They would have been smarter to include a high pass filter on the mains and feed the sub-out full range since most subs have filtering built in anyway.
Good review. I wish other audio reviewers would perform ABX tests. That's the only way to truly compare equipment. So few do it though and they even get a bit "testy" when you bring it up.
Thanks very much for including ABX test in your reviews. It's a quantum leap ahead of any subjective or objective reviewer. This industry feels like it's in the stone age sometimes.
I think it's fine to keep griping about the subwoofer output not high-passing the mains. It's also not very aggressive at only -3dB, so won't mix well with the steeper drop off from ported speaker designs (or even sealed). Maybe it's meant to be combined with a subwoofer that has its adjustable own low-pass filter?
Wow, once you delegate bass duty to the subwoofer system, a high pass on bookshelf mains would allow your mains to sound much better, because they're not having to reproduce low frequencies that they weren't able to do a good enough job on anyway. Hence, I have to echo Erin's sentiment 100%; if you're going to have a subwoofer system, you need to be able to filter the mains by default.
I think the majority of "audiophiles" would never want to do a blind test with their own equipment fearing they would have to admit they basically spent a lot of money where it wasn't necessary. I believe this would really apply to the older guys who won't admit that their hearing abilities just ain't what they use to be. I know mine aren't so I don't get too anal over these things.
Thanks for the amp review. Looks like it will work for a system that won’t need a lot of power including power to rock out, as you said. Very reasonably priced which is good news. Consumers need good affordable equipment. Rock on!
To the point and great review, was interested in your take as I have 2 A07 Max running in mono mode and they can't be beat for the $130 I spent. Also all the class D with TPA3255 say they get "300 wpc", not just Aiyima. 😆
This seems like any other Aiyima amp just within another form factor. Maybe we could find some cheap AB amps in the same wattage we could review? All these 3255 amps are good but they have been reviewed to death at this point. I remember talking about this chip on the diyaudioforum many years ago, and we all bought and tested them. Its weird that its taken mainstream purchaser so many years to discover them.
I have a denon AVR-X4500H and use 2.1 for music. I have a big pair of tower speakers that are 4ohms and can handle 300w rms each. Do you think it would be worth getting an external amplifier to drive these or do you think I wouldnt notice any difference? I keep getting tempted by all your reviews of these powerful little amps 😂
I'd love to see a review of the RSL iA225.1 amp. It's a little 55wpc with a sub output / selectable 90Hz HPF, and they publish some specs that look decent given the $110 price. Would be cool to see independent verification of their specs and get some idea of load dependency.
I have one. I’d be surprised if it does more than 40w at 8ohm. The HP is really nice. I wish it was rated for bigger power source. It’s rated to 24v only.
Man, thank you for saying that! I've been trying really hard to get the setup looking good. I tried the green screen route but didn't feel like it fit well. I was really hoping this setup would look good so it's great to hear that feedback.
A compact, quality, utility amp could come in really handy for all sorts of projects ... if it's a good value. Thank you for your endless endurance at making quality reviews (reviews that are of excellent quality ;).
How do your neighbors rate the amps (from next door and across the street)? Do they hear the dynamic range from that distance? (I'm trying to be humorous).
Thanks, and keep hammering the point about the lack of a HPF for the mains. They got SOO close to an awesome product by even having a variable LPF when most others are fixed, but they fumbled on the 1 yard line by not having a HPF as well. Not sure why so many brands keep failing on that feature, but maybe if you beat the dead horse long enough, they will take notice. The WIIM amp is still the only desktop/mini amp that got it right.
TI TPA3255 - Hmmm, the same chipset as used in the new WiiM Amp Pro... I can only hope that the implementation over in the WiiM camp will be equally as good 🤞
Well, if u went on ASR, you would hear different stuff, people take his as a sell out cuz he says outloud his subjective opinion... The only point in which I agreed, is the possibility of Erin's bias concerning kef products... The problem is they actually make good stuff. Nevertheless, I read through their arguments, mostly no water in them. What made me furious was Amir, he basically ridiculed Erin's test and opinions, without any examples... I'd only say two things, Thank you Erin Fok of Asr
I think they’ll sound very similar, but as Erin says it’s all about power, I’d be interested which ones give the most power. I’m still torn between the Fosi V3 mono & the ZA3 paired and used as mono.
