Dayton Audio HTA20 Hybrid Tube Amp Review

[Hart]

Well it shows you can make money on Amazon by creating a pretty box, fill it with whatever, and make a lot of money. On the bright side still better than that ghastly Carver Crimson 275 tube amp priced at $2,750. So save yourself $2,500 and get something slightly less ghastly. I think the guts of that Carver amp look suspiciously like a board from a 70's walkie talkie I had as a kid.

 

[JayGilb]

It’s a $185 tube amp with poor performance.
It’s cute and with the lack of high end, it’s perfect for an old person who wants to relive the past.

Thanks again Amir.

 

[pma]

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.

OK, I was wrong with the tube function, it is not a power tube and the transformer would be there to get plate voltage. However, if you design a hybrid tube + solid state power amplifier, as I did as a combo of tube gain stage and class A power stage, then there is no problem to get 2Hz - 200kHz bandwidth and quite low distortion. However, those remarks about "warm sound" etc. is a marketing nonsense. The amp was indistinguishable from completely solid state version.

 

[Curvature]

I call it the audiophile conspiracy amp: actually, provably sounds different.

(Edit: To be clear, the Dayton Audio HTA20, not any of the other ones mentioned in this thread.)

 

[DSJR]

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.

Devil's advocate here -

The lf rolloff is passable I reckon as the smaller desktop-style speakers (rather than properly set on high stands higher-end speakers) distort like crazy below 100Hz anyway. the hf rolloff below 15kHz isn't as huge if the Y axis was squashed as in 'olden days' to 5dB per division and the 5dB or so roll-off will soften the tone somewhat I feel. Amirs more revealing plots make it look tons worse really

Anyway, boxes like this are toys, electronic trinkets really, aren't they? Yeah, it's poor and another fifty dollars may well have improved things, but for this low price, maybe we're looking too sternly at it?

 

[MediumRare]

Maybe the goal was to nostalgically sound like AM radio?

 

[Nzama]

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

This is for me the biggest impact ASR has had. On my choices first of all. As a checkpoint before spending hard earned money! And Amir you have been at the start of this movement!

 

[beagleman]

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!?!?

I looked at the FR graph again, I mean yeah its "Bad" but due to scaling, in reality, its down 2 Db points are about 50Hz and 13KHz, I mean listenable for sure, but in no way "High Fidelity"

Phone handset?, Naw not even close. More like an mid tier 80s radio shack all in one music system.

 

[mhardy6647]

I mean yeah its "Bad" but due to scaling, in reality, its down 2 Db points are about 50Hz and 13KHz,

 

[diddley]

I think you should't pay much attention to what amazon says about a product, every thing is rigged nowadays.
and for the review the DUT is a gadget, has nothing to do with decent audio and enginerering.

 

[DSJR]

Maybe the goal was to nostalgically sound like AM radio?

I believe that AM radio only goes to 5kHz or so, which is still enough to hear some sibilant sounds, unless this is distortion 'filling in?'

 

[mhardy6647]

I believe that AM radio only goes to 5kHz or so, which is still enough to hear some sibilant sounds, unless this is distortion 'filling in?'

Maybe 7 kHz on a good day. The 10 kHz channel spacing, at least in the US, limits the bandwidth.
There have some wide-band (relatively speaking) AM component tuners produced over the decades -- most notably during the brief but heady era of AM-FM simulcast stereo in the US prior to the FCC's adoption of mono-compatible MPX stereo FM broadcasting in the very early 1960s.

Here's one, e.g.

Well... this particular Heathkit (i.e., that orange thing on the bottom -- Heathkit called it luggage tan) has MPX FM stereo built in, but still featured completely separate AM and FM tuner sections a la the slightly earlier and aforementioned simulcast stereo tuners.


"multiplex-engineered"

The Fisher 80 on the top predates the simulcast stereo scheme.

 

[Yasuo]

So happy to see another tube *anything* fail. I'm such a bad person...

 

[Redman43]

Made for those over 70 who don't hear anything above 5000hz anyway?
In that case both function and design are bang on

 

[Billy Budapest]

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

Let me fix that:

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

 

[DVDdoug]

isnt that how early tube amps really were?

They varied a lot.

As others have mentioned AM radio had (and has) limited frequency response, as did the recordings.

Overall, "high-fidelity" was rare. I remember the 1st time I heard a good system and my impression was, "wow! Bass and treble at the same time!" I also remember hearing a system with some highly-regarded speakers. I don't know what the other equipment was but I assume it was an "audiophile" setup. I think the owner was playing a distant FM station because the hiss from the tweeters was BAD!

Growing-up in the 1960s and I had a tube radio, my parent's stereo had tubes, and our TV had tubes. Most of it would be considered "unlistenable" today. In the 70's I had a 1950's car with an AM tube radio... Not great, but it wasn't until later in the 1970's that we got an FM rock station in our town.

Also in the 70's when I was in high school, somebody gave me a couple of tube amplifiers. (I don't know when they were made.) One of them had rolled-off highs. The other one was a McIntosh and it sounded "perfect". As far as I know, McIntosh always made good amps. But the McIntosh I had was mono.

 

[PristineSound]

My question is, have there ever been any tube electronics that performed respectably measured on ASR?

 

[Power Pop 23]

My question is, have there ever been any tube electronics that performed respectably measured on ASR?

I consider the performance of the Aiyima T20 Tube pre-amplifier as measured recently by Amir to be 'respectable'.

 

[sam_adams]

Amplifier was stable on power up:

Apparently, its only saving grace. Well, it is a tube amp after all and it delivers on the 'Tube Sound' that aficionados desire. Anyway, good review, @amirm!

 

[SuicideSquid]

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.

View attachment 484038

These aren't remotely comparable though, that's the problem. This is almost completely flat between 40Hz and 15kHz, with a slight bump to subbass and droop to very high treble. This Dayton amp is already down -0.5dB at 5kHz!! That's two octaves below where the amp you're comparing it to starts to droop, and the low frequency rolloff on the Dayton is already down 0.5dB at 100Hz - that's 2.5 octaves higher than where the low frequency rolloff happens on your cited amp.

For a point of comparison, on the amp you cited, 40Hz, which is an open E string on a bass guitar, is +1dB - a very slight bump. On the Dayton it's -3dB, which would be audible on its own, but then if you paired it with a set of speakers that were already down a few dB at 40Hz, you'd be getting basically no true bass at all.