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Thanks for the info Mr.Pass. You truely have the best job on earth! Maybe something like what you mentioned will be amp #2. Aleph J here we come! I wonder then if I should just get a different xformer for the Aleph and save the B1 xformers for a project like this!
I'm on board to group by them
I'm on board to group by them
Hi Dady
I write e-mail to company and hope this 2SK77B transistors be not cost a leg and arm or simply not for sale ...wait and see ???
say away please
Hey Zen! Can you stay away from this thread?
I just sent an email , asking for free samples
dozen of each
signed as Mighty Zen Mod Boy
(hoping they'll pay for shipping)
Hey Zen! Can you stay away from this thread?
I just sent an email , asking for free samples
dozen of each
Hi amigos Zen Mod and Dady
That be cool but for the moment not response from Japan company
do you have received something in the mail box ?
Have a nice day
Sorry, misprint - 1.5nF
Keep in mind Ciss varies quite a bit between examples, the ones in B1's are actually selected into pairs. Also, the figure given (IIRC 2nf not 3) is at Vds 0 which is not realistic for real world conditions in an amplifier, obviously. It is lower with higher Vds, and fortunately not as non-linear as with MOSFETs.
Still, it's quite difficult to drive it, the part's mu is approximately 10-15 (again, varies depending on actual part and operating point) but if you are thinking transformer coupled, the drive requirements get quite difficult. Keep in mind Ciss is not the only capacitance, there is Crss which gets multiplied by the amplification factor of that stage, and you get something easily on the order of 3-4nF. At first approximation, let's use the time constant of this capacitance and source resistance as the HF roll-off point, you get 20kHz -3dB for R=2k. Unfortunately, you need well below that for the non-linear capacitances not to prohibitively rise distortion as frequency rises. Look at 200 ohms. Transformer input makes it worse as you get resonant peaks.
Compared to that, A pair of 2SK82 will give you nearly the same result just with 4 times less problems
It is doable, for sure, but not in a dead simple topology like the L'Amp, unless you already have a really low impedance output on a preamp.
I did receive a nice present from a company in Japan named FAL, which included
a small quantity of 2SK77B, the parts used by Digital Do Main.
They are rated at 300 watts, and I have built one prototype single-ended amp
which looks a lot like the SIT-2 but with 40 watts output. It is quite
spectacular, and the circuit will become public a little later this year.
Nelson, do you have the original 2SK77 to compare? If yes, how do they compare to the new 2SK77B?
Home made silicon?
Well, we have learned that Digital do MaiN rolls their own 2SK77B trannies, see here Digital do MaiN - Wikipedia, the free encyclopedia
I wonder, do they make them in the owner's garage, or .. ? I would guess some local silicon smith would come handy!
Any knowledge on this?
I have enough JFETs and SITs in the form of 2SK82/2SJ28 for my own use, but better amplification can be a case if such things take off: New audio format has purists singing praises
/RK
Well, we have learned that Digital do MaiN rolls their own 2SK77B trannies, see here Digital do MaiN - Wikipedia, the free encyclopedia
I wonder, do they make them in the owner's garage, or .. ? I would guess some local silicon smith would come handy!
Any knowledge on this?
I have enough JFETs and SITs in the form of 2SK82/2SJ28 for my own use, but better amplification can be a case if such things take off: New audio format has purists singing praises
/RK
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