Your comparison of the the two amp systems, one with a lot more power, has me wondering about the sound difference between increasing the amp's volume vs increasing the signal volume from the source. Is it better to crank up the amp, or crank up the volume on the pre-amp (for instance)?
Good review 😊 Tho one thing - the video title question: “the Best Budget Amp so far?” … How do you think it compares to Fosi’s new V3 monos? Same chip, similar price
Instead of telling everyone every amp sounds the same, maybe ask yourself, why do these amps sound the same? There may be something in your system negating any damping factor/output impedance of your amplifier thus making 2 different amps sound the same. What is it? Your speaker cables. Yes, speaker cables have resistance and can take away any DF and high DF amplifier has. But speaker cables are Snake Oil! 😱 Blasphemy.
@@richardgrant418 ^Pretty much. AND, if you look at 95% of the amplifiers out there, regardless of topology, they pretty much measure FLAT +/- 0.5dB from 20Hz-20+kHz, so THERE'S THAT, LOL. @dicmccoy Yes, when you add nearly any length of speaker wire to the output terminals of an amplifier, that Damping Factor Spec goes out the window. On Andy Wehmeyer's company website, Audiofrog, he has a Tech Brief/Article that explains why the "Damping Factor" is pretty much a non-issue. Andy was a product developer/manager at JBL/Harman for over a decade and worked alongside Floyd Toole, Sean Olive, and many of their other amplifier and loudspeaker engineers. There is also a recent Damping Factor test with measurements on the "RAW-CAt" RU-vid channel that might be interesting to watch. Cheers.
Good to see you doing your things again. Now, compared to the Dayton Audio APA150 I don't see how this product is better. The Dayton can be bridged, has the transformer built in, line sensing on/off and a crossover low pass frequency control all for $199.00. I Would really like to see your comparison video if possible. Oh btw the Dayton claims 75 wpc @ 8 ohms.
I'm curious if they simply couldn't implement an adequately transparent, switchable, variable highpass in the main output. Is that a fair assessment at this price and output characteristics?
@DearSX TBF, the March Audio P501 Monoblock amplifiers that Erin used in his Blind A/B/X subjective listening tests are for all intents and purposes considered to be "Audiophile" grade amplifiers. The P501 amplifiers use the Purifi Eigentakt 1ET7040SA modules which are about the closest thing to a pure "straight wire with gain" that you can buy, meaning that the output signal = the input signal with no additional distortion, color/flavor, or deviation. Yes, the March Audio monoblock have more output capability before distortion rises significantly, but all things being equal otherwise, the differences are simply the ability to play a given set of loudspeakers to a bit higher level. An amplifier's output power should be chosen based on the sensitivity of the speakers, their rated power handling, your listening distance/how large your listening room is, and how loud you desire to play said speakers. And with more excellent "real-world" test such as this one by Erin, we can be more confident in our choice when comparing two or more different amplifiers for use in our particular system and listening room. As Erin noted, both amplifiers "sound the same", but his reference March Audio monoblocks can drive his speakers to a bit higher SPL. Whether or not that is necessary in your particular setup depends on the factors previously noted above as well as the dynamic capability/threshold of dynamic compression of your particular speakers. If others are of the opinion that an "Audiophile" amplifier should in some way embellish the sound via some type of affect on or deviation from the source or input signal, that's fine but another topic entirely. An amplifier that isn't neutral or accurate to the original input signal may sound "better" with some music depending on how it was mixed and mastered, but it may also sound worse with other music, so you are giving up any consistency and confidence that you are hearing the true sonics of the source as finalized and approved by the artist and engineer. A recording/mixing/mastering engineer would instead reach for any number of EQs or EFX processors to "embellish" the sound characteristics to their liking, rather than swapping/rolling amplifiers (or cables) to achieve a specific or desired sonic character.
