diyAB Amp - The "Honey Badger"

[ostripper]

Originally Posted by discrete

Nice job!

I notice a small error on the new layout: C1's furthest pad is not connected.

That is on purpose. With a long , large poly ... you would drill the hole , put the long lead through , bend it underneath .. solder it. This is to avoid having a "antenna" of a long trace for those that just use a 5mm wima.

I will try to refine C1's layout , regardless.


T93YB -
T93YB 25K 10% datasheet

No problem.

OS

[ostripper]

Originally Posted by Josip_Del

And one my small suggestion rather stupid can you just add another pin for trimmers which not in line like Vishay T93YB type.

Here it is....

Universal large input cap trace w/jumper. Fixed !

Staggered 3 pin 2.5mm lead spacing / or inline 2.5mm trimmer pads. Fixed !

Broader sourcing is a asset for this project.
OS

[ostripper]

Originally Posted by smartx21

Bias set?

Yes , 22mv between these TP's would give you 50mA per OP device. You could probe between either TP 1/2 and the "OV tp" for 11mv , as well.

OS

[dadod]

Originally Posted by ostripper

Yes , 22mv between these TP's would give you 50mA per OP device. You could probe between either TP 1/2 and the "OV tp" for 11mv , as well.

OS

This is to low. You should target voltage no current according to Self.
dado

[ostripper]

Stock TO-3p Sanken OEM = 8-9mv Re

What I run = 10mv Re (.22R)
Sound is golden - no issue.
Self was using old devices in his book.

Vbias control is there to allow for whatever the preference is.
If they have a large heatsink - run at 100+ ma , whatever they like.

OS

[ostripper]

I am old , only have one set of eyes , no one in my house or neighborhood could possibly help (they know not what they see )

So , please look over this color draft of the project.

RED = +60V /positive rail
BLUE= - 60V /negative rail
GREEN = earth and signal ground
YELLOW = (dark yellow) - output trace / NFB
orange = positive OP stage drive
light blue = negative OP stage drive
pink = non-inverted small signal path to VAS

Reprinted , all devices have ample "real estate" (clearance) , all power semi's can be easily accessed with a screwdriver. Screenprint will show sections of circuit (LTP , cascode/CM , VAS, Vbe) for curious new builders .

For convenience , the final schematic is also below.
OS

[smartx21]

Sorry, maybe I missed something: there is a zener diode mark in schema (D3, near R18), that my eyes can't get to see. Please, help.

[ostripper]

Originally Posted by smartx21

Sorry, maybe I missed something: there is a zener diode mark in schema (D3, near R18), that my eyes can't get to see. Please, help.

That is a "planned" thing as well. Some would like to reference the cascode with a 12-15v zener or even an led string (3 smd blues/5 smd reds - it works - done it.) So it can be either D3 OR R18 .... this will be in the "Cascode/current mirror"
section of the "Options" text. wish I was 21 .. sheesh !

OS

[farjon]

Originally Posted by ostripper

For convenience , the final schematic is also below.

The only problem with OS are some LTPs and VASs drawn upside down...

Very curious about the sound.

[smartx21]

Originally Posted by Sound_Buster

The only problem with OS are some LTPs and VASs drawn upside down...

Very curious about the sound.

Sound_Buster, the time has come for you to start a brazilian group to build OS´s amps! His job deservers our efforts. I think that we could help develop this project if many of us built this beauty!
It makes a long time I wish to do this, but it seems there´s never "a final schematic"!!
(sorry for this last statement, but I am no researcher or developer... I could only build it "as is", and evaluate the sonics and overall performance.)