Yaqin MC-84L Tube Stereo Amplifier Review

[DanielT]

Tube harmonics are not the same type of distortion found on headphones or speakers.

What do you mean now? When Amir measures to loudspeakers he reports THD , 2nd,3nd,4nd,5nd Harmonics. Two speakers as an example of that:


Then speakers can have a very uneven FR while having very low distortion (some electrostatic loudspeaker (ESL)) or vice versa (although this is not that common).

 

[Doodski]

2nd,3nd,4nd,5nd Harmonics.

For your English skills today the way to express this is 1st, 2nd, 3rd, 4th and 5th or first, second, third, fourth and fifth.

 

[DavidM1]

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

Quite a few SMSL products. Surprising to me given the excellence of their DACs.

 

[oscar_dziki]

We found the best lamp amplifier in the world!

 

[DanielT]

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

Or construct something yourself, if you have the time and knowledge. At 1 kHz. Does this DIY tube power amp look good?


A little OT rant: In my eyes, it's a rather strange solution. The tubes are not visible because they are in the chassis. It's the cozy tube glow you want to have and see, right? Fans for cooling, why? Why not passive cooling via a large enough heatsink? Never mind, there are those who seem to build it and they seem satisfied and happy so fun for them.

faktiskt.io • Visa tråd - GDS-projekt, rörslutsteg - slutfört

SIY had comments on Morello's tube pre amp and thought it was over-engineered. Whether it's the same with the Morellos's tube power amp, I don't know?

For those of you who have the knowledge and think it's fun to check, here it is the construction and schematic:

Index of /Morello/Tube-poweramp

 

[DanielT]

For your English skills today the way to express this is 1st, 2nd, 3rd, 4th and 5th or first, second, third, fourth and fifth.

I missed it. You are right.

 

[Old_School_Brad]

Or construct something yourself, if you have the time and knowledge. At 1 kHz. Does this DIY tube power amp look good?
View attachment 401030

A little OT rant: In my eyes, it's a rather strange solution. The tubes are not visible because they are in the chassis. It's the cozy tube glow you want to have and see, right? Fans for cooling, why? Why not passive cooling via a large enough heatsink? Never mind, there are those who seem to build it and they seem satisfied and happy so fun for them.
View attachment 401031

faktiskt.io • Visa tråd - GDS-projekt, rörslutsteg - slutfört

SIY had comments on Morello's tube pre amp and thought it was over-engineered. Whether it's the same with the Morellos's tube power amp, I don't know?

For those of you who have the knowledge and think it's fun to check, here it is the construction and schematic:

Index of /Morello/Tube-poweramp

Installing power electronics inside a wooden crate seems like a poorly thought-out decision..

 

[totti1965]

I wish someday we can test some competent tube equipment. I simply don't understand how these companies build such trash?

I have amps fully opened on boards with crappy proto board front ends (read: no shielding at all, anywhere) with over twice the sinad as this!

SINAD ist logarythmic! So, if you speak about 80 dB - your amps are 100 times better!

 

[totti1965]

I missed it. You are right.

I need your advice (American, not Swedish native speakers!) In German, we say „in der fünfziger Jahren, in den sechziger Jahren - also: in den 50er Jahren, in den 60er Jahren“ - What is correct English form? In the 50ieth? In the 60es? Or in the 60th???? I am thinking of the 10 years when they have gone to the moon. Can you tell me? And: is there a difference here between correct Oxford English and American English?

 

[DanielT]

Installing power electronics inside a wooden crate seems like a poorly thought-out decision..

It was one of the people who built it who used it wooden crate. Seems a bit strange.

Here another who built with metal chassis:


In any case to link back to the thread.As pointed out by many, it is possible to construct much better tube amps than Yaqin MC-84L. In addition, for those who have the knowledge and the hobby time, it can probably be really satisfying to build DIY tube amplifiers.

 

[JSmith]

logarythmic

Logarithmic...

in der fünfziger Jahren, in den sechziger Jahren -

In the fifties (50's), in the sixties (60's) etc.

also: in den 50er Jahren, in den 60er Jahren“

In the fiftieth year (50th), in the sixtieth year (60th) etc.


JSmith

 

[DanielT]

I need your advice (American, not Swedish native speakers!) In German, we say „in der fünfziger Jahren, in den sechziger Jahren - also: in den 50er Jahren, in den 60er Jahren“ - What is correct English form? In the 50ieth? In the 60es? Or in the 60th???? I am thinking of the 10 years when they have gone to the moon. Can you tell me? And: is there a difference here between correct Oxford English and American English?

Are you asking me as a Swede about that? Unfortunately, I only have rudimentary knowledge of when and how Oxford English or American English shall be used.

BUT, among other things, the Oxford comma is taught here:
.....
If you really wanna
Leave out that Oxford comma...

 

[totti1965]

Logarithmic...

Thanks a lot - and the L-word: I knew something was wrong - but not exactly what! LOL

 

[totti1965]

Are you asking me as a Swede about that? Unfortunately, I only have rudimentary knowledge of when and how Oxford English or American English shall be used.

