A Budget Amp Comparison



Budget Amp Comparison – Crown, Nuprime, Parasound


Everyone who begins their journey to audio nirvana probably begins the same way; with a bunch of research and wondering if they have spent “wisely”.

For those just starting out or just looking to make a change, this is a comparison of three budget amplifiers.  All three seem to have found a pretty good market following which probably means their price/sound performance is acceptable. Hopefully this comparison/thread will be helpful to new people entering the hobby…and hopefully this thread will invite comments from others who might have additional ideas about starter amps around/below $1000.

The three amplifiers are:

Crown XLS 2000/2 Class D ProAudio Amp - $499 new

Nuprime STA9 Class D Home Audio Amp with a Class A input stage - $649 new

Parasound Halo A23  high bias Class A/B Home Audio Amp - $995 new

(The most obvious amp missing from the group is the Schiit Vidar at $700 which also has a pretty good reputation and deserves consideration)

The other equipment these amps were paired up with during the comparisons include an Oppo 103, Parasound 2100 preamp, Tekton Lore loudspeakers, Blue Jeans RCA Cables and homemade OFC stranded, twisted, shielded speaker cables.


Crown XLS 2000/2002

The entry end for a new amplifier is probably $4-500 and the Crown is a pretty interesting amplifier at this price level. Designed by Harman International for pro audio applications but with consumer audio connections included as well (RCA inputs & banana/spade/bare wire speaker connections). This is a class D amplifier which Harman engineered to be powerful, reliable, clear, stable with tough loads and stable with crappy AC line voltages that might be found at a music venue.

The XLS 2000/2 has a surprisingly powerful low end, very wide soundstage extending 3’ beyond the speakers (but not very deep), decent midrange and top end. The Crown is silent with a black background and relatively musical overall.

A couple of great and really appreciated features include “no speaker thump” turn on and gain controls located on the front of the amp. The gain controls are fantastic when you have 98db efficiency speakers like the Lores. With no gain controls, you often only have the preamp/DAC at the 8-9 o’clock position and the loudspeakers are screaming…but if you also have a subwoofer that is connected to the preamp, you likely have to turn the sub gain controls all the way up which can sometimes compromise the sound. With the Crown XLS2000 you set the amp gain down allowing you to set the preamp volume up and your sub will sound its best. (You can also use the gain controls to equalize the left right volume if need be without the degradation you can sometimes get from balance controls).

This amp is insanely powerful…1050 watts into 2ohms per channel, 375 watts into 8 ohms and 650 watts into 4 ohms…bridgeable to mono with over 2000 watts. The input voltage required to drive to full output is 1.4 volts so it can pretty easily be driven directly by most CD players and DACs without a preamp.

On several occasions I emailed Crown with questions and always received a prompt reply that was helpful.

My overall feeling is that this is a really good starter amp for someone on a budget, for a second system, for a college kid, etc. Pretty good sound, bullet proof, tons of power, lots of connections, and all the connections needed for double duty use in dj applications and other pro audio type gigs as well as home audio…and less than $500.


Nuprime STA9

The amp is beautifully packaged and this by itself gives you a certain level of confidence as you open the box. In most (but not all) areas, the STA9 is a step up from the Crown. Although the soundstage presented is not as wide, it is deeper and more dimensional. Although the bass is not as powerful, it is more tuneful (better pitch). The midrange and top end have better definition with slightly better instrument separation. Head to head, the Nuprime sounds  more musical.

Both the Crown and the Nuprime are class D and weigh about 10lbs…but the Nuprime is about half the overall size. Nuprime says it designed this amp with a Class A input favoring 2nd order harmonics. This may explain why the Nuprime idled at 103 degrees and ran at 107 degrees while the Crown remained at room temperature and the fan never kicked on.  Like the Crown, the Nuprime is also dead silent and has a very black background.

A couple things I didn’t appreciate so much about the Nuprime: the on/off switch is on the back, it frequently thumped my loudspeakers when turning on and of (as well as when the oppo or the preamp turned on and off) and it didn’t have gain controls which made it much more difficult to integrate with the subwoofer.

The Nuprime is rated at 120 watts into both 4 ohms and 8 ohms and bridgeable to 290 watts mono.

Like with Crown, my email correspondence with Nuprime was always answered in a timely manner.

Based on sound alone, this amp is worth a try. You may not experience some of the things that bothered me…or they may not bother you.   If you don’t need the power of the Crown and you have a little more money to spend, this might be a good choice.

