Question about Class A

I believe the krell amp has a fan and ibais which makes it run cool and it only uses a lot of electricity if it is being driven hard.

Did a little surfing. 
If it were me, and the power was sufficient, I'd try find a nice tube preamp, then try the Schiit first. Then, look at:
Sugden https://www.ebay.com/itm/255374915799?mkevt=1&mkcid=1&mkrid=711-53200-19255-0&campid=5338381866&toolid=10001&customid=8bd2bd48-88d9-11ec-bf81-623639343262
First Watt https://www.usaudiomart.com/details/649809695-first-watt-f7/
Krell, near St. Louis https://www.usaudiomart.com/details/649784277-krell-ksa-100-class-a-power-amplifier-w-original-box-packing-documentation/

The Sugden a21se is $3250, not certain where you are seeing an a21 for $2500. They do not go on sale. Any how, I love my A21se, best amp I ever owned. Yea, it gets hot, big deal. The trade off is holographic euphoric liquid sound. Nothing I’ve tried in past can touch it, it’s in a league of its own. Yea, there may be better and with more bells and whistles, but at what cost? I don’t need all that, I just want a pure class A single ended solid state amp, and I got the original, the sugden.

I happily am bound to efficient horns by my relatively inexpensive Dennis Had Firebottle SEP amp (12 to maybe 17 wpc)...bought it a few years ago when it was 3 or 4 months old for about 1200 bucks. Best hifi amp I've ever heard over many decades...Had is the Alexander Dumble of hifi.

Forget anything about marketing and of course Krell 175 doesn’t have 175 Watt Class A, even most of Pass Labs amps don’t. Normally you will have 20-30W Class A, producing a heat of more than 100-150W for that kind of power. I doubt there is a good cheap Pure Class A out there, because design, materials and heat dissipation will make it heavy and expensive.

There are some reasonably priced designs upto 10W but then you have to go with horns.

For speakers, if you choose SE (and for Class A IMHO only SE(T) has a meaning), not only they must be sensitive but also an "easy" load. Try to find a dealer that has such an amp and go and listen to it. You might not like it, or you may become enthusiastic about it (I am and cannot go back to anything else).

Regarding dynamics my Hydor 140W pure Class A rocks a house and its dynamics makes you jump from couch. But it is true, most of Pure Class A, due to low power and other compromises needed.

You may be surprised at how good Schiit Aegirs are at $799 each. Use 2 where each one is in mono mode giving you about 80 watts/channel into 8 ohms.

You will be very hard pushed to find something of better value.

Since you can audition Sugden at the dealer in your area go take a listen and see what you think. Class A does make a difference if done right.

Check out this CODA No. 11 power amp. About $2200usd. Pure class A, makes 100wpc into 4ohms.

Im extremely pleased with my CODA amp.

Your weak link is the recording or file your playing!

If it’s recorded properly it will sound good. My gear sounds different if the file is at a low kbps etc.

I just hit an integrated Class A B Rotel A-14.

it’s all SS and sounds really good! Prior I had Peachtree Class D, PS Audio class D 

Arcam Class AB. 

the Rotel has better Bass than PS Audio or Arcam.

the Peachtree 150 was v good. But I like the Rotel

a lot- lots of Terrific features! I’m using it at softer vol

and thus it’s functioning in Class A most of the time!

it’s revealing as well/ 

I finally after Quad ESL, Quad amps, McIntosh,

and Boulder products decided to relax a bit !

My speakers are 4 and 6 ohm sets- no problems at all.

Rotel is a super bargain given the correct match between room and speakers.

I have 2 Class A amps. The KRELL K-300i integrated and KRELL Duo 175XD stereo amp.  The K-300i has the first 90 watts Class A. The 175XD has 175 watts Class A. They are not heavy, not hot, nor do they burn electricity at a high rate. Most importantly they sound amazing with very strong bass. 

