LateSit

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Without Mr Pass and many contributors to the Pass Labs Forum, I wouldn’t have a clue what is concerning a class A SIT audio amplifier.
Those information helped me to build an SIT amp with a complementary lateral mosfet, my LATE - SIT

Point to point wiring I finished the power stage, which included an BUZ905D and an THF-51S.
The driver stage at the moment is an 8 dollars EBay 6J1 tube preamp, will be modified for best coupling to the gates.

YouTube
 

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@Nelson Pass

Thanks for your comment,
I tried firsthand with IRFP9240, then ALF08P16 and realised that they perform poorly under 16 Ohm load.
The BUZ905D is much better from my third approach, the Vgs window from my ten samples varied between -2.95 to -3.05.
It has a margin about 2V from Vp pinch off of the THF-51S.

Thanks again

@WalterW

Hi,
Just finish the driver, will do all measurements by tomorrow, having all midnight oils burned.

Cheers

.
 

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DN2540 Driver

It is a classic DN2540 cascode driver, Ids = 70mA, will release circuit diagram when all settings are done.
 

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6J1P driver

Mondayitis? Not really, back to 6J1P driver for a final decision.
In a crudely state this EBay preamp is full of noise from 12Vac doubler.
Her plate voltage and current are governed only by a resistor, no hated here, just seen it as an unpolished opal.
Will combined with DN2540 as CCS and perhaps another EBay order for an 6J1P preamp to be modified as buffer but within Mr Pass philosophy “simple and elegant” .

Cheers


.
 

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Joined 2010
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Mondayitis? Not really, back to 6J1P driver for a final decision.
In a crudely state this EBay preamp is full of noise from 12Vac doubler.
Her plate voltage and current are governed only by a resistor, no hated here, just seen it as an unpolished opal.
Will combined with DN2540 as CCS and perhaps another EBay order for an 6J1P preamp to be modified as buffer but within Mr Pass philosophy “simple and elegant” .

Cheers


.

10/10 loving this just for the photos of your workbench.

The project looks pretty great too. ;)
 
Have Patience

i try to be patient :)
do you need gain or just a buffer to drive the amp ?
what is the value of the two zener ?

Hi Juanito,
Seems you are an expert in trench combat, hihi.
Get a piece of copper plate, cut it, drill holes, tape threads then polish it to perfection.
It is my interpretation of having patience.
For the DN2540, I drive it directly with my android phone, you might tailored it to suit your needs.
Zener, any will do with value higher than your source voltage and lesser than Vgs breakdown, I use 2 x 5V zener in série.


Cheers
 

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Hi Juanito,
Seems you are an expert in trench combat, hihi.
Get a piece of copper plate, cut it, drill holes, tape threads then polish it to perfection.
It is my interpretation of having patience.
For the DN2540, I drive it directly with my android phone, you might tailored it to suit your needs.
Zener, any will do with value higher than your source voltage and lesser than Vgs breakdown, I use 2 x 5V zener in série.


Cheers

Hi Pascal, that is a nice set of tapping screw you have! :)
Does the pink candle with tapping screws on it have some purpose?
I can't help my curiosity.. :D

BTW the ground is connected to V+ and also the Source of lower DN2540 bias resistor. Is this done on purpose too?
 
Last edited:
Hi Pascal, that is a nice set of tapping screw you have! :)
Does the pink candle with tapping screws on it have some purpose?
I can't help my curiosity.. :D

BTW the ground is connected to V+ and also the Source of lower DN2540 bias resistor. Is this done on purpose too?

Hi Chul,

Hawk eyed wise man :cool:

Pink candle, haha, poor man lubricants for threading and bicycle chain.

Source of lower DN2540 bias resistor to ground purposely, not an error.


Cheers



.
 

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