 

Parasound Halo A23

The Halo was also beautifully packaged (double boxed) with a very clearly written manual included. Parasound describes this amp as high bias Class A/AB…meaning that for the first watt or two, it operates as class A and then operates as A/B as more watts are used. (Pass labs has a very nice description of what actually happens http://www.firstwatt.com/pdf/art_leave_classa.pdf    )  I can’t say that I actually noticed any difference or if there was actually a change from Class A to A/B but I can say that in my system in my room, the Halo sound was a pretty big step up from the Nuprime (which was a step up from the Crown). The soundstage can best be described as immersive (deep and wide) with a strong, detailed low end, detailed and silky mids and highs with good instrument separation and very musically engaging.

Like the Crown and Nuprime, the Halo has a black background with no speaker hiss whatsoever. The Halo has a very effective relay that never thumped my loudspeakers. The operating temperature remained under 90 degrees for the first hour and then gradually climbed to 105 degrees by the third hour so ventilation may be needed. The Halo has gain controls on the rear and the on/off switch is on the front.

The Halo is rated at 125 watts into 8 ohms, 225 watts into 4 ohms, is bridgeable and will drive 2 ohm loads but not at full power at 20hz. Email response from Parasound was also quick.

If you can afford $1000 (new) or $700 (preowned), this is the best sounding amp of the group and deserves strong consideration. Another point worth mentioning is resale; Parasound has a good reputation and their products seem to resell pretty quickly on Audigon with prices that hold up pretty well over time.


Final Thoughts

Until you have a chance to try a piece of equipment in your home in your system in your room, you can only speculate as to what it will sound like and what quirks will drive you crazy. No matter how good the reviews and forum comments are its definitely worth the price of return shipping to try equipment for a few weeks before deciding.


snapsc
I was wondering how the Halo 23 compares with the Schiit Vidar, which I'm partial to based on my impressions of the Schiit Bifrost, and on other factors.
More than a decade after widespread commercial acceptance, Class D amps are still widely considered to exist on the "low fi" end of the "hi fi" scale. Just about every thorough measurement exercise has confirmed that the pulse width modulation technique in amplifiers suffers from rising distortion at the upper end of the audible spectrum. Even some reputable longstanding industry people who manufacturer Class D amps have recommended against their use as "full range" amplifiers in high fidelity systems. When first introduced, they were hailed as near ideal solutions for subwoofer use. That too hasn't changed over time. They are still excellent for that purpose - clean, efficient, and reliable.
As for the Nuprime having a "class A" input stage, that's more advertising "hokus - pokus" than any legitimate feature that sets it apart. The majority of modern amp schematics I've seen for decades have shown a simple differential input that is Class A biased with quiescent current sinking via the emitters. Crossover distortion is and always has been a problem for output stages. Typically, what makes a good Class A/AB amplifier are Class A input and driver stages with an output stage that runs class A for the first 10 watts or so - switching to B when output swings to 10 volts or so.

As for the Halo A23, while it is a nice sounding well made amplifier, prospective owners should be aware that some of John Curl's dc coupled , wide bandwidth designs have suffered reliability problems. High frequency parasitic oscillation can creep in from a variety of sources in any high slewing rate, wide bandwidth amplifier. Undetected, it can result in widespread component damage and failure. The great sound is nice to have - while it lasts. Before one blindly adopts the "zero capacitor" signal path mantra, one should consider just how many excellent sounding amps exist that use feedback capacitors in the voltage amp stage for dominant pole compensation. Capacitance and inductance exist everywhere, whether or not such devices are intentionally placed in a circuit for a desired effect.  Careful management of these sources of energy storage is what separates merely good amplifiers from the truly great ones.
Musical Design amps by John Hillig truly are musical and reliable.  10 years ago I had a D-75 ( 75w/ch } which just played music, as if whatever solo instrument I hapeened to be playing a record of was actually in the room. Currently I have a 150B ( B model  has upgraded caps etc.)... my friend with the big Quad found were the most transparent amp he'd ever played on his 'stats.  "Nuf said.
Used, most of these amps go for under $1000 - if you can find one. 
If anyone is looking, another great budget amp that's not getting attention with reviewers is Class D Audio. Custom designed class D amps with great specs and sound. Made in USA, buy direct (no, I'm not affiliated). www.Classdaudio.com

SDS-470 has balanced inputs plus RCA, with adjustable gain. 2-ch amp for $695 provides 300W into 8 ohm, or 600W into 4 ohm with better than .02% THD.

This was my first amp purchase, very pleased with soundstage, and details. Powers a set of of Magnepan 3.7i admirably.