You might want to look at some of the newer GaN amps.  Those from LSA, AGD, and the upcoming amp from Atmasphere seem to embody a lot of the benefits of Class A amps without the absurd electricity penalty.  When Atmasphere is embracing and producing a GaN amp, you gotta believe the gap has been narrowed to near nil.  I’m a Class A amp fan too, but it seems to be a near dinosaur at this point. FWIW. 

Sugden invented it. Do it.

Rogers High Fidelity EFH 200 Mark III...... And only 5X his budget!😂

Rogers High Fidelity EFH 200 Mark III !! Great tube integrated amp 100 watts / channel Class A. Hand made in MA w/ top quality parts & point to point wiring. Great sound, great build quality & lifetime warranty. Amongst the very best. 

I wouldn’t get too hung up on the class of amplification since a good sounding amplifier is a good sounding amplifer...

Good amps can be had in every class. Concentrate on good amps not design. 

I have three Class A amplifiers....A Yamaha M45 that is both Class A and Class A/B with the push of a switch, A Tubes4HiFi ST120 Dynaco clone Tube Amplifier and a Pass Labs First Watt F5v2.....Here is what I hear... The tube amplifier is magnificent. Easily the best sounding amp to my ears in my room with my speakers (KEF LS50 Metas or Magnapan MMG).....Try as I may, I can’t really hear any difference with the Yamaha M45 either in A or A/B.....The First Watt sounds like the tube amplifier. Fast tight bass, great midrange/vocals....Just one heck of a great sounding amplifier......BUT, Does it sound better than an ADCOM 555 or a Sound Artist SA200ia? ..... Not sure....There are so many great sounding amplifiers out there...Both past and present vintage.

The Speakers that I have are Martin Logan Motion 40’s and they are rated at 92db sensitivity.

With the Vincent, I think they sound great.

From what I have read and watched, 92db should be sensitive enough for lower wattage amps but I am realistic, I know with some lower wattage amps and Class A, I may get beautiful mid-range but lack in the bass department a bit.

But I am not hung up on huge bass so maybe wouldn’t be a big deal.

IME, in addition to higher heat and lower efficiency, there are also sonic trade-offs between Class A and Class AB amplification. After extended living with both, IMO it is not so much about one being better than another but more about selecting the type of amplification that sounds best with the types of music you listen to and with your specific speakers. Class A amplification can sound organic and natural (likely due to the absence of switching between A/B) but, at least in my experience, the trade-off can be a loss of dynamics or pure grunt compared to Class AB amplifiers of the same power rating. However, I wouldn’t get too hung up on the class of amplification since a good sounding amplifier is a good sounding amplifier regardless of class so it is more about what works best with your speakers and the music you listen to.

Better to look for something used and go up the Sugden line a bit.

As was already mentioned the efficiency of your speakers will greatly impact how well a low power Class A integrated will drive them. But having said that in or about your price range (Used) I would recommend a Cary CAD 300SEI or a Pass INT-30A. The Cary is Tube and the Pass is SS. 

Chuck  

Thanks for the recommendations.

Luxman will probably be out of my budget unfortunately, as beautiful as they are.

@gdnrbob , yes, you are right. I guess I won't know until I try it. Of course I hope it sounds good.

Cary Audio looks nice too but still above budget.

Unless I can find these units around $3K or under, probably won't work for me.

I think so far, the Sugden might be a good candidate.

@jay73 ,

I think your speakers will be the determining factor regarding how tubes/class A will sound, and whether it will be 'better'.

Bob

I have a Cary Super Anp with 2 monos on same body.

25 w a side an 200% constant for trannys 50 watts aside Class A.

k-88 .

Ran it 48 eight hours straight , just made my room hot ,

Makes a large jump in tone and depth in the classical and jazz I listen to ,on 2 main Quad and Totem that both take some power ! My 2K Omega’s are fantastic

on jazz with one driver , but 25 watt Cary is too much for them .

Point: Transformers are the heart of tube amps .

If you get a chance to audition, the Luxman 509 and 590 are good.  They are much the same except for the A vs. A/B outputs.  It may help you figure out if Class A alone is worth pursuing for its own sake.