tinitus said:
What seems to me:
Parallel operation doubles the output current available into the load.
Into 8 ohms, each amp is able to deliver 2.5Amp (classA 1.25A bias)
Total 5A class A into 8ohms .
5Ax5Ax8ohms=200w max=100w rms.
Bridging operation is another story which doubles the output voltage available into the load.
Correct me, please, if i am wrong.
HIbobodioulasso said:
Your calculation are OK except you need at least +-44V rails to get 100Wrms at 8 ohms, i.e. Vpeak~44-4 =40 , Prms=40x40/8 = 200/2=100Wrms. If you have 24V rails i.e. 20 peak due to losses you will still get 25rms at 8 ohm, but for 4 ohm you will have not 12wrms class A (50WRMS CLASS B) as before , but 50 Wrms. Prms 20X20/4=100/2=50Wrms and all these to FULL class A
kzeprf22 said:
You are right, thanks.
My calculation was only stating the class A limit, not the real available power limit imposed by supply rails voltage.
So, as you said, the interest of parallel operation is to allow 50W class A into a 4 ohms load. And also more available class A power into complex/reactive loads .
tinitus said:
I use this one.(see post 4239)
Scroll down to Quad 606 schematic
http://quad405.com/
Of coarse you can double it if you have no 2x18v xformer but a 2x38 one.
If you did not get yet any transormer, it is simpler to do as Nelson recommends.
Attachments
Ok, thanks
Each board their own respective supply
Ofcourse, I remember it now, true balanced it is
ehhh, maybe its really best when both boards share the same supply, or at least same trafo, and have no issues with any small differences, knowing that balanced could be critical to tolerances
And the possibility to turn it into a normal stereo could be a nice option too
This could make me rethink my usual favour of building monos have to think about it
Each board their own respective supply
Ofcourse, I remember it now, true balanced it is
ehhh, maybe its really best when both boards share the same supply, or at least same trafo, and have no issues with any small differences, knowing that balanced could be critical to tolerances
And the possibility to turn it into a normal stereo could be a nice option too
This could make me rethink my usual favour of building monos
have to think about itAnother stupid question
Problems with low impedance is usually in the bass region
Will it be audible if amp leaves classA at low frequencies
If amp leaves classA at say 50-100hz, will it also leave classA at higher frequencies as well, even if it delivers power well within the classA operation at say 1000hz
Problems with low impedance is usually in the bass region
Will it be audible if amp leaves classA at low frequencies
If amp leaves classA at say 50-100hz, will it also leave classA at higher frequencies as well, even if it delivers power well within the classA operation at say 1000hz
tinitus said:Another stupid question
Will it be audible if amp leaves classA at low frequencies
If amp leaves classA at say 50-100hz, will it also leave classA at higher frequencies as well, even if it delivers power well within the classA operation at say 1000hz
Not sure of both on those questions. I would think if there is only bass then it wouldn''t be audible. However, if you've seen a complex wave on a scope and there is high frequency mixed with the bass then it would seem like the whole output stage would leave class A. Maybe this is where intermodulation distortion becomes a problem.
tinitus said:
If amp leaves classA at say 50-100hz, will it also leave classA at higher frequencies as well, even if it delivers power well within the classA operation at say 1000hz
Simplicity is not that simple . . . ?
Or trying to make simple things be complicated . . . ?
A music signal wave is mixture of many different frequencies . . .
If any point of the envelop curve (formed by peak points) of the music signal is cutting and leaving Class A bias, the music signal is leaving the Class A bias. Remember that the music signal wave is mixture of many different frequencies . . . I believe you know all already, don't you . . .