A guide to building the Pass F4 amplifier

Thanks everyone for all the encouragement and insight. Thanks 6L6 for the support. This is all inspiring.

Now I just need to decide between the F4 and Aleph J, or nor worry about my balanced sources and go single ended. I like the flexibility of the F4.

Most have said that the F4 is the sound of your preamp. Since I have an Aleph P and have not used it in and ideal situation, does anyone know the sonic signature of it? This will help me decide in my amp choice.

Thanks again for the encouragement.
 

6L6

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The Aleph P does not have a bucket of gain... However most people don't need anywhere near as much power as they think, so it might be plenty with an F4.

There is no doubt in my mind that it will sound fantastic.

The Aleph J is SE or BAL in, and will go to full output with that preamp. It will also sound wonderful.

Check your PM.
 
After what has seemed like an eternity I'm ready to finish wiring my F4. But, I'm not clear on hitching the amp boards to the Peter Daniel power supply. One section has V+ and Ground, the other V- and Ground.
 

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Excellent, thank you. Just wanted to be sure I wasn't missing something that may be obvious to others. So that leaves the rectifier side, which I assume I wire just as shown in the F5 thread, and the chassis ground - which I know ties to the ground of the iec outlet...and from there I'm lost again :).
 
A CL60 is designed to pass "normal" currents.

I asked a few times about the modified Bridge Rectifier version of the Disconnecting Network.
No Member came forward with evidence of "safe" to use" as suggested.

I tested it.
The size of the explosion surprised me.
Even more surprising was that I could not detect any damage or changed parameters in the Disconnecting Network components.
I now recommend the bridge rectifier Disconnecting Network.

I have never put a CL60 to such a "test"

Two reasons:
1.) I am not on a 110/120Vac Mains supply
2.) I don't have any CL60 NTCs

Maybe you should try to find "evidence" that what you and Pass are suggesting is safe on 110/120Vac fault currents.
 
I think a little clarification is in order for those of us who aren't EE's.one would assume that if this is the grounding scheme utilized in production FW amplifiers that it is perfectly safe for our homebrew editions. Is this not the case? Also, other than a lightning bolt ( which would be stopped by proper protective equipment long before reaching any of my components ),when and how is a kA going to make its way to ground through my amp. Please elaborate.
 
the Fault Current is limited by the impedance of the Source (the Mains supply) and the impedance of the house wiring.

This can be much less than an ohm.
With a 240Vac supply having a maximum voltage of 359Vpk, the Fault Current that can flow can approach a kA.

Look at your MCBs. They are rated for maximum non fault current and also rated for ability to break Fault Current. I expect to see 6kA or 10kA on UK MCBs.

Even RCCBs (RCDs) are rated for their ability to break Fault Current.

Gone out and checked, all my Merlin Gerin and Dorman Smith are rated 10000 (=10kA)

If you are going to work with Mains Powered projects, then it is your responsibility to make your self aware of the risks.
 
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