AMPED 2400 800 Watt(?) Stereo Amplifier Review

AMPED 2400 Overview

The AMPED 2400 is marketed as a high-performance, two-channel amplifier delivering 400 watts per channel into 8 ohms and 800 watts per channel into 4 ohms, with both channels driven. AMPED employs AUSP™ Class D technology—a hybrid approach that combines a Class A analog input stage with a high-efficiency Class D output stage, which they claim achieves the best attributes of both designs.

The power stage of the AMPED 2400 uses a highly efficient Class D design based on the Pascal platform, which has been proven in the field for many years. But can this amplifier truly deliver the performance the manufacturer claims, and is it worth the hefty $6,000 price tag? That’s what I aim to determine in this review and test report.

AMPED claims its products are “made in the USA,” but there’s a catch. Like many manufacturers, they use globally sourced parts—so if full transparency is important to the consumer, a more accurate statement would be “assembled in the USA.” One might assume AMPED products would be exempt from tariffs, but I watched this model’s price climb from about $5,000 when it was released to $6,000 after the tariffs took effect. Nobody is immune, and this reflects the unfortunate new reality of paying more and getting less.

The AMPED 2400 doesn’t give any “audiophile” vibes based on its looks or build quality. In fact, if I’m being honest, it gives me Radio Shack project box vibes like when I used to build audio amplifiers for fun back in my college days in engineering school. Thanks to its Class D efficiency, this unit only weighs 17lbs so it’s the easiest 400 watt/ch amplifier to lug around that I’ve come across. Looks aside, performance is what matters most to me so let’s take the 2400 for a spin to find out if it’s truly AMPED!

 

AMPED 2400 Backpanel 

The AMPED 2400 sports XLR and RCA inputs though the XLRs are fake balanced which I will get into in the measurement section of the review. There are 12V trigger I/Os and a pair of high quality 5-way speaker binding posts (odd they didn’t include 2 pairs), a red on/off switch and detachable power cord.

All measurements were conducted using our Audio Precision APx585 8 Channel HDMI Audio Analyzer. 

For more information about how we measure power amplifiers, please see:

Basic Amplifier Measurement Techniques

AMPED 2400 Power Amp Testing Considerations

The AMPED 2400 utilizes Pascal Class D amplification which typically don't lend themselves well on the test bench for continuous tone testing. In fact, it doubtful this amp will pass the new FTC Final Amplifier Rule of August 2024 (16 CFR Part 432) based on the manufacturers rated power.  The preconditioning period is specified: 1/8 power with an 8-ohm load for one hour. This isn’t as much of a problem as to the test that has to be conducted after preconditioning. A serious concern of the new amplifier ruling is the time duration specified for rating full power, something which was always a bit vague or at least loosely enforced in prior FTC rulings. After the input signal has been continuously applied at full rated power for at least five minutes, the amplifier needs to be able to function:

 "at any power level from 250mW to the rated power at ALL frequencies within the rated power band of 20Hz to 20kHz without exceeding 1.0% of total harmonic distortion plus noise (THD+N) at an impedance of 8 ohms."

The AMPED 2400 was unable to sustain rated output power for more than a few hundred msec due to the internal built in protection. More on this later but suffice it to say, if we are following the new FTC Amplifier Ruling, than the 400 watt/ch rating at 8 ohms and 800 watts/ch at 4 ohms that AMPED rates their 2400 model doesn’t adhere to it.

Balanced vs Unbalanced

The AMPED 2400 features both RCA and XLR inputs. Ordinarily, one would expect better performance from the XLR (balanced) connections, but that didn’t seem to be the case with this product. The amplifier gain measured 29 dB for both unbalanced and balanced inputs, which is a bit unusual since there’s typically a 6dB difference between these connection types—balanced inputs on the amplifier side are usually -6 dB compared to unbalanced, while balanced outputs on the preamp side are +6 dB relative to unbalanced. This is standard practice in most consumer and pro audio equipment, though I’ve encountered exceptions such as the AMPED 2400. Interestingly, SINAD was 3-4dB worse for the balanced inputs than for the unbalanced ones, and channel-to-channel variation measured slightly higher as well.

Bottom line: There doesn't appear to be any strategic advantage to using the balanced connectors on this product.

AMPED 2400 Unbal vs Bal SINAD 

Frequency Response vs Power & Distortion

Before getting into the power testing, I always like to see how an amplifier behaves at 1 watt, where it spends a great deal during normal usage.

 

AMPED 2400 1 kHz FFT @ 2.83Vrms (1 watt, 8 ohms)

Despite I’m not using the AUX25 precondition filter for the APx585, the out of band noise from the Pascal modules was manageable and not corrupting the test results due to slew induced artifacts. The 2^nd order harmonics were 104dB below the fundamental 1kHz tone which is excellent. No power supply hum was detected either.

