R1
0V65/1R5=0A43
0A43 x 24V = 10.4W of heat
so , with 2x18Vac , you can make sort of dual mono PSU - one secondary (and rest of PSU) per channel
80VA being perfect
0V65/1R5=0A43
0A43 x 24V = 10.4W of heat
so , with 2x18Vac , you can make sort of dual mono PSU - one secondary (and rest of PSU) per channel
80VA being perfect
Using the equations from Hammond Transformer's application note (pdf link) , I get 35VA. How do you arrive at 80 VA?
(18V * sqrt(2)) * 0.43A * (1 / 0.62) * 2 channels = 35.3 VA
Tank you Mr Pass and Zen for your imput , i appreciate your help 😉
i am gonna make that nice stuff quickly and will tell you what 😉
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i am gonna make that nice stuff quickly and will tell you what 😉
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one more question guys .
what is the sensitivity of the build ,i actualy have no more than 2 v rms for it , may i need a préamp ?
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what is the sensitivity of the build ,i actualy have no more than 2 v rms for it , may i need a préamp ?
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A "simple follower" is an example of a "follower". A follower is an amplifier whose gain is +1.0 -- the output follows the input.
If you want 1.5 volts RMS at the output, you need to apply 1.5 volts RMS at the input.
If you want 1.5 volts RMS at the output, you need to apply 1.5 volts RMS at the input.
ok, but if the output is the same as the imput , where is the amplification ??
if the amp doesnt amplify the signal , what does it do ??
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if the amp doesnt amplify the signal , what does it do ??
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Most of the time the output of a CD will
be a couple of volts. But it's made to supply
this voltage a load that is in the 100's of ohms
or higher and only provide a few ma of current.
So typically we hook it to a power amp that provides
both voltage and current gain. But what we were
talking about here is a situation that we don't need
any voltage gain but do need current gain and that
is what this circuit does give us a lot of current gain.
be a couple of volts. But it's made to supply
this voltage a load that is in the 100's of ohms
or higher and only provide a few ma of current.
So typically we hook it to a power amp that provides
both voltage and current gain. But what we were
talking about here is a situation that we don't need
any voltage gain but do need current gain and that
is what this circuit does give us a lot of current gain.
ok , i got it !!!
this amp amplifys the current not the voltage , my load ( measured impedance ) is 10 ohms , so if my voltage is let say 2 v the current will be 200 ma and so my power 400 mw , if i want more wattage i have to increase my voltage , i that case i do need a preamp .
.
this amp amplifys the current not the voltage , my load ( measured impedance ) is 10 ohms , so if my voltage is let say 2 v the current will be 200 ma and so my power 400 mw , if i want more wattage i have to increase my voltage , i that case i do need a preamp .
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Ask yourself: if a gain-of-one amplifier ("simple follower") is a dumb idea, why would Nelson Pass design and publish one?
Mark , you did not get it , i am not an electronics , you may read my words that way .
the skills of Mr Pass are way way beyond my understanding , and your ( kidding !!) , i made an F6 with great pleasure , it sound like live music , so if someone knows about it , he really do ;-)
i just try to understand , what is what and what is for , like every F... newbies in every matter , it suck for those who knows and i am sorry for that .
i got the point , lately but finaly .
remeber that it's all about audio , pleasure , and fun ;-)
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the skills of Mr Pass are way way beyond my understanding , and your ( kidding !!) , i made an F6 with great pleasure , it sound like live music , so if someone knows about it , he really do ;-)
i just try to understand , what is what and what is for , like every F... newbies in every matter , it suck for those who knows and i am sorry for that .
i got the point , lately but finaly .
remeber that it's all about audio , pleasure , and fun ;-)
.
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Fab, if you go back to the begining this was an idea for a special amp for a very special type driver namely a compression driver. Some of these drivers like the TAD 4001 put out up to 110 db with one watt input. I think most of us are happy with something that
will hit 100 db peaks and to do so with this driver you would only need .1W
will hit 100 db peaks and to do so with this driver you would only need .1W
Woody , i understood what the simple follower is for , it tooks my time , as for everybody when the matter is not yours 😉
my drivers are JBL 2426j , not that far from the TAD idea 😉
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my drivers are JBL 2426j , not that far from the TAD idea 😉
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Cool looking project! Thanks for sharing. I see you split the plane on the back to separate the pre from the power section. May I ask what the second ground pad is for (on the edge of the board)? What input jfets are you using? Are you paralleling the resistors just so you can use smaller ones to get a higher power rating?
Not picking on things, just want to point out there is no thermal relief on R6 if that was intentional or not. (Is it intentional?)
Not picking on things, just want to point out there is no thermal relief on R6 if that was intentional or not. (Is it intentional?)
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Not a PCB expert but I always try to direct dirty and clean grounds separately.
Those two polygons on the top are just little cooling planes for the paralleled 0.6W resistors.
(they don´t get particularly hot though anyway)
I would use 2SK117GR as I have some.
Yes, see above, I parallel smaller resistors instead of one power resistor.
Saw the thermal relief and other little things that I cleaned up already, thank you!
Might not even get this produced as I might just use the perfboard version.
I made about 5 layouts for ~1W buffers recently just for fun if you´re interested.
(Szekeres style buffer, Class-A-buffer from misterzu here in the forums, 3xLME49600)
The forum is full of all sorts of goodies. One only has to look for them.
Those two polygons on the top are just little cooling planes for the paralleled 0.6W resistors.
(they don´t get particularly hot though anyway)
I would use 2SK117GR as I have some.
Yes, see above, I parallel smaller resistors instead of one power resistor.
Saw the thermal relief and other little things that I cleaned up already, thank you!
Might not even get this produced as I might just use the perfboard version.
I made about 5 layouts for ~1W buffers recently just for fun if you´re interested.
(Szekeres style buffer, Class-A-buffer from misterzu here in the forums, 3xLME49600)
The forum is full of all sorts of goodies. One only has to look for them.