F4 power amplifier

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#2,821
Thanks Doug,

Perdone me I have understood only 2/3 "things". What do you intend as "more gain" ? The F4 is current gain only, so I suppose you are referring to previous stage , the tension gain stage who is driving the F4 ? Am I right?

I agree about quality, but I have a biamp and I need a new amp only for the Bass ( woofer up to 400Hz) so Class A seems to me a waste of money 🙄
Since my friend have experience and good skill with tubes, I am serching an easy bass follower AB class ( 70-80W). This is the reason
because I have asked if it is possible swap the class into AB.

Cheers,
Paolo
 
#2,826
Very Thanks indeed Mr. Pass and Doug,

It is exactly that I need : a "simply" powerful AB follower for my woofers wich I can drive with tubes . Zero overall feedback and minimal number of stages also 😀
This nice hybrid will has a hard mission: soubstitute my belowed
Threshold 4000...:devilr: Very difficult , but I am confident !:angel:

Thanks again,
Paolo
 
#2,827
Leben RS28C

I've just acquired one of these preamps to go with my pair of DIY F4s. The Leben is a great preamp and is unusual in that it has a user variable output up to 80v (sic), so is a great match for the F4. They sound terrific together driving my Quad 989s 🙂
 
#2,830
May turn up, would be needed let me write a treatise, that the raised pasta raising only and exclusively then suitable it F4 amplifier, if at least 0.3 were tensenesses which can be measured on the source resistance. But may be not too much more, because it roasts already then. Of course beside the suitable permits, if your lawyers approve it, eh, Nelson?
Of course you received a brainwave if you believe it now, you are out then, dared already protected the patent:

Raised pasta raising strictly with Class A Power amplifiers.

You may establish the contact with my lawyers if you desire it.
Or my psychologist, that let him provide something stronger to me.

It would be necessary to draw it up possibly, what kind of music has to sound meanwhile. I believe it, depends on an occasion. At this time at the time of Christmas certainly suits J.S.Bach Weihnachts Oratorium BWV248.
The lecturer is not all the same possibly.
My wife would say it sure now, let me not drink more beer.
She says it always though.

But you are not angry because of it, eh?

Gyuri
 

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#2,832
Pasta raising.

Well, let us see that the idea works then!

I hope for it, it before me speaking it is recognized already now, nothing it does not make sense the raising cheapo AB class onto amplifiers to trust, because its result will be unpleasant deafness really.

Gyuri
 

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#2,833
You believe it, how that our beloved Nelson's lawyers are so finesse that they tied it up:
May not be pasta raising to use the amplifier!
They did not give a thought to it according to me, it is necessary to send them next in this wise.

Gyuri😀
 
#2,836
Gyuri said:
May turn up, would be needed let me write a treatise, that the raised pasta raising only and exclusively then suitable it F4 amplifier, if at least 0.3 were tensenesses which can be measured on the source resistance. But may be not too much more, because it roasts already then. Of course beside the suitable permits, if your lawyers approve it, eh, Nelson?
Of course you received a brainwave if you believe it now, you are out then, dared already protected the patent:

Raised pasta raising strictly with Class A Power amplifiers.

You may establish the contact with my lawyers if you desire it.
Or my psychologist, that let him provide something stronger to me.

It would be necessary to draw it up possibly, what kind of music has to sound meanwhile. I believe it, depends on an occasion. At this time at the time of Christmas certainly suits J.S.Bach Weihnachts Oratorium BWV248.
The lecturer is not all the same possibly.
My wife would say it sure now, let me not drink more beer.
She says it always though.

But you are not angry because of it, eh?

Gyuri
Click to expand...



Gyuri,
Those look like nice LARGE heatsinks....
Nelson mentioned previously.

http://www.diyaudio.com/forums/showthread.php?postid=1679367#post1679367

You can probably get the thing to heat a room or two..
 
#2,837
Ja, Hungarian silver, according to this expensive.

I do not know it exactly to define, till when I may go away with the steady current because I am a fakir, and Nelson's method in this manner at me cannot be trusted!

Gyuri

May help possibly to define the pasta, if it does not grow (raise) but porcupine, then already a lot the current.
 
#2,838
ZM F4 Headphone amp adjustment

I've built Choky's headphone version of the F4 and wondering about gain adjustment - what should I be aiming for? Rail voltages are at +-15V and I am starting with 100mV across the source resistor. Also, I find dc offset wavering quite a bit, do I adjust for dc offset with input shorted to ground?

Thanks for any help
 
#2,839
Re: ZM F4 Headphone amp adjustment

twitchie said:
I've built Choky's headphone version of the F4 and wondering about gain adjustment - what should I be aiming for? Rail voltages are at +-15V and I am starting with 100mV across the source resistor. Also, I find dc offset wavering quite a bit, do I adjust for dc offset with input shorted to ground?

Thanks for any help
Click to expand...


:clown:

gain of F4 is already ~ 1 , so you really can't care less for that issue .

regarding bias adjust - it's common procedure for all stages - grounded input
 
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