AB100 Class AB Power Amplifier

[east electronics]

The request for Global demands for Tip 142-147 raised after that but manufacturers don't know how to make them any more ....One claims that cooking instructions lost just after WW2

 

[osscar]

I still can not get to work emu usb 0404 sound-card under windows 10 (beta driver does not work - it freezes my computer - it's time to buy something new ...) ... hope someone will build this and measure the harmonic spectrum correctly. The amplifier works still perfectly - low frequencies are great ... and other frequencies also satisfy me. Bias / offset very stable also.

 

[Abx74]

Hi everyone,
Has someone tried the Kroto's PCB or everyone is still waiting for the official Papa's version?

Damien

 

[jacco vermeulen]

Maybe they're waiting for the board layout to facilitate Sanken STD03N/STD03P devices.

(it's said, best ever audio darlingtons on the block)

 

[Ultrasparc]

Would I have to make many changes to the circuit to use +-60V for this amplifier? I have a transformer out of an Onkyo tx-nr709 on hand that would yield this...or should I just buy a proper transformer to yield the +-50?

 

[osscar]

ztx 450/550 are 60V max , but i think ztx451/551 80V transistors will fit fine. VA stage transistors will have to dissipate approx 0.6W, its seems fine even without heat sinks...I think it will work with 60V

 

[Ultrasparc]

Thank you. I was going to get the ztx453/553 since they are 100V parts.

 

[osscar]

Yes i agree - these will fit for 60V rails ! What transistors would you place in VA stage? I measured in LT spice - bd140 / 139 gives a little lower 2H than MJE 340/350, although the total THD is the same almost at bias 50mA per output transistor and 1W output at 1 an 10 Khz (my LT spice and real "amp" amplifier have a reduced gain from original article ).

 

[Ultrasparc]

KSA1381 & KSC3503 as per Kroto's layout. But the bd140/139 seem to be more readily available.

 

[osscar]

the same here - either bd / mje from local good suppliers or ksa or Japanese transistors from ebay (with a great % to buy fake), but BDs will be .I would like to have transistors with a slightly higher V than BDs for 60 V rails..

 

[Ultrasparc]

MJE 340/350 look more attractive then, and still very easy to source through Mouser. I appreciate all your help and guidance osscar... Thank you.

 

[osscar]

tnx, but many don't like them - low Ft etc, old transistors, high capacitance...

 

[osscar]

in my amp they sounds fine, at least to my ears
btw im listening ab 100 now - sounds so nice

 

[Ultrasparc]

I happen to have some 2sa1930's and some 2sc5171's laying around also.

 

[osscar]

I throw them in spice - seems works fine - reduced second harmonic, no oscillation.
.MODEL Q2SA1930 PNP(
+ IS=10.000E-15
+ BF=210
+ VAF=78
+ IKF=10.000E-3
+ XTB=1.5
+ BR=.1001
+ VAR=100
+ IKR=10.000E-3
+ ISC=10.000E-15
+ CJE=3.252E-12
+ CJC=63.196E-12
+ MJC=.33333
+ TF=83.239E-12
+ XTF=10
+ VTF=10
+ ITF=1)

.MODEL Q2SC5171 NPN(
+ IS=10.000E-15
+ BF=210
+ VAF=100
+ IKF=10.000E-3
+ XTB=1.5
+ BR=.1001
+ VAR=100
+ IKR=10.000E-3
+ ISC=10.000E-15
+ CJE=2.0000E-12
+ CJC=38.866E-12
+ MJC=.33333
+ TF=83.239E-12
+ XTF=10
+ VTF=10
+ ITF=1)

 

[onkal]

Is there any pcb ?

 

[neno70]

hello .. there are no news about this project ... new pcb? thank you

 

[Ultrasparc]

I throw them in spice - seems works fine - reduced second harmonic, no oscillation.
.MODEL Q2SA1930 PNP(
+ IS=10.000E-15
+ BF=210
+ VAF=78
+ IKF=10.000E-3
+ XTB=1.5
+ BR=.1001
+ VAR=100
+ IKR=10.000E-3
+ ISC=10.000E-15
+ CJE=3.252E-12
+ CJC=63.196E-12
+ MJC=.33333
+ TF=83.239E-12
+ XTF=10
+ VTF=10
+ ITF=1)

.MODEL Q2SC5171 NPN(
+ IS=10.000E-15
+ BF=210
+ VAF=100
+ IKF=10.000E-3
+ XTB=1.5
+ BR=.1001
+ VAR=100
+ IKR=10.000E-3
+ ISC=10.000E-15
+ CJE=2.0000E-12
+ CJC=38.866E-12
+ MJC=.33333
+ TF=83.239E-12
+ XTF=10
+ VTF=10
+ ITF=1)

Thank you oscar. I am a newb and have not learned to use simulators. I really appreciate your help.

 

[inyashd]

DOGC-H amplifier by Dr. Borivoje Jagodic -pcb

Hi,

I recommend you DOGC-H amplifier by Dr. Borivoje Jagodic. It uses current-dumping topology. It is class AC and sounds very good! (better than class AB amps). If you want PCB, PM me and I will send you PCB in Eagle format.

Please send pcb format in pdf of DOGC-H amplifier by Dr. Borivoje Jagodic

 

[onkal]

I think this Project made to baloon.