Recommend a desktop nearfield speaker for me

Two points: 1 - The technology of the LS-50 simply did not exist when the LS3/5A was developed - using KEF drivers, if you recall. Time moves forward.

2 - Any power amplifier will drive any speaker. The question is how loud. In the case of the LS-50, it's sensitive 85 dB 1w/1m. A 20 w amp will drive them 13dB above that - 98 dB. 2 speakers adds another 3dB, so that combination would yield a peak SPL of 101dB

at 1M. KAllowing for 12 dB of peak headroom, that means you system would support average listening levels of nearly 90dB, or what most would consider quite loud. Doubling the power adds just 3dB, a just noticeable increase. 

With your requirements for desktop use, the KEF LS-50 and 20W/Ch tube amp listening a less than 1M should work quite well. Any LS3/5A derivative will be 2-3 dB less sensitive and be subject to the driver integration issues several others have already discussed. 

I have the original LS-50 in my small office, driven by a 20W/ch Class D amp, with a Bluesound Node source. I am very pleased with the results. In that small of a space, the lack of the lowest bass octave is hardly an issue. 

The Omegas will deliver beyond your expectationt at close quarters and at normal listening distance. Their efficiency will also allow for lower volume clarity without thinning out, and the imaging of single driver  speakers is legendary.

Hi atriya, I will give you some input as I am/have been on a somewhat similar journey as you. I have had a couple of the speakers on your list and use some LTA gear.

The clincher for me out of all the speakers I tried so far were the Neat Petite’s.

Here is my list of nearfield speakers I listened to or were on my list: Neat Petite Classic, Dali Menuet SE, Philharmonic True Mini, Ascend Acoustics Luna V2, Harbeth P3-ESR XD. Elac Carina, Source Speaker 1.5WCA, ATC SCM7, ProAc Tablette 10, Audience 1+1, JMR Folia Jubilee, Physics Audio, Sonus Faber Lumina 1

Of everything that I have tried, this is what sounded best to me for a nearfield setup: Chord Qutest DAC, LTA MZ3 preamp/headphone amp, Orchid Audio GAN monoblock amp, and Neat Petite speakers.

My current setup is: Qutest, LTA Z10, and Neat Petite speakers. This setup sounds good at low volume but runs out of drive/headroom at higher volume. But, oh my, the Z10 with upgraded tubes is glorious as a headphone amp.

Speakers I tried: CSS P215, Omega Baby Alnico Monitors, Focal Aria 906.

If I just listened to Jazz the Omega’s were wonderful. The Focal’s were just too big and I didn’t gel with them.

I have the KEF LSX II’s for my wife in our office. I will say they are super versatile, convenient, and I am amazed at what they can do.

This thread has spurred me to think about finding some little bookshelf speakers to use in my gym/shop. My needs aren’t much different from the OP’s, so I hope I’m not hijacking the thread. The speakers must be: less than 12-in high, because they’ll sit on a workbench under a shelf; front-ported or sealed-cab, because they’ll be up against a wall; and easy to drive with low-watt tubes, as I’ll be using a 10w push-pull EL84 integrated. So far, only the Proac Tablette 10 seems to fit all criteria. Other ideas? What have I overlooked?

EDIT: I just realized the Devore Micr/O would also fit the bill, albeit at a higher price-point.

@wrm57 based on your criteria

NHT SuperZero 2.1 
Fyne F300     
Ascend HTM-200SE     
Polk Audio T15     
Sonus Faber Lumina  
Paradigm Premier 100B 
Q Acoustics 5020       
Diapason Micra III Excel
Diapason KARIS III       
Diapason Karis WAVE   
Acoustic Energy AE100 
Usher s-520          
PSB Imagine XB     
Mission LX-2 MKII 
GolderEar BRX     
Triangle Bro2
 

These all under 12", over 87db sensitivity. I did not check the port, I am adding it to now to my database. It's sorted by height. I can send you all the data, 24 columns.