100W Ultimate Fidelity Amplifier

[apexaudio]

Hi M. Mile, first of all happy new year for you. How many volts should I put on red circle condenser. This topologi FH14 has VI limiter ? Because looks like.

Thanks in advance

Pozdrav

Use 100uF/25V and yes there is VI limiter on FH14.
Pozdrav

 

[kandimba]

Thanks for your reply
Pozdrav

Use 100uF/25V and yes there is VI limiter on FH14.
Pozdrav

 

[Bilbon]

Hi! What is the ideal bias current for the AX-11 at 38+38 VDC?

 

[Bilbon]

I'm having a little problem with the AX-11. The amp works well, good sound, the outputs transistors (MJ15003/15004) and drivers (MJE15032/15033) are only warm, but the pre-drivers (MJE340/350) get very very hot. The bias sensor are a BD679. Supply with 38+38 VDC and bias set at 50mA (I replace the 4k7 resistor with a 5k pot). Any idea what it might be?

 

[Project16]

I'm having a little problem with the AX-11. The amp works well, good sound, the outputs transistors (MJ15003/15004) and drivers (MJE15032/15033) are only warm, but the pre-drivers (MJE340/350) get very very hot. The bias sensor are a BD679. Supply with 38+38 VDC and bias set at 50mA (I replace the 4k7 resistor with a 5k pot). Any idea what it might be?

The BD679 is darlington transistor and I'm not sure i fit.

 

[Bilbon]

The BD679 is darlington transistor and I'm not sure i fit.

Yes, it's darlington, but here in the topic is mentioned that it works ... Would it be better to replace with a BD139?

 

[Project16]

Yes, it's darlington, but here in the topic is mentioned that it works ... Would it be better to replace with a BD139?

Sir Apex will answer much better than I do.

 

[apexaudio]

I'm having a little problem with the AX-11. The amp works well, good sound, the outputs transistors (MJ15003/15004) and drivers (MJE15032/15033) are only warm, but the pre-drivers (MJE340/350) get very very hot. The bias sensor are a BD679. Supply with 38+38 VDC and bias set at 50mA (I replace the 4k7 resistor with a 5k pot). Any idea what it might be?

It is ok, you must use heatsink for MJE340/350/
Regards

 

[Bilbon]

It is ok, you must use heatsink for MJE340/350/
Regards

Thanks Apex, I will provide heatsinks for the transistors.

 

[Bilbon]

MJE340/350 with heatsink...🙂

 

[thiagomogi]

I'm having a little problem with the AX-11. The amp works well, good sound, the outputs transistors (MJ15003/15004) and drivers (MJE15032/15033) are only warm, but the pre-drivers (MJE340/350) get very very hot. The bias sensor are a BD679. Supply with 38+38 VDC and bias set at 50mA (I replace the 4k7 resistor with a 5k pot). Any idea what it might be?

MJE350 and 340 are not pre-drivers and rather VAS, as Mr. Mile mentions that it is good to have heatsink.
A wise choice to improve ax11 performance is to place the transistors faster and with lower COB in the "heart" of the amplifier which is the VAS.

Thiago

 

[Bilbon]

MJE350 and 340 are not pre-drivers and rather VAS, as Mr. Mile mentions that it is good to have heatsink.
A wise choice to improve ax11 performance is to place the transistors faster and with lower COB in the "heart" of the amplifier which is the VAS.

Thiago

Thanks for the information. Can you give me examples of good VAS transistors in the brazilian market?

 

[thiagomogi]

This is a big problem, in Brazil it is difficult to find good transistors. I buy from the mouser.

Thiago

 

[uranium2000]

Here's the file for you to DIY.

https://www.dropbox.com/s/m8qma092ijh7vuu/AX-14 Ver. 2.0.rar?dl=0

Regards,

@wiljj78 can you please post gerber files for this AX11 layout ?



regards,

 

[Hadighorbani]

An externally hosted image should be here but it was not working when we last tested it.

Hi
what is the probleme?
my HX-11 not work in first time
this two resistors are burn after connect supply to terminalllllllll
why?
any one have an correct and tested pcb for Hx-11?

https://pictub.club/image/sEz2g7

 

[apexaudio]

An externally hosted image should be here but it was not working when we last tested it.

Hi
what is the probleme?
my HX-11 not work in first time
this two resistors are burn after connect supply to terminalllllllll
why?
any one have an correct and tested pcb for Hx-11?

https://pictub.club/image/sEz2g7

2N5551 reverted polarity on this pcb...

 

[Hadighorbani]

2N5551 reverted polarity on this pcb...

i try it today
thank you

 

[Hadighorbani]

do you have a DC and short circuit protection for this amp?

 

[Hadighorbani]

2N5551 reverted polarity on this pcb...

I reverted 2N5551
Now the 2sc5200 and irf9540 is hot when power is on

 

[Hadighorbani]

https://pictub.club/image/sqFdAH
https://pictub.club/image/sqF0B7
https://pictub.club/image/sqF8LU
https://pictub.club/image/sqFD5o