A guide to building the Pass F4 amplifier

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Joined 2017
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which is better?

Hi friends!

I'm not sure which way to take:

Toroid mounted vertically at the front, rectifier/CRC behind it on the floor
or
Toroid mounted on the floor, rectifier/CRC on top of it

?

Not sure about the radiation of the toroidy 18V 500VA. Assuming it is not a problem because it'd be a problem both ways.
I somehow see it like:
Tranny mounted vertically = better accessibility
Tranny underneath PSU = better weight-balance of the beast. CRC would be closer (above) the transformer...

thermally I don't see a problem (circulation is good either way)

thanks for hints!
david

PS: All seems well up to this point, soft start kicks in on itself, next is I'll test with the PSU connected. Whoo-hoo! Still not sure about the front-plate-design (switch, logo and such.) I may call it "F-4-less amp (that took me ages to build)"

EDIT: Forgot the images!
 
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I put mine under the PSU and it works just fine.
 

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Joined 2019
Paid Member
I know installing a cap across Hot and Neutral is the right thing to do.
But what does it do, exactly? Prevent a spark, right?
(wondering a bit why it doesn't short hot'n neutral, but don't dare to ask this, hihi:confused:)

I found this site very informative. You may too.

ABC's of Safety (Interference Suppression) Capacitors for Tube Radios

This thread also gave me a few tidbits of info. Standard discussion of "should we or shouldn't we?", but I like to read pros and cons as I learn.

X2 Line capacitors
 
Hi,

I wanted to present my tiny F4 project. Maybe it will be inspiration to those with lack of space for regular F4 monster.

Case: MINI DISSIPANTE 3U - 1MNPDA03/33/300N (330mmx303mmx124mm)
PSU: 2xSMPS300REh +/-24V. One per channel.
@ 200mV bias the heatsink temperature reaches ~54C. SMPS ~40C - so there is still capacity to go higher
It is actually crippled F4 version driven by es9038pro directly . Thank you all for all your tips.

Copule of months ago I posted such approach with SMPS and wrote that one unit failed. The issue was that I created short circuit and since that this unit was not working good. Once I repleaced the SMPS unit with the new one everything went back to normal. So this amp has been running like that for four months already with absolutely no issue ever since ...

And of course, as far as sound, the results are absolutelly fantastic!!! I got another F4 running on big toroid with massive caps so I got comparison.

Cheers,
 

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