@@bbfoto7248 Speaking of EQ... I found there is a deep division among audio types. The Eq crowd vs the purists that think Eq ruins a system. Just like Jesus would say where the synagogue at? The sound engineer that mastered the recording would say where the Eq at. All systems sound different and need to be tuned for listening volume, distance, room, speakers.
What is a good small amp like this that has XLR inputs and a low pass filter? Preferably even a remote. I have dual TTs with mixer on a bunch of Kallax units for my records thus space is limited. Even considered powered speakers like the SVS.
Good review...looks like it does exactly what it supposed to do ....amplify the input signal unchanged ....nicr that you compaired it to a more expensive and powerful amplifier....don't know if the speakers are hard to drive but it would be nice to have the results with some notoriously hard to drive speakers to push the limits. The 10 amp power supply would also be a useful comparison.
Look up what the typical channel separation (crosstalk) is for even the best audiophile vinyl LP and you'll realize that just about ANY modern amplifier easily bests that spec. 😛 Somehow, even vinyl LPs such as Pink Floyd's DSOTM provide an incredible soundstage and L/R stereo imaging regardless of the medium's channel separation limitations. ;-) In addition, the in-room "acoustic crosstalk" that we live with every day is orders of magnitude above any amplifier. IOWs, for all intents and purposes, the crosstalk on any modern or even vintage amp is a non-issue. And Erin's measurements obviously DO show Distortion vs. Frequency.
Thanks much for the helpful review! I would love to know how differently the A70 would perform with the 10A GaN power supply. Too late for that determination, I guess. Might you hazard a guess, Erin? Or might viewers who have the 10A ps share their experience? I am most concerned to learn if the amp becomes hot with the 10A ps. Thank you!!
Erin, how would the A70s with upgraded Sparkos compare to an Audiolab 6000a? I'm looking to find out if they're even in the same ball-park of performance. Thank you.
Got the Aiyima A70 and love it. I left it on 24/7 for 2 days, just little warm to touch, however on the third day, it gets warmer to touch, so I turn the 07 off after each usage. Then as I soon as I played a few track at low volume, it starts get warm right away. Sound quality is great, just the warm to touch makes me worry abt its longevity. On the other hand, my Fosi ZA3 in stereo mode is not quite that warm as the Aiyima 70. Any thought abt the warm to touch of the Aiyima A70 ?
Erin's just invalidated the entire amp industry. Everything over $300 is artifice, and only then if they have all the bells and whistles. Erin - you just took 100K jobs and un-employed those folks. How are they going to put food on their families? It's your job now.
Can you use 2 of the A70's as Mono Blocks therefore doubling power? 2 A 70's with 2 upgraded power supplies only equals $440 USD...a bargain. Great videos...THANKS
This looks super clean for a 200$ stereo amp with a subwoofer out. I use a benchtop power supply with amps like this, and it looks like this thing could easily handle the 48v 10a or even more, as the distortion coming near the max power may very well be from the power supply running out of juice rather than the amp having issues
What the amp can handle from an external power supply is really going to partly depend on the thermal design of the PA.. sometimes a lack of careful manufacturing of the product or the thermal integrity of the design, can limit the amp thermally, which will reward you with a dead amp if pushed too much too often.
Is benchtop power supply a brand or just a type of power supply? What brand and model do you have? I tried to shop for benchtop power supply and got more results for construction power tools and kitchen counter tops.
@@shipsahoy1793 true, but I can clearly see heatsinks that a noctua fan can help along and looking at the amps parts specs, it's capable of taking in nearly 300wpc so running 48v 10a or more is likely to be just fine with some cooling.
@@robertlogue3794 lol benchtop power supply is a generic name for an external power supply in its own case that can fit on the work bench. you need to look for an external power supply that can be adjusted to the voltage that you want and has the current capacity that you need for that voltage while maintaining the size and weight that you find acceptable. A linear power supply will be larger and heavier whereas a switched mode power supply will be smaller and lighter, but you have to be sure that it's not going to introduce any noise or interference. I have a nice clean Daiwa switcher, but I don't think they still make them.
@@Luke-qs2cg sure, if you pull away more heat with convection cooling, of course that will keep the device junction temp down and the device mtbf up, as long as there's a good thermal connection between the device and the heatsink.
