Man what a sweet little amp. I have this on top of my fridge powering some JBL 4309 studio monitors that are set on top of my kitchen cabinets. I’m blown away at what it offers. You can spend your whole budget on speakers and stick a kick ass stereo into any space. It’s quite amazing.

This amp (iA255.1) when I connected it to my cd player sounded amazing. The clarity was really good and with more than enough power to drive my C-Note speakers that I just built. I was going to put this into my garage but now I think it may end up in my office and I'll just have to get another one for the garage. Don't know how something so small can sound that good and have all those features but I'm impressed.

This little DAC amp is amazing. All metal construction with metal knobs and powerful enough to drive even my large speakers. Perfect little high end amp ! Sounds amazing. I have to thank the cheap audio man because I would have never found this !!! Hopefully they will make different models of these with a toslink in and a remote. And if they would make ia little larger to get rid of the external power brick it would be better then perfect !!! Would love to put this under my TV next to my cable box if it had a toslink, remote and internal power supply. Hopefully l will see this in the future 🙏🏻

This is amazing, great sound and build quality. So happy to see an American company make something like this so if there is a problem or question you can speak to someone. Hope to see other models like this in the future with 2 tubes and a remote. Powerful little amp, great price and a 2 year warranty what more can you ask for !!!

Love it. Powerful, clean sound from an impossibly small package. Although I don’t intend to give up my $1500.00 class A/B and replace it with this, nor would it be a fair comparison, this little amp has several applications for me. There is no better product for this price, and I’ve looked hard. For those who wish it had this feature or that ability more, the cost would be more and it wouldn’t be in a package this small. A well engineered product. The silver controls look great.

Great set of features for a 2.1 desktop setup. Plenty powerful for nearfield. I never go past 25% on my Kef R3 or LS50s. The sub-out is volume controlled and also controlled by the tone controls. Tone controls have notches to keep them zeroed. Wish volume control wasn't so linear so I can us more rotations rather than limiting it to only 25% of knob. Binding posts cramped. No controller. Great value tho!

I've been using the ia255.1 for a few days now and it's so much better than I expected it to be. I've used 10 different Chi-Fi desktop amps already including the Aiyima T9 standard and Pro as well as their new A07 Pro. I look for units with a sub input and try them all out. This one blew them all away with ease!

I find the addition of the hi pass filter is the real differentiating factor here, having the ability to shift the majority of the bass loads to the sub allowing for much cleaner mids and highs from the current Jamo 2.1 setup I'm using really makes this amp shine like no other in it's price class.

The Infineon chip used here also is allowing for more detail being heard over the TPA 3255 chip used by virtually all of the other Chi-Fi amps in this class. The depth of sound (left to right, front to back) is also much improved here over the 3255. The only advantage that chip has over the one used here is the ability to really get more power out of it. But power isn't everything after all and the Infineon chip has plenty for desktop use and it's driving all of my speaker setups that I own including some pretty hard to drive sets surprisingly. All in all, it's got more than enough juice for all but the most inefficient speakers.

Summing up, I really like the overall package presented by the ia255.1. The usb-c input, sub input, the hi pass filter, the tone controls with an honest to goodness detent in them (way too many Chi-Fi units missing that!!) and the overall build quality make this a bargain that'll be hard pressed to be beat. Great job RSL. Highly recommended!

The iA255.1 amplifier is an impressive little piece of gear,sounded so good i upgraded my speakers.Love it !

Where to even begin? As an audiophile for over 55 years, I've run the gamut of gear ranging from hundreds to tens of thousands of dollars. At my ole' age now, I've confined my audiophile efforts to a desktop, near-field environment - so the size and performance of components are essential to me.

Over the past 3 years, I've experimented with over 22 different Chinese-made, compact class D amplifiers, most of which didn't impress - except for a few. I won't mention the brands and model numbers of the ones that did manage to impress because I'm here to rate the RSL iA255.1 amp, which is superior to every model.

It is a welcomed surprise to see an American audio company - and an audiophile-level one at that - stir the waters with their rendition of a very compact class D amplifier. And before you remark, "Well, it's made in China also," let me remind you that it's a reality that some items may get outsourced, yet in most cases the design parameters and research begin with the audio engineers on this side of the pond.

Having said that, this RSL iA255.1 amp is quite different. Yes, it has some typical class D audio issues, which I'll address in a moment, but let's get on to the superlatives:

1. When it arrived, the RSL iA255.1 amp surprised me with how compact (small) it is! I mean that for those of you who delve into the world of Chi-Fi, this model is roughly the size of many Fosi, Aiyima, and Nobsound products. Appearance-wise, what makes it different is its visual design - all black, solidly constructed (for the price), and featuring solid silver knobs with black line indicators. In my opinion, it looks great and should fit in most places to be sure. To simplify things, this RSL iA255.1 amp looks like an audiophile design in a compact package.

