Best Class A Amp under $2,000 used?

Pass Aleph 0s. It has a lot of power, so it should be able to drive just about any speaker. Next to my Krell 250, the Pass was a much better sounding amp in just about every way. The Krell did bass a little better.

How much power you looking for? Is weight a factor, age, color?

Yes it is good question.  I want one silver in relatively good shape about 4-5 years old.  I'd like about 250 -300 watts.  

@ puffbojie

Do you want an integrated, or a poweramp?
As the Wadia dac has a digital domain volume control so it can go direct into a poweramp.

If power amp, used Parasound Halo A21, "John Curl" design pedigree don’t come much better,usually go for around the $2k.
And it has gain controls on the back so you can set them so to use the Wadia’s volume at close to full, so there’s no chance of "bit stripping"

This ones only $911 at the moment, give it a whirl. and the seller has impeccable feedback.
http://www.ebay.com/itm/Parasound-A-21-2-Channel-Power-Amplifier-Silver-/292094136006?hash=item44022acec6:g:hc0AAOSwSypY~C93

Good review from HiFi News.
http://www.hifinews.co.uk/news/article/parasound-halo-a21-pound;2350/10014

Cheers George

Pass Labs.

Never saw a true class A amp with that much power! They are limited to low power output! BTW, That Parasound is not class A.

Agree, you’ll find class A/B with perhaps high bias design in this price range. Pure and exclusively class A high wattage for 2K dollars? Not very likely. 
Charles

Class A at 250 watts is rather difficult to find at this price range. The issues you will face with this much Class A Power is  "Heat" your amplifier will generate and the electrical power required for such a setup, would probably mean you need a dedicated 20amp circuit to your listening room.

@jmcgrogan2
I never thought that was possible. Thanks for the info!

Here's a pair of Aleph 2 monoblocks for $1,100: https://www.audiogon.com/listings/solid-state-aleph-2-monoblocks-aleph-2-monoblock-amplifiers-2017-04-26-amplifiers-33460-lake-worth-fl--2

100 Watts Class A

Your Dali's are 88 dB so 100 W would be more than enough to drive them.

I'm pretty sure that there is no amp out there that runs Class A with 200 Wpc into 8 ohms as the amp would problably weigh over 200 pounds. For example, the old Classe CA-400  weighed 120 lbs and did 400 Wpc into 8 ohms & 800 Wpc into a 4 ohm load but it's Class A was the first 80 watts then it went into Class AB. The Classe CA-301  did 300 & 600 Wpc into 8 and 4 ohms but it's Class A was the first 60 watts before going into Class AB.  I know this because I owned both amps. I don't think any manufacturer would bother to make a amp with full Class A up to 200 watts or higher. If you want a great Class A amp, solid state, it's hard to beat Pass Labs.

I would be fine with an amp that went into a/b mode after so many watts.  I'm assuming that it makes less difference after a certain volume level and would drive down cost.  Is that correct on both counts? What about specific models in the used 3 k range?  Any recommendations with the updated criteria? 

My Krell which is a class a/b amp runs class a for 50w and my Vandersteens are 86db/1 w. Not being a headbanger with the volume control and with the size of my room I don't believe the amp has ever run above that point. I like the Pass Aleph 5 class a at 60w and those are below $2000 and should work great with your Dalis.

Thank you @digepix .  I will have a look!

" Here's a pair of Aleph 2 monoblocks for $1,100"

Are you sure those amps are not counterfeit or prototypes? I had most of the Aleph's and none of them looked like the ones in the pic's.

" I like the Pass Aleph 5 class a at 60w and those are below $2000 and should work great with your Dalis."

After reading that, I just wanted to update my post. An odd thing about the Aleph series is how they rate the 0s that I recommended above, and the 5. The 5's are 60 wpc and the 0s is 40 wpc (Not to be confused with the 0's which are the mono versions of the 0s's. 80 watts per mono).