 

AMPED 2400 Frequency Response @ Full Power for 500msec (2CH Driven, 8 ohms)

 

AMPED 2400 Frequency Response @ Full Power long sweep time (2CH Driven, 8 ohms)

After preconditioning, I ran full bandwidth sweeps of the 2400 and was able to achieve 380 watts/ch, both channels driven, 8 ohms from 20Hz to 20kHz <1% THD+N if the sweep time was shortened to just 500 msec. I’ve never had to run a faster sweep to get a power test until I tested this Pascal Class D amp module. Adjusting the source until I was able to get max continuous power without the unit going into self-protection, I was able to run a standard sweep (2 sec) without the amp shutting off and it delivered 280 watts/ch, both channels driven from 20Hz to 20kHz. When I reran the test for 5min at any given single tone frequency from 20Hz to 20khz, the actual output power dropped to 190 watts/ch, both channels driven per the new FTC Ruling which is about half the manufacturer’s rated power. By strict FTC standards under the new rule, this would be a 190 watt/ch amp with 3dB of headroom. 

 

AMPED 2400 Power Bandwidth 4 ohms 2CH Driven

The AMPED 2400 is rated for 800 watts/ch at 4 ohms, both channels driven but it was unable to deliver on its promise. I measured 540 watts on CH1 and 625 watts on CH2 at under 1% THD+N, both channels driven from 20Hz to 20kHz for a 500msec sweep. This is still impressive power output from an amplifier weighing a measly 17lbs, but it’s NOT 800 watts/ch continuous into 4-ohms like the manufacturer is claiming.

AMPED 2400 Power Sweep Tests

Running the standard 1kHz power sweep tests on the AMPED 2400 presented challenges, just like the full bandwidth tests but the results were interesting nonetheless.

 

AMPED 2400  1kHz PSweep (2CH) - 8 ohms

The AMPED 2400 produced 416 watts/ch, both channels driven into 8 ohms at 1% THD+N and 328 watts/ch under similar test conditions at 0.1% THD +N. Anyone familiar with how I test amplifiers knows, I prefer amplifier manufacturers to rate power before the knee of the distortion graph which in this case would be about 280 watts/ch. The rise in distortion above 100 watts shows the linearity of power vs distortion isn’t as good as today’s best Class D or linear amps for that matter. Still, I was at least able to reproduce the manufacturers claim of 400 watts/ch into 8 ohms for this test scenario.

 

AMPED 2400  1kHz PSweep (2CH) - 4 ohms

The AMPED 2400 did NOT like to be power swept at 1kHz into a 4 ohm load very much for the typical sweep times I use to test ALL amplifiers. It current limited quickly and I was only able to measure about 280 watts on CH 1 and 230 watts on CH 2 with both channels driven at 0.1% THD+N for 4 ohm loads. This does NOT meet the 800 watts/ch spec of the manufacturer and certainly NOT by the new FTC mandate of a 5min sweep time. In real world, I didn’t have any problems driving the 4 ohm Arendal Sound 1528 Bookshelf 8 speakers I had on loan when testing this amplifier but I did note it’s sonic signature wasn’t as buttery smooth as I heard with other amplifiers driving the same speakers.

 

AMPED 2400 CEA 2006 Dynamic Power – 8 ohms

 

AMPED 2400 CEA 2006 Dynamic Power – 4 ohms

The AMPED 2400 did NOT reach its rated power during our CEA-2006 burst tests, which most closely resemble real audio program material. I’ve actually never encountered an amplifier that failed to meet its rated continuous power in burst testing—until the AMPED 2400. Typically, amplifiers deliver more power in short burst tests like this, but in this case, the burst duration appears to exceed the trip circuit threshold of the AMPED 2400, limiting its output under these conditions. To be fair, almost none of the Class D amplifiers employing SMPS-regulated power supplies produce higher dynamic burst test results than their 1 kHz sweep power ratings, by nature of design. This amp was the exception since the test duration is shorter for the burst tests than the sweep tests and it allowed us to see a glimpse at the power this amplifier could produce if the limiter didn't kick in to protect it. Based on these bench results, I would not rate this amplifier at 800 watts per channel into 4 ohms.

