F4 power amplifier

[Nelson Pass]

16V would be the minimum I would go for, and I think that would
do it.

 

[lykkedk]

I think, this also count's for C3/C4, or do i have to go higher here, as culture mentioned ?

Jesper.

 

[Babowana]

C3/C4 . . .

If no problem in buying, I would use minimum 25V rating and well . . .

 

[luvdunhill]

I'm assuming the 0.0033 capacitor in the schematic is 3300pF? I was thinking about trying the Evox Rifa metalized paper X2 rated caps here...

 

[Nelson Pass]

Yes is .0033 uF. This should be an AC line rated part.

 

[Andrzej Sochon]

grounding

Hello,

I would like to share grounding idea of my ballanced f4. Peter Daniel helped me, thank you very much, Peter, so I hope attached drawing will help some of novices too.

Wishing Nelson quick and full recovery,
Andrzej

 

[luvdunhill]

Re: grounding

Hello,

I would like to share grounding idea of my ballanced f4. Peter Daniel helped me, thank you very much, Peter, so I hope attached drawing will help some of novices too.

Wishing Nelson quick and full recovery,
Andrzej

looks good. What are the things that look like pots in the diagram on the input?

 

[Andrzej Sochon]

Re: Re: grounding

looks good. What are the things that look like pots in the diagram on the input?

There are two simple rotary switches at one axis, 12 positions, with bunch of 1% precise resistors,
a.

 

[bubba177]

why does the case of the xlr go directly to chassis ground and not through the thermistor ? and don't some xlr connectors have the xlr case grounded to pin 1 internally?

 

[BrianDonegan]

why does the case of the xlr go directly to chassis ground and not through the thermistor ? and don't some xlr connectors have the xlr case grounded to pin 1 internally?

The thermistor isolated chassis ground from mains ground, unless there is a short. You want the signal ground connected to the star ground and only one connection to mains ground.

You really do not want the XLR case connected directly to the signal ground. This could cause a ground loop.

 

[carpenter]

Re: grounding

Wishing Nelson quick and full recovery,
Andrzej

What happened to Nelson?

 

[paulb]

Surgery. He hinted that it was a hernia.
http://www.diyaudio.com/forums/showthread.php?postid=1482282#post1482282

I had my hernia surgery to thank for keeping me from doing a work stint in the Arctic several years ago. Silver lining!

 

[Variac]

I had the honor of visiting Nelson's atelier a couple of months ago, and while I was there I realized that I had never actually seen the big Pass Labs amps! I thought that I had, but apparently the mental images I had were from photos. ( i DID know that I hadn't heard them before) The massiveness and scale was shocking- more like locomotives than electronic components. The place reminded me of a documentary I once saw about Aston Martin production- a worker with a single massive engine block on a stand, bolting the engine together from perfectly machined pieces...Nelson's place is quite similar but with a California vibe rather than an English one.. There were very few amps there that one person would be advised to lift!

 

[carpenter]

Surgery. He hinted that it was a hernia.
http://www.diyaudio.com/forums/showthread.php?postid=1482282#post1482282

Be well, Nelson.

 

[Nelson Pass]

Thank you. I'm recovering well from Thursday's surgery.

recovering well = not dying from superbug infection

For the record, it was not a hernia, but something I had never heard
of, but it makes for no difference.

Another martyr to audio...

 

[carpenter]

Thank god they didn't remove your sense of humor...

 

[jacco vermeulen]

but something I had never heard of, but it makes for no difference.

Speaking of veri-similitude

 

[Zen Mod]

Speaking of veri-similitude

you're really fnutz !

 

[jacco vermeulen]

similitude

 

[Manu]

...

recovering well = not dying from superbug infection

How right you are!

Wish you the best, Mister Pass.

Manu