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Tony's 300B (standard model)

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Cornell Dubilier 320uF/450V high voltage electrolytic capacitors (made in USA) work with the 10H/250mA choke to make CLC filtering. This is important to reduce noise from power supply and increase S/N ratio.

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For the input and driver stages, we used German ROE 100uF/100VDC cathode capacitors for each 6SN7. For power tube 300Bs, used Dale 1K ohms, 50W cathode resistors and ROE cathode capacitors. Coupling capacitors between input and driver stages and between driver stages and 300Bs are red TRW 0.25uF/250VDC film caps. Resistors are 1% metal film resistors. We think that those components have high quality and are stable enough. The most important is those components can achieve more balanced sonic performance for 300B.

6SN7-300B-3-20.jpg


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So I've finally got my hands on the new 300B.

First, here's 2 pics showing the interior of both amplifiers. Sorry I haven't got the time to make images of the hand-made transformers on this new 300B. I've asked Tony to say more about this side of the build. I hope Tony is going talk about a Chinese gentleman who's some 60 years old. He makes each transformer by himself, totally by hand. I've suggested to Tony that he takes some photos of this chap and gives a brief history of this transformer maker's life and experience. I'll leave it to Tony and others to make any technical comparisons and comments.

Moving on to listening impressions, I'm continuing to play my Pencil 7's with Alpair 7 drivers, no filtering of anykind. The Accuphase DP65 CD player remains in service as the source. I've swopped over all the valves (tubes) apart from a new set of Full Music 300B's. These are the same grade as those used on the earlier amp. There is some additional listening pleasure already detected in the first day's of use of this new 300B:

The new 300B amp is more refined in the mid to upper bands. Female vocals benefit. One example is the motet Pie Jesu featuring the Dallas Women's Chorus (Reference Recordings: Requiem). Soprano solo's come across with depth and control while the portrayal of the organ low notes were deep and rich. Nothing is over-done with this amp in the vocal's department. Its all very natural, rather organic, so refreshing to hear the music, not the system.

Surprisingly, musical dynamics have also improved. I expected this side of the musical equation to be more restricted but Bizet's Carmen Fantasy (Harold Faberman - First Impression Music) and Torero Carmen Suite (Mikhail Pletnev, Russian National Orchestra - Deustsche Grammophon) sound really top class. The percussion in these tracks is spot-on, nothing under-done or over-cooked. The shear accuracy of these renditions is particularly pleasing.

Orchestra is really nice. Elgar's Pomp and Circumstance (Top Music Int. Ltd) was harmonious. No single section of the orchestra came forward beyond a natural acoustic reference point, so the renditions were typical to those found by listening to a concert in a decent hall. This amp reminds me of the old days when systems had balance. The term "High Fidelity" has been banded about to the point of abuse but here's Ted Jordan's definition. It well reflects the output from both of these 300B's with an extra emphasis on the new model.

"High Fidelity was defined as ‘The closest approach to the original sound’ where ‘the original sound’ was considered to be the natural sound of vocal and instrumental music."

The biggest test for me personally has to be piano. The Tsuyoshi Yamamoto Trio's arrangement of Smoke Gets In Your Eyes (First Impression Music) is very demanding for any system. Any distortion, hum or other extraneous inputs will become evident. The first notes are struck quite hard, moving on to very refined quite sections in the rendition. Tony's new 300B takes all this in its stride, no fuss, no complaints or any dramas, it simply delivers the signal necessary for the Alp7's to do their work.

Summing up, I already liked Tony's earlier 300B and I shall continue to use it. This amp is still excellent and can hold its head up high. It remains smooth and detailed with a performance and charterter not far behind the new model. The new 300B is so utterly natural to the point of being organic. I naturally closed my eyes while listening to these tracks (and many more), the system transported me to the live venues. Its a real treat to further explore my CD collection and regain a degree of satisfaction no felt for some time. How nice it is to return to a greater musical "reality". I can sit down on a Sunday afternoon with a glass of wine in my hand and simply relax and soak up the music. Oh bliss, this amp does this for me.

Credit must also go to the system as a whole. I count myself lucky that all these components work together so harmoniously. I'm so glad that I invested in the Accuphase DP65; And I also credit Scott Lingren for an excellent cabinet design, his Damped Air Coupler work does much justice to the Alpair 7 drivers.

So, to Tony and Thomas I say "Keep up the good work", let's see more amps flowing from Twin Audio in the future.

Cheers

Mark.
 

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Hi Mark,

Thank you very much for your comments on the 300B amps and nice photos you took. The tube amplifiers we design and make are for the people who love music. We will be happy if people enjoy music when listening our amps. I believe our 300B amps can be well matched Mark Audio full range speakers. Thanks Mark's great efforts on his speaker drivers. The sound of speakers is so natural and balanced. Advantages of amplifier and music sources can easily be performed through the speakers of Mark Audio. I love Mark's speakers.

We will keep up our work and do better as possible as we can.

Cheers

Tony.
 
Mr. Zhu is the maker of the transformers for Mark's new 300B amp. He is 62 years senior engineer with 40 years experience making audio transformers. He's now retired from a transformer factory, but continues to make transformers for special orders. All Zhu's transformers are hand-made and tested by Mr. Zhu personally. He selects only high grade materials, typically Japanese Z11 steel for his cores. Sometimes he will use some special vintage material like the latest 300B for Mark. These transformer cores are rare Chinese vintage, called “Golden Sand” which were forged in 1950s. Mr Zhu has a collection of vintage transformer components from which he uses to make "specials".
 
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