100W Ultimate Fidelity Amplifier

[apexaudio]

Voltage 2x32vac on transformer will be OK, but you must disconnect transistors from heatsink, use liskun isolator.

[apexaudio]

Originally Posted by AndrewT

The way we were before we allowed computer nerds to take over the world !

New way for 'hand made' pcbs
Homemade inkjet pcb printer-1 - YouTube

[irwanks]

Originally Posted by apexaudio

New way for 'hand made' pcbs
Homemade inkjet pcb printer-1 - YouTube

it was a modified inkjet printer

[JOHN BALI]

Originally Posted by apexaudio

Voltage 2x32vac on transformer will be OK, but you must disconnect transistors from heatsink, use liskun isolator.

Like this picture?

I'm happy now, thanks to Apex

These AX17s just passed the test easily
the sound is very clear even I use ugly speaker without enclosure
just for first test...
both of AX17's offset are very low, I try to hear any hum but nothing on that speaker just like it was disconnected from the amp
maybe my cheap digital tester was broken, I also can't measure voltage on 0R33.

my AX17s not use trimpots, because i don't trust trimpot that I bought.
I replace 220 + 1k trimpot with single 330ohm resistor & I got about 2.30volt on C7(100nF)
Is this voltage need to be increase or decrease?
AX17 using TEF right, or just similar look?
so if I increase to 3,2volt(with big heatsink & enought supply) it is possible?
because there was someone told me that he run the TEF amp with 3,2volt bias voltage, even more..

For other DIYer you also need to try this AX-series
I also want to make the AX14 like what Apex recommended to compare with this AX17.
As usual with new way hand made PCB(my version)


Thanks again

Regards

[apexaudio]

Set 15mV across 0,33R for 50mA bias. PN voltage is 550mV like zener voltage, and you can't set bias with measure Vbe multiplayer voltage, and for TEF it's will be about 3,2V for any bias current. With 2,4V on Vbe multiplayer amp work in class B.
Regards

[apexaudio]

Originally Posted by JOHN BALI

Like this picture?

I'm happy now, thanks to Apex

These AX17s just passed the test easily
the sound is very clear even I use ugly speaker without enclosure
just for first test...
both of AX17's offset are very low, I try to hear any hum but nothing on that speaker just like it was disconnected from the amp
maybe my cheap digital tester was broken, I also can't measure voltage on 0R33.

my AX17s not use trimpots, because i don't trust trimpot that I bought.
I replace 220 + 1k trimpot with single 330ohm resistor & I got about 2.30volt on C7(100nF)
Is this voltage need to be increase or decrease?
EAX17 using TEF right, or just similar look?
so if I increase to 3,2volt(with big heatsink & enought supply) it is possible?
because there was someone told me that he run the TEF amp with 3,2volt bias voltage, even more..

For other DIYer you also need to try this AX-series
I also want to make the AX14 like what Apex recommended to compare with this AX17.
As usual with new way hand made PCB(my version)


Thanks again

Regards

Any sound difference SanKen vs Toshiba

[JOHN BALI]

Okay, so I need to increase it to 3,2volt & also measure voltage on both 0R33
the more important is the voltage on those resistor. Ok, I get it

Originally Posted by apexaudio

TEF for 4 ohm load.

I just go back on this page, TEF for 4 ohm load
If there any possibility to try this amp on 2 ohm load?
Maybe on 2 x 25 vac
I just want to know
my plan is used this amp on 8ohm speaker

Any sound difference SanKen vs Toshiba

When I test it at first time I don't use good speaker
but I hear a little sound difference SanKen vs Toshiba
Toshiba seems clearer (mid high) than SanKen, but the bias not really fair I guess
since Sanken maybe need a more bias (my guess)
I will set proper bias then
I will make it sure when I finish this project
Perhaps I also can make visual measurement with any PCscope

Regards

[apexaudio]

Originally Posted by JOHN BALI

Okay, so I need to increase it to 3,2volt & also measure voltage on both 0R33
the more important is the voltage on those resistor. Ok, I get it


I just go back on this page, TEF for 4 ohm load
If there any possibility to try this amp on 2 ohm load?
Maybe on 2 x 25 vac
I just want to know
my plan is used this amp on 8ohm speaker

Regards

For 2 ohm add another pair of outputs, and VI limiter is recomanded, but for home audio it's work without changes.

[Zinyx]

I have made PDF file, if someone want print more PCB in one page A4, everything is a mirror reflection for thermo-transfer.

[apexaudio]

Originally Posted by Zinyx

I have made PDF file, if someone want print more PCB in one page A4, everything is a mirror reflection for thermo-transfer.

Thank you,
Regards