2. The rear panel has the typical inputs that you'll find on many of the compact Chi-Fi class D models on the market, but I do have issues with the speaker binding posts. I have 6 different speaker cables on hand that I use - those being from Audioquest, Micca, Blue Jeans Cables, and a few others. On two of my speaker cables, which include 12 gauge OCC wiring and banana plugs, even though plugged in all the way, I was either only getting one channel of sound, or when wiggling them around, I would get no sound. At first, I thought, "Oh no, my amp is defective," but I then tried other speaker cables after ruling out other issues). I found that my Audioquest, Micca, and Blue Jeans cables functioned just fine and their banana plugs firmly gripped the binding posts without any movement. However, the other 3 pair - all audiophile-level cables, but made overseas - had issues with their seating properly, thus resulting in sound dropouts. So in my opinion, if there is one area that can be improved, it would be to reinforce and look at other binding post designs. I do realize that to keep the cost low where it is, some sacrifices had to be made.

3. Let's talk sound. To begin with, when you first turn on the RSL iA255.1 amp, it may initially sound like some inexpensive, compact class D amps - that is somewhat bright, and periodically thin sounding (depending on the genre of music you listen to). However, having been around for quite some time, I've long since learned that I allow gear to warm up/break-in, and then leave them on (with the exception of tube amps which I will turn off at the end of the day) to achieve vastly improved audio results. And this RSL iA255.1 amp is no different. I turned it in and left it on for 24 hours before I even started listening seriously.

4. After a 24-48 hour warm-up period, the sound improved and warmed up quite substantially. But before I get into the nuances of its music reproduction capabilities, allow me to point out that this amp has a very open sound, can be very dynamic, and seemingly moves the sound-stage on a wide strip in front of the speakers (at least my speakers, that is). This amp also (uncannily so for the genre) showcases an unusual amount of front-to-rear depth, and provides the listener with a sense of immediacy that I've "not" yet experienced with any of the Chi-Fi class D amps (again, over 22 of them). Now go figure. How is RSL capable of managing to achieve this feat with such a diminutive and inexpensive design?

5. Bass lines are solid and full with much reach. The speakers I'm using to listen to this amp include the KEF Q150s and Q350s, along with a pair of Warfedale D320 bookshelf speakers. I have an 8" active subwoofer under my desk - I alternate between a Presonus 8" model and a Mackie 8" model. The midrange and treble frequencies (depending on the instruments playing) can still be a bit bright at times, and "sometimes" thin, but the air around the instrumentation, the instrumental placement, sound-staging, and the correct timbre of each instrument, results in an immersive experience that I've not yet experienced with any other small amps.

6. As an aside, there is only one other American company that designs a very small class D amp, but is also manufactured in China (and is smaller than the RSL model) and that is Micca, with their Oregain A250 amp. It has no bass/treble controls and although sounds very nice for a class D amp, pales in comparison to this RSL iA255.1 amp.

7. As an audiophile (or Hi-Fi enthusiast - whichever term you prefer), I evaluate music using mostly classical music sources, big band jazz, and other instrument groups (featuring many different instruments) that incorporate voices. I strongly feel that to properly evaluate music, you should be able to judge various instruments at play - not just several. For this being such an inexpensive amplifier, the RSL iA255.1 punches far above its weight, and this is just the first offering from RSL in this genre. I can only imagine what RSL will come up with future in the budget, compact class D category.

8. I have several recommendations that I would like to make - ones that I believe can only make this line much better. Those being:

a. Please incorporate the ability for the user to change out the Op-Amps (Op-Amp rolling). To be able to experiment with various Op-Amps, especially the Discrete designs, can make a world of difference in the sound qualities of a class D amplifier. In all the amps that I own where Op-Amps can be changed out, I've inserted either Burson or Sparkos Labs discrete versions of Op-Amps, and they noticeably improved the sound of those instruments. In line with this, if interchangeable Op-Amps are incorporated, the covers should be easily removable - and not give the user a fit trying to figure out what to take off first.

b. Something which many amps (in this category) seem to leave out, is the addition of a "Balance" knob which would be a great addition - but its omission from this design is understandable since we're trying to keep things compact.

c. One minor point here (and again, I realize a price level determines what is incorporated), improve the quality of the connectors (and binding posts) on the rear of any new budget class D designs. I've already addressed the speaker-binding issues I experienced above.

9. In closing, I'm still absolutely stunned (in a most positive way) by how such a small and inexpensive amplifier can produce the sound that it does I can say without reservation, that it gives the listener a truly immersive experience (dependent of course, on the other associated gear being used). Great job RSL, you truly deserve a well done for your first foray into the budget, compact class D arena. I can't wait to see (and buy) more of your future releases.

As an aside, this review will be placed on other websites as I also write reviews for a dozen Hi-Fi and Audiophile clubs.

Ben Herrmann, North Carolina

Among its other talents, this is a great desktop companion to a computer and a set of any RSL speakers new or old. It will easily fit on a desk and make more than enough volume for any office. The sound is clear, detailed and expansive. It makes voices sound real and really delivers that impact for drums and bass.

Unbelievable sound in such a small package.