The 0s is a much bigger, costly and more powerful amp than the 5. I have no idea why they would rate it for less power. Its just something to be aware of.

don't forget the Acuphase's and Luxmans that were pure class A many out there for under $2000 now.

Regarding amps mentioned, I tried Pass Aleph 0`s with Martin Logan Quests and they did not drive them well.  The Class'e CA-300 did fine, but not strictly class A.

For 250 watts of pure class A, a pair of Threshold SA/12e’s would definitely work, however if you find a pair, they would be well above $2000. Here’s a nice Threshold within your budget,

http://www.usaudiomart.com/details/649302974-threshold-s350-power-amplifier/

This amp could also be changed to pure class A, but only at 60w/ch. You would need to send it back to Jon Soderberg of Vintage Amp Repair.

With regards to Glennewdick's comment -  
What about the more vintage class A power amps such as Acuphase or Luxman?  Which models were you thinking?  

What about 70's power amps like Marantz, Sansui or Pioneer?  Are these considered garbage sounding vs the modern age or are they comparable? 

Part of my inspiration to move to solid state was a purchase of a Kenwood 700 M which I think sounds amazing compared to my ICE powered amp. I figured a modern solid state version would be even better.  The Threshold looks nice.

That Threshold "e" series was the last Nelson Pass design at Threshold. Also, the recent work on the amp was done by Jon Soderberg. He worked for Nelson Pass at Threshold, so there is no better Threshold tech anywhere.

Interesting  - thanks!  

Why did you want pure class A.  As all have said most amps are high biased to hold in class A until a threshold wattage requirement is surpassed then it operates in A/B. I have never been sure of when Class A resumes during a peak then drop .   I owned Klipsch Palladium 1Ks which were biased to class  A for 125 watts.  I never knew when it changed.  *not a great amp anyway!

I had no idea most class A type amps switch into alternate AB power after a set threshold. This is really cool though.  Just looking for advice on a great solid state choice in the 2k -  3k range.  So far Pass designs are king.  Let me know if there are any others. Bryston??  

Most folks around here know that the boys at Coda were Threshold designer engineers... Threshold is the company that Nelson Pass sold before starting Pass Labs... The Coda stuff definitely has the Pass characteristics and run very high levels of Class A.  You can occasionally find a few of their amps in your price range.

A  Pass labs f6  50wpc into 4 ohms it has a but of Sevreal flavors Jensen transformer inputs, to a Fet stage,  then mosfets all pure class A . 

Sumo made some pure Class A amps,  but none of the power rating discussed here.  I believe 3 different designers....
Sumo The Nine and The Gold  60 watts and 100 watts by Jim Bonjiorno
Sumo Nine Plus updated from Nine by Rich May 65 watts (Nine is Better)
Sumo The Ten by Jason Stoddard  100 watts

puffbojie --

What’s the reason for your inkling towards class A amplifiers? I’m not trying to discourage you, but going for a pure class A amp (i.e.: which rules out high bias or class A to A/B shift designs) - with the potential and worthwhile sonic advantages they carry - within a limited budget and high wattage requirement is nigh on mutually exclusive. It seems to me there’re a lot of "class A" designs labeled as such which really aren’t, and in case you’re intend on pursuing true, pure class A I’d say stick with what is really that (and forget about 100+ watts, let alone >50 watts), or go with any other design that isn’t strictly class A and stop thinking about them as anything other.

Largely I believe it’s a marketing ploy to boast class A capabilities which really aren’t (instead pseudo this and that), not least connecting them with high wattage specifications - a combination that’s supposed to sell as an audiophile’s (sonic) wet dream. There are likely class A/B designs out there that, while they wouldn’t claim to be anything other than class A/B can have sonic traits that go closer to pure class A designs than those designs that flaunt class A "to some extend."