I've got a little SU-1 and an SA300 running my system and sometimes I look at these little things and go "look how big you are! Look at the Wharfies going!"
How does this compare with Emotiva Basx A2m @$279 or Monolith M2100X @$399? If the form factor is not crucial, I would buy class AB amps over these toys.
@swllz Their are plenty of "crappy" Class A/B amplifiers out there as well, even ones that "look" and have been previously regarded as "high end" or "sound quality" amplifiers. Not all Class A/B amplifiers are created equal! The beauty can be just skin deep. If we put this Aiyima side-by-side with another same Aiyima amp, but place one of them inside a "high end" D'Agostino amplifier housing, I can guarantee that 99% of the listeners in a sighted subjective listening test will choose the "D'Agostino" amp every time, LOL. Search for the following short blog post article that will take less than 5 minutes to read: "Audio Musings by Sean Olive - The Dishonesty of Sighted Listening Tests" (sean olive blogspot 2009/04)
The 12V trigger makes this perfect for AVRs that process 2ch more than they power, nice review. When it rains it pours. Hang in there Erin. A rainbow 🌈 brighter than your new background is just around the corner!
The difference between my amps was the bass. It was a night and day difference. As to why? Was it the difference in Dampimg Factor/Output Impedance? 🤷🏼♂️ I was comparing a pair of Class A/B IOTAXV pa3's in bridged mode vs pair of VTV Purifi Eigentakt 1ET400a's. Anyone and everyone would be able to tell the difference in your ABX test because like i said, the difference in bass isnt subtle. The bass on the IOTA's come across as "muscular" but when you compare it to the bass on the Purifi, thr IOTAs come across as bloated/wooly. The Purifi comes across as lean, but ultra controlled amd detailed. When you stop comparing the amps, then the bass on the Purifi's dont come across as lean anymore. Maybe stop comparing amps with similar Damping Factors/Output Impedances? But also don't use garbage wires that has higher resistance that could negate that Damping Factor. And that could also be the main reason why you're not noticing a difference. Loom at your cables and termination. Gets something that measures fairly low in resistance like .00474 ohms for 6 ft. If you have something that measures .0300 or higher, then you're really taking away any damping factor a class d amps has.
@aiyima make it a tiny bit bigger for the power supply!!!??? should work, just add more ventilation. just please, dont make the holes look goofy. charge 300. filter for high-pass to the mains as Erin and ASR ppl suggest. make the knob cool. this could really win lots of sales. let me know if you need some design pointers actually. that is a specialty of mine and i have some ideas. edit: and taller feet!
I am pretty sre I am not alone in thinking that a vid on the advantage of high pass filters improving the performance of mains, inclding differences between 2-way v. 3 way, would be very interesting. Love your stuff, I have learned a lot.
The power brick delivers 480 watts maximum 🤔 if so then Simply take away the amplifiers inefficiency and a few watts for the preamp section then divide the remaining watts by the channel count and then you end up with a Theoretical max power output for the amp...to do 300 watts, it would need a 700 watt power supply, not 480
How would you compare this with the Aiyima 80A Pro? Woukd it be an upgrade? This new unit has balanced imputs which would go nicely with my Pioneer DJM 450.
Great educational review. Your gentle approach would work with DACs and headphones. And even to products outside audio. Don't limit your talents. Eager to watch your career.
I understand willing to have a low pass AND a high pass. At this price point, I would probably opt out, as the components that would be used would probably be cheap and affect the sound on the mains. Pretty sure that would be audible. If it were to be done in DSP, then, it'd be cool, but this unit has analogue inputs, so it would need to do A/D, apply DSP, then go through D/A before sending it to the amplifier section. I have the little miniDSP 2x4HD and having tried that, I wouldn't recommend the extra A/D-D/A conversions. It does affect the sound. Best combination would be to use digital inputs on a unit like the 2x4HD, then you have one or two channels of subs, and two channels of mains to be amplified by a little unit like the A70. Thanks for the reviews!
