FET-hex explendit amplifier

Cleaner...
 

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fab

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In addition, If you intend to follow Lazycat published amplifier ground connections scheme for its VsSA you may consider adding more terminals for GND connection on pcb ( for main central gnd of amplifier thus for main power supply caps gnd, zobel, speaker return gnd, etc...) or
you may prefer your main amp central gnd closer to the main power supply gnd.

I do not know if there is an accepted preferred gnd scheme be between 2 above options...
Fab
 
In addition, If you intend to follow Lazycat published amplifier ground connections scheme for its VsSA you may consider adding more terminals for GND connection on pcb ( for main central gnd of amplifier thus for main power supply caps gnd, zobel, speaker return gnd, etc...) or
you may prefer your main amp central gnd closer to the main power supply gnd.

I do not know if there is an accepted preferred gnd scheme be between 2 above options...
Fab

No fab with one GND faston spad i achieve all ground necessary ground connections : speaker, chassis, PSU (see the picture how i manage LC recommandations)

For supply spad i don't want them too near signal board connection...In the better case i desire GND/+V/-V connection near output section but i want apply that here i need to grown up board length...i didn't want that

Marc
 

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I am just thinking about universal board (just few resistor values differend), board for BJT can take o/p transistors:

-BJT
-IRFP
-2SJ/2SK

The only difference for mosfets would be another driver pair (required for BJT outputs). I have asked few posts before about adding another pair of drivers for mosfets (so we will have 8 transistors in direct signal line) - but had no response.
I will test that on wednesday (will have some time), have some 2sj201/2sk1530 in stock so why not try them on.

Idefixes
Have you got link adress for that psu board ?
 
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I am just thinking about universal board (just few resistor values differend), board for BJT can take o/p transistors:

-BJT
-IRFP
-2SJ/2SK

The only difference for mosfets would be another driver pair (required for BJT outputs). I have asked few posts before about adding another pair of drivers for mosfets (so we will have 8 transistors in direct signal line) - but had no response.
I will test that on wednesday (will have some time), have some 2sj201/2sk1530 in stock so why not try them on.

Idefixes
Have you got link adress for that psu board ?

Funny i was thinking at somethink quite near but a little different :
=>Input board+Output board (Mosfet or BJT or Latfet)

For PSU => capacitance multiplier

Marc
 
I am just thinking about universal board (just few resistor values differend), board for BJT can take o/p transistors:

-BJT
-IRFP
-2SJ/2SK

The only difference for mosfets would be another driver pair (required for BJT outputs). I have asked few posts before about adding another pair of drivers for mosfets (so we will have 8 transistors in direct signal line) - but had no response.
I will test that on wednesday (will have some time), have some 2sj201/2sk1530 in stock so why not try them on.

Idefixes
Have you got link adress for that psu board ?

For Mosfets you don't need drivers, and for Lateral mosfets, you also don't need bias servo. But drivers with Mosfets (both lateral and Hex fet) will double the slew rate. They will just make amp better, so if there is place on pcb you can use them with any of the output transistors: BJT, Hexfet or Latfet. But you must test the stability of the amp if drivers are used.
 
For Mosfets you don't need drivers, and for Lateral mosfets, you also don't need bias servo. But drivers with Mosfets (both lateral and Hex fet) will double the slew rate. They will just make amp better, so if there is place on pcb you can use them with any of the output transistors: BJT, Hexfet or Latfet. But you must test the stability of the amp if drivers are used.

Tuesday is THE day of tests so I will post results.
Regards
 
Just tu confirm, BG1 is working with fets OK. I have soldered 2sj201/2sk1530, replaced gate resistors with 100R and putted two zeners. Bias is setting up ok. At the moment I have as bias transistor bd139 and cold amp setted up to 45mA bias is dropping to 38mA after 10min playing of music (so is not too bad).

Idefixes
If you will made a room just for two zeners on the board there would be posibility to solder BJT or mosfets at output.

Sound with toshiba mosfets has really rich top end, worth every penny I have spent on them.
 

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