A number of “tricks” have been used to claim both high power and Pure Class A. While it is perfectly OK to bias an amplifier into partial Class A while allowing additional power for short term transient headroom often this is done without declaring the true operating parameters. Commonly the amplifier is claimed to be “Pure” Class A, and yet only delivers Class A performance up to a percentage of its output power. Other schemes have been invented that cause the amplifier to vary its Class A operation depending on how loud the music is. The idea being that it only runs in Class A to as high a power as needed moment to moment, and thence avoids the heat. This causes the music to modulate the amplifier’s design parameters, and in turn introduces other forms of distortion.

http://www.pureaudio.co.nz/?page_id=165

To my mind it’s about being honest with the design a manufacturer is going after, and call it by its right name. I’m aware that where class A to a limited extend (i.e.: pseudo) is more or less (usually less) openly declared is to inform the potential buyer what may be inherent to the design, but it’s still trying to sell a trait that in its diminished state may have marginal effect among many other design decisions, or even severe compromises.

If anything I’d go after designs that are topologically simply and "no nonsense," and if you’re still going after pure class A I’d have a keen eye on what really is and what isn’t (and lower your wattage expectations to no more than 30-40 watts). From personal experience I can recommend the pure class A amplifier Belles SA-30 (30 watts), but its class A/B sibling SA-100 is said to be sonically very close. I can imagine those can be had used in the $3k range.

Sorry for the confusion.  I think my speakers require too much power for me to consider a pure Class A that I could afford.   I like the sound of the Kenwood 700 M over my Peachtree Grand (ICE Power) so was going to move to solid state / with DAC for the living room.   Phusis info was very good.  I'm totally Ok with A/AB designs.  If an amp can drive the speakers at class A for the first 20% or so I am totally ok with that.  Basically what would you look at with 2-3k budget on used market? 

puffbojie --

I’m inclined to reiterate: where does your favoritism for Class A designs come from - is it first hand experience with particular pure(?) Class A amplifiers, or is it more like the mere thought of what Class A is said to represent a la, say, a smooth, liquid, warmish, open and effortless imprinting? I’m just trying to get a bearing on your sonic "inkling."

Going by more traditional Class A/B solid state designs perhaps I’d be looking for a used Belles SA-100, if they’re even around (but don’t count out the pure Class A SA-30, which is much more powerful than its 30 watt rating would indicate), the integrated Belles Aria (which can be had new within your budget), as well as amps from Symphonic Line or Modwright. I believe any of these options represent a relatively authentic, smooth, dynamic and coherent sound, and seem to have a sturdy, no nonsense build quality and topology use.

Maybe I’d consider some Class D alternatives as well, like a (used) Devialet 120 or NuPrime ST-10 and the integrated NuPrime IDA-16 (including DAC) - the latter two of which can be had new within your budget. To my ears Class D designs sometimes exhibit a smoothness and liquidity one associates with pure Class A designs, though without attaining quite the same degree of texture, reverberate capabilities and overall naturalness. My main gripe with some Class D amps (not that this is necessarily representative of Class D sound) has been a slightly too polished and processed feel to the sound - even "filtered." Still, there’re very good options here as well.

Pass Labs has received a favorable mention here, and while they're no doubt highly resolved and "sophisticated" sounding, very high quality amps I've found them sonically to be too well behaved and on the verge of being boring. Indeed very much "hi-fi," but less like "live" sound. Just my 2 cents..

What is a better amp/ deal:

The Threshold 350e mentioned in the above thread or this Pass x 3 amp with link below?

http://www.usaudiomart.com/details/649340044-pass-labs-x3-150w-x3/?utm_campaign=new-watchlist-added&...

OK, here is a pair of Bryston 7B-ST monoblocks that are slightly above your budget ($2,600):
http://www.usaudiomart.com/details/649345505-bryston-7bst-amplifier-pair-two-for-sale-as-set-only/

- 800 watts per channel with 1 or 4 Ω load
- 500 watts per channel with 2 or 8 Ω load 
- parts and labor warranty until February 2020  
- switchable between balanced XLR or unbalanced RCA inputs

These puppies will drive pretty much anything!

Listen to a Parasound Halo. They're very good for the price. 
By coincidence, I have one for sale. 

