Got a Chinese tube amp and now world is upside down

[svtcontour]

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.

Oh awesome! cant wait to do this on the weekend

 

[anmpr1]

1) So out of curiosity, I picked up a cheap tube amp from Aliexpress - branded as OldChen. Its an EL34 single ended. I figured for the dirt low price of about $330 (canadian money) including shipping, I can mess around with it and see what I think.

2) Anyway connected this, and let it warm up for 20 mins.

3) So ... is it the fact there is even order harmonics?

1) The only downside to a mail order Chinese amp is whether it lasts. You really don't expect warranty or repair service from halfway around the globe. I've owned an example of this type since 2005, and it's worked fine for 15+ years. Nothing to complain about. I think I paid about three hundred dollars for it. Not much more, I'm sure. I only bought it because I'd spent some time in Shenzhen, and thought it would make a nice souvenir.

Model VP-16. An operation out of Shenzhen, branded Dared. The entire line had a nice feng shui, and this unit was rated at about 12-16 watts per side, depending upon how much distortion is served up. SS rectification, stainless chassis, and three line inputs plus volume pot/selector. Gloss side panels, and a lucite 'cage' that lights up (blue LED) when the amp is on.

Currently have a set of Marshall branded 6v6GT tubes that look horrible. Like they are corroded where the glass meets the base. Yet all work fine. Not the original tubes--probably rebranded OEM Shuguang black glass. The 6SL7 came with the amp, so it's probably Shuguang, also.

With LaScala loudspeakers it can play as loud as you probably ever want it. It's small and looks (and runs, for tubes) cool.

2) I think tubes are generally ready to go after about a minute warm up. I don't see any benefit to waiting longer than that.

3) I don't have any idea about harmonics, other than once having a matched set of Electro Harmonix that didn't last very long.

 

[svtcontour]

1) The only downside to a mail order Chinese amp is whether it lasts. You really don't expect warranty or repair service from halfway around the globe. I've owned an example of this type since 2005, and it's worked fine for 15+ years. Nothing to complain about. I think I paid about three hundred dollars for it. Not much more, I'm sure. I only bought it because I'd spent some time in Shenzhen, and thought it would make a nice souvenir.

Model VP-16. An operation out of Shenzhen, branded Dared. The entire line had a nice feng shui, and this unit was rated at about 12-16 watts per side, depending upon how much distortion is served up. SS rectification, stainless chassis, and three line inputs plus volume pot/selector. Gloss side panels, and a lucite 'cage' that lights up (blue LED) when the amp is on.

Currently have a set of Marshall branded 6v6GT tubes that look horrible. Like they are corroded where the glass meets the base. Yet all work fine. Not the original tubes--probably rebranded OEM Shuguang black glass. The 6SL7 came with the amp, so it's probably Shuguang, also.

With LaScala loudspeakers it can play as loud as you probably ever want it. It's small and looks (and runs, for tubes) cool.

2) I think tubes are generally ready to go after about a minute warm up. I don't see any benefit to waiting longer than that.

3) I don't have any idea about harmonics, other than once having a matched set of Electro Harmonix that didn't last very long.

View attachment 316615

I actually did notice that even after about 5 minutes my amp was ready to go. I read online that one should wait like 20 mins but I think even 5 min was fine Also thats a neat looking amp right there.

One thing I did with mine is put it on a APC R1200 voltage regulator set to 110V as I think most chinese tube amps use that voltage for the transformers and so running in North America, they are kinda pushed harder at 120V. Mine runs a bit cooler that way. Top of the transformer tops out at 119F now rather than 126F

 

[DMill]

I actually did notice that even after about 5 minutes my amp was ready to go. I read online that one should wait like 20 mins but I think even 5 min was fine Also thats a neat looking amp right there.

When biasing my tube amp every thing comes up to a stable voltage within 2 minutes or less.

