As part of a circuit im wanting to make I need to use 6 0.22f 50v electrolytic Capacitors to achieve 1.2F of total electrolytic capacitor power (so to speak).
The problem is that i cant find these capacitors ANYWHERE. any thoughts?
The Circuit is
and his completed project with these mammoth capacitors is
I think ive found the capacitors i need, 220mf 50v is the same as 220000uf and is the 0.22 farad i was looking for, the only thing that worries me is that the site it is from is selling six for $1.50?!
**broken link removed**
if the capacitors are what they say they are then ill get started right away
No, those are 22uF. They are mis-labeled. Have to be really careful when looking at caps, as people often use mF to mean uF. It's an old style of rating.
In fact, if you were to take it literally, those would be 22 Mega-Farad capacitors.
Just so you have a better understanding of what you are looking for, a 220000uF cap will be the size of a soda can or bigger. This is starting to get near the super-cap size of things. Although I agree with Nigel that this seems like pretty massive overkill.
This assumes that the output stage remains listenable all the way to clipping. The peak voltage into 4Ω would be significantly lower due to the 0.5Ω emitter resistors, IR losses in the mains transformer and diodes.
Anyway, interesting priorities, 128W standby for 55W output. (7.1 channel system would be >1kW standby.)
You failed to notice it's a class A amplifier, you can't treat it as a class AB one. In any case, 70V HT rail gives you around 100W in to 4 ohms, not 130W - overdriving the amplifier to produce 130W would be grossly distorted, and the amp wouldn't last long.
It seems silly to build such a large class A amplifier
70V HT rail gives you around 100W in to 4 ohms, not 130W - overdriving the amplifier to produce 130W would be grossly distorted, and the amp wouldn't last long.
It depends on how much voltage loss the output transistors have and how low the distortion is, for 100W into 4R you need 28.3V peak and at 35V a 6.7V loss sounds reasonable for low distortion.
It depends on how much voltage loss the output transistors have and how low the distortion is, for 100W into 4R you need 28.3V peak and at 35V a 6.7V loss sounds reasonable for low distortion.
You're ignoring the drop in the HT rails under load - I've repaired, designed, and built many amplifiers over the decades - 65/70V gives you a reasonably decent quality 100W.
And on the voltage drop across the rectifiers (which increases with current). But mostly on limitations of the amplifier itself, to get as close to the rails as possible you require extra higher voltage rails to feed the drivers - and this is quite often done.
I imagine it'll be more of a problem for bass frequencies.
VERY, VERY much so. One reason power output is commonly specified at 1KHz - but a decent amp will specify RMS power from 20Hz to 20KHz (or so) as well.