Class A does often sound very good - I used Classe DR3 VHC which with 45 watts will drive low efficiency speakers like Apogee Scintillas, and Belles A.

I don't think you will find, nor need anything like the Class A power you are asking for to drive just about any speaker out there.  You'd be amazed what amps that are well under 100 watts in true class A can do - but you may want to consider that they are running all the time, putting out anything not used in amplifying signal as heat. In one system I run a pair of DR3 VHCs and in summer it gets pretty darned hot in there.

Others made pure Class A amps of modest output - Electrocompaniet, Bedini, and they would drive the heck out of very difficult loads. 

For $2k you should be able to pick up some A/B amps with sturdy power supplies that will give very good sound - if you were closer, I'd offer you a Rowland I have for sale!

if you can find them NRG A400 will give you what you want not sure if you could get them under 2k, I don't know anything that can touch them.

Might I suggest a different direction? 1) a pair of Crown PS-400s. ($700-$800 used) Heavily biased into class A, plenty of power,excellent specs,bullet-proof build quality, and sound pretty darn good! A Crown Macro or Studio Reference these got an A rating for sound quality from TAS,Stereophile and other audio mags, unreal power 760wpc-8ohms,1,100wpc-4ohms !
($1100-$1500 used) Best of all but hard to find for your price. Any of Jeff Rowland,s bigger amps.  They all sound great!

...he's not listening.

Perreaux PMF 1850. 170 watts of Mosfet power..  can't be beat for sound quality and will cost less than $1000.00. 

I have no idea why people here don't just answer your question. There are a few very good class A amps to chose from. The best under $2,000 used?  That's a hard question to answer because there is no best. It all depends on what kind of sound you are looking for. If you want a very detailed sound, try the older Krells, want a more musical sound, Thresholds, and if you like something in between, Mark Levinson. These older amps are still killer machines and would still be fine in a system today. I didn't put specific models because there is lots to chose from, so do your research on which model you like most. Good Luck!!!!!

+1 @nordicnorm

There's also the Bryston 4B series that fall within your budget and power requirements

Thank You for all of the feedback and recommendations on these questions.  I am going to take a few days to look some of these amps up.  I wish I could sit in a room, listen and compare them over a couple of days but I get a feeling that is not going to happen (ha)

Interesting @lowtubes that the older amps can still hang with more modern technology. I like the idea of a professionally refurbished older amp because some of them have a great cosmetic appeal as well.  The Belles SA-100 and most Pass amps have a great look to them as well.  About 20% of my choice would be based on this ( especially since I can't hear them). 

@Phusis -Thanks for the well written piece.  I didn't know that some of the better D amps draw comparisons/characteristics of class A.  Nothing wrong with liquidity.  I have a Peachtree Grand which is ICE and nice but I find it sort of lacking bite and texture at lower volume levels.  

One thing I didn't mention is that my Kenwood 700 M & Wadia Dac 321 is in a smaller carpeted room and the Grand system is in a larger room with a tiled floor.  The larger room does have a rug, furniture and broad band sound panels.  I will have to do an amp switch to make sure it's not the room vs the amps.  

You might start with Audio Bluebook on this site.  See what's in the market.   https://bluebook.audiogon.com
The triodes (valves) plus Class A power supply appears preconception more than a criteria which assures a quality experience. 
Unreasonable constraints elevating legacy technology (& sub-optimizations) works against you, not for you.  There is a point in the used market where you are just buying someone else out of their boat anchor.  This is business built on scale.  As the components, and various engineering trade-offs, of legacy systems become rare- available inventory inelasticity changes the value...non-linearly.   This all works against you.  Still- "may the odds be ever in your favor", though. 

@sumwhat  Are you saying there is (less than optimal) legacy equipment available at some price points while (optimal) legacy equipment at perhaps higher price points ?


"As the components, and various engineering trade-offs, of legacy systems become rare- available inventory inelasticity changes the value...non-linearly.   This all works against you."