 

[NoMoFoNo]

I've tried three different tube amps for fun. First was a Gemtube X-1, an 8wpc el34 that I really enjoyed. Next, a tiny APPJ MiniWatt 3wpc thing that I used in a near field office set up. Last, I currently have a kinda weird Dared 6L6 amp that uses a separate box for the power supply, with each channel in its own box. Wood, chrome, 18wpc, also fun and pleasant to use in the winter, but a little hum from the toroid and a little noise on one channel, so certainly imperfect.

I greatly appreciate the state of the art devices from the likes of Benchmark and Purifi. I love trying out chip amps as they improve greatly in front of our eyes. I've got a couple of good Class AB amps in use right now. But sometimes it's fun to try things out and the Chinese low power tube amps can be an easy entry into something different.

In some ways they have helped me to appreciate that the 'MO POWER' brigade is just wrong when considering my amplification needs, and probably the needs of many listeners. With high sensitivity speakers, or with speakers on a desktop, even the little 3wpc MiniWatt would play loud and sound good doing it. The 18wpc Dared has plenty left when driving my JBL Studio 590s as loud as I would ever want it to be.

Kinda like playing records. Greatly imperfect but can be charming, captivating even.

 

[svtcontour]

I've tried three different tube amps for fun. First was a Gemtube X-1, an 8wpc el34 that I really enjoyed. Next, a tiny APPJ MiniWatt 3wpc thing that I used in a near field office set up. Last, I currently have a kinda weird Dared 6L6 amp that uses a separate box for the power supply, with each channel in its own box. Wood, chrome, 18wpc, also fun and pleasant to use in the winter, but a little hum from the toroid and a little noise on one channel, so certainly imperfect.

I greatly appreciate the state of the art devices from the likes of Benchmark and Purifi. I love trying out chip amps as they improve greatly in front of our eyes. I've got a couple of good Class AB amps in use right now. But sometimes it's fun to try things out and the Chinese low power tube amps can be an easy entry into something different.

In some ways they have helped me to appreciate that the 'MO POWER' brigade is just wrong when considering my amplification needs, and probably the needs of many listeners. With high sensitivity speakers, or with speakers on a desktop, even the little 3wpc MiniWatt would play loud and sound good doing it. The 18wpc Dared has plenty left when driving my JBL Studio 590s as loud as I would ever want it to be.

Kinda like playing records. Greatly imperfect but can be charming, captivating even.

Very well said. I guess its about enjoying things and not always being serious

 

[audiofooled]

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.

Could it be the case that it can also alter FR or even ILD's to somehow enhance the stereo effect? Especially in cases of music that is rich in harmonic content and natural recorded reverb, combined with big and sensitive speakers it can make an audible difference?

If it would act like a compressor then could it really alter the FR or audibly distort in such a way to enhance some details that normally went unnoticed?

In case of an well designed tube amp and an uncontrolled test, the differences don't even have to be real, you just don't return to the exact listening position as before and you begin noticing some differences just because you know you've changed something? Bias that the change is somehow always for the better?

 

[Pluto]

Could it be the case that it can also alter FR or even ILD's to somehow enhance the stereo effect? Especially in cases of music that is rich in harmonic content and natural recorded reverb, combined with big and sensitive speakers it can make an audible difference?

I would suggest that there's less audiophile-mysticism than you imply above. Reverb is, usually, quite a low-level phenomenon. Another characteristic of reverb is that, if heard in isolation, it is usually highly "stereophonic". W-I-D-E, you might say. It therefore follows that if you use a compressor to boost the relative contribution of quiet reverberation, part and parcel of this package is a subtle increase in overall width.

An simple experiment you can try without too much difficulty is to convert some normal stereo content from its usual left/right (AB) format to sum and difference (MS). Then reconvert the MS back to AB while increasing the relative level of the S content*. Once you are aware of the audible effect of a small (say 3-6dB) increase in the S channel, much of the above will become clear and you will see how it's nothing to do with any mysticism but rather, audio engineering 101.

*Incidentally, the conversion process from AB to MS and back again is 100% symmetrical and reversible.

 

[RayDunzl]

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.

