Bada PH12 headphone amp review: Tube vs. Solid St.

The Bada Ph12 may be the best headphone amp you can buy, if you are looking for an amp that combines the best qualities of a solid state amp with the best qualities of a tube amp. Let me explain.

I used to listen to my Grado HP-2 and AKG 340 headphones though my David Hafler 110 pre-amp, a fine high end pre-amp that was designed also as a headphone amp. My Stax phones had their own amp, run through my speaker leads. I had many other headphones and earphones over time.

A few years ago, I added a Headroom Cosmic for portable use in my car, with the Etymotic 4S and iRiver IMP400 CD player. Nice clean sound.

Then I sold the Cosmic and added the Lehmann Black Cube linear – a great home solid state amp that really opened my ears, featuring Class A output stage (with no opamps and no global negative feedback in the output). The Cosmic's power supply, as a portable, could not match the superb power supply of the Lehmann, and it showed in the sound. I used the Lehmann in the car with an inverter. With the addition of the Eastsound E5 CD player, I had superb high end headphone sound with my Etymotic 4S, Sennheiser HD650 and later my Sony SA5000 headphones, powered by the Lehmann.

I love the solid state's definition, detail, neutrality, focused sound images fixed in space to where you could easily point to them, bass that is deep, tight, and well defined, and the dynamics with lightening fast transients and impactful crescendos. The Lehmann’s clean amplification delivered the goods through my headphones.

Only one problem – as with all solid state amps including the best Class A designs such as the Aleph (Pass labs) which I have listened to extensively. There is some leanness to the tone, a lack of body to the timbre that you can only fully capture with tubes. This can vary with particular amps but is inherent in transistor sound.

Then I was given a tube headphone amp by a dear friend visiting in Asia. This was a Meixing (Ming Da) MC66AE. It was a SET Class A design with three transformers corresponding to the three tubes. I fell in love again with tube sound. My tube experience goes all the way back to when I was a teenager with Dynaco 60 watt monoblocks on each channel and a Dynaco tube pre-amp. I grew up on tubes, audiologically speaking.

The tubed MC66AE gave me the full-bodied tones, lush liquidity, sheen and shimmer of treble, glow of second violins, etc. However, the bass was of rich tone but not so tight as with solid state. Also, some detail was smoothed over at times, and the transient attacks were slightly less impactful than solid state amps. I missed the Lehmann’s strong points when listening to the MC66AE but missed the tubed MC66AE’s lush richness when listening to the Lehmann.

I felt I could not bounce between them but did not know which one to sell. To tube or not to tube, that is the dilemma of many audiophiles. However, I also was thinking of getting another Lehmann with the UBS option. So I sold the Lehmann as it was the one that received the first buy offer.

At the same time a Chinese audiophile friend advised me of the new Bada PH12 and recommended it, saying it was better than the well-regarded Opera Consonance Cyber 20 and even better than the Ming Da MC66AE. I ordered some of the Bada PH12 with another E5 CD player and sold the MC66AE before the Badas arrived. I gave my son a Bada PH12 headphone amp and an E5 CD player, and kept two for myself.

I realized immediately that the Bada was something special – my Lehmann sound had returned but with something added - more body to tonal timbre – no more of the leanness typical of solid state.

I believe the Bada PH12 offers the best of solid state sound with the best of tube sound. It is a Single Ended, Class A, no negative feedback, and OTL (no transformer in the output to color the sound) design.

Now the OTL design offers the most natural sound but generally lacks the full dynamics of tube transformer-output and solid state amps. Some OTL headphone amps (Antique Sound Labs for example) come with a transformer output as well so you can restore dynamics by switching from OTL to OT output, then switch back for more natural sound. Yet the Bada has dynamics and transient impact, and deep well-defined bass, equal to the solid state amp. How can this OTL tube design do it?

The Bada is a lion in sheep’s clothing. It has the highly regarded Toshiba J200/K1529 Mosfets in the output stage. That is how it can combine the best solid state characteristics with the best of tube sound. Bada has been building hybrid designs for years and they know their stuff. This hybrid does as intended – no identity confusion in the sound. But the PH12 is high end all the way and has no resemblance to its much cheaper (but well regarded) one-tube hybrid cousin.

