MOSFET Amplifier IRFP240/IRFP9240

[apexaudio]

what instead for irfp240/irfp9240?out of stock here

2sj200/2sk1529

 

[Tube Pro]

Thanks Mile...

 

[udhay_cit]

My PCB work without the Toshiba Transistors

Hi, anybody interested in my PCB work for HV350.2 without the Toshiba transistors. I replaced all the 2SA/2SC series Toshiba transistors with available 2N series. I cont find the Toshiba transistors in my city so i cont comment the performance difference b/w the original apex design and my design.

Just now i finished the design work so i didn't tested that.......

I will post my pictures after the testing now find the attachment ......

Thanks Mile

Regards
Udhay

 

[apexaudio]

Hi, anybody interested in my PCB work for HV350.2 without the Toshiba transistors. I replaced all the 2SA/2SC series Toshiba transistors with available 2N series. I cont find the Toshiba transistors in my city so i cont comment the performance difference b/w the original apex design and my design.

Just now i finished the design work so i didn't tested that.......

I will post my pictures after the testing now find the attachment ......

Thanks Mile

Regards
Udhay

Thanks for share your pcb design,
Regards

 

[apexaudio]

Hi, anybody interested in my PCB work for HV350.2 without the Toshiba transistors. I replaced all the 2SA/2SC series Toshiba transistors with available 2N series. I cont find the Toshiba transistors in my city so i cont comment the performance difference b/w the original apex design and my design.

Just now i finished the design work so i didn't tested that.......

I will post my pictures after the testing now find the attachment ......

Thanks Mile

Regards
Udhay

On your pcb track from emiter of BC546 (clip indicator) to -75V missing.
Regards

 

[apexaudio]

Hi Apex, i dont think your vas is unusal, its a cfp, I use it in alot of my amps, what is unsual is the your temp compensatiom circuit, Im still guesing how it could work.
The thought has come to mind that the cfp transistor that gets mounted on the heatsink has something to do with it but Id have to build it to see the exact effect.

Yes CFP in VAS give temp compensation to the amp, but when amp is hot this circuit reduce bias to almost half of adjusted current: 200mA to 120mA per MOSFET, that is the reason to add Vbe multyplayers with one transistor on heatsink and other not, there is no problem with underbiased. Temp compensation without underbiased can be made with LED in emiter of Vbe multyplayer like in my DC Servo Mosfet Amp.
Temp stability of this amp in usual home aplication is satisfacted, and underbiasing with full power in PA aplication reduce disipation.
Any version of this amp work great, and build it to see effect.

 

[najjachi]

Hi Apex. Is the heatsink with dimension 300x190.5x56 mm enough for the stereo version of the APEX350.2 amplifier?

Regards.

 

[apexaudio]

Hi Apex. Is the heatsink with dimension 300x190.5x56 mm enough for the stereo version of the APEX350.2 amplifier?

Regards.

Yes this heatsink is enough for stereo (see post #246), only for PA you need to add fan cooler,
Regards

 

[najjachi]

thanks!

 

[apexaudio]

Heatsinks from post #246 are made of recicled aluminium by melt, and have only half wait compare to industrial.

 

[apexaudio]

Hello Mile
Do you mind posting the schematics for the OP based version?
Thanks!

HV250 schematic

 

[apexaudio]

HV250 is much older than HV350, discounted for long time but still worked.

 

[Krisfr]

Hi, anybody interested in my PCB work for HV350.2 without the Toshiba transistors. I replaced all the 2SA/2SC series Toshiba transistors with available 2N series. I cont find the Toshiba transistors in my city so i cont comment the performance difference b/w the original apex design and my design.

Just now i finished the design work so i didn't tested that.......

I will post my pictures after the testing now find the attachment ......

Thanks Mile

Regards
Udhay

Do you have a schematic of this? Thanks

 

[apexaudio]

HV23

Thread start with this schematic.

 

[apexaudio]

Amp from schematics with 5 pairs mosfets.

 

[khalsa]

hi apex send the pcd drawing 5pair mosfets

 

[apexaudio]

hi apex send the pcd drawing 5pair mosfets

Use this if you want, but I not suggest to use IRFP240/IRFP9240 for that power and rail voltage it's not realable.
Regards

 

[khalsa]

hi apex thanks for suggestion

 

[Tube Pro]

Use this if you want, but I not suggest to use IRFP240/IRFP9240 for that power and rail voltage it's not realable.
Regards

Hi Mile,

why did yo say you don't suggest those IRFs for that rail voltage? Is that too high?
How about if we use +/- 67vdc? (or 45-0-45 secondary transformer)

Regards.

 

[apexaudio]

Hi Mile,

why did yo say you don't suggest those IRFs for that rail voltage? Is that too high?
How about if we use +/- 67vdc? (or 45-0-45 secondary transformer)

Regards.

For safety reason +/-80vdc is maximum suggested voltage, and U can use 4 or 5 pairs outputs.
With +/-67vdc ,and 4 pairs outputs U will have very realable amp.
Regards