In-room "Room Corrected" Playback vs Raw Source CD via RTA in REW

Can You Trust Your Ears? By Tom Nousaine

The 'quality' in sound reproduction is quite easy to assess, subjectively - if one wishes the sound system to be an effects unit, or "put on a performance" which is particularly spectacular on certain recordings that's a different matter; and then preference will most assuredly play a part. IME...

www.audiosciencereview.com

AB neutrality of in-room response?

I think it should be possible, you put another speaker above your speaker, create several in-room corrections for your speaker. then you play pink noise on the upper speaker and record it at LP (convolve the recording with the correction curve of the mic). you than AB the pink noise from above...

www.audiosciencereview.com

 

[lashto]

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.

Thanks for the link. An interesting review and the device is much better than expected (for the price).
Looks like those Oldchen/Laochen amps are quite popular in the far east. Beautiful chinglish from a product page:

...
is well-known brand in china, this EL34 series is already sold more 10 milles copies, it's the most popular tube amps.
...
This amps's development and marketing time has more than 10 years
...

• Bass is surging strong.
• Middle frequency is soft and mellow voice,
• High frequency is crisp and clear.
• Even used to listen to the POP or dance music can be shocking endless,
• Bounce efforts andclear resolution makes the sound never tired.
• Thousands of people are full of praise for this amplifier in manufacturer's site

 

[Cwopete5]

My primary integrated amp is a Black Ice Audio Fusion 3502S with Tube Amp Doctor (TAD) EL-34s power tubes, Genalex Gold Lion 12AX7 preamp and 12AT7 driver tubes. I have a really nice Vincent Audio SV-500 hybrid integrated amp as my secondary. My phono preamp is a Darlington Labs MM5, which is "Not recommended" by ARS. Turntable is a U-Turn Audio Orbit Theory with Ortofon 2M Bronze Cartridge. Speakers are Wharfedale Diamond 240s. There's a bunch of power filtering and DC blocks in my system because the power here is terrible. My favorite spoof component are the Snake Oil RCA interconnect cables. Overall I'd say my system would be designated "100% Not Recommended" by ARS. But it sure sounds wonderful to my ears. I'm so glad I left the spectrum analyzer at work after I retired. Happy listening!

 

[Doodski]

My primary integrated amp is a Black Ice Audio Fusion 3502S with Tube Amp Doctor (TAD) EL-34s power tubes, Genalex Gold Lion 12AX7 preamp and 12AT7 driver tubes. I have a really nice Vincent Audio SV-500 hybrid integrated amp as my secondary. My phono preamp is a Darlington Labs MM5, which is "Not recommended" by ARS. Turntable is a U-Turn Audio Orbit Theory with Ortofon 2M Bronze Cartridge. Speakers are Wharfedale Diamond 240s. There's a bunch of power filtering and DC blocks in my system because the power here is terrible. My favorite spoof component are the Snake Oil RCA interconnect cables. Overall I'd say my system would be designated "100% Not Recommended" by ARS. But it sure sounds wonderful to my ears. I'm so glad I left the spectrum analyzer at work after I retired. Happy listening!

No PEQ? That would improve the sound quality in a big way.

 

[Cwopete5]

No PEQ? That would improve the sound quality in a big way.

Nope. I've rolled more than my fair share of audio tubes to get the tone I was looking for.

 

[Doodski]

Nope. I've rolled more than my fair share of audio tubes to get the tone I was looking for.

Well PEQ will change the sound as much as a better set of speakers would. If you change you mind we have many to choose from.

EQ Software for Windows, Linux, macOS, iOS/iPadOS and Android.

Any suggestions are welcome. Post suggestions here. I will gather the details and add them. Thanks. :D This will be organized as results come in. @sweetchaos made a guide for PEQ filter data input and operation. For crossover software go here. Windows: AutoEQ four easy steps to make your...

www.audiosciencereview.com

 

[Cwopete5]

Very content and happy with how I set all of my gear up.

Me too.

