A guide to building the Pass F4 amplifier

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#2,343
status quo

here's what it looks like...
I enjoy contemplating wires 😀
 

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#2,345
🙂🙂
Oh, those spades... they're residue of my unplanned build. I just went after that :cheers: splendid build-guide before I made up my mind about the layout, and they're soldered so good that I didn't dare to try removing them. I'll cover them with shrink tube.

BTW I'm thinking about making a transformer-box — for aesthetics and maybe isolation too, and I'll probably will give it it's own foot underneath the chassis (according to this article in LinearAudio)
 
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#2,348
myleftear said:
🙂🙂
Oh, those spades... they're residue of my unplanned build. I just went after that :cheers: splendid build-guide before I made up my mind about the layout, and they're soldered so good that I didn't dare to try removing them. I'll cover them with shrink tube.

BTW I'm thinking about making a transformer-box — for aesthetics and maybe isolation too, and I'll probably will give it it's own foot underneath the chassis (according to this article in LinearAudio)
Click to expand...

Thanks for the link. What a beautiful build.
 
#2,351
protection - why not - sleep is better, if nothing else

tap to big xformer , if you're using center tap as GND - protection circuits often use AC sense as base for operation ( enabling fast power- off) , for which you need connecting directly to GND and one secondary side of big Donut

if you're using 2 bridge arrangement for big Donyt(s), better to use small xformer
 
#2,353
Zen Mod said:
tap to big xformer , if you're using center tap as GND (...) , for which you need connecting directly to GND and one secondary side of big Donut

if you're using 2 bridge arrangement for big Donyt(s), better to use small xformer
Click to expand...
😕
Not sure what I'm seeing, I'd say 2 bridge arrangement, so no connection to my big bugger? DOH!
Please tell me what I see here
 

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#2,356
Just a little sidenote:
If you‘re building your F4 with the boards mounted vertically (like most here have), I‘d recommend to doublecheck your trimpots are accessible (have the screw towards the top of the amp).
Thus, adjusting bias will be a pleasure to do and even could be made accessible with the chassis closed...
 
#2,357
myleftear said:
erm, sorry, but, I'm not sure about the speaker protection unit.
Is it worth/recommended to use it?
And, can I just tap a secondary of the big transformer (2 x 24V 500VA), or do I better install a tiny second one?
Click to expand...


The speaker protect board is also a startup delay so you don't hear any thump out of the speakers on power up. They alone made it worth the effort to me.


You can tap onto the main power supply to drive it, but having a load on one half of the supply upset my OCD so i went with a dedicated transformer.
 
#2,359
Hi guys!
Sharing my experience here for those who want to experiment.
I have built this with 16R (you can use 4 or 8 if you like)

IMG_1718.jpeg


I am driving my F4 with a type 26 preamp to a 45 amp
IMG_1721.jpeg

IMG_1722.jpeg


I have tried this before and I like it. Now it sounds even better than I recall (only change is the resistor load from the white coffin type to present).
I also tried BA2018 linestage with Muses 72320 volume control to DHT amp instead of DHT preamp-DHT amp (I tried 01A with great results too) driving the F4. Superb!!

IMG_1724.jpeg

IMG_1728.jpeg

Next stop is Muses to DHT amp (passive!) then some other amps to try.
Truly worth the effort and I am glad I built the F4.
Abe
 
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