If you wanna rock out with these mini amplifiers you really need 4 ohm speakers I started building my own speakers just to have fun with these little amps 😅
How would you compare this with the Aiyima 80A Pro? Woukd it be an upgrade? This new unit has balanced imputs which would go nicely with my Pioneer DJM 450.
@@robertendsley8312 Sounds about right, he’s got so many people fooled into believing the mouth diarrhea he spews on every video. It’s the most cringe audio channel on YT
Thank You Erin for the unbiased and technically sound review. I have a question about the pre-out connection. Was the pre-out a mono output or does it do stereo signal. I have Aiyima 07 max and pretty much impressed with its capability to drive Wharfedale Lintons. I connected 3.5 mm stereo pin to pre out with stereo RCA ends. I’m getting signal to only one channel. So I presume the pre out is a mono signal. Please correct me if I am wrong. 😊😊😊
@drsuresh9 I would think that the 3.5mm Stereo miniplug AUX OUT jack on your Aiyima 07 Max is stereo...as long as the amplifier itself is not switched to MONO mode. I would confirm that your 3.5mm-to-RCA cable is not defective, and if it is good, contact Aiyima. FYI, on the manufacturer's product page for the amp, one of the diagrams shows the 3.5mm miniplug to Left & Right RCA cable going to a PAIR of Active Speakers, indicating that it SHOULD be Stereo. They also show it going to another amplifier that has Two Knobs and two of something else (RCA jacks maybe), which also suggests that it is a Stereo Output. But they also show it going to a single active subwoofer. Unfortunately, their specs and documentation aren't completely clear about this.
In the A07 it is stereo. It is also a stereo input. I have connected my phone to it via a dongle dac and can thus play music from my phone. I don't know if this is also the case with the A07 max and A70.
Hi Erin, an interesting review. I have been using Aiyima's A08pro for almost 2 years and it did wonders to me . I have been using one of the most musical amp from 47 Lab before and this A08pro does the same magic with more power which is truly amazing and go from strength to strength with better front end equipment added onto it. Tried their A07max and never liked it since it is lacking the musicality. So I wonder if A70 sound character is similat to A07max or more musical? If it's a more musical , I may give it a try, thanks in advance!
@@jari121 All amps are not same, or else there won't be tens of thousanads of designs , brandss and models exisiting in this world. I trust my ears when A/B comparing it myself between different models. All cars are equal, why buy a porsche if a cheap but reliable brand can take you from point A to point B safely?
@@ericlo6370 Did you make ABX tests like Erin? It always makes me laugh when someone makes these comparisons to cars, like comparing coffee makers to airplanes 😄.
@@ericlo6370 I also don't think that the current tests can show everything audible, but the ABX listening tests will certainly reveal if there are differences in the sound of the two devices. Maybe it's good to stop here.
Erin, the link to the product is to a page where it is sold out. There are other ones that aren't sold out right now that you could switch over to if you wanted.
That thing looks like a Fosi. The overall chassis & finish is extremely similar. Starting think both companies are, instead of competing, working together to flood the market with these cheap, small form factor amps. They could be trying to bury the, albeit more expensive, better Western built ones. The same thing appears to be happening with DACs & headphone amps. I've heard these cheap Chi-fi amps are OK for near-field, low volume listening but not much else. I'll be sticking to the Western brands. Even if I have to save for longer. The old saying still rings true - You get what you pay for.
No mention of the balanced connections. Amps should come with at least 2 inputs standard. And did it come with a remote? If not then is it meant for a desktop/near field system?
Appreciate another detailed review! I was wondering if you left out your multi tone power test for a testing related reason, or just convince / gear setup during moving?
Great review. Looks like class D amps are way past being only for subwoofers, this looks like great value. Just need to find something with a remote (preamp/TV) to hook it up to.
The fact that MANY professional Active/Powered Studio Monitors used for recording, mixing, and mastering music are primarily using built-in Class D amplifiers, even in products like the $16k Kii Audio Three monitors that several respected mastering engineers use, is a confirmation and endorsement that Class D is NOT inferior to other topologies. Most of these active studio monitors are using some variation of the Hypex Class D modules (UcD/Ncore/Nilai), or the Purifi Eigentakt 1ET400A Class D modules similar to Erin's "Reference" March Audio P501 monoblock amps which use the Purifi 1ET7040SA.
