what does everyone think of this amp?


2004-12-25 12:24 pm
lt cdr data said:
hi Mike I think its complete, q208 is output biasing/vbe.

q216 is the pre driver, the collectors are obviously the voltage amplifiers

There is no collector resistor defining the pre-drivers as voltage amplifiers and nor is the VBE multiplier is adequately implemented.

The schematic lacks major key factors to act as an amplifier, is it really complete or you might forget something to draw.
MikeB said:
Hmm, i think it's not functional at all ?
The biasing in the outputstage is not defined at any point,
collectors from predrivers connected to base of drivers
without any resistor defining a voltage ?
Also, i can't see how the vbemultiplier should work ?
Is the schematic incomplete ?


I agree. This schematic doesn't work. There are some missing connection, and/or missing parts.

I think that the anode of the CR202 should be connected to the collector of Q210 and 212, and the cathode of the CR203 should be connected to the collector of the CR211 and 213.
With this modification the bias will works, and I think the amp too.

This do not surprise me Jacco, you have own brigth, happyness, clever, full of life

Some guys do not like that..... as you put them over shadows, your words so loud that they turn silent, your heat show them how they are cold.

Well, sometimes you turn "terrible" too..but nobody is perfect!

They are less in quantity than your left hand fingers, our club of happy guys are growing fast, and slowly the "dark side guys" will join us.

You have been clear, transparent, funny sometimes, some guys take notes of your words to find contradictions there.... never mind, and he happy.... this is the answer.

I have been dedicated to 4 good friends...forum friends.... we founded some diy together system...we elect some circuit and we do it together and we discuss the circuit.

As everything in life, we are turning tired of that....and all of us returning to our old and good forum.

Thank you by friendly reception, but really i never was completelly out, and was reading posts...but without time to enter.

regards Jacco...V8 sounds as music to me.

I think the amplifier, shown here is good, may sound interesting...

And alike everything in this life, need some modifications here or there.

But is an wonderfull effort made to produce clear sound, i am sure treble, will be nice.

C206 an C207 must be tuned, changing values from 8 pf to 33 pf, watching 40 to 80 khz sinusoidal sine captured over speaker, 1/3 ... around 1 watt over speaker and go changing both, one each time, to reduce triangle wave shape on sinusoidal wave shape....i am not sure will work on that circuit, but normally, in other stages, as VAS, this works that way...also the material used to construct the capacitor can produce different sound.... hehe....i learn that one month ago...yeah.... seems crazy to me too....but try it!


I realize that this thread is very old, but I own the amp in question and would love it if the schematic discussed is accurate, as I haven't been able to locate one before. Any more comments as to it's viability(?)

Thanks and Best Regards, Barry