All you have to do is use the IRFP240 and IRFP9240. You'll get some 2nd
harmonic from the P channel device.
They run about 1.1 W. Use a larger 5 watt if you like.
When it's resting 1.1W...at rated power into 4 ohms a bit more methinks.
"It's not dead, it's just resting"
Monty Python - Dead Parrot - YouTube
You've not heard my neighbor's when he gets home @3:30 a.m.
Now back to the subject matter at hand. I haven't yet pulled apart one of my F5's but using P3 on the Multisimulator I can get the THD% down to 0.005% @10W into 8R and 0.001% @1W. These would seem to compare quite favorably with the charts in the AX article.
ok, small question
if using two seperate heatsinks per channel
and they are elctrically isolated
then semis can be mounted directly only using grease, and no insulator
I do know some say NO this, