Got a Chinese tube amp and now world is upside down

[raindance]

Actually where I purchased from it was listed as 10wpc and mine was the model without BT (I didnt want the extra stuff in it). I read online that most of the chinese amps are overrated on power and some are saying 6-7wpc is probably more reasonable at low distortion levels. Wish someone had tested one

I have a single ended kit amp from China that was rated at 10 watts per channel. I would have expected 6 or 7 watts from an EL34 in class A without a UL tap on the output transformer and with cathode bias, but measurements show about 3 watts into 8 ohms before observable clipping on a scope. It still sounds decent and gets enough volume out of 89dB speakers for listening in a small room.

 

[JeffS7444]

I speculate that you are hearing bad/great harmonics adding "juice" to your music. Some folks pay thousands of dollars to experience it, but it seems you've managed the feat for $330, which sounds like a fair deal to me.

 

[svtcontour]

I would put money on you preferring the valve amp for sub-optimal recordings. Even a year from now. Particularly anything erring on the thin/bright side. I prefer my VTL valve amp with a pair of 97db Tannoy V12s. With two subs. I also have Neumann KH310s and though more accurate, they are pretty ruthless when it comes to exposing bad recordings. Always great to have both, I say!

You have a very good point! So I've voiced my speakers to be fairly neutral (or as much as I can just passively crossed over) and the high frequency driver is a titanium compression driver. I wonder if its a little unforgiving and the tube then makes a lot of the music feel more pleasing and thats why I like it. Hmmm. Ok time to find some truly reference material and switch between my solid state/tube and see what I think! All subjective of course

 

[svtcontour]

I speculate that you are hearing bad/great harmonics adding "juice" to your music. Some folks pay thousands of dollars to experience it, but it seems you've managed the feat for $330, which sounds like a fair deal to me.

Ya I was fully prepared to hate this thing because the idea of tubes in this day and age seemed silly. LOL. Then I got seduced somehow lmao

 

[Doenerkunde]

Here is a german YouTuber showing a look inside and performing some tests:

There is a small hype surrounding Old Chen tube amps in Germany since some Hifi Youtubers (Snakeoil Audio, IAmMad) mentioned and/or reviewed them favorably.

EDIT: He measured 85dB SNR and at 1khz the amp produces around 3W at 1% K3.

 

[svtcontour]

Here is a german YouTuber showing a look inside and performing some tests:

There is a small hype surrounding Old Chen tube amps in Germany since some Hifi Youtubers (Snakeoil Audio, IAmMad) mentioned and/or reviewed them favorably.

EDIT: He measured 85dB SNR and at 1khz the amp produces around 3W at 1% K3.

Oh fantastic. I'm checking it out. Great find So all in all, quite a low power amp but watching to see what he says

... so having now watched the video. Seems its a very reasonable performer - low power aside!

 

[levimax]

I am surprised no one asked this but did you do an actual level matched "quick switch" listening test preferably blind? Unless levels are matched within 0.1 dB and switching takes less than a few seconds any listening comparison is not going to be reliable. I have tested SS vs Tube amps and was certain I could hear obvious differences. I then went to the trouble of setting up a level matched quick switching set up and suddenly all the differences disappeared. This test was the most valuable thing I have ever done during my many decades in the hobbly, it would be well worth the trouble.

 

[svtcontour]

I am surprised no one asked this but did you do an actual level matched "quick switch" listening test preferably blind? Unless levels are matched within 0.1 dB and switching takes less than a few seconds any listening comparison is not going to be reliable. I have tested SS vs Tube amps and was certain I could hear obvious differences. I then went to the trouble of setting up a level matched quick switching set up and suddenly all the differences disappeared. This test was the most valuable thing I have ever done during my many decades in the hobbly, it would be well worth the trouble.

Oh sorry didnt mention that. I do try and level match. The way I do it - not sure if this works but I basically feed the amp a tone at the desirable volume I want with one of my amps, then put a resistor on the output and measure the voltage drop across, then I do the same with the other amp and get it set to the same voltage.

I think the first time I was listening, the volume ended on most of my music having peaks of about 85db. After some initial testing and forming a general decision, I skipped further level matched testing. I just went with enjoying the music. Next step could be blind testing but that would have to be when I have friends over and it likely wont be a quick switch.

 

[Pluto]

is it the fact there is even order harmonics?

I'm not convinced that any of the usual simplistic explanations (typically one or more of Class A / crossover characteristics / lots of even-order harmonics etc. etc.) apply here.

Here is my theory, in a post from aeons ago that, IMHO, explains why tube sound is so revered by some.

 

[LTig]

Oh interesting. So say something like 2-4 ohms? I may have 10W resistors of those values.

Yes, try both single and also in series (6 Ohm)

 

[kemmler3D]

I'm not convinced that any of the usual simplistic explanations (typically one or more of Class A / crossover characteristics / lots of even-order harmonics etc. etc.) apply here.

Here is my theory, in a post from aeons ago that, IMHO, explains why tube sound is so revered by some.

I think you must be on to something here. It's a little sparkle from the THD and compression. Also, depending on the power characteristics of the amp, the "attack" of the compressor might be audible, so you get relatively more snap from transients in the bargain. If the tube amp is designed in a lucky way, it will all add up to a "sweetener box" for most content.

I mean, there is a reason that many studios run many / all tracks through a "tube pre" (software or hardware) by default, it adds that little bit of liveliness. No wonder that people might want to salt the food a bit more after it gets to the table.

 

[LTig]

Oh sorry didnt mention that. I do try and level match. The way I do it - not sure if this works but I basically feed the amp a tone at the desirable volume I want with one of my amps, then put a resistor on the output and measure the voltage drop across, then I do the same with the other amp and get it set to the same voltage.

