M-3000 mk3

And 7 years later. Now KT170. a Tungsol’s new beam tube released in 2020 , and more and more manufacturers are adopting this vacuum tube.
Allnic also put it into the T-2000 30th anniversary integrated amplifier in 2021, and finally in this year the M-3000 gets benefit from it and became MK3.

The M-3000 MK3 is bigger and cooler than the previous one even from the outside design. Each weighs 36kg.
The front panel design has also changed, and the power switch on the right side moves to the front and turns into a button one.
Nickel permalloy output transformers and power transformers with extremely low voltage fluctuations, which account for a large share of Allnic Sound, become bigger in size.

If you look more closely, there are big changes that should be seen as almost a different model.
First of all, it is KT170. This vacuum tube has a completely different shape from the KT150 and is larger in size.
Above all, the plate loss has been increased from 70W to 85W, enabling bigger output.
When the tube gets bigger, the capacitance increases and the treble sounds are not pretty, The KT170 overcomes such weaknesses and is said to operate very stably.

and The second change is the adoption of the driving tube 6S4.
In MK2, a pentode E282F was used with a triod connection, but this time it was changed to a 6S4 triode.
It was the tube which excitedly drived output tube KT150 when I reviewed A-2000 25th anniversary SE last year.
The 6S4 has an internal resistance of 3.7 kΩ, a voltage amplification factor (mu) of 16, a current amplification factor (gm) of 4.5 mA/V, and a high plate loss of 7.5 W,
enabling powerful driving of the output tube.

In fact, It is no exaggeration to say that 90% of the sound of a vacuum tube amplifier is determined by the first stage tube and the driving tube.
In particular, the driving tube is one of the most important variable that determines tone and musicality.
CEO Kang Soo Park said, “The 6S4 is a very rare vacuum tube with good characteristics.
After changing the drive tube to 6S4, I got a more stable and musical sound (compared to the pentode with triode connection).

The main character responsible for the first stage and securing most of the 28dB voltage gain of this amplifier, the pentode 5654, survived in MKIII as well.
The plate resistance dropped from 200 kΩ to 10 kΩ by triode connection.
The lower the internal resistance, the more current can be discharged and the low frequency fidelity increases.
For each channel, the flow is the first stage (5654 x 1) -> drive and phase inversion (6S4 x 2) -> output (KT170 x 4).