Hey Guys - I've got a F4 question.
What preamp should I use?
-just kidding-
The F4 has ~+-23v as we know. I was going to use irfp140/9140 outputs. simple 'nuff, but here's the quandary - and my ignorance is shining here😉 I've decided to bridge them. Does this mean that the outputs will see twice the +-23v across them in the bridged configuration?
The 140 is a 100v fet, so you can see my concern...
Thanks!
What preamp should I use?
-just kidding-

The F4 has ~+-23v as we know. I was going to use irfp140/9140 outputs. simple 'nuff, but here's the quandary - and my ignorance is shining here😉 I've decided to bridge them. Does this mean that the outputs will see twice the +-23v across them in the bridged configuration?
The 140 is a 100v fet, so you can see my concern...
Thanks!
mpmarino said:Hey Guys - I've got a F4 question.
//////// and my ignorance is shining here😉 //////////
exactly
greedy boy

just usual over-engineering question:
what about 2SK1530/2SJ201 ?
they're just little more complementary than usual suspects...
is that worth the fuss ..... ?
what about 2SK1530/2SJ201 ?
they're just little more complementary than usual suspects...
is that worth the fuss ..... ?
Zen Mod said:
exactly
greedy boy
![]()
Well, I guess that clears it up for me. Thanks!
🙂
A question for Nelson,
Mr Pass,
I know you did a fair bit of research into which commercial preamplifiers would work well where voltage is concerned with the F4. Can you possibly provide a list of the balanced operation preamps that work well in terms of votage output?
Thanks very much for the consideration,
C
Mr Pass,
I know you did a fair bit of research into which commercial preamplifiers would work well where voltage is concerned with the F4. Can you possibly provide a list of the balanced operation preamps that work well in terms of votage output?
Thanks very much for the consideration,
C
I forgot to say
CONGRATULATIONS! on a very fine review.
http://www.6moons.com/audioreviews/firstwatt6/f4_3.html
Respect,
C
CONGRATULATIONS! on a very fine review.
http://www.6moons.com/audioreviews/firstwatt6/f4_3.html
Respect,
C
Re: I forgot to say
BTW, follow Chris' link for the completed review...
chrismercurio said:CONGRATULATIONS! on a very fine review.
http://www.6moons.com/audioreviews/firstwatt6/f4_3.html
Respect,
C
BTW, follow Chris' link for the completed review...
mpmarino said:Hey Guys - I've got a F4 question.
The F4 has ~+-23v as we know. I was going to use irfp140/9140 outputs. simple 'nuff, but here's the quandary - and my ignorance is shining here😉 I've decided to bridge them. Does this mean that the outputs will see twice the +-23v across them in the bridged configuration?
The 140 is a 100v fet, so you can see my concern...
Thanks!
Seriously,
I know I'm a greedy boy and all that ... but ...
I'm not sure about this - will the 100v irfp140 / 9140 see the full swing of both amps in bridged config. I'm thinking that it will still see only +-23v but I'm not 100% sure

Please?? I'll give you a cookie 🙂
Peter Daniel said:In bridged config. the output devices will see exactly same voltage (+/-23V)
The concept is shown in the attached picture.
When the upper amp swings towards +23 V, the lower swings towards the -23 V rail, putting all that voltage (46 V) over the loudspeaker.
NB! Dynamic loudspeakers and magnetic pick-ups (moving coils for example) are born symmetrical.
RK
Attachments
mpmarino said:
Seriously,
I know I'm a greedy boy and all that ... but ...
I'm not sure about this - will the 100v irfp140 / 9140 see the full swing of both amps in bridged config. I'm thinking that it will still see only +-23v but I'm not 100% sure
Please?? I'll give you a cookie 🙂

Variac said:Yup, if you wanna hear Lil' Punkin' pre with the mighty F4's then the West coast USA BURNING AMP is the place to do it.. Oct 20, 2007
Variac
salas said:This thread produces serious circuits through comedy.I LIKE 😀 😀 😀 😀
naah........
I just decided to make

probably F4 will not be suitable for any preamp duties in that case , even if his size will be adequate

all that for 15W/600E (doubling power all along to 2 ohms , where it will be current limited) ;
fussnote name for it can be DoKxxxMkxaCDoBT (Death of KrellxxxMkx and Certainly Death of Blow Toarch)

I am very envious! Really beautiful!
Could you please tell me the heatsink height (i.e. would they clear my rack) and where you got them?
TIA
Giulio
Could you please tell me the heatsink height (i.e. would they clear my rack) and where you got them?
TIA
Giulio
Heat sink height is 165mm... I got them from a privat person, here in DK - Sadly i don't think he got any more of them....
I am really glad with them.... just need stink...
They are run balanced with a bosoz, real good, but only to approx. 1/2 strenght...
Jesper.
I am really glad with them.... just need stink...

They are run balanced with a bosoz, real good, but only to approx. 1/2 strenght...
Jesper.
Thank you Peter and R-K, it is like I envisioned. The confirmation makes me much more comfortable.
Bla bla blaaaah.
I had a feeling you were busy working on something - I look forward to the reviews😉
_____________________________
Jesper - quite nice!
Zen Mod said:
Bla bla blaaaah.
I had a feeling you were busy working on something - I look forward to the reviews😉
_____________________________
Jesper - quite nice!
mpmarino said:...............
Bla bla blaaaah.
.........
I gave you an answer .............
http://www.diyaudio.com/forums/showthread.php?postid=1296687#post1296687

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