100W Ultimate Fidelity Amplifier

[apexaudio]

Originally Posted by cjkpkg

Here is a pic...The speaker protects are not hooked up yet but it did not thump at all upon startup or shutdown.

Nice work, and nice picture. I suggest to revert positions of transformer and PSU and you have short wires instead long from AC input to the transformer and from transformer to PSU. Bias transistor (BD139) must be connect on heatsink with outputs.
Regards

[davidus]

Hi, mr. Slavkovich.

Are there any changes to be done with parts if I want to use your PSU-5 design with +-36V AC?

Thanks

[ahmadfay]

Originally Posted by ahmadfay

hi all,
why ax 20 which I have made the volume more slowly than the ax14, if this is so the character of ax 20 (ax 14 TEF)?
thanks

Apex hai ...
what is my post? is there any comment from you? thanks

[profards]

mr apex.., good advising! i am going to use my stock mj15015s and '016s in Nazirdigi's 4 pairs ax20. as i read the MJ's pdf online i knew its less powerful than what they are using here as powers. i am planning to maximize as possible the supply voltage to its safe extent. what can you advise? thank u vry mch sir.

[profards]

@Nazirdigi.. congrats for your vry successful 4 pair ax20 and its protect.. can u post here their pcbs for printing? i thank u much in advance..

[profards]

btw expert friends, i am planning also to make an amplifier for my lead guitar. can this also be excellent? i am going to have this in a single channel and i think a pair of outputs is enough. thanks to u all

[sonal kunal]

Hi miles, I assembled AX-20 amp I have attached layout. Problem with this layout is, there is no connection between Q9 - Q18 and Q8 - Q17. I easily fixed by using MJE340-50 lead as jumper at copper side. My problem is I am not able to adjust bias, amp is playing music every thing seems right.

[ahmadfay]

hi, Sonal Kunal
if you look at the scheme, there will be a dc current that comes out on the speaker output, because there is one diode 'IN 4007' an inverted installation, the voltage of the diode is positive. you try to watch another scheme,
Regards

[sonal kunal]

yes thats in layout but in board I have place correctly, there is only 10-15mV dc at output. I'll post picture soon.

[sonal kunal]

I connected amp in series with 10Ω resistance, when nothing seems to burn I put fuse and tried to adjust bias but was not able to, even winding trim-pot to full. Amp was playing music but with crossover distortion at low volume.