How big is a 'medium sized' room in your estimate. I can use my basement as my music room but I am not sure if you categorize that as 'small, medium or large'. Affiliate link will be nice.
In other reviews, I think Erin stated that his main listening room was ~14' x 17' x 9' and he considered that to be "Medium" size, but don't quote me on that. It's all relative to the size and S.F. of the type of home you live in (an apartment in Japan, an average older war-era suburban home, or a more modern McMansion), but IMO, a room that's 12' x13' x 8' (LxWxH) or smaller is a "Smallish" Room, 15' x 18' x 8'-9' is a "Medium" Room, and 18' x 24'+ x 8-12' is a "LARGISH" Room. Having said that, a typical basic no-frills 2-car garage is 24' x 24'. And I'm not sure I would consider that very Large. 😛
Excuse my daft question in advance, don’t you add a sub when your speakers don’t go down to sub levels, not to take over from your main speakers? I’ve done it with my Wharfedale Lintons, which have great bass extension, but not sub frequencies, so my sub just fills out the bottom end.
Yes, generally you add a subwoofer (or a few) when you want to experience those ~60Hz and lower notes in music or movies with real authority. Your Lintons have good bass extension, but they as you said, they can't reach down low with authority, so you've added the subwoofer. However, adding a subwoofer to *most* speakers, even if they already play down into the 40Hz or 30Hz region, and also applying a High-Pass Crossover Filter to your main speakers somewhere in the neighborhood of 80Hz to 60Hz (sometimes lower depending on the speakers), will in simple terms take some stress off of the main speakers and allow them to play "cleaner" and a bit louder before audible distortion or graininess becomes noticeable. This will depend on the design of the speakers. It may not make much of a difference with a good 3-way design that has a separate, dedicated midbass/bass driver. But for a 2-way "bookshelf" or "stand-mount" speaker, the single 5.25" or 6.5"-7" midwoofer is tasked with playing both the majority of the Midrange AND the lowest Midbass/Bass notes and information. The Wavelengths, and therefore the inward & outward motion of the cone (Excursion or Xmax) are significantly increased for the driver at frequencies below ~100Hz. This means that for the lowest frequencies, the cone has to move in & out A LOT more, while at the same time the cone is also trying to make multiple shorter/smaller movements (cycles) to produce the higher midrange frequencies. So, what can happen is that while the speaker is playing those low notes, the resulting large in & out excursion of the cone will "modulate" the higher/shorter wavelength midrange frequencies that the cone is trying to reproduce at the same time. This causes what is know as Intermodulation Distortion (IMD), and it usually increases any time the speaker is tasked with playing lower & lower notes. When you add a subwoofer with a Low-Pass Crossover Filter of say 80Hz, and also apply a High-Pass Crossover Filter at 80Hz for the main speakers, now the cone movement or +/- excursion of the mains will be significantly reduced, which generally results in lower IMD and lower distortion overall, so the higher midrange frequencies will usually become clearer and "smoother" and have more detail. In addition, the impedance load of the speaker will usually become easier for the amplifier to drive, because the main speakers are no longer having to play near their Resonant Frequency (Fs) where the impedance rises sharply (shown as a tall peak on the impedance vs. frequency graph on the left side at the lower limits of the particular drive unit}. Look at any of Erin's Frequency vs Distortion Graphs in his more recent speaker reviews. In his measurements as well as others' proper measurements, you will ALWAYS see a significant to moderate rise in distortion on the graph as the frequency goes Lower and Lower (the odd-order distortion...3rd, 5th, 7th order harmonics, etc., and/or the even-order distortion...2nd/4th/6th order harmonics, etc.). In most of Erin's reviews, he also shows what happens to the distortion levels IF you were to apply a ~80Hz High-Pass Crossover Filter to the speakers as if you were going to add a subwoofer. In most cases, the distortion will become at least a little bit lower overall, and/or lower in particular frequency regions. Sometimes the odd-order distortion (most offensive) will become lower while the even-order distortion remains similar, or vice versus. Depending on the quality and design of the speakers, the distortion may be drastically