Kaei Design - Tap 1

INTRODUCTION

There’s this new company named KAEI that is catching some eye in the current audiophile scene. They produce AMPs and DACs, most of which are Tube Hybrids.

Although I haven’t received the AMP with a DAC built in, the review will be solely based on the AMP section of the TAP-1 with PSU, which comes at a price of $410 without discount. Fortunately, they do provide discounts almost every time on their website.


PACKAGING

TAP-1 with the PSU comes in a huge black cardboard box. The inner housing of the casing is very nicely padded to avoid any type of damage during transportation. The wall of the box is strong enough to withstand a few drops. Fairly compartmentalised to house all the cables and accessories. The PSU and the AMP is divided by a thick wall of foam so there won’t be any chance of collision.


ACCESSORIES

The AMP+PSU comes with very good accessories to get you going after receiving the unit. It consists of

1. Power Cable

2. 4.4 to 4.4 Interconnect

3. 3.5 to 3.5 Interconnect

4. Power Adapter

5. 2 X Rubber Bands

6. USB Cable

7. AMP unit

8. PSU unit

The quality of the Power Cable is Good enough, but the adapter felt a bit cheap and aftermarket. Interconnects are OK in construction and quality, but the USB cable is not that good. Although I don’t think that it would matter that much I would’ve liked a bit better USB & Adapter cable.



BUILD QUALITY

The AMP and PSU are both made from metal. The PSU is a slab of Metal, and the AMP does include a bit of glass into the aesthetics to give the tubes a peek. The design is very industrial and robust to touch and feel. I never dropped it so can’t say much about its durability but if you ask me, it wouldn’t be a good idea to drop this slab of metal in any surface, it won’t be good for the unit/the surface.


DESIGN

The PSU only indicates the power with a blue LED. And I am glad to state that the blue light is not too powerful to illuminate the whole room. You can tape it to get the absolute black operating device. The PSU is slightly bigger than the AMP unit so it’s not a very symmetrical relation.

AMP unit is beautiful to look at. It comes with a glass window from where you can peek through the tubes. The tubes are not self-luminated though. The whole tube area gets lit by a warm red LED light if you choose to turn on the TUBE Mode in the AMP. You will get a large volume wheel that doesn’t feel that premium but does the work properly.

The set is accented with gold touches here and there & it looks luxurious to my eyes.



The back of the AMP unit consists of a various number of switches and ports & they are.

1. Power In port

2. Input Signal Attenuator (ATT – which comes as -6dB & 0dB switch)

3. Tube Bypass (BYP TUBE)

4. USB C Charging in

5. Power Indicator

6. GAIN SWITCH (Which comes as 10dB & 0dB switch)

7. Line/DAC mode switcher

8. USB DATA in port

9. Power on/off switch


VOLUME WHEEL

The volume wheel is very average to touch and feel. The grip is rubberized and feels robust to tackle. The smoothness of the wheel is OK, will remind you a lot of the JDS ATOM 2 AMP. Smooth enough and slightly frictionless. The slope of the body is actually very helpful since the ground height is low and that slope helps to get the finger around the wheel.

Now leaving all these aside let’s talk about the Power Delivery.

This unit has been provided by the AG as an ongoing tour of KAEI in India. No one asked me to write anything about this product. All thoughts and opinions are mine and honest to my findings.



POWER OUTPUT

The unit is powerful to run any IEM. I have tested a lot of IEMs with this, and it had zero problems whatsoever. The most demanding IEM I tried with it was the Singularity and it drove it well enough.

With 300 ohms Sennheiser HD600 the power was well enough to enjoy. Although you won’t get all the good benefits of the tube amp in HD600 due to the Hybrid Architecture. I will discuss this further in the Sound Quality section, but the power is well enough for IEM & most headphones.

Although it is not a great idea to believe the maker to trust when it comes to the measurements, I was unable to find any other measurements on the internet, thus I am judging this blindly.

The added PSU will provide you with extra current so that you can drive even more powerful transducers with it. The improvements that the amplifier got with the PSU is very noticeable and will give you a much larger headroom to play with EQ.





SOUND QUALITY


SOUNDSTAGE

The soundstage on KAEI is expansive. It’s not like someone switched on a knob that just expands the soundstage, it’s more like pushing the transducer to produce the most holographic staging they can. This might indicate that the upper mids are a bit pushed back which helps smooth out the tonality a bit but if we only talk about the staging, it felt effortless. No peculiar timbre quality popped up; no mushiness showed up in the localization points. In three words the soundstage on TAP1 AMP is bigger, better, and physical.


RESOLUTION

It is very surprising to me that an AMP that sounds this smooth can also resolve incredible amounts of details, but this one does that. Somehow ChiFi triggered some connections in our minds that smooth-sounding equipment can’t be that resolving due to the psychoacoustics and all but TAP-1 just hits it out of the park in terms of resolution. It might not produce texture as well in the instruments but the fidelity with hich complex tracks got rendered through the TAP-1 is very impressive.

TONALITY

Tonality was also very surprising to me. I expected it to sound warm and bassy, but I was Wrong. It had a very flat sound in the low end. The bass it not something I got with this Amplifier. Although the midrange is very sweet sounding and impressed me a lot. But The main thing that will impress you the most is the rendition of the upper-mids and treble. Each song will sound smooth and organic. No harshness can be noticed anywhere. This might not satisfy treble heads, but it does provide a beautiful richness to the sound that most of audiophiles love. Overall, it’s a thick, not overly warm and rich-sounding amplifier.

