Dayton Audio HTA20 Hybrid Tube Amp Review

[amirm]

This is a review and detailed measurements of the Dayton Audio HTA20 Hybrid stereo tube amplifier with included DAC and Bluetooth. It is on kind loan from a member and costs US $185.

This is a cute looking tube amp! It even has the obligatory enclosure for a transformer (don't know if there is one under it or not). Tubes instantly glow bright orange which tells me they are LED lit. Much prefer this to blue LEDs and such.

There is a ton of functionality here if you look at the back:

You have dual analog input, Bluetooth and USB. There is a sub out which I did not test. A nice selector changes input. Volume control is also nice to use although channel matching was not perfect as you will see in measurements.

Dayton Audio HTA20 Amplifier Measurements
I started testing with the RCA input:

The "good" news is that the copious amount of distortion is second Harmonic which some folks believe is good (I am not in that camp). That does limit SINAD to some of the worst I have tested:

Since distortion is limited by the amplifier section, I did not expect, nor got better numbers with digital USB input:

If anything, we now have a spray of noise and other interference intermodulating with tube distortion products. Nor was there a benefit in noise department:

I was shocked how bad the frequency response is, despite company spec, in both analog and digital domains:

So I jumped to power measurements and called it done:

Amplifier was stable on power up:

Conclusions
Marketing department put a long of demands on engineer to deliver and deliver they did on feature list. Price was kept low as well. Sadly, the measured performance while in line with other tube products, severely fails the frequency response test. We could argue about audibility of distortion but not frequency response. Maybe they thought they remove the highs to make the amp sound "warm," and cut out the bass to make it more capable of driving speakers. If so, this should have been documented.

I can't recommend the Dayton Audio HTA20. Hopefully they revise and fix the frequency response errors.
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As always, questions, comments, recommendations, etc. are welcome.

Appreciate any donations using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

 

[amirm]

Specifications
Maximum Power Output (Peak) ..............45W x 2 @ 4 Ohm
RMS Power Output ..................................15W RMS x 2 @ 4 Ohm
Total Gain: ................................................28 dB
Total Harmonic Distortion .......................<0.5% @ Maximum Rated Output
Frequency Response ..............................20 Hz – 20,000 Hz ( 1 db)
Input Sensitivity .......................................315 mV
Channel Separation .................................53 dB
Minimum Speaker Impedance ................4 Ohm
Signal To Noise Ratio ..............................75 dB
Digital Section PC-USB .....................................................up to 16-bit/48kHz
Bluetooth ..................................................5.0
General Power Requirement .................................100V-240V, 60/50 Hz
Standby Power Consumption ................8W
Amplification ............................................Class A/B
Dimensions (W, H, D) ..............................9.2 x 6.2 x 4.2 in. (234 x 157 x 107 mm)
Weight ....................................................... 2.55 lbs. / 1.15 kg

 

[Talisman]

this practically identical one is also sold as fosi audio t3

 

[SuicideSquid]

I was reading this thinking "this seems pretty passable if you want to hear what a tube amp sounds like on the cheap" until we get to the frequency response graphs. That's just shocking. Complete fail.

 

[pma]

That's just shocking. Complete fail.

Frankly, what have you expected? And based on what?

 

[Talisman]

Frankly, what have you expected? And based on what?

Frankly? It doesn't seem like much to ask for with a frequency response that extends fairly flat from 20Hz to at least 15kHz... that amplifier will be incapable of reproducing any frequency in the lower octave, from any amplifier at any price it's the bare minimum you can expect.

 

[Sokel]

H2 at the 50's, that's a proud tiny tube amp!
Complete FR fail though, by that alone it's a hard pass.

Thanks Amir!

 

[SuicideSquid]

Frankly, what have you expected? And based on what?

Reasonably flat frequency response? That's the worst high and low rolloff I've ever seen. You're basically losing two full octaves at both ends of the spectrum.

 

[pma]

Frankly? It doesn't seem like much to ask for with a frequency response that extends fairly flat from 20Hz to at least 15kHz... that amplifier will be incapable of reproducing any frequency in the lower octave, from any amplifier at any price it's the bare minimum you can expect.

Could you do better job with that tiny output transformer? The transformer is what makes tube power amp performance. It makes no sense to produce such a small tube power amp. Other than "tube sales" rule.

 

[Talisman]

Could you do better job with that tiny output transformer? The transformer is what makes tube power amp performance. It makes no sense to produce such a small tube power amp. Other than "tube sales" rule.

Is it? The virtually identical Fosi Audio I posted (it looks like the classic design rebadged with minor modifications by many manufacturers) is actually a standard Class D with a tube preamp.