As configured with three Shugang 6N8P tubes, the Bada is closer to the neutral sound of the Lehmann than to the rich, lush liquidity of the MC66AE. It does have more timbral body than the Lehmann - a plus of its tubes. It has the best of both, though leaning more to the Lehmann sound with the tubes it comes with.

I then used some old Namking 6H8C tubes on hand – the 6H8C is a Russian number designation for the excellent 6NS7 - in place of the 6N8P tubes. This shifted the sound slightly more toward the MC66AE – added some more smoothness, richness, liquidity, etc. The Russian 6H8C tubes give even more liquidity and richness than the Namking 6H8C tubes – a very seductive and enjoyable tube sound

Which is best? The accurate and neutral reproduction of the signal afforded by the original 6N8P tubes supplied with the amp, or the enhancement of tone and seductive appeal of the 6NS7 (6H8C) tubes? I like both and much depends on the recording. The Sony SA5000 seems better with the 6NS7 tubes while the Sennheiser HD650 may be better with the stock tubes.

I then got the Electro Harmonix Gold EH 6NS7 (with gold pins only – be sure before ordering as some sellers label it Gold as their own grade from testing and not EH’s grade) and see how they are. Wow! They were liquid and rich, used all around in the three positions, but used only as the two output or driver tubes (in the two rear positions), with one Shugang 6N8P (original) in the single front (input or power) position, I got the most natural and realistic sound I have ever heard with my Sony SA5000 headphones and Eastsound E5 CD player. Who says CDs sound bad? They are great with this setup.

The best combination for my favorite Sony SA5000 headphones is using one 6N8P (that comes with the Bada) as the front tube, then two Electro Harmonix Gold 6NS7 tubes in the rear as output tubes. This gives you more of a rich and full-bodied tube sound than you get by using all three 6N8P but more of a solid state sound than you get by using all three 6SN7 tubes, Plus the most natural instrument timbre. With this tube set up I get all the definition, detail, neutrality, focused sound images, bass that is deep, tight, and well defined, and the dynamics with lightening fast transients and impactful crescendos of the best solid state amps - but not solid state leanness of tone. I also get full bodied and naturally rich timbre of the best tube amps. I get the best of both worlds.

Variations of sound signatures are thus provided by using different brands of tubes, You can dial your own sound to match your other equipment. The Bada provides a platform that allows different tubes to voice their own thing in their own distinct manner, while enhancing and improving that voice by adding desirable solid state qualities. This is truly a remarkable achievement.

The Bada is encased in a beautiful and thick aluminum housing. It has a huge power transformer that is about 3 inches tall and 5 inches in diameter, used in the amp power stage but not in the output stage (no transformers and no opamps are used in the output stage). Top quality parts such as from Solen, and an Alps volume control, are used. It is hefty and weighs about 16 pounds. Power is sufficient to drive any headphone. When you turn it on, it slowly powers the unit over about 24 seconds before full power is reached, then it is ready to play. This greatly prolongs tube life. It is a new model in China, and available at present only in the 220 volt mode. I bought a quality converter rated at 200 Watts (the Bada draws 50 Watts so an 100 Watt converter would be fine). This very nice noiseless converter connects to the 110 volt wall outlet, and then the Bada PH12 plugs into the converter. I use the converter switch to turn the converter and the Bada on simultaneously, for one-switch convenience.

The sound is fantastically real with two EH Gold 6NS7 tubes in back and one Shugang 6N8P tube in front. I wonder if gets any better for someone who wants the best of solid state with the tube timbral body. Right now it can be auditioned in Gainesville, Florida (contact [email protected]) and Apopka, Florida (contact [email protected]

High end equipment is labor-intensive and the Chinese have cheap and highly skilled labor. For years the Chinese made high end equipment for such producers as Mark Levinson. In the last 5 years, the Chinese have focused more on their own independent brands and are producing the highest quality products at low prices (as well as cheap products at extremely low prices). My experience with recent Chinese equipment has been extremely positive.

Freq response is 10HZ to 50000 Hz plus or minus 1/2 db - very flat.

Harmonic distortion is .6 %

Noise is - 95 db

Recommended headphone impedance: 30-600 Ohms