F4 power amplifier

[nonoise]

The 35A will probably be the If rating of the bridge, the slow blow fuse is on the primary of the transformer were the current is much lower than on the secondary the maximum the bridge will see is a function of the output impedance of the secondary winding of the transformer and the // combination of the power supply CRC section and the actual load
(amplifier).

In other words much higher than 2.5 A

 

[luvdunhill]

The 35A will probably be the If rating of the bridge, the slow blow fuse is on the primary of the transformer were the current is much lower than on the secondary the maximum the bridge will see is a function of the output impedance of the secondary winding of the transformer and the // combination of the power supply CRC section and the actual load
(amplifier).

In other words much higher than 2.5 A

I see, this makes perfect sense. Thank you!

I guess all I need is the working voltage for the 220uF capacitors. Does anyone know what the minimum would be here?

 

[Jaac]

You could try http://www.clofis.nl/ and order some of their Seifert heatsinks.

Looks like some sk56 from fischer elektronik or the kl-146-200 from Seifert. Got both of them. The Fischer ones are better finished. See my photo album for the pics

 

[DocLorren]

Thanks guys for the links to shops for big heatsinks in Europe.
Jaac: pretty impressive chassis you are building there! Mighty tranformer lying left to the heatsink. Your heatsinks will stand up to the task of converting all that current to heat you think?

 

[Jaac]

Thanks guys for the links to shops for big heatsinks in Europe.
Jaac: pretty impressive chassis you are building there! Mighty tranformer lying left to the heatsink. Your heatsinks will stand up to the task of converting all that current to heat you think?

The amp that you see on the photo's is the finished aleph 5 and having 40 volt dc rails drawing 2 amps thats 160 watts in idle to dissipate by the heat sinks. They get hot, not hotter then a X150.5. tomorrow i will measure the temp of my heat sinks and also of a pair of XA100 to compare with. For the F4 i think the sinks will do the job but i also have some other sinks here at my house and they are bigger and they need some cutting i think to use them for an amp.

 

[jleaman]

The amp that you see on the photo's is the finished aleph 5 and having 40 volt dc rails drawing 2 amps thats 160 watts in idle to dissipate by the heat sinks. They get hot, not hotter then a X150.5. tomorrow i will measure the temp of my heat sinks and also of a pair of XA100 to compare with. For the F4 i think the sinks will do the job but i also have some other sinks here at my house and they are bigger and they need some cutting i think to use them for an amp.

I think you can build a nice x1000 with that piece

Jase

 

[luvdunhill]

I guess all I need is the working voltage for the 220uF capacitors. Does anyone know what the minimum would be here? [/B]

hm, 25 V DC maybe?

 

[Studley]

Transformer question for NP

Nelson

I've ordered a pair of the Plitron 300VA 18v trafos through the group buy. These have the"type 7" primaries which are suitable for 115v or 230v. I'm in the UK and I've just been advised that our mains is in fact 240v +/- 6%. Plitron tell me that these trafos can handle up to 230 +10%, which means they might be just about be ok for worst case of 240v+6%.

Do you use their type 7 trafos in your commercial offerings that are bound for the UK, or do use their type 5 which are configurable for 240v? (Hoping for some additional comfort from you here!)

thanks
Ian

 

[Nelson Pass]

I use the 240's, but I don't think you should worry, as Plitron
is very conservative, and besides that, we put a Thermistor
in series with the primary.

 

[Studley]

Thanks Nelson.

 

[jleaman]

SO is any one running their F4 with the Peter Danial boards ?

Jase

 

[traw]

yep, i am.

http://www.diyaudio.com/forums/showthread.php?postid=1266017#post1266017

 

[Srajan Ebaen]

question for traw

Can I use your shot of your DIY F4 with the following photo credit for my review of Nelson's commercial F4, just to show the kind of hands-on excitement this stuff inspires below the radar of the mainstream? See attached link. I'da sent you a direct e-mail but I'm too new here to be allowed

http://www.6moons.com/audioreviews/firstwatt6/diyf4.jpg

 

[Variac]

Your e-mail and PM's should be working .. You are not on any sort of
moderation- You are a Registered Member. If you are having troubles please telll me.

Welcome aboard

Variac.

 

[traw]

yep, i am.

http://www.diyaudio.com/forums/showthread.php?postid=1266017#post1266017

That is fine by me... maybe I'll get a faceplate on it though the plitron can be eye candy to us diy'ers heheh.

EDIT: using Peter Daniel's nice boards

 

[Srajan Ebaen]

Thanks.

That's swell - and I'll mention the Peter Daniel boards in the credit -

 

[Babowana]

Re: Thanks.

- and I'll mention the Peter Daniel boards in the credit -

Hmm . . . good advert.
How come a commercial guy selling the boards of other's in this place?
Meanwhile, why the others wherever they are doing the same blaimed?
Confusing . . . really . . .

 

[apassgear]

Re: Re: Thanks.

Hmm . . . good advert.
How come a commercial guy selling the boards of other's in this place?
Meanwhile, why the others wherever they are doing the same blaimed?
Confusing . . . really . . .

As far as I know PD does not make a business on those boards, just check the price.

I see it as a community service for all DIYers... don't kill that attitude!

 

[Babowana]

Re: Re: Re: Thanks.

As far as I know PD does not make a business on those boards, just check the price.

I see it as a community service for all DIYers

Well understood.
But, if another guy declares so, the same principle applied?
If I do, it's a community service while if others do, it's a bad thing?

Maybe I'm too extreme and thinking wrong . . .

 

[chrismercurio]

If I remember correctly...

Peter did not want to do this until he had the blessing of Nelson Pass. The boards have Nelson's name right on them giving credit where credit is due and were only created with express permission.

C