This is correct but the impedance of your speaker is not constant. You can expect higher SPL from the tube amp where the speaker's impedance is higher than your resistor. Thus occurs is at the resonance frequency of the woofer (low bass) and in the highs (inductivity of the tweeter voice coil). The resulting frequency response looks like a loudness curve which results in a fuller sound compared to the ss amp.

 

[svtcontour]

I'm not convinced that any of the usual simplistic explanations (typically one or more of Class A / crossover characteristics / lots of even-order harmonics etc. etc.) apply here.

Here is my theory, in a post from aeons ago that, IMHO, explains why tube sound is so revered by some.

Oh very interesting post and thread there. Thank you for that link

 

[svtcontour]

This is correct but the impedance of your speaker is not constant. You can expect higher SPL from the tube amp where the speaker's impedance is higher than your resistor. Thus occurs is at the resonance frequency of the woofer (low bass) and in the highs (inductivity of the tweeter voice coil). The resulting frequency response looks like a loudness curve which results in a fuller sound compared to the ss amp.

Oh that could then explain why it sounds more 'alive' and dynamic then. Interesting. I wonder if there is an RTA tool that can plot SPL over time at a decent sample rate and do it for a duration of a song) then I'd do the setup like I did - and play back, then compare the two and see how their low and high points differ. Checking Room EQ Wizard just in case...

 

[Pluto]

there is a reason that many studios run many / all tracks through a "tube pre" (software or hardware) by default, it adds that little bit of liveliness.

It is, in fact, the revelation of a bit more low level detail, a function of the typical transfer characteristic of most tube kit. The trouble is that once you start over-using the power of this kind of processing, it looses its value. Modern recording doesn't appreciate the value of using techniques like this, sparingly.

 

[Deleted member 21219]

So its a honeymoon phase

Pretty much.

Here's what I've noticed. Listener finds amp (or speaker) that "wows" them. They buy it. They love it ..... for a certain length of time. Then, for some reason, the device loses its charm. So they re-tube, or get a sub, or reposition their speakers. That usually doesn't do it, so they go buy another speaker, or another amp, or both. If they're looking for equipment that "wows" them, they can surely find it (with a salesman's "help"). So they take the new stuff home, where it sounds great .... for another year. Then the process repeats itself all over again.

That's going down the rabbit hole ...... and it never ends.

People forget that it's not the equipment that "wows" you, it's the music. Personally, I love Beethoven's 7th Symphony. I can listen to it on great systems, or I can listen to it on so-so systems, or I can listen to it on a damn car radio. I love it on all of them. Sure, I'm aware of the differences in the systems, and I prefer the more accurate ones ..... but I'm ignoring the equipment and listening to the music.

What about you?

Jim

 

[TimF]

Years ago I went this route with Little Dot. I'm not going down that path again.

 

[Timcognito]

Pretty much.

Here's what I've noticed. Listener finds amp (or speaker) that "wows" them. They buy it. They love it ..... for a certain length of time. Then, for some reason, the device loses its charm. So they re-tube, or get a sub, or reposition their speakers. That usually doesn't do it, so they go buy another speaker, or another amp, or both. If they're looking for equipment that "wows" them, they can surely find it (with a salesman's help). So they take the new stuff home, where it sounds great .... for another year. Then the process repeats itself all over again.

That's going down the rabbit hole ...... and it never ends.

People don't remember that it's not the equipment that "wows" you, it's the music. Personally, I love Beethoven's 7th Symphony. I can listen to it on great systems, or I can listen to it on so-so systems, or I can listen to it on a damn car radio. I love it on all of them. Sure, I'm aware of the differences in the systems, and I prefer the more accurate ones ..... but I'm ignoring the equipment and listening to the music.

What about you?

Jim

I like the 6th, Pastoral and Concerto #5, Emperor's but everything else you said I'm in alignment.

 

[kemmler3D]

I wonder if there is an RTA tool that can plot SPL over time at a decent sample rate and do it for a duration of a song) then I'd do the setup like I did - and play back, then compare the two and see how their low and high points differ. Checking Room EQ Wizard just in case...

Yes, REW will do this, just play music while you capture using the RTA tool instead of using pink noise as you normally would. I would be surprised if you don't see at least 2dB of variation here and there.

 

[svtcontour]

Pretty much.

Here's what I've noticed. Listener finds amp (or speaker) that "wows" them. They buy it. They love it ..... for a certain length of time. Then, for some reason, the device loses its charm. So they re-tube, or get a sub, or reposition their speakers. That usually doesn't do it, so they go buy another speaker, or another amp, or both. If they're looking for equipment that "wows" them, they can surely find it (with a salesman's help). So they take the new stuff home, where it sounds great .... for another year. Then the process repeats itself all over again.

That's going down the rabbit hole ...... and it never ends.

People don't remember that it's not the equipment that "wows" you, it's the music. Personally, I love Beethoven's 7th Symphony. I can listen to it on great systems, or I can listen to it on so-so systems, or I can listen to it on a damn car radio. I love it on all of them. Sure, I'm aware of the differences in the systems ..... but I'm ignoring the equipment and listening to the music.

What about you?

Jim

Hah well luckily I've got a bunch of gear to alternate between and try until I figure out whats going on.

I'll list some songs and or albums that get me happy for one reason or other Obviously there is a ton more but things flying off the top of my head

Dave Brubek - Take Five
Bela Fleck - Flight of the cosmic hippo
Enya - Exile
Deadmau5 - I remember
Dominique Fils-Aime - Birds
Philip Glass - Religion
Brian Bromberg - Slang
Metallica - Damage Inc.
Yello - Junior B
Vivaldi - Vivaldi concerto violin RV 578
Bach - The Toccata and Fugue in D minor