The Scoop On Elekit’s Brand-New 300B SET Amp: Introducing The TU-8600
Victor Kung of VKMusic.ca has given us the green light to share a very exciting announcement. The long-awaited replacement for Elekit’s 300B SET amp (which we loved to death) has arrived. Well, it’s almost here. The amp will make its’ North American debut at the LA Show next weekend (June 2-4). After that I will be receiving the prototype for a full review!!
Availability on these shores is scheduled for late September.
The following is the press release and some tasty photos. Enjoy.
VK Music announcement
YOU asked for it. YOU got it!!
We listened to your requests, and the highly-regarded ELEKIT designer, Mr. Fujita, has taken these requests into consideration. We are happy to present to you the release of the newly designed 300B amp (late September 2017).
The new 300B amp has a lot of improvements over its predecessor (the TU-8300R).
Here are a few of its new features/specs:
- Tube Set : 12Au7 X 2 + 12 AX7 X 1 + 300B X 2
- Now compatible with low to high impedance headphones
- Frequency response (-3dB) : 10Hz – 80kHz
- Max. output (THD 10%) : 8.3W + 8.3W (input voltage : 250mV r.m.s)
- Residual noise : 42uV rms (IHF-A)
- Power consumption : 80W when no signal; 80W at max. output
- Power voltage : 100V, 115V, 200V, 230V, 50/60Hz)
- Dimensions : W385 x H217 x D323 mm, including projections
- Weight : Approx. 12kg, excluding AC cord
Come see us at booth 180-181 at the LA Audio Show on June 2 – June 4, 2017. Please come preview this wonderful product from ELEKIT.
‘sounds’ promising. any speculation on the price?
Victor mentioned a ballpark, that sounds very competitive, however there are a few hurdles to clear before they finalize. All the Elekit amps are very well priced given their performance.
Thank you Mr. Fujita and Mrs Tamura to make this happen for LAAS
The parts and chassis were available on May 22. I guessed Mr. Fujita did not sleep to assemble and test the amp because the amp must ship out to LA on Thursday May 25. He told me the sound is amazing… I guess so…
Please stay tuned !!
I’m very interested to see what’s in store. The older incarnation had a very nice power supply and a couple of stages of 12AT7 gain with NFB.
With two 12AU7s and a 12AX7, I’m curious to read about Mr Fujita’s new design for the input. I imagine it will still use some feedback as the rated sensitivity (250mV with a bias around 60V) suggests more gain than a simple 12AX7+follower musters and less gain than multiple stages (open loop) achieve.
I’m sure it will be a winner.
Here is the comment from Mr. Fujita.
This explains why he used 12AU7 x 2 and 12AX7 x 1 instead of 12AT7.
1. To achieve higher stability of NFB, the overall NFB amount is decreased, and instead, cathode feedback is applied to 300B.
(This is why the third winding for cathode NFB is added to the OPT.)
2. Applying cathode NFB requires bigger driving amplitude for 300B.
3. To achieve such large driving amplitude, 12AU7 is more suitable than 12AT7, as its max. rating is higher than 12AU7.
4. Since the gain of 12AU7 is smaller than that of 12AT7, 12AX7 is used for the first stage.
Mr. Fujita conducted the circuit simulation to make sure his theory is correct, and confirmed that bigger amplitude can be achieved when 12AX7x1+12AU7x2 than 2x12AT7.(The driving ability of 12AX7x1+12AU7x2 with TU-8600 circuit is 200V peak-peak without wave clipping.)
Here is Bob from California to comment about Mr Fujita’s design
Mr Fujita has addressed the design differences which in part distinguish tubes such as the KT88 from the 300B employed in this new design. The value of adding cathode feedback is to provide buffering within the circuit design rather than relying entirely on feedback provided through the OPT NFB winding. The driver tube substitution refers to the different Mu values of the 12au7 and 12at7. This is a very sophisticated refinement which theoretically could provide significant consistency and stability in the resulting performance.
This is an interesting difference from some other 300b designs such as the Audio Note design which has no NFB reference whatsoever in their design. Mr Fujita may know that NFB feedback is designed into the Audio Note P-P. EL-34 design much as he employed in In an alternative fashion in the TU-8340.
I’m now wishing for a new model with at least 2 line inputs. No doubt this is a great amp.
you can use tu-8500 to have more input