Bora is a nice guy from Serbia - Yugoslávia

[andrewlebon]

Dear DR BORA
greetings thank you sir for replying its easy modification i will make it thanks once again for helping me
warm regards
andrew lebon

[NMOS]

Originally Posted by boraomega

Andrew, this is older version with 24V regulator for relays supply and it wasn’t reliable. Please make a small modification and replace that with simple one transistor stabilizer as on attached schematic. I know PCB isn’t designed for this, but modification is so simple it shouldn’t be a problem to do.

Hi boraomega

Im confused and have a problem....

how to connect Omni protection Point 7 and 9
in quasi complementary output stage

like Legend Stage master MK2 or Quasi NMOS

because Point 7 and 9 get full negative rail voltage trough 0,22 OHM resistor

any solutions ?

[boraomega]

OMNI is for complementary outputs and not for quasicomplementary. Quasi output stage has to be modified.

[NMOS]

Originally Posted by boraomega

OMNI is for complementary outputs and not for quasicomplementary. Quasi output stage has to be modified.

I dont have much experienece how to modifed for Quasi output stage,

can you share your knowldege / offer schematic what to do for Quasi

cheers

[andrewlebon]

, this is older version with 24V regulator for relays supply and it wasn’t reliable. Please make a small modification and replace that with simple one transistor stabilizer as on attached schematic. I know PCB isn’t designed for this, but modification is so simple it shouldn’t be a problem to do.

just remove ic 7824 the 2 10uf caps and the jumper to modify pcb for transistor stabilizer put TIP 41 WHERE 7824 was orignally
1 put 24 volt zener diode from base of tip41 to where jumper was taken out to ground
3 put 3.3k 1 watt from collector to base
no tracks to be cut PCB has all holes marked on it
warm regards
andrew lebon

[NMOS]

Originally Posted by andrewlebon

, this is older version with 24V regulator for relays supply and it wasn’t reliable. Please make a small modification and replace that with simple one transistor stabilizer as on attached schematic. I know PCB isn’t designed for this, but modification is so simple it shouldn’t be a problem to do.

just remove ic 7824 the 2 10uf caps and the jumper to modify pcb for transistor stabilizer put TIP 41 WHERE 7824 was orignally
1 put 24 volt zener diode from base of tip41 to where jumper was taken out to ground
3 put 3.3k 1 watt from collector to base
no tracks to be cut PCB has all holes marked on it
warm regards
andrew lebon

ok thanks for Info....will make new PCB, its easy for me but need a little time

if interested I can share it for supplier

I hope to get update for Omni to protect Quasi output stage

[Walkalone]

Originally Posted by Walkalone

Hi Dr. Bora and everybody! I'm new in forum.
I've read this topic, from page 1 to here. I'm interested in building the Sigma & Techno amps. They look seem similar topology, only difference is between BJT and MOSFET in OPS. My computer does not CAD program to draw the PCB. Someone please send to me the PCBs of both (top & bottom)?!

Somebody can help me?
Top & bottom PCB layout of Techno & Sigma. (Send to my email: Nguyenthecuong1987@gmail dot com)
Very thanks for help me!!!

[irvynejay]

pcb ready for testing

Thanx Dr.Bora

[Adib Pramudia]

Dear Dr.Bora
I'm completing the purpose of spare parts on the stage driver amplifier Sigma
2SA1407/2SC3601 or 2SA1406/2SC3600 the Sanyo brand. BJT brands like this are hard to find in my town. Is there a replacement series of other brands such as the brand Sanken, Toshiba or other brands. Thank you

Good Luck,
A.Pramudia

[Adib Pramudia]

Dear Dr. Bora,
Your e-mail about BJT I've read, your response so quickly. Thanks a lot

Good luck,
A.Pramudia