BUT, among other things, the Oxford comma is taught here:
.....
If you really wanna
Leave out that Oxford comma...

Weird Al Yankovic - I used to know his Michael Jackson Parodie: Fat (instead of BAD). But this song was new to me…

 

[Mr Vinyl]

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.

Noisy fuzz box? I think a lot of people think 'distortion' as some sort of fuzz. Were are not talking about guitar tube amps here where they are purposely pushed to their limit. A tube amp for home listening is way more subtle, unless of course the amp is defective or the speakers are low impedance. I encourage everyone to go into a highend hifi store and do a blind test between a tube amp and a solid state amp. It's a question of taste, after all. Maybe the chef didn't add enough seasoning?

 

[BDWoody]

I encourage everyone to go into a highend hifi store and do a blind test between a tube amp and a solid state amp. It's a question of taste, after all.

Good luck getting them to set one up that has any validity, even if they know how which they likely wouldn't, and if it's a decent tube amp, good luck telling them apart. I think people vastly overestimate the ability to hear that relatively modest level of distortion you'll get from all but the most egregious fuzzboxes at the end of the day, but those glowing tubes can be lovely. The noise levels are typically going to be the most objectionable, and will be exacerbated given that most speakers suitable for tube amps tend to be quite sensitive, so you're much more likely to actually hear it.

Maybe the chef didn't add enough seasoning?

That's possible, and adding more after a bite or two would be perfectly reasonable. Tube amps don't give you that choice, they load up every piece of music, every instrument, every voice, every sound effect that comes through them with the same extra load of noise and distortion (whatever is baked into the circuits) no matter whether it was seasoned in a way you might have enjoyed more had you not loaded it up with more. To want to just add noise and distortion indiscriminately to everything isn't the choice I want to make.

 

[dananski]

I got curious and tried playing some music through my usual tube amp sim a while back. Fairly similar harmonic distortion to this (although with controls to adjust), and it adds some of whatever's going on below the test tone frequency too. The sound was... interesting. Lightly distorted guitar in recordings got turned fuzzy, almost metal, voices lost natural quality but gained, well an effect. Violin was unlistenable. I can maybe understand playing around with that, but paying extra to be unable to disable the distortion makes no sense to me. Even in creating music you don't just slap the exact same effect on everything in every track!

 

[GXAlan]

Tube amps don't give you that choice, they load up every piece of music, every instrument, every voice, every sound effect that comes through them with the same extra load of noise and distortion (whatever is baked into the circuits) no matter whether it was seasoned in a way you might have enjoyed more had you not loaded it up with more. To want to just add noise and distortion indiscriminately to everything isn't the choice I want to make.

The way I look at it, there are two camps.
1) It’s all sighted bias. Tubes sound just like solid state amps.

In this case, you buy tube amps for decorative/aesthetic reasons. We probably should be more gentle in criticizing purchasers of low SINAD gear if it is inaudible. It’s like gatekeeping the enjoyment of music in that you have to have the right gear when everything is inaudible.

2) There are subtle but audible effects. This is where I stand. Here the common criticism of it being a mandatory effect is commonly described. I find this a specious argument since it would be akin to saying that having headphones gives you a fixed mandatory presentation on the sound that you cannot control as compared to speakers. People can have tube amps to go with speakers and a neutral headphone. People can have no headphones or no speakers.

With tube amps, people are free to integrate amplifier switchers, free to use more than one sound system, or free to use tubes which apply a fixed effect all the time based upon preference.

In that regard, testing of tube amps isn’t about SINAD, but more about things like channel balance, control of AC mains noise, power output, and maybe noise (although the noise may provide beneficial masking effects). We just have SINAD for consistency, but focusing on SINAD is academic.

I wouldn’t buy this tube amp due to the poor channel balance not due to its distortion profile.

 

[WOLFAGRAM]

Hello Folks.

SINAD ist logarythmic! So, if you speak about 80 dB - your amps are 100 times better!

If he speaks about 80dB, they are only 16 times better (not 100). Twice as good would be about 50dB. The scale is a Log scale, but dB is one tenth of a full unit (Bell).

Cheers.

 

[AndreaT]

Amir, when was the last time you measured a tube amp that had no distortion?
To be fair, tube amps are sought after for a certain pleasing sound, caused by mainly even-order distortion. Solid-state amps have distortion as well, but they are of a different kind. So does digital, but is unlistenable.
I like to view tube distortion, as opposed to sterile cleanliness, like looking at a 70s photograph with all its imperfections than a pristine modern one where everything looks plastic or even cartoonish in its 'perfection'.
Listening to vinyl has distortion as well. In fact, even a lot of the modern music we listen to - 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.

Equivalent to say that a Botticelli painting looks better with tinted glasses. Distortion bring more distance and imprecision to the reproduction of music. As such is adding multiple additional “veils of Maya” to the perception of the composer, director and orchestra intentions. So, I beg to disagree with your description of lack of distortion as “cartoonish”.