"Fosi Audio T3 is a stereo tube Bluetooth Hi-Fi amplifier that delivers warm and natural sound quality, superb audio fidelity, and high efficiency. You can create a 2.1CH home audio system by connecting 2 passive speakers and 1 powered subwoofer through the T3 to enjoy hi-fi music. It provides clean and bright mid and high frequencies, full and impressive bass, and a wide soundstage for an exceptional listening experience.
Fosi Audio T3 is also a tube headphone amplifier, featuring a 3.5 mm headphone output capable of driving headphones with an impedance of 16–300 Ohms, offering a massive soundstage and effortless dynamic range.
Exclusive design. The T3 features RCA/Bluetooth input, volume/bass/treble controls, passive speaker/powered subwoofer/headphone outputs, easy setup, and compatibility with most home stereo systems — all combined with a stylish appearance.
True audiophile sound. The T3 is equipped with 6F2 tubes to achieve a warm sound with Class D efficiency. It delivers 50W x 2 RMS power, providing enough drive for speakers with strong dynamic response and enhanced sound detail.
What you get: T3 amplifier x1, Bluetooth antenna x1, 6F2 vacuum tubes x2, power cable x1, user manual x1, worry-free 24-month warranty, and friendly customer service."

 

[Puddingbuks]

Wow, 189 dollar to get that true “musical” tube sound with some nice and warm distortion.

 

[DanielT]

Thanks for the test Amir. You write:
I was shocked how bad the frequency response is, despite company spec, in both analog and digital domains:

...-Severally rolled of in both ends

With that, the Dayton Audio HTA20 cannot be considered hifi. Given the abysmal FR, it is probably the amplifier world's equivalent of: No highs, no lows. Must be Bose.

 

[Nzama]

Is it? The virtually identical Fosi Audio I posted (it looks like the classic design rebadged with minor modifications by many manufacturers) is actually a standard Class D with a tube preamp.

"Fosi Audio T3 is a stereo tube Bluetooth Hi-Fi amplifier that delivers warm and natural sound quality, superb audio fidelity, and high efficiency. You can create a 2.1CH home audio system by connecting 2 passive speakers and 1 powered subwoofer through the T3 to enjoy hi-fi music. It provides clean and bright mid and high frequencies, full and impressive bass, and a wide soundstage for an exceptional listening experience.
Fosi Audio T3 is also a tube headphone amplifier, featuring a 3.5 mm headphone output capable of driving headphones with an impedance of 16–300 Ohms, offering a massive soundstage and effortless dynamic range.
Exclusive design. The T3 features RCA/Bluetooth input, volume/bass/treble controls, passive speaker/powered subwoofer/headphone outputs, easy setup, and compatibility with most home stereo systems — all combined with a stylish appearance.
True audiophile sound. The T3 is equipped with 6F2 tubes to achieve a warm sound with Class D efficiency. It delivers 50W x 2 RMS power, providing enough drive for speakers with strong dynamic response and enhanced sound detail.
What you get: T3 amplifier x1, Bluetooth antenna x1, 6F2 vacuum tubes x2, power cable x1, user manual x1, worry-free 24-month warranty, and friendly customer service."

So is it same chassis different amp?
Wow

 

[JeremyFife]

Not all amplifiers sound the same ... I think even I could hear that HF roll-off. Nasty.

Thanks for the review

 

[Sokel]

Not all amplifiers sound the same ... I think even I could hear that HF roll-off. Nasty.

Thanks for the review

The only thing that is making this remotely resembling an amp is its 25dB gain, all the rest are

 

[tomtoo]

Useless gimmick

 

[amirm]

FYI, this amp has 440 reviews on Amazon alone! Average rating is 4.5. These products remain so popular.

 

[French Meloman]

FYI, this amp has 440 reviews on Amazon alone! Average rating is 4.5. These products remain so popular.

Excellent work, once again. The fact that it gathers more positive customer reviews indicates that the human ear adapts quite well to a truncated and distortion-colored playback. It would be amusing to play this technological horror to those who claim to have golden ears in a blind test, telling them that it is a very expensive device (100 times its actual price). I think some would not be able to help but find it good.

 

[milosz]

Even at this price, the engineers could have done better. That frequency response - what is this, a 1950's Bell Telephone handset under test?

Are the tubes even in the circuit? Is this a tube input gain stage with some kind of cheese- based class D output section?

WTF!?!?

 

[solawind]

I was reading this thinking "this seems pretty passable if you want to hear what a tube amp sounds like on the cheap" until we get to the frequency response graphs.

isnt that how early tube amps really were? They are expected to have frequency rollofs. Maybe not as severe as the one reviewed, but still, -2db at 18k starting from 3khz
If so, it should give you that "tube amp" sound, even a bit exaggregated one. Yes, it measures completely wrong. But tube sound is wrong and some ppl are just bored with completely trasparent dacs nowdays and lookng for wrong sound so maybe it is what they are looking for, including that harmonics energy.