Erno Borbely "Milennium" All Fet Class A Power amp 75W RMS

[BenY]

I used this jig with R1 2.2KΩ, your vertical is Id (mA) and your horizontal is VGS (V)?

Yes..
You cannot drive these fets that high on these conditions

 

[merlin el mago]

So for you K982 with more than 2.15V of VGS aren't genuine?

 

[merlin el mago]

Your J148/K982 are not genuine, VGS is too high.

Mine are supplied by Erno Borbely, are you sure yours are genuine?

 

[merlin el mago]

I measured VGS across Q3 2.57V, Q4 2.50 & Q5 2.30V, Q6 2.41V so I want to increase Q5 & Q6 at the same voltage like Q3 & Q4.

Or have I to change any of resistors value of R13, R15 or R16?

Have I to increase or decrease the VGS value of Q5 & Q6 to reach same VGS like Q3 & Q4?

Please help.

 

[BenY]

Mine are supplied by Erno Borbely, are you sure yours are genuine?

You may be right, By comparing the curves to the data sheet, already raises questions about the authenticity of the parts.

It is quite possible my parts are fakes... I did not get them from Mr. Borbely.

 

[merlin el mago]

Attached pic as reference if can help you.

 

[merlin el mago]

Fixed the issue, found R5 150R with 220R in place of 150R. Now I have 3V across R15 and 0V DC offset trimmed with P3

 

[Williams Audio]

CLASS A
ther is is somebody that tested or has measured specifications of the class a pwr amp
best regards
williams