reduced, or have only a minor effect when adding the HPF. EDIT: Frequencies below roughly ~100Hz become more and more omnidirectional and non-localizable, meaning that if they are low in distortion and are not providing tactile feedback or causing things to buzz or rattle in the room, you can't distinguish what direction they are coming from. So, there is less of a need to have your Left & Right speakers play these low frequencies, and a decent subwoofer is much more suitable for the job of reproducing the lowest octaves. Also note that even with all of the mono bass frequencies coming from a separate subwoofer, your main speakers can still provide Left-to-Right "Stereo Imaging" of these bass frequencies because those frequencies USUALLY have upper harmonics tied to them that will be reproduced by you main speakers. For example, when you hear a low note plucked on an upright acoustic bass, while the fundamental note may be mono in nature, all of the strings resonate sympathetically and produce upper harmonics, AND the actual "pluck" sound that is generated is also much higher in frequency, and adds a harmonic transient that is tied to that same fundamental note that helps you to locate its position in the soundstage. Crikey! Sorry for the long-winded reply, LOL. I hope that makes some sense. 😛
Great review and I am thankful for the explanation of impedance versus resistance. So now we have 2 reputable reviews of the A70 by Erin and ASR. Erin's is with the 48V 5A power supply while Amir M.'s are with the 48V 10A power supply. The only difference that I can see is that the Amp went into protection at 4 ohms in this video (5A), but that didn't happen on the ASR review (10A), reaching about 200 WPC. The post filter feedback loop (PFFB) is what distinguishes this mini amplifiers from others in the same class.
Erin, Do you or anyone here, know of a wattmeter that can be connected in between an amp and speaker. I'd like to see how many watts my usage is. I have found that Simpson makes a wattmeter that I could build a box with connectors, but maybe there is an affordable off the shelf unit. Thanks, Kevin
If you just want to know a ballpark figure and you have a decent digital multimeter, you can measure AC voltage from speaker terminals. Then its the (result voltage)x(result voltage)/(Ohm value of your speakers) and result is the power in Watts. If you want to know how loud one Watt is, even a cheap multimeter gives accurate readings if you play a sine wave of 60hz (with proper multimeter you can use 1khz sine wave). 2.8 Volts AC with 8ohm speakers equals 1W, 2Volts if 4ohm. And be warned, it's loud...
@@MikkoRantamo Thanks a bunch. I have used a VOM in the past. In fact I had my Simpson 260 connected to a speaker in my shop and watched it hit 30vac at times. Very expensive VU meter. hehehe But, fun to watch and I got lots of questions about it. I think I'm going to buy the Simpson wattmeter and give that a try when the $ is available. Thanks again and all the very best.
Leaving something turned on versus continually running it at max power with a static load for days at a time or two completely different things. I hope you understand that now.
@@ErinsAudioCorner My friend! It takes years to test a product based on reliability criteria. In all respects. And you managed to do it in a few days. And give a verdict: a reliable amplifier. This is not serious my friend. Keep your tech reviewer brand up!
Did you run any 1 kHz squarewave tests? I've tested a few of the moderm Class D amps, and it's surprising how much ringing I would see...I was curious how this one compares in that regard. Also, were you able to look at the harmonics of the amp? What chip does it use?
Ringing in a square wave is a natural consequence of limiting the high frequency extension. Class-D amps have output filters to remove HF switching noise that class-ab do not need, so class-ab might extend to a higher frequency (but not nessisarily, IMO a sensible amp design will have filtering to keep it operating only within the desired use range.) In other words l, you need not be put off by what looks like ringing in a squarewave test.
seems like these little ch'amps amps keep getting repackaged with not much difference in feature set, and the prices keep inching up.. it seems like not that many moons ago, you could get an amp like this for $80 instead of $160.
@@FOH3663 Idk .. I'm a firm believer that government never actually solves anything, with or without money involved. They really haven't a clue how to help the average man with anything, or they do and don't care to service anyone but themselves.
