100W Ultimate Fidelity Amplifier

[zry9833]

UPC1342 OK

 

[shabusf]

Here is the list of change,
Bc546/556 for bc547/557
A1220/c2690 for 340/350
Mje15034/15035 for 1837/4793
Mjl3281/1302 for 1943/5200

Offset is on the high side, actually one channel is around 6mv another is 17mv, but no problem so far, no hiss or hum.

For the sound, high is very good comparable to class A amp, bass is not as deep as I would like it to be. I will change the main filter cap and see what happen. Now I'm using panasonic I plan to change to Nippon chemical.

Regards,
C.S.

Thank you for sharing your experience with us

Sha

 

[shabusf]

If you match the hfe of i/p pair closely, you can get a very low offset.

Hi Prasi,
Do you mean to say Q1 and Q2?

Thank you.
Sha

 

[prasi]

Yes

 

[shabusf]

Yes

Ok, Thank you

Sha

 

[avtech]

UPC1342 OK

 

[Sunny22g]

Plz see this

Hi guys plz see this .It's OK or not

 

[Sunny22g]

Plz see this

 

[alex mm]

Sunny22g,
First, you have to change fuses with smaller type 5X20mm , missing input capacitor and ground lift resistor, don't forget to link A points with wire under PCB . Cut PCB at normal size, make some hols in corners . Pcb was tested and it's functional .....
Regards Alex

 

[Sunny22g]

Sir thanks for reply.this is now pic of PCB.i have 2 change 1st main transistors 5200 1943.2nd 470 uf 100 volt.is that ok

 

[desertstorm]

APEX AX 20R

 

[shabusf]

Plz see this

The real diy board.. Congrats

Between, which version of PCB is this, 1.4 or higher?

Thank you
Sha

 

[Sunny22g]

Bro it's ax40

 

[Sunny22g]

Can I use 55_0_55 15 amp transformer for ax40.i use 5200 .1943 pair.or 470uf100 volt.guys plz tell

 

[shabusf]

Can I use 55_0_55 15 amp transformer for ax40.i use 5200 .1943 pair.or 470uf100 volt.guys plz tell

Hi Sunny22g,
AX40 or A40, hope it is A40. And 55-0-55 volt AC is little high for A40 I think. Better get advise form experts over here.

Thank you.
Sha

 

[thimios]

APEX AX 20R

Is this pcb available in black&white for home etching?

 

[chat72]

I've built ax14 and gsin is a bit high, how do I reduce gain without messing up the performance and stability of this amp.

Thank

 

[Junie]

Sunny22g,
First, you have to change fuses with smaller type 5X20mm , missing input capacitor and ground lift resistor, don't forget to link A points with wire under PCB . Cut PCB at normal size, make some hols in corners . Pcb was tested and it's functional .....
Regards Alex

Alex it's been a long time, i hope everything is fine with you.
Do you have an extra AX40 pcb to sale?

Regards,
Junie

 

[Sunny22g]

Chat 72. Bro it's to gain resistor r8 .What u use upper like 1k 2 k then gain is low.when u come down then gain up

 

[chat72]

Chat 72. Bro it's to gain resistor r8 .What u use upper like 1k 2 k then gain is low.when u come down then gain up

Thank