100W Ultimate Fidelity Amplifier

[apexaudio]

I test al transistors, they all seem ok, the amp worked for a few minutes then it died, i'll post some measurements tonight.

You must describe problem (oscilations, overheating...) just died can't help.

 

[thimios]

I test al transistors, they all seem ok, the amp worked for a few minutes then it died, i'll post some measurements tonight.

Are these tranzistors in wrong position or they are different parts?

 

[smartx21]

Please, is there any PCB design other than Juan Vargas' for AX-20P?
I'd like to build this amp, and some inspection before building is always welcome.
Also impressions and hints would be nice.
Thank you all.

 

[rombe570]

The amp doesn't oscilate but I have 28vcc on out on both chanels, some tranzistor is malfunctioning, i measured all of them, they seem ok. I'll be back with some mesurements when I get home.

 

[rombe570]

I've done some measurements on final transistors:
The psu in +/-30v, and on the output is 28vcc
2sa1943

GND-B-29.6v , B-E -0.02

GND-C-30 , B-C- 0.04

GND-E-29.5 , E-C-0.03



2SC5200

GND-B-29.4 , B-E 0.02

GND-C-28.9 , B-C 0.02

GND-E28.9 , E-C 0.02

 

[apexaudio]

I've done some measurements on final transistors:
The psu in +/-30v, and on the output is 28vcc
2sa1943

GND-B-29.6v , B-E -0.02

GND-C-30 , B-C- 0.04

GND-E-29.5 , E-C-0.03



2SC5200

GND-B-29.4 , B-E 0.02

GND-C-28.9 , B-C 0.02

GND-E28.9 , E-C 0.02

Measure voltage on input and VAS transistors... check diode polarity there is mistake in first post.

 

[rombe570]

I' ve checked the othe chanel and it works i have 12mv on output with input shorted and conected to gnd.

 

[sonal kunal]

I've done some measurements on final transistors:
The psu in +/-30v, and on the output is 28vcc
2sa1943

GND-B-29.6v , B-E -0.02

GND-C-30 , B-C- 0.04

GND-E-29.5 , E-C-0.03



2SC5200

GND-B-29.4 , B-E 0.02

GND-C-28.9 , B-C 0.02

GND-E28.9 , E-C 0.02

Voltage reading taken incorrectly or written incorrectly.
2SA1943 collector should be negative -30v and 2SC5200 collector +30v from GND.

what psu you are using smps or transformer with bridge and filter caps.

Regards
Sonal

 

[rombe570]

They might be written incorectly, i'll be back with some measurements tomorrow. This problem is at one chanel the other one seems to work post #4547. My PSU is +/-30VCC

 

[rombe570]

Chanel one works, I replaced the fuses with 10R resistance and set to 115mv voltage drop., with input shorted I have 12mv on output.. I even made a sound test on a small speaker before I destroied it.

 

[thole]

AX14 PCB Compact Size

Size : 72mm x 61,5mm
Using 1/4w resistor
Some contribution to APEX amp Series

Regards

 

[apexaudio]

Size : 72mm x 61,5mm
Using 1/4w resistor
Some contribution to APEX amp Series

Regards

Nice work,
Regards

 

[thimios]

Nice work,
Regards

What pcb version you prefer for this AX-14?

 

[thole]

Apex AX14

This just redesign, just move fuse on a side.

Regards

 

[apexaudio]

What pcb version you prefer for this AX-14?

PCB from post #1

 

[thimios]

This just redesign, just move fuse on a side.

Regards

Yes i see that is a beautiful pcb, but drawing a pcb isn't an easy way.Apex know this.
Most of good amplifiers are drawing haven fuses close way each other,i believe that isn't without any reason.This way (+,-,gnd traces close each other)minimize the EMI.

 

[apexaudio]

Yes i see that is a beautiful pcb, but drawing a pcb isn't an easy way.Apex know this.
Most of good amplifiers are drawing haven fuses close way each other,i believe that isn't without any reason.This way (+,-,gnd traces close each other)minimize the EMI.

Yes like SR800 pcb

 

[thimios]

Yes like SR800 pcb

SR800???
Where is this

 

[apexaudio]

SR800???
Where is this

In thread: http://www.diyaudio.com/forums/solid-state/173462-studio-reference-amplifier-112.html

 

[remle114]

AX14

Preparing my AX14