That is one way.
Another is to cascode like Borbely using JFETs, which is much simpler.
In this case, because of the 4mA or so bias, I would recommend using J111 / J174 as cascode devices (instead of 2SK246 / 2SJ103).
You should get a good 5V Vds on the Toshiba's then.
And yes, have done that many times in various circuits, including my AX-J 100W.
Patrick
Another is to cascode like Borbely using JFETs, which is much simpler.
In this case, because of the 4mA or so bias, I would recommend using J111 / J174 as cascode devices (instead of 2SK246 / 2SJ103).
You should get a good 5V Vds on the Toshiba's then.
And yes, have done that many times in various circuits, including my AX-J 100W.
Patrick
Attachments
Erno Borbely article:
http://www.borbelyaudio.com/adobe/ae599bor.pdf
http://www.borbelyaudio.com/adobe/ae699bor.pdf
http://www.borbelyaudio.com/adobe/ae599bor.pdf
http://www.borbelyaudio.com/adobe/ae699bor.pdf
slr 5000 said:hi all
is the f5 scalable to higher power levels like the aleph series of amps
say more output devices and voltage with bigger sinks to match
if so would 100w into 4 or 8 ohm be doable
im currently using 2x f5 to biamp some esl and i love the sound at low volume but they do struggle at anything over half level
i know the f5 is not suitable to drive my esl but the sound is so nice id prefer to look at ways of getting more power than to build another amp
cheers
It wont be an F5 anymore, and the sound you like may be gone too
I fear the same even with just double output pairs
I suppose that just the slightest change, and it will sound different
Maybe you need a good 60-100watt, class AB and 1ohm stable
I will probably get shot for saying that
tinitus said:still 25watt
Not true, and there are many other advantages to go this way.
Though this is quite a long story...
http://sound.westhost.com/bi-amp.htm
See all the article and specially go to:
1.4 - Actual vs Effective Power
if music were a single frequency, then multiple amps and multiple speakers would be no louder than a single amp and speaker.tinitus said:Ehh, in some cases sure, but I would say that really depends
Anyway, that could be a lot of power consumption, and still 25watt
But we all know that music is not a single frequency.
bobodioulasso said:
Not true, and there are many other advantages to go this way.
I know
And sounds like impressive setup
But you also admit to use 150watt AB on woofer, which was my point, sort of
Though. when I suggested paralel output transitors with slightly raised bias, it was turned down with " no more power and still 25watt"
Kind of same thing
As would be a more powerful power supply, mono amps etc.
Though I understood it was about having more power to drive ESL
And thats what I relate to
I asked for impedance specs, but no reply
I dont know if active crosssover and multiple amps is a possible option with ESL
We may misunderstand each other
I plan to do 2way, and use F5 to drive a compression driver/horn, and AB amp to drive 18" woofer
So we do agree, sort of
bobodioulasso said:
Can't you help me to find the right post?
Starts from post 4366
ESL
Isnt the problem having very low to infinite impedance
yes, output current is proportionnal to input voltage in a C.F. amp.
Some amplifier designs mix the two kinds of feedback.
http://pagesperso-orange.fr/jm.plantefeve/systeme.html
see: Voie "médium" à contre-réaction mixte
Some amplifier designs mix the two kinds of feedback.
http://pagesperso-orange.fr/jm.plantefeve/systeme.html
see: Voie "médium" à contre-réaction mixte
pro said:I don't think so. A current feedback is good for an impedende as much flat is possible. With an infinite impedence, the voltage swing will clip at very low volume.
If you read the article, you may discover "current feedback" is
misnamed, and really is more like low impedance voltage feedback.
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