if one were to make some approximate classifications, one might say that 82dB - 86dB is low sensitivity, 87dB - 91dB is medium sensitivity, 92dB - 96dB is high sensitivity and 97dB and up is very high sensitivity.
 
A speaker that is 3dB less sensitive requires twice the power to produce the same volume level, and one that is 3dB more sensitive requires half the power to produce the same volume level.
 
Average listening levels often don't require more than a handful of watts, but when the music encounters large dynamic peaks, they could require 20 or 30 times the instantaneous power.  It depends upon the recording, as many recordings are compressed to limit dynamic range so that they will sound decent on a large variety of systems.
 
But if the amplifier can't supply the power required for the peaks, the top of the waveforms are cut off or "clipped" in most solid state amps (NAD has a circuit that reduces power and they call it "soft clipping") which results in distortion and harshness, and can potentially damage speakers, particularly tweeters.
 
Tube amplifiers by nature have "soft clipping" and although they may have higher distortion specifications than solid state amps, the harmonics produced by overdriving are not as unpleasant or damaging.
 
Your 88dB sensitive speakers are medium efficiency and as mentioned, wouldn't require enormous amounts of power, but their maximum sound level capability will also be ultimately governed by the physics of the 3" woofers, cabinet size, voice coil power handling capability and maximum cone excursion.
 
But I still think you can realize an improvement with a quality amp of higher power than what you currently have.
 
Steve

Steve is right. I was a little skeptical about a 3 inch woofer being a claimed 88dB/w/meter as Silverline states, so I looked up the review from Stereophile which really places it at 85dB/2.83V/m. Given that it is a nominal 8 ohm loudspeaker, that's about 85dB/w as well.

All the more reason to get a big amp with this speaker. A 30 watt job will have truncated dynamics unless you listen softly or if you have a very small room. Look for 100 watts or more at least, and those Class D Audio options are pretty good actually, especially the SDS 254 or 258.

Best,
Anand.

[JLM]

Any power amp (even the digitals) should also have a relatively large power supply.  This will avoid "hollow" watts (that meet bench testing for steady loads at 1,000 Hz, but don't do well in real world reactive load use).  Some vendors, especially the mainstream ones, tend to publish the largest possible numbers versus more "usable" values.  Note that full range speakers need more "real world" power to handle power hungry deep bass.

I'd tend to look for "real world" amp ratings inline with the speaker manufacturer's upper range of suggested wattage.  It's much harder on the speakers to over drive a small amp into clipping (that destroy tweeters) than overload the speaker with clean power.

"Quality" IME refers to value and I agree that I'd take quality before quantity (within consideration of the sizing guidelines I listed above).  Many professional reviews will indicate how well an amp drives a given speaker and from that you can try to induce how they may work for you.

Goodsound.com strives for the good but inexpensive.  One of their fairly recent highly recommended big integrateds is the Anthem 225 (225 wpc @ 8 ohms), although $1,500 may not fit your idea of inexpensive.  Here's three enthusiastic reviews of the amp:

http://www.goodsound.com/equipment/anthem_integrated_225.htm
http://www.avguide.com/review/tested-anthem-integrated-225-integrated-amplifier
http://www.ecoustics.com/htr/reviews/4447

[JLM]

If you only have digital source(s), other options exist involving simply using a power amp:

1.) Just add a $750 Eastern Electric Mini DAC (a well respected DAC which includes multiple inputs, a tube output stage, and a volume control (so if you have all digital inputs no pre-amp is needed);

2.) Add whatever DAC with stepped attenuators (inline volume controls plugged directly into the back of the power amp);

3.) Use one of the Logitech music players (Squeeze Box, Duet, Touch) as your source directly into power amps (as they have quality digitial volume controls).  Note that most digital sources use cheapy volume controls that uniformly lowers volume (loud or soft), instead of reducing loud and soft sound by the same percentage, thus losing low volume sound.

[ken]

If you don't mind tubes this definitely plays louder than it's power rating would lead you to believe and it was just listed today. 

http://www.audiogon.com/cgi-bin/cls.pl?intatube&1294534654&/Cayin-TA-30-Bizzy-Bee/Grzybek-

[Mass. Wine Guy]

What say you about this NAD amp? Looks good:

http://cgi.audiogon.com/cgi-bin/cl.pl?ampstran&1294329779

Or someone pointed this out, but I don't know the company:

http://www.audiogon.com/cgi-bin/cls.pl?ampstran&1292629839&/ATI-AT1202-Channel-Power-Ampli

Or should I save up a bit more and buy a used Van Alstine amp?

Thank you for tolerating my questions and for your help.

[Steidl Guitars]

What say you about this NAD amp? Looks good:

http://cgi.audiogon.com/cgi-bin/cl.pl?ampstran&1294329779

In my opinion, NAD is good gear for the money.  Just so you know, that is a power amp, not an integrated. 

[Mass. Wine Guy]

Oops. Right you are. A power amp. I currently run separates, so I'm open to buy either if I find something good.

[Mass. Wine Guy]

There is a Musical Fidelity X-150 integrated amp for sale on the Canuck Audio Mart. Has anyone ever bought off this forum? Is anyone familiar with this amp and its power output? Is it ok to buy an older model amp such as this?

Frank Van Alstine has a used Omega III 400 amp for sale, too. Any opinions/thoughts on this would be most welcome.

Thank you.

[lafortts]

Do you still have the cap-151?  Looking for a phono board that will fit my 151.

[marvda1]

here is an usher power amp that can be used as an integrated amp.
http://app.audiogon.com/listings/solid-state-usher-r0-8-power-amplifier-best-amp-in-its-class-for-anything-near-its-price-rated-at-2012-12-19-amplifiers-80907-colorado-springs-co

[Mass. Wine Guy]

Sorry I never updated my thread. For the last couple of years I've been using and enjoying a Bel Canto Evo2 Gen II integrated class D amp. I think it sounds fabulous.

[marvda1]

sorry, i wasn't looking at the dates.