korben69 said:
Hi,
Mine don't match, but I noticed that the difference does show up as a small voltage mismatch which can be adjusted out with the pot that balances voltage between upper and lower groups of mosfets. IIRC, the voltage mishmatch seemed to match the difference in mismatch between the jfets.
Hi Carpenter, thanks.
Where do you place the pot to adjust voltage ?
I've missed the link... what are the specs of the pot ?
Where do you place the pot to adjust voltage ?
I've missed the link... what are the specs of the pot ?
korben69 said:
I'm rusty on which pot (P1 or P2). Just read the text and use the pot that adjusts the offset voltage.🙂
Edit: According to Peter Daniel's checklist, it's P2 that adjusts the DC offset. BTW, he's ordering more F4 pcbs. Go to his thread and purchase some if you're able.
anubisgrau said:
not much DIY job left on that link
Jacco is Jaccovitty 😉
he meant that there you certainly can find one - in one piece ....
are you really so desperate , regarding F4 ?
Zen Mod said:
i don't know what you mean by desperate, i've just thought that some shops would be clever enough to offer all the parts for sale - at least that's what i'd might do if selling parts. no hard feelings anyway
I put together a "sort of" kit -- for the matched IRF's, TL431, zeners, JFETs and the source resistors -- you supply the other discretes (res and caps) and led. You know where to find me.
anubisgrau said:
there is no hard feelings , in any way ;
with "desperate " I meant - are you so curious to try F4 ......?
FR fever 😉
Minimum Impedance
How stable is the F4 when connected to speakers that drop below 4 ohms? 2 ohms? 1 ohm? Will I have a cool arc welding light show in my living room?
Thanks,
C
How stable is the F4 when connected to speakers that drop below 4 ohms? 2 ohms? 1 ohm? Will I have a cool arc welding light show in my living room?
Thanks,
C
Re: Minimum Impedance
Oooooh, why not add a mirror disco ball and get back to us when it's all over...😀 😉 😀
chrismercurio said:
Oooooh, why not add a mirror disco ball and get back to us when it's all over...😀 😉 😀
I tossed that in as a joke. I really DO want to know about connecting the F4 to low impedance loudspeakers.
Thanks,
C
Thanks,
C
Re: Minimum Impedance
It's stable into anything I've tried. Depending on the values of
the Zener diodes, you will run out of current. Sotck, it poops out
around 10 amps peak, implying full swing into 2 ohms.
chrismercurio said:
It's stable into anything I've tried. Depending on the values of
the Zener diodes, you will run out of current. Sotck, it poops out
around 10 amps peak, implying full swing into 2 ohms.
High/low bias function?
I was wondering if it was possible to implement a low bias function for back ground listening?
I was thinking of af switch for changing the bias setting resistors?
I was wondering if it was possible to implement a low bias function for back ground listening?
I was thinking of af switch for changing the bias setting resistors?