An illustrated guide to building an F5 - Page 25

Nelson Pass · 11th July 2011, 03:00 AM

Quote:

Originally Posted by merlin2069er

this other side is giving me headaches.

How does your head hurt specifically?

Woody1911a1 · 11th July 2011, 10:48 AM

merlin , your brother is wrong . you must zero both pots by measuring across r3 and r4 ! cw and ccw mean nothing . as ZM told you it all depends on the board design , the pots and the way you installed them .

cheers Woody

Zen Mod · 11th July 2011, 10:55 AM

I'm wearing this one :

Itsmee · 11th July 2011, 03:39 PM

Quote:

Originally Posted by Zen Mod

I'm wearing this one :

Didn't know you where into the Propellerheads

merlin2069er · 11th July 2011, 03:46 PM

Quote:

Originally Posted by Woody1911a1

merlin , your brother is wrong . you must zero both pots by measuring across r3 and r4 ! cw and ccw mean nothing . as ZM told you it all depends on the board design , the pots and the way you installed them .

cheers Woody

Ok, I knew he was wrong.

When you have them both pots set to ~ "0", isn't one mosfet on and the other off? Will you see .00v at R11 & R12 or just one of them?

CanAm Man · 11th July 2011, 04:26 PM

Quote:

Originally Posted by Nelson Pass

It's more interesting when you wire them randomly.

Or replace the pots with photocells......that way, sometime during the day or night, the bias will set itself properly....for a few minutes.....

(Actually, I keep a little 3 x 5 file card in my folder with my F5 notes, BOM, schematics, etc...... just to remind me in which direction to tweak my pots, whenever I go in to fine-tune my bias settings....)

6L6 · 11th July 2011, 04:29 PM

Propellerheads (Band) -- In a nutshell, they are awesome!! It's a shame they are gone...

Woody1911a1 · 11th July 2011, 07:46 PM

Quote:

Originally Posted by merlin2069er

Ok, I knew he was wrong.

When you have them both pots set to ~ "0", isn't one mosfet on and the other off? Will you see .00v at R11 & R12 or just one of them?

you will see 0v at both

merlin2069er · 11th July 2011, 08:16 PM

Quote:

Originally Posted by Woody1911a1

you will see 0v at both

Ok, something is out of wack. When I've got both pots at "0", I've got R11 @ .35v and R12 @ .0v (or vise versa).

I've think I've gone over the circuit carefully, I can't account for the offset.

Any suggestions?

Zen Mod · 11th July 2011, 10:24 PM

suggestion ?

something is wrong - either with pot(s) , or with your measuring of them

11th July 2011, 04:29 PM	#247
6L6 diyAudio Member Join Date: Oct 2010 Location: Denver, Colorado	Propellerheads (Band) -- In a nutshell, they are awesome!! It's a shame they are gone... __________________ llustrated Build Guides - Pass Pearl 1 - Pass B1 - - Pass F5 - Pearl 2 - -O2 HPA - - Pass F4

11th July 2011, 10:24 PM	#250
Zen Mod diyAudio Member Join Date: Jan 2003 Location: ancient Batsch , behind Iron Curtain	suggestion ? something is wrong - either with pot(s) , or with your measuring of them __________________ my Papa is smarter than your Nelson ! tnx to clean thread ; Cook Book ; PSM LS Cook Book ; Baby Diyaudio FORUM ; Mighty ZM's Bloggg;I'm dumb

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11th July 2011, 10:48 AM	#242
Woody1911a1 diyAudio Member Join Date: Nov 2010 Location: Marblehead Ma	merlin , your brother is wrong . you must zero both pots by measuring across r3 and r4 ! cw and ccw mean nothing . as ZM told you it all depends on the board design , the pots and the way you installed them . cheers Woody