100W Ultimate Fidelity Amplifier

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R

RSK

Member
Joined 2004
still4given said:
Hi Guys,

An update about my A class PSU. I ordered some BF245A's and they came in today. I installed them and the PSU still didn't work. With further investigation I discovered that I had installed 500R trimmers rather than 5K. I swapped out the 5k trimmers and reinstalled the BF246 jfets and it works flawlessly. Sorry for all the fuss. If anyone wants my layout for the BF246 just let me know and I'll post the files.

Blessings, Terry
Click to expand...

Terry,
Any difference in sound?
 
still4given

still4given

Member
Joined 2004
Apex Goodness!

A class PSU fed with 20-0-20vac and set to +-18vdc into the Apex non-inverting LinearPre. That is feeding an Apex F100 which is powered by the Apex F100 PSU/Protection circuit. I'm feeding the F100 PSU with 44-0-44vac giving +-61vdc rails. The sound is absolutely stellar! This setup is definately going to find its way into a case in the near future. Highly recommended.

Blessings, Terry
 

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Y

yakusa

Member
Joined 2011
Finish second board ax14 and im having some issues. I get 45v at bias. Also 45v at output. Psu is 45+-, input grd is connceted to psu grd. Checked all components and they are in the right place. Adjusting bias resistor doesnt change either. Thanks for any help
 
Last edited:
still4given

still4given

Member
Joined 2004
Hi Evan,

I'm not sure what the target was that Mile had in mind when designing the F100 but I have been pleased with the sound. The addition of the F100 PSU/ board has made it a very usable unit. The protection seems to work very well. I know, I tripped it a couple of times with careless probing this morning. I know this is the wrong thread to discuss it.I has its own thread but I had it handy and wanted to test the LinearPre and the A class PSU.

Blessings, Terry
 
still4given

still4given

Member
Joined 2004
yakusa said:
Finish second board ax14 and im having some issues. I get 45v at bias. Also 45v at output. Psu is 45+-, input grd is connceted to psu grd. Checked all components and they are in the right place. Adjusting bias resistor doesnt change either. Thanks for any help
Click to expand...

Sounds like you have a solder bridge somewhere of a bad solder joint. A test I almost always perform now before starting up an amp is doing a diode test on each transistor. I try to use the trace leading to the pin rather than the leg itself. This will often reveal a bad joint of short. If that doesn't reveal the issue then I reflow all the solder joints.
 
apexaudio

apexaudio

Member
Joined 2010
still4given said:
Hi Evan,

I'm not sure what the target was that Mile had in mind when designing the F100 but I have been pleased with the sound. The addition of the F100 PSU/ board has made it a very usable unit. The protection seems to work very well. I know, I tripped it a couple of times with careless probing this morning. I know this is the wrong thread to discuss it.I has its own thread but I had it handy and wanted to test the LinearPre and the A class PSU.

Blessings, Terry
Click to expand...

Nice work, F100 is mini PA amp with hi-fi sound.
Regards
 
prasi

prasi

Member
Joined 2014
sites.google.com/site/analogdesign1234/
Paid Member
still4given said:
Apex Goodness!

A class PSU fed with 20-0-20vac and set to +-18vdc into the Apex non-inverting LinearPre. That is feeding an Apex F100 which is powered by the Apex F100 PSU/Protection circuit. I'm feeding the F100 PSU with 44-0-44vac giving +-61vdc rails. The sound is absolutely stellar! This setup is definately going to find its way into a case in the near future. Highly recommended.

Blessings, Terry
Click to expand...

So, what member rohin was telling is true... A-class PSU does make a difference!.
 
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