Yaqin MC-84L Tube Stereo Amplifier Review

[tomtoo]

The designer after reading this review:

View attachment 400777


Joking aside, great review as always. The multi-tone distortion record will be hard to beat.

Haha the designer the night he desidet to build a tube amp.

 

[audiotron]

It takes big balls to be the worst.

 

[GXAlan]

Amir, when was the last time you measured a tube amp that had no distortion?

Not by Amir, but by me:

Sonic Frontiers SFS-80 Review (Vintage Tube Amplifier)

Sonic Frontiers SFS-80 Tube Amplifier: A "new" benchmark to beat from 1992 Up next on testing gear that would be impossible to ship safely... the Sonic Frontiers SFS-80 tube amplifier. 70 lbs, all concentrated in the transformers. Believe it or not, Sonic Frontiers is a company we all know...

www.audiosciencereview.com

74 dB SINAD with tubes

 

[Old_School_Brad]

Of course! Unfiltered wide-band speakers in flimsy cabinets, or some esoteric 1st order crossover multiway with a vintage 1920s woofer and piezo tweeter thingy.

Ugh! Just seeing "piezo tweeter" makes me cringe. I can’t stand them, probably because of all the cheap disco speakers from my youth. It’s funny -I could definitely tell the difference between good and bad sound back then, and I have fond memories of most things from that time. But piezo tweeters? Absolutely not.

 

[Mr Vinyl]

Not by Amir, but by me:

Sonic Frontiers SFS-80 Review (Vintage Tube Amplifier)

Sonic Frontiers SFS-80 Tube Amplifier: A "new" benchmark to beat from 1992 Up next on testing gear that would be impossible to ship safely... the Sonic Frontiers SFS-80 tube amplifier. 70 lbs, all concentrated in the transformers. Believe it or not, Sonic Frontiers is a company we all know...

www.audiosciencereview.com

74 dB SINAD with tubes

Ah, I heard that one back in the day. A great Canadian tube amplification manufacturer. They even had a tube-based cd player if I'm not mistaken.

 

[milosz]

This amp is a good match for vinyl - has similar SINAD to vinyl playback. I wonder how many bits of multi-tone "clarity" a vinyl playback chain has. 5? 6?

 

[Tom C]

The good point though: Here’s an opportunity to take a close look at the bottom end of the SINAD scale finally

View attachment 400643

I much agree. This is the strong avoid range. I expect about anyone can easily hear any item on this part of the chart sounds worse than what they typically listen to. That is, audibly worse than almost anything else out there.

 

[jayapple]

Here are more detailed pictures.

It does look very fancy, but if you make it by hand you should only cost half the price.



In addition, there are many products, they seem to have their own design style, large luminous light bulbs, seem to be very attractive.

These shiny amplifiers are very large, and the main cost should be transformers and light bulbs, but the price is ridiculously high.

 

[Hayabusa]

This is a review and detailed measurements of the Yaqin MC-84L Stereo Tube amplifier. It is on kind loan from a member and costs US $600 on Amazon.
View attachment 400615
The picture doesn't do justice to the nice design of this amplifier. The transformer case in the back nicely contrasts with the chrome parts. The latter does make the labels hard to read though when looking from above:
View attachment 400616
One set of binding posts is available for 4 ohm and the other, 8 ohm. Seeing how speakers don't have constant impedance, nor are advertised correctly as such, I feel bad for people trying to figure out which posts to use (common criticism for all such amplifiers). Let's see how it performs.

There is a headphone jack in the back which I did not test.

Yaqin MC-84L Stereo Tube Amplifier Measurements
For all but 8 ohm power test, I used the 4 ohm tap. Let's start with our dashboard:
View attachment 400617

We have the high harmonic distortion which we kind of expect. But a lot of mains noise comes along for the ride, causing intermodulation with our main 1 kHz, making for a mess. SINAD which is the sum of all unwanted "stuff," lands the amplifier at the bottom of our rankings:
View attachment 400618

View attachment 400619

Noise is a step above but still nothing remotely to be proud of:
View attachment 400620

Frequency response is flat enough if we ignore varying performance between channels:
View attachment 400621

Crosstalk is one step above mediocre:
View attachment 400622

You get a better feel for distortion when we use 32 tones to simulate "music:"
View attachment 400623
Not pretty. Same story for 19+20 kHz tones:
View attachment 400624

The amplifier is fairly rated at 12 watts, assuming you don't care about distortion:
View attachment 400625
One channel is having trouble above 2 watts which we also saw in the dashboard. So maybe it is a bad tube or something. Best of luck to a customer figuring that out without this type of measurement.

If we "only" allow 1% distortion and noise, available power shrinks to a trickle:
View attachment 400626
Yes, that is only 2 watts!

Using 8 ohm tap, we get similar results:

View attachment 400627

Sweeping frequencies we see the typical rise in distortion with frequency. But also increase in distortion at low frequencies (transformer saturation?):
View attachment 400628
I am showing both channels. Dashed line is the "good" channel.