And with tube bypass on, the richness goes away slightly while giving you cleaner sonics which I didn’t use that much.

Now when we’ve talked about the sonics of this machine let’s talk about some things that impressed me the most on this AMP.


ORGANIC SOUNDING

This AMP has a special ability to make even harsh-sounding tracks smooth and relaxing. Let’s take HD600 as an example. The treble on HD600 is tuned in such a way that poorly recorded music sounds a bit harsh, but with the TAP1 the edges are magically turned into music. The piercing effect on high volume also magically vanished completely. Although the low-end wasn’t there as much as I wanted since the output impedance of the AMP was very low, the treble on the other hand made it sweet sounding. This effect is not just reflected in the headphones, it’s prominent in all the transducers I tried with it. And the best thing? Resolution, there were no hints of smoothing out on that front.


In the song Hotel California (Hell Freezes Over) – Each and every trailing edge was preserved ignoring the sudden peaks in the harmonics of the guitars. The crowd sounded too realistic & spacious.


NATURAL COHESION

Each transducer I tried with it suddenly became more cohesive and liquid in nature. This phenomenon was previously observed by me on high-end tube amps where the voltage swing becomes so high that sometimes it takes little extra effort to control drivers, causing wetness to the sound that adds a beautiful musicality to the sound. TAP1 reminded me of the same feeling but without the missing control where notes get overlapped.


NEAR FLAT TONALITY WHILE DOING ALL THESE THINGS

I own a RoseTechnics RT5000 which does a lot of effort to make sound that this AMP is making, and that thing is way costlier than TAP1. So, if by including the tubes KAEI can give me that kind of tonality, I am OK with not having enough voltage to begin with.



DRAWBACKS

Well, it’s not always Sunshine and Rainbows, there are some downsides that I must mention. And they are

CABLE LENGTH

The cable length as an included accessory is very short. The interconnects have an angled termination which makes them usable but otherwise the power adapter cable and power cable both are very short.

TOUCH & FEEL

Although the product is built like a tank but that is one of its biggest problems. It feels like a college project more than a Boutique Brand. The switches and all work great but the feeling and design it pretty meh. The sharp edges don’t provide any convenience either.

WEIGHT

In hybrid AMPs, PSUs are required to provide extra current, and I have no problem with that. It’s just the weight is so heavy to use it as a portable device that it is very hard to carry it without the carry case (which is big).

RINGING EFFECT

Although this effect is persistent with every AMP and there is no exception here too. It suffers from ringing with touch/rattle. Although the ringing goes out in about 30-45 seconds.

BASS REGION

I would be nitpicking at this point, but I was expecting a bit more low-end elevation from the tubes which I didn’t got but it’s a good thing Objectively since you get to hear the Transducers with a lot more precision, but the 2nd Order harmonics excited me a lot to crave a bit more low-end. And that’s where the EQ came handy which made me question if this is even a drawback or not. Because the flexibility I got with both aspects of the sound (with EQ) is just more versatile and not sacrificing (like warm tube sound) of the other.



ENDING

This concludes the review of KAEI TAP-1 with PSU. If you ask me,

Is it worth the price? Yes, if you want a tonally intact sound.

Is it portable enough to carry everywhere? No, but can be transported easily.

How’s the sound? Excellent, natural with absolutely zero harshness.

TAP-1 Portable Tube Amp (Without DAC and PSU)
Big thanks to Sandeep Agarwal for the loaner as part of the Audio Geek India Tour.
This is my first experience with a tube amp, and I have to say, KAEI has completely exceeded my expectations. From the moment I started playing my tracks, everything came alive—vocals, instruments, the entire frequency range. It made justice to all the elements in the music, and I found myself rediscovering songs I thought I knew so well. I have to say, it sounded beautiful.

Sound Quality​

The soundstage is also quite impressive—wide and open, with good separation between instruments. Imaging is spot on, too I tested it with — Sennheiser HD650 and Truthear Hexa—and the TAP-1 powered all of them effortlessly. The HD650 paired especially well, with the amp bringing out the best in its smooth, balanced sound. Whether you're using high-impedance headphones or IEMs, the TAP-1 has enough power to handle it without breaking a sweat.

Build and Design​

The build quality is rock solid. It feels like a tank—durable, but not overly fancy. It’s a bit heavy for a portable amp, so I’d say it's more suited for home use rather than taking it on the go.

Power Supply and Extras​

You can also get the optional PSU, which improves power delivery and gives the sound a little extra polish. It’s not essential, but if you want to get the most out of the TAP-1, it’s a worthwhile upgrade. Plus, KAEI includes a lot of interconnects in the box, so you won’t need to buy anything extra to get started.

Final Thoughts​

For anyone looking for a portable tube amp with great sound and build quality, the KAEI TAP-1 is a solid choice. It offers a warm and immersive sound and it drives a wide range of headphones with ease. It’s not the lightest or most compact, but it’s built to last and delivers great performance for the price. I was so impressed I ended up ordering one for myself. Definitely worth checking out if you're into tube amps or just want to add some warmth to your setup.