excellent look great nice build, sir question did you found with no problems the semiconductors BF245? they are 4 on the PCB does the regulator perform really well the adjustment work ok I'm asking because I haven't see not many pictures of the build PCB by the way I have the new Apex P30 layout if I tested and work correctly I will share gerber and Sprint Layout 6 files here but I need to be sure is correct before I order a few sample PCB to tested
Best Regards
Juan
YES I found the BF245 without a problem, and why not do the APEX P30ZF
there is a Apex P30ZF? nice, oh let me explain why I want to build the Apex P30 I'm a PC user so the output audio of the PC doesn't exited for the amplifier enough so that is why I need it but if Apex P30ZF is ready why not right? thank you for share the files I'm gonna adjusted a bit I'm on that right now have a great day sir and hi from Puerto Rico
Best Regards
Juan
This post has 12,000 replies which is great, but sadly would take a lifetime to read it all. Therefore, this question might have already been answered. In the interest of learning new things:
What exactly makes this amplifier the ultimate fidelity amplifier?
My observations based on the circuit in post #1:
- The input stage is un-degenerated. So, while great for noise, it will distort quite a bit.
- The second stage recycles the base current of Q8, but the distortion mechanism is really due to the base current of Q6 as consequence of its emitter/collector current being modulated by the base current of Q8.
- The output stage looks quite vanilla, i.e. no better than other amplifiers.
I noticed the compensation is non-Miller, but I cannot comment on what this will do to distortion without playing a bit with the amp.
Any insights would be appreciated since I am quite puzzled about what is special here.
Thanks!
- Sandro
What exactly makes this amplifier the ultimate fidelity amplifier?
My observations based on the circuit in post #1:
- The input stage is un-degenerated. So, while great for noise, it will distort quite a bit.
- The second stage recycles the base current of Q8, but the distortion mechanism is really due to the base current of Q6 as consequence of its emitter/collector current being modulated by the base current of Q8.
- The output stage looks quite vanilla, i.e. no better than other amplifiers.
I noticed the compensation is non-Miller, but I cannot comment on what this will do to distortion without playing a bit with the amp.
Any insights would be appreciated since I am quite puzzled about what is special here.
Thanks!
- Sandro
there is no joint point of view.
by reading this thread for years and drawing (quite) a few of PCB's by schematic and than building them... I have learned quite a bit of... everything,in theory and in practice(input output variations).... a lot of people have a lot of individual experience so they have a lot to say about it,and there is no just one truth...it is not the same for everyone. some liked the sound of simple amplifier as it is AX11,other preferred A40. many differences in basics but they are all by the meaning of users-the one:ultimate fidelity. some say "make it simple",other say "no pain no gain"... and it is all individual. I have built AX11 and A40... and I prefer both. so...the question is still open. try some.
by reading this thread for years and drawing (quite) a few of PCB's by schematic and than building them... I have learned quite a bit of... everything,in theory and in practice(input output variations).... a lot of people have a lot of individual experience so they have a lot to say about it,and there is no just one truth...it is not the same for everyone. some liked the sound of simple amplifier as it is AX11,other preferred A40. many differences in basics but they are all by the meaning of users-the one:ultimate fidelity. some say "make it simple",other say "no pain no gain"... and it is all individual. I have built AX11 and A40... and I prefer both. so...the question is still open. try some.
Hello,
I have already built the P30 it is really excellent preamp .... I would also like to build this P30ZF, where can I buy these PCBs? thank you very much
hello guys I kept on re-drawing the A class PSU that Mr. Mile made and I just add a few modern options I would like to know if the BF245A can be replace by other ones or equivalents here are some images and original layout
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hello guys I kept on re-drawing the A class PSU that Mr. Mile made and I just add a few modern options I would like to know if the BF245A can be replace by other ones or equivalents here are some images and original layout
Hi Juan,
I built it with 2SK246 and it works fine but they have a different pinout.
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oh thank you I can then re-trace them to the 2SK246 pins
I was searching online and wow they are gone, and they are some on EBay but I'm afraid of counterfeit semiconductors they scare me 
weird to answer my own question but take a look here:Toshiba 2SC4793/2SA1837 reborn
Please take into consideration, that the package of the new parts are smaller, which means not 100% compatibility.
Sajti
Yes, You need to reduce 3x47kohm between the bases of the ccs, to 36kohm.
Sajti
A Class PSU prototype PCB ordered
hey guys I check the layout for a few hours and is completed I order just a few to test if all goes well and some one is interesting on the gerbers let me know I don't mind to share at all
I ask the question about the LED and no one replay is fine I hope all goes smoothly
hey guys I check the layout for a few hours and is completed I order just a few to test if all goes well and some one is interesting on the gerbers let me know I don't mind to share at all
I ask the question about the LED and no one replay
is fine I hope all goes smoothlyAttachments
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