AMPED 2400 Power Table

		AMPED 2400
# of CH	Test Type	Power	Load	THD + N
2	CFP-BW	380 watts*	8-ohms	1%
2	CFP-BW	280 watts	8-ohms	0.2%
2	CFP-BW	540 watts*	4-ohms	0.1%
2	FTC 2024 5min Rule	190 watts*	8-ohms	0.12%
2	1kHz Psweep	416 watts	8-ohms	1%
2	1kHz Psweep	328 watts	8-ohms	0.1%
2	1kHz Psweep	280 watts **	4-ohms	1%
2	1kHz Psweep	230 watts**	4-ohms	0.1%
2	1 kHz Psweep	350 watts	4-ohms	0.01%
2	Dynamic PWR	363 watts	8-ohms	1%
2	Dynamic PWR	724 watts	4-ohms	1%

AMPED 2400 Power Measurement Table

* tested as quick sweep (500msec) to avoid tripping protection circuits. Final Amplifier Ruling of August 2024 (16 CFR Part 432) mandate is now 5min for rated power which this amplifier can NOT do.
** unit entered current protection

The AMPED 2400, like most Pascal Class D based amplifiers are difficult to power sweep on the test bench due to their extremely sensitive protection circuitry. This is an unfortunate design limitation of the amplifier but doesn’t often prove to be problematic during real world usage. The Pascal based amplifier is time tested and in my experience, has been a reliable platform for long term use cases. 

Signal to Noise Ratio (SNR)

 

AMPED 2400 SNR @ 1 Watt (a-wt)

I always measure amplifiers at 1 watt so that apples to apples comparisons can be made between different products that have different maximum output capabilities.  If you want to know the SNR at rated power, then you simply take the 1 watt rating and add 20* log (V*R)^1/2 / 2.83) where V = Vrms and R is the load. With a 0dBFs input signal, I measured 89dB (a-wt) at 1 watt (8 ohms) which is  a very good figure as far as low noise floor is concerned. Translating the 1-watt SNR measurement to the 400-watt rating yields 115 dB, which falls a few decibels short of AMPED’s 118 dB specification. That difference isn’t concerning, though—it could simply be due to the use of the AUX25 filter during testing.

Listening Tests

I placed the amp in the Audioholics Music Room system, featuring Revel F328Be speakers and, at the time of this review, a pair of Arendal Sound 1528 Bookshelf 8 speakers. In this setup, I found the sonic differences between this amp and others in the comparison to be more noticeable when driving the more demanding Arendal 1528s. While both sets of speakers are rated at 4 ohms, the Revels enjoy a significant sensitivity advantage (91 dB @ 2.83V/1m for the Revels vs. 86 dB @ 2.83V/1m for the Arendals), so they don’t tax the amplifier nearly as much. The trade-off is that the large triple 8" floorstanding Revels actually have less bass extension than the oversized “bookshelf” Arendal 1528s, which use a single 8" driver.  

My reference amps in this system include the Denon A110 integrated amplifier and the Cambridge Audio EVO 150 streaming amp. Of the three, the Cambridge had no issues powering the Revels but clipped hard with the Arendals at high listening levels, especially with bass-heavy music—and the clipping was very audible. The AMPED 2400, on the other hand, had no trouble driving either set of speakers to levels beyond my comfort zone. However, I felt the Denon A110 sounded less edgy on the Arendals than the AMPED 2400.

The AMPED 2400 is clearly a very dynamic amplifier, but to me it had a more forward presentation compared to my buttery-smooth Denon, especially when driving the Arendals. Some listeners may prefer that livelier, more incisive character to the Denon’s laid-back sound, but much of this comes down to personal taste, room acoustics, and the type of loudspeakers being driven. The AMPED 2400 had no troubles cleanly driving either set of loudspeakers to very loud listening levels in my space. Bench tests aside, this is a very powerful amp when playing real world music and not test tones.

Design Drawbacks

In my opinion, some Pascal Class D amplifier OEM modules are best suited for active speaker designs where the focus is on peak power delivery rather than sustained output without additional tinkering to the design. The power supply is a single-stage, power-factor-corrected flyback converter that relies on energy stored in the DC electrolytics, which limits sustained low-frequency power compared to 1 kHz testing.

According to Pascal’s application note, you can stiffen the supply rails with additional capacitance and balance the load by inverting one channel (both input and output). I haven’t seen many OEM designs implement this approach, though the Storm Audio PA16 MK II Pascal implementation allows for continuous power testing (see measurements below).

Sustained high-frequency output cannot be achieved on the bench with the AMPED 2400 amplifier, as it is intentionally protected against overheating or damage to the output capacitors. It’s worth noting that the Achilles’ heel of this design is also one of its strengths—Pascal-based amplifiers remain among the most reliable and time-tested Class D platforms on the market, promising excellent longevity for those who choose them. The manufacturer stands by this with a generous 5 year warranty. 

