F3 Builders Thread

[CeeVee]

hehe, indeed ZM, meet you there soon.

F3 is something i'm doing slowly it has to come out right.

Dificult was to find the right heatsink so that it wasn't any bigger than necessary, there is another german brand that has the same thing.

The power jfets i got in the first GB here, got the dificult bits...



🙂

 

[luis.martins]

Luis...it seems we will have 2 F3 here in Lisboa.

Hi CeeVee,

Indeed, we'll have two F3s in Lisbon, although I must warn you that it will probably take me the whole year to build it. At least... 🙂

Where are you sourcing parts from? Drop me an email if you'd like, my email is the forum's username on google mail.

Take care,
Luis

 

[valleyman]

For consideration. I don't know if these are real or not though

http://cgi.ebay.com/ELNA-SILMIC-II-3300uF-50VDC-ELECTROLYTIC-CAPACITOR_W0QQitemZ120309149732QQcmdZViewItemQQptZBI_Electronic_Components?hash=item120309149732&_trksid=p3286.c0.m14&_trkparms=72%3A1205|66%3A2|65%3A12|39%3A1|240%3A1318|301%3A1|293%3A1|294%3A50

 

[Peter Daniel]

I'm quite confused about the PS caps.

You may check this thread for more info: http://www.diyaudio.com/forums/showthread.php?s=&threadid=136037&highlight=

In my F3, I used 2 x 15,000/63 Nichicon Super Through per channel.

 

[luis.martins]

Thank you Peter, I believe that thread will clear my doubts about the PS.

Valleyman, you can get those Elna caps here:
http://www.audio-cube.nl/elna.htm

They're more expensive but I'd rather pay a little more that order them through eBay from China.

 

[rhing]

Elna Silmic II Caps

According to the Elna RFS Silmic II datasheet, there are no Elna Silmic II's with the 3300uF/50V value. They still might be legitimate, but I cannot find any Elna reference that mentions this value.

 

[luis.martins]

rhing, in the link I just posted above they have the 3300uF/50V but they state it's not Silmic II, it's the older model no longer in production.

 

[CeeVee]

You may check this thread for more info: http://www.diyaudio.com/forums/showthread.php?s=&threadid=136037&highlight=

In my F3, I used 2 x 15,000/63 Nichicon Super Through per channel.

Same place i got mine Peter, unfortunatley the promotion is gone.

 

[CeeVee]

Hi CeeVee,

Indeed, we'll have two F3s in Lisbon, although I must warn you that it will probably take me the whole year to build it. At least... 🙂

Where are you sourcing parts from? Drop me an email if you'd like, my email is the forum's username on google mail.

Take care,
Luis

Don't worry Luis i'm in no hurry either...got my Orions to keep me happy while i'm making them😎

 

[themystical]

Anybody have the set-up instructions for this amp?

 

[flg]

Anybody have the set-up instructions for this amp?

"set-up instructions" I believe are the same for any aleph amp. But you may want to tweak the "current source gain" "to taste". Search for "aleph current source" or read the ZEN V4 article at passdiy.com I think NP explains the pro's and con's there 😉

 

[flg]

Or of coarse, the ZV9 article on passdiy.com 😉 should also clear up any questions
😀

 

[themystical]

Thanks!!!

 

[Melon Head]

Hi Nelson
Does the power JFET need to be attached to a heatsink?
If so, what is th best way to do it?

 

[Nelson Pass]

Yes it does. I clamp it to the main sink with a screw and big thin
washer. You need some thermal grease, and if the anodizing is not
thick, an insulator.

😎

 

[flg]

We all (ya'll) must be off building F3 things. I've been slowly working out what I think, I would like to try where. I've heard very little F.B. as to what would be good. Mostly only N.P. telling me the cheap way. And, I understand that. But, that is subjectively the less than ideal way... This is DIY damn-it 😀
So, I've got some SilMic IIs for C4, C5, C6, C7 and some BiPolar BGs for C2 and C3. I've also got 4/ch 1000uF SilMic IIs to series paralell into a Bi-polar 1000uF output cap for C1 (upper mid or tweeter amp). And a Rel Audio Cap ppt theta 10u to bypass those...
Hmmm...
I'm about to order the 5W mils for R3, 4, 5, and R6, 7, and 8, can't forget R9 and I already have a 100ohm for R10.
I have Vishay metal foil tweak pots for P1 and P2 but they don't fit (for now at least) so I'm going for some cermet Vishay types...
I'll go with MK132s for R1 and 2 just because I can 😉 And I have a silver mica that would work nicely for the C9 cap.
Most of the other Rs will be Holcos...
If I could only find some better semiconductors???
I suppose It's O.K. to discuss PSU stuff here too??? I haven't really thought much in that direction. I have a killer, clean, 47Volt supply with 7A+ continuos capability... wee'll see...

 

[Ryssen]

Does the F3 invert the signal?

 

[Snokker]

testing output caps

After some 50 hours of burning in I did some testing on the new Rifa Evox 15000 uF in the output. Even compared with Black Gate's they are really OK. They really measure well (high frequency pulse trains and square waves).
And more importand, they really sound well! The specs pdf is too big ! 🙁 Just look for Rifa Evox PEH200 (Farnell has them)

 

[Zen Mod]

Does the F3 invert the signal?

nope - if spk is connected as drawn

 

[Melon Head]

Sounds good to me FLG.
What has it cost you so far?