 

[bethslave]

Question for the OP. Are you still enjoying the amp? I've had a similar experience and now long term relationship with a Gemtune PA1501 which I bought based on this review:

Reviewing the Gemtune APPJ PA1501A 6AD10 Stereo Tube Amplifier

I recently picked up an interesting little tube amp via a group buy on Massdrop, the Gemtune APPJ PA1501A stereo tube amplifier. Try saying that three times fast! It’s a cute little single-en…

retrovoltage.com

I purchased it just for fun in 2019 specifically for near-field desktop use and wound up liking it a lot. I wasn't too concerned about power or distortion, I just wanted general competence in electrical design, frequency response and noise floor. It's a surprisingly good match for my Advent Baby II speakers which are rated at 89 dB at 1W/1m. I dusted off an old Fisher 10 band graphic EQ to boost the bass and use my PC as my music source with Tidal or Radio Paradise. The system sounds much better than it logically should and passing time doesn't seem to change that. It gets as loud as is polite in an office setting. Tube life doesn't seem to be a concern. One that it shipped with was a little microphonic so I purchased a pair of cheap NIB Sylvania replacements that have now been in use since 2019. Subjectively I prefer my desktop system to my main system for several 1950's recordings such as 'Cast Your Fate To The Wind' by Vince Guaraldi, 'Take 5' by Dave Brubeck and several Miles Davis tracks. That's fairly consistent with what others have already posted here.

Reading through this thread I'm glad the non-tube people understand that it's okay to experiment and just have some fun sometimes!

 

[anmpr1]

Reading through this thread I'm glad the non-tube people understand that it's okay to experiment and just have some fun sometimes!

First, you should not worry (nor express any emotion, one way or the other) about what 'non-tube' people think. Don't rely upon others to justify what you consider 'OK behavior' (or thoughts). At least within the realm of hobbies, which is pretty trivial in the scheme of things. I mean, it's not like we're talking morality, for crying out loud.

Second, your point about 'having fun' is most important. Too often folks committed to one view or another miss the point. I'm reminded of Theo Bikel, who in Frank Zappa's 200 Motels, quipped, "We understand how hard it is to laugh these days, with all the terrible problems in the world!"

 

[wunderkind]

Hear! Hear!

What matters most is whether you like the sound from your system. Are your feet tapping away? Head bopping along?

 

[Gibsonian]

Hear! Hear!

What matters most is whether you like the sound from your system. Are your feet tapping away? Head bopping along?

Air guitar, bass or drums playing along? Dancing like a fool? You know you got something going when this goes on, but could be intoxicants as well...........

 

[egellings]

So out of curiosity, I picked up a cheap tube amp from Aliexpress - branded as OldChen. Its an EL34 single ended. I figured for the dirt low price of about $330 (canadian money) including shipping, I can mess around with it and see what I think. I was prepared to hate this thing because I've always had solid state and hate mushy bass, softness and lack of detail.

My speakers are open baffle DIY and fairly efficient. I am guessing at around 95db @ 1w or higher like even 97. I also dont listen very loudly. Typically low 80's on the peaks .. maybe mid 80's. Occasionally tapping 90db on peaks if I'm feeling very crazy LOL.

Anyway connected this, and let it warm up for 20 mins. Then sat down and started listening to music and I'm just shocked. Subjectively, I find it neutral with no apparent "tube sound", bass is nice and firm and its plenty clear and resolving and for whatever reason, I'm hearing more subtleties. When I go back to my solid state, they are there, but just ever so slightly more subdued.

Subjectively, its better on anything that has vocals and real instruments or anything recorded in a live open space. The solid state is still better for pure electronic or dance /EDM if very loud volumes are needed. So at this point, I am finding it hard to go back to the solid state. I invited a couple friends over who are solid state guys and now they are tempted to buy the same little amp because they agreed, it sounds better and more involving.

So ... is it the fact there is even order harmonics? Is there any benefit of pure class A of a single ended. Trying to understand why I'm listening to music for hours a night instead of sleeping since getting this thing. Make it stop LOL.

Could be a response peak in the midrange region that might be sweetening things.