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Juson Audio JTA35 Tube Amplifier, DAC & HP Amp Review

Rate this amplifier:

  • 1. Poor (headless panther)

    Votes: 92 36.8%
  • 2. Not terrible (postman panther)

    Votes: 103 41.2%
  • 3. Fine (happy panther)

    Votes: 49 19.6%
  • 4. Great (golfing panther)

    Votes: 6 2.4%

  • Total voters
    250

amirm

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This is a review and detailed measurements of the Juson Audio JTA35 stereo hybrid tube amplifier including DAC, Bluetooth, Phono input and headphone out. It was sent to me by the company and costs US $180.
Juson Audio JTA35 Tube Stereo Amplifier DAC Headphone Amplifier Phono stage VU meter review.jpg

As if all that functionality was not enough, we even have a pretty VU meter! And oh, motorized volume control remote control too!
Juson Audio JTA35 Tube Stereo Amplifier DAC Headphone Amplifier Phono stage VU meter back pane...jpg

There is even subwoofer out!

Overall build feels good and polished. Speaker terminals are oversized for class (good) and we even have built-in power supply. Let's see how it measures.

Juson Audio JTA35 Measurements
Let's start with the power amplifier:
Juson Audio JTA35 Tube Stereo Amplifier DAC Headphone Amplifier Measurements.png

Don't expect super clean performance from a tube amp especially at this price and that is what we get. Noise is high and shows up in our SNR tests:
Juson Audio JTA35 Tube Stereo Amplifier DAC Headphone Amplifier analog Dynamic Range Measureme...png


Distortion is fortunately frequency independent:
Juson Audio JTA35 Tube Stereo Amplifier DAC Headphone Amplifier Multitone Measurements.png


Crosstalk is poor:
Juson Audio JTA35 Tube Stereo Amplifier DAC Headphone Amplifier analog Power crosstalk Measure...png


Frequency response has peaking at the low and upper end:
Juson Audio JTA35 Tube Stereo Amplifier DAC Headphone Amplifier analog frequency response Meas...png


Impedance is low though as we see from difference between 4 and 8 ohm. There is a sharp cut off which existed even when I switched to digital input:
Juson Audio JTA35 Tube Stereo Amplifier DAC Headphone Amplifier Coax digital frequency respons...png


Here are the power sweeps:
Juson Audio JTA35 Tube Stereo Amplifier DAC Headphone Amplifier analog Power 4 ohm vs frequenc...png


If we allow more distortion, power increases with good bit of heardroom:
Juson Audio JTA35 Tube Stereo Amplifier DAC Headphone Amplifier analog max and peak Power 4 oh...png


Interestingly we get almost the same amount of power into 8 ohm (we are current limited):
Juson Audio JTA35 Tube Stereo Amplifier DAC Headphone Amplifier analog Power 8 ohm Measurements.png


Same voltage advantage exists when testing headphone out with more power delivered at 300 ohm:
Juson Audio JTA35 Tube Stereo Amplifier DAC Headphone Amplifier 300 ohm Measurements.png


Juson Audio JTA35 Tube Stereo Amplifier DAC Headphone Amplifier 32 ohm Measurements.png


Finally, I tested the RIAA equalization using phono input:
Juson Audio JTA35 Tube Stereo Amplifier DAC Headphone Amplifier Phono Stage Measurements.png


Kind of strange response with channel mismatch.

Conclusions
It is hard to imagine so much functionality being in such a reasonably priced but quality (physical) implementation. It even went after the soft spot in my heart with that VU meter. The other part of my heart was not pleased with measurements that are lackluster across nearly entire suite. Company support has been fantastic though and when I gave them the option to ditch the review they chose to have it be published anyway! Not enough companies send me products and fewer still don't mind results like this. For this, they need to be praised. Hopefully future products will have better objective performance.

Not having any use for tube products, I can't recommend the Juson Audio JTA35. If you are situated otherwise and looking for a very low cost of entry and high functionality, you may dig what JTA35 has to offer.

Manufacturer Specifications are provided in post #9 below.

------------
As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
 
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Talisman

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I appreciate the commitment to offering an honest product, accepting to highlight its strengths and weaknesses without hiding. The performance is objectively poor for a main audio but it could be nice in the bedroom with the valves and vu meters in a relaxation system.
The only thing I don't like is the wrong frequency response, it's something I can't tolerate in 2024 from an amplifier at any price
 

Talisman

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Do providing companies always have the option to ditch your reviews? How many reviews have you ditched until now?

Thanks for the review!
Yes, Amir explained it in a thread, if the company sends the product Amir allows them to decide whether, after seeing the results, they want to publish it or not. Obviously this benefit does not exist if the product is provided by a user or purchased by Amir
 

Sokel

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Packing all that and still managing to get near the 0.1% THD+N being a tube amp is remarkable.
Other tube amps proudly present specs like this.

What's not nice is it's FR,they could make a better job on this.

Thanks Amir!
 
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amirm

amirm

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Do providing companies always have the option to ditch your reviews? How many reviews have you ditched until now?
Over the nearly 2000 reviews, I would say maybe 10 to 12 times. It is a courtesy I provide to companies that volunteer to send me gear. The usual scenario is the company not knowing the emphasis we have on objective performance and what those objectives are. As a result, most products that fall in this category are rather obscure.

Since most of my reviews come from member gear, stuff I have bought, and companies who know their gear will perform, very few fall in this category. I get to provide this without it impacting the work I do in any meaningful way.

Here are the Manufacturers Specifications:

IMG_0542.jpeg
 
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welwynnick

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It's not that bad for a cheap tube amp, I'm quite impressed, but just a bit disappointed about the noise. Surely it doesn't have to be that high?

The frequency response is strange. It looks as if its analogue inputs are digitised. How ironic for a tube amp.

Perhaps an analogue pass through would help.

Nick
 

Angie87

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The data from the testing of hybrid tube amplifier is not good than digitals.But the sounds of tube amplifier is more nature,warmth and comfortable.
 

Haskil

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The data from the testing of hybrid tube amplifier is not good than digitals.But the sounds of tube amplifier is more nature,warmth and comfortable.
Digital amplifier? Do you have any popular commercial examples of digital amplifiers?
 

YSC

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I actually gave it fine rating, was thinking about giving it great also, reasons:

1) The FR boost in bass and 20khz is not ideal, but less than 1db peaking likely doesn't matter in real application as it's way more irregular in real use case for the speaker or headphone to make those anywhere near audible

2) distortion is poor for Hi-Fi sense, but at least it is the 2nd harmonics dominanting which is what tube ppl supposed to like, with multitone shows that flat SINAD I would suspect that is on purpose

3) distortion channel balance is actually exceptionally good, usually for products to have high THD+N chances are one channel is much worse

So yes, it is not hi-fi, but if someone is craving for the "tube noise/magic", this does seems to do it correctly, and for the price, it won't hurt as a small toy to go "enjoy" low-fi once a while would it?
 

Sokel

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I actually gave it fine rating, was thinking about giving it great also, reasons:

1) The FR boost in bass and 20khz is not ideal, but less than 1db peaking likely doesn't matter in real application as it's way more irregular in real use case for the speaker or headphone to make those anywhere near audible

2) distortion is poor for Hi-Fi sense, but at least it is the 2nd harmonics dominanting which is what tube ppl supposed to like, with multitone shows that flat SINAD I would suspect that is on purpose

3) distortion channel balance is actually exceptionally good, usually for products to have high THD+N chances are one channel is much worse

So yes, it is not hi-fi, but if someone is craving for the "tube noise/magic", this does seems to do it correctly, and for the price, it won't hurt as a small toy to go "enjoy" low-fi once a while would it?
Agree.
I mean traditional PA amps like Crown XLi 800 don't do much better ,they even have a much worst distortion pattern.

With some dense music I could be more than ok.
 

Chagall

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Thank you Amir for the review.

I know you don't do listening tests for DACs and amps, but in this case, it would be curious how this does as a headphone amp subjectively.

Congrats Juson Audio for having balls!
 

DanielT

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Thanks for the test Amir. It was fun to see how such a small cheap tube amp performs.:)

I appreciate the commitment to offering an honest product, accepting to highlight its strengths and weaknesses without hiding. The performance is objectively poor for a main audio but it could be nice in the bedroom with the valves and vu meters in a relaxation system.
The only thing I don't like is the wrong frequency response, it's something I can't tolerate in 2024 from an amplifier at any price

I absolutely agree with you about Juson Audio JTA35 poor frequency response. That was a bit sad BUT beyond that for all the features there are and a pair of tubes that shine at a price of US $180. It's ok, I think.:)

I remember a very expensive tube amplifier that cost $3,000, and the data was similar to this. I don't know what to say, but maybe cheap is enough for this kind of distortion amplifier
And Juson Audio JTA35 costs $180. It actually doesn't perform too badly anyway, considering the price and the fact that it's a tube amp.:)

This was appropriate. The company has posted a video on YouTube. If you want to see more of what it looks like::)

 
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