How to build the F5

[6L6]

So a cascode on top of the front end to keep the Jfets from frying, and what else?

Sounds interesting.

 

[Zen Mod]

no frying , no Herr Mueller , sweetspottier

read F3 article

 

[rade95]

no frying , no Herr Mueller , sweetspottier

read F3 article

Zen Mod what is your point? I read F3 and ZM #8 articles. I am not talking about SE Class A JFET/MOSFET amp, but PP Class AB amp. To my knowledge FW hasn't designed such an amp yet, PassLabs did, several in fact. If I missed FW design or if this has been discussed in some other FX threads, pls point me to the thread, but F3 or ZM #8 is _not_ what I am looking for.

 

[Zen Mod]

cascoding , same as modulated cascoding , is covered in FW F3 article

I was replying to 6L6 , without seeing that his post is more reply to your's , then general question

whatever - idea about lighter biased F5 is covered already , somewhere in F5 threads

 

[rade95]

No problem, if you can point the page where this was discussed I would appreciate it. I want to have a lower bias but higher +- rails, that would make MOSFETs work in class AB switched mode, producing more power. I doubt that this can be done without having a new driver stage.

 

[Jallhalla]

Stupid question, but its taking me way to long to search up the answer:

Where on the schematic does r35 and the led go? Can i use any led and a 50k trimmer pot to adjust the light to my taste? I like them dim. I´m making my ft p2p wired, and the picture of the board tells me to little.

Also the original schematic differs quite a lot from the one in the store now. What are the big difference in functionality?

Again, I know these questions are stupid, there is just to much irrelevant information out there.


Thanks!

 

[Zen Mod]

yup - led and trimpot will do - connect it between any side of PSU and gnd ;

regarding differences between F5 origigi and store pcbs - search for Cviller's blog

 

[labjr]

Stupid question, but its taking me way to long to search up the answer:

Where on the schematic does r35 and the led go? Can i use any led and a 50k trimmer pot to adjust the light to my taste? I like them dim. I´m making my ft p2p wired, and the picture of the board tells me to little.

Also the original schematic differs quite a lot from the one in the store now. What are the big difference in functionality?

Again, I know these questions are stupid, there is just to much irrelevant information out there.


Thanks!

There's even another different F5 schematic in the F5 Turbo manual which I think is the latest version.

Pot. P3 is added to tweak input symmetry for lowest distortion.

The input resistors R1&R2 are new values and configured differently. Thermistors TH1&TH2 are not connected to the rails. Not sure what those changes accomplished. Probably subtle differences.

 

[AudioSan]

TH1 and TH2 is connected to the other side (after) source resistor. insted of before source resistor.

 

[Jallhalla]

That is what I´m talking about. Why are we doing this? Have searched for a while now. The blog only mentioned the cascoding and more output mosfets. I´m bulding the standard first.

Do you know any place in trondheim to get sheet aluminium and aluminium angles, by the way?

 

[AudioSan]

it can be done eighter way
you can try Trondheim stål.

 

[Jallhalla]

Haha, I was hoping for a "do it this way, ´cause its better!"

Thanks, I´ll call them tomorrow!

 

[duder1982]

Is there a bom out there with mouser part #s.
Thanks

 

[6L6]

There isn't.

However, the community would be very grateful if you made one...

 

[max426]

Look at post 930 in this thread

 

[duder1982]

Look at post 930 in this thread

The post before it has a excel spreadsheet but my virus protection blocks it.

 

[duder1982]

There isn't.

However, the community would be very grateful if you made one...

Well since I have to do the foot work with Mouser anyway maybe I can give their bom program a shot. As long as I get feed back from the community if something isn't right so it can be corrected for future folks as my self.

 

[duder1982]

p1,p2,p3 I am stuck on these, on trying to find the right ones. Anyone have any ideas.

 

[buzzforb]

Bourns 3299W or 3296W

 

[duder1982]

Thanks Buzz, If mouser's site would just speed up I would have this wrapped up for it to be picked over.