Hi,
only just found and couldn't stop reading this thread.
Roender,
Superb.
Could the quality of sound be, in part, due to the very few capacitors in this design, nine in all? There are twice as many transistors (18) excluding the 6output devices and almost all of these are high fT and high hFE.
only just found and couldn't stop reading this thread.
Roender,
Superb.
Could the quality of sound be, in part, due to the very few capacitors in this design, nine in all? There are twice as many transistors (18) excluding the 6output devices and almost all of these are high fT and high hFE.
niner said:
http://www.diyaudio.com/forums/showthread.php?postid=1354022#post1354022
The heatsink has 0.37C/W (300x150x25mm).
Hello everybody, my first post on this forum!
@roender I'm mesmerised ! Congratulations for an excellent amp, I'm really impressed by your skill and knowledge!
I have a few questions about your design. I hope they don't sound stupid, but i am a newbie in electronics and I have quite a hard time trying to understand how amplifier work. So why have you chosen higher supply voltages for the input stage than for output stage? Why is the current source Q17,D8 and R20 connected to the anode of D17(and not the positive supply rail)? What is the purpose of C7?
Thanks in advance for the answers. Maybe you could point to me some good sources of information about amplifiers and electronics.
Once again I congratulate you, and I wish you good luck on your projects!
@roender I'm mesmerised ! Congratulations for an excellent amp, I'm really impressed by your skill and knowledge!
I have a few questions about your design. I hope they don't sound stupid, but i am a newbie in electronics and I have quite a hard time trying to understand how amplifier work. So why have you chosen higher supply voltages for the input stage than for output stage? Why is the current source Q17,D8 and R20 connected to the anode of D17(and not the positive supply rail)? What is the purpose of C7?
Thanks in advance for the answers. Maybe you could point to me some good sources of information about amplifiers and electronics.
Once again I congratulate you, and I wish you good luck on your projects!
Hi Emanuel,
The only stupid question is the one you don't ask.
Are you doing EE at Politehnica Bucuresti?
Way bigger rail voltage in front than in output stage? It's a folded cascode design, with limited voltage swing in "VAS" at cascode base reference voltage.
"Why is the current source Q17,D8 and R20 connected to the anode of D17 ?
That's a very good question! You are the only one who see that and ask about reasons.
The firs stage is a class A stage and I like to have symmetrically currents in every class A stage I design, with as little as possible return currents to ground, to keep the zero reference clean.
The role of C7 is to slow down voltage response in output stage bias circuit.
Mihai
The only stupid question is the one you don't ask.
Are you doing EE at Politehnica Bucuresti?
Way bigger rail voltage in front than in output stage? It's a folded cascode design, with limited voltage swing in "VAS" at cascode base reference voltage.
"Why is the current source Q17,D8 and R20 connected to the anode of D17 ?
That's a very good question! You are the only one who see that and ask about reasons.
The firs stage is a class A stage and I like to have symmetrically currents in every class A stage I design, with as little as possible return currents to ground, to keep the zero reference clean.
The role of C7 is to slow down voltage response in output stage bias circuit.
Mihai
Thanks for the answer! I see that your design is more clever than i thought! I really like your way of implementing current sources. Fancy that!
. Now i see that a good amplifier has a lot of "secrets" and much thinking and work behind. Keep up the good work!
About Politehnica Bucuresti, you came close. I'm doing Automatics.
. Now i see that a good amplifier has a lot of "secrets" and much thinking and work behind. Keep up the good work!About Politehnica Bucuresti, you came close. I'm doing Automatics.