Some more modern Class D amplifier designs (e.g., ICE Edge, Purifi, Hypex) do not share these limitations in sustained power testing. The maximum output of the AMPED 2400 also varies between 120 VAC and 230 VAC operation, so connecting to 230 VAC may provide additional power benefits not reflected in this report.

Conclusion

I have mixed feelings about the AMPED 2400 stereo amplifier. At its $6K asking price, it doesn’t represent strong value—which I could overlook if it compensated with exceptional build quality, aesthetics, or brand pedigree. Unfortunately, that’s not the case. The AMPED 2400 sports a utilitarian, project-box-style chassis that lacks the visual refinement or design language expected at this level. This isn’t a component you’ll proudly display in your listening room. By contrast, the NAD M23 (MSRP: $4,799) not only looks and feels more premium, but it also measures better—despite offering slightly less power—and costs substantially less.

The AMPED 2400 feels like a product meant to live out of sight in an equipment rack rather than being a showpiece. For $6K, you could instead choose a beautifully engineered Class AB amplifier such as the Anthem STR or Parasound Halo A21+, both of which are more powerful, aesthetically refined, and stable enough to deliver their rated output continuously without tripping protection circuits or exhibiting instability into 8 or 4 ohm loads.

If your preference leans toward Class D, it’s hard to ignore the Legacy Audio Powerbloc². Built around the proven IceEdge amplification platform, it’s not only more visually appealing but also fully stable under continuous load testing—something the AMPED 2400 struggled with during our bench evaluations.

To its credit, the AMPED 2400 sounds better than it measures, offering a clean, dynamic presentation that’s more than competent in real-world listening. I suspect most buyers will be happy with the sound of this amplifier on all but the most difficult to drive loudspeakers and under extreme listening levels. I would have no problems using this amp in my guest room system to power towers under review and it would do those products justice with excellent amplification. Still, the question remains: are you comfortable spending six grand on an amplifier that can’t meet its rated power specifications and looks more at home in a DIY rack than a high-end audio setup? 

Personal Long Term Views on Pascal Amplification

To be clear, I’m still a fan of Pascal-based amplification. I use a 200-watt x 16-channel PA 16 MK2 Storm Audio amplifier to power the bass-managed surround speakers in my 9.5.4 primary theater system without any issues. I also have a higher-powered Pascal-based 8-channel amplifier driving my active RBH Sound SVTRS active reference speakers, delivering 1,500 watts to the bass modules, 500 watts to the mids, and 250 watts to the tweeters in each speaker. Each speaker features four 12-inch subwoofers powered by the 1,500-watt module. I’ve rarely encountered clipping with that amplifier, though I have reached its limits during intense, bass-heavy movie scenes that left me wanting more. RBH Sound does offer higher-power solutions for larger rooms, which I may consider in the future to further increase bass headroom. Having the higher rated power modules from Pascal ensures you have more dynamic range to hit program peaks without audible clipping. 

Storm Audio PA16 MK II Pascal Power Test Comparison

I was curious to see how my reference StormAudio PA16 MKII Pascal-based amplifier would perform on the bench to determine whether it suffered from the same limitations as the AMPED 2400—and was pleasantly surprised that it did not! The PA16 MKII uses the S-Pro2 Pascal module, but StormAudio clearly put extra effort into its implementation, allowing it to handle full-bandwidth continuous testing with aplomb. Although it’s rated at 200 watts per channel x16 (all channels driven), I measured a remarkable 223 watts into 8 ohms and 436 watts into 4 ohms, unclipped, during the 1kHz power sweep tests (<0.1% THD+N), and it was able to sustain power for the full five-minute test per the new FTC Amplifier Rule when driving a 1kHz tone.

Storm Audio PA 16 MK II 1kHz Psweep 1CH Driven - 8 ohms

Storm Audio PA 16 MK II 1kHz Psweep 1CH Driven - 4 ohms

 Storm Audio PA 16 MK II Frequency Response @ Full Power  (1CH Driven, 8 ohms)

 Storm Audio PA 16 MK II Frequency Response @ Full Power  (1CH Driven, 4 ohms)

For continuous full bandwidth power testing, the Storm Audio PA 16 MK II delivered 200 watts/ch into 8 ohms and about 400 watts/ch into 4 ohms < 1% THD+N.

Not once during any of my testing did the Storm Audio PA 16 MK II amplifier shut down or go into current protection. I’ve had this amplifier in my reference rack for over four years, powering all of the surround speakers in my 9.5.4 system without any issues. Pascal makes a very stable amplifier platform, but proper implementation is essential to get the most out of its performance.

Unless otherwise indicated, this is a preview article for the featured product. A formal review may or may not follow in the future.