Our power on/off test shows instability on top of noise at these events:

View attachment 400629

Fortunately if you wait a minute or so, everything stabilizes:
View attachment 400630

Conclusions
The Yaqin MC-84L made a very positive impression on me with its modest size and super nice industrial design. And reasonable price for such tube products. Performance though, set a new record with respect to how bad it is, taking over the slot for the worst measured amplifier to date. The amp has 42 reviews on Amazon with average of 4.5 stars. Folks must be very tolerant of noise and distortion out there!

I do like the company honesty when it comes to power rating and even SNR.

Needless to say, I can't recommend the Yaqin MC-84L valve amplifier.

------------
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/

Really curious how this would sound

 

[amirm]

Really curious how this would sound

I can tell you that it will sound muddy and then distort like hell when you crank it up at all. I passed on doing that test because people complain that you have to have the "right" speaker for such amps....

 

[Gord]

Specs:
Spec:
AC Voltage: AC115V and AC230V optional
Output Power: 2x12W(7ohm--8ohm)
THD:≤2%
S/N Ratio:≥80db
Frequency Response: 6Hz--90kHz
Input Sensitivity: 250mV
Input Signal Level:≤300mv
Max Power Consumption:≤90w
Tubes: 6P14x4pcs, 12AX7Bx2pcs
Size:320*275*150mm
Net Weight:10kg

Features:

• A High-Quality Tube Amplifier: Despite its affordable price, the Yaqin MC-84L amplifier is a remarkable audiophile-grade ultra-linear push-pull, full Class A tube amplifier.
• Premium Grade Construction at a Fair Price:a majority of the components are of audiophile grade, produced by some of the best companies in the industry . MKP capacitor for reducing AC to DC voltage,famous Shuguang tubes:12AX7B, superior magnet wires on the transformer core,top-quality output transformer, high-quality volume potentiometer.
• Impressive Sound: This amplifier delivers pristine audio quality, making it an exceptional addition to your sound system; Push-pull Circuitry: This design ensures minimal distortion, optimal efficiency, and high power output.
• Powerful Output: It is only 12 watts per channel, but compared to transistor amplifier, it actually can output more than 60 watts.
• Outputs: The amplifier can function as either a headphone amplifier (with a 6.3 mm headphone output) or as a high-quality tube amp capable of driving loudspeakers.

Did you listen to it? How does it sound?

 

[Gord]

I can tell you that it will sound muddy and then distort like hell when you crank it up at all. I passed on doing that test because people complain that you have to have the "right" speaker for such amps....

Yes, it would probably need a high efficiency speaker.

 

[JakeK]

Features:

• Powerful Output: It is only 12 watts per channel, but compared to transistor amplifier, it actually can output more than 60 watts.

What?

If we "only" allow 1% distortion and noise, available power shrinks to a trickle:
View attachment 400626
Yes, that is only 2 watts!

When measured in a similar way to modern hi-fi transistor amps it's only 2 watts, not 'more than 60'!

Do they mean you can get 60 watts if you allow 10% THD? 10% THD may be what some high power PA amps are rated at but they output 100s of watts.

 

[pma]

Yes, it would probably need a high efficiency speaker.

…… which would not help either.

(It has too high intrinsic noise + buzz)

 

[amirm]

Did you listen to it? How does it sound?

Have you been to the moon?

 

[DSJR]

I've got those (HFC) somewhere, if only I knew where... I remember Martin being very fond of conrad-johnson and Audio Research. The SINAD might've been mediocre, but quite a bit better than this one, and didn't they produce respectable power? I might even have considered giving them a try if the price wasn't so far out of my league.

Look those issues up, you'd be surprised how very poor they were - In any case, many D70s that found their way here, blew up very expensively I was told by an (distributor) Ab Sounds dealer at the time...

 

[JSmith]

Have you been to the moon?

JSmith

 

[JakeK]

I'm not in the market for a tube amp so I don't need to have an opinion on this but this measures awfully bad even for a tube amp. The lie in the specs about it being 'powerful' and 'actually can output more than 60 watts' also seems pretty unforgivable. Then the lack of a phono stage makes this device seem pretty pointless for the target market who will surely want to play vinyl. I feel like I know enough about this device to rate it 'poor'.

 

[AudioSceptic]

For what might be worth, in 1999 I auditioned extensively a CJ integrated tube amp vs a Krell KAV-300i. The price was equivalent, the store was pushing for the CJ. Through my ears the Krell was superior on every count (besides being way more powerful). I bought the Krell and it served me well until I moved on to class D (Amirm’s fault ).

Ah, Krell, another brand I was interested in, but again, too pricey for me.

 

[BDWoody]

- unbeknownst to many - was recorded with some sort of tube equipment in the signal chain for added warmth and other qualities. So whether we like it or not, the music we listen too will most likely have distortion - whether it is added by our amplifier, or baked into the recording.

I think most are aware that tubes can be used for effect during the creation of music.

Personally, I don't want that effect added to everything without discretion. I'd prefer to hear Ian Anderson's flute, or Whitney Houston's voice without dirtying them up with some noisy fuzzbox.

A chef putting seasoning on my steak before serving doesn't mean adding a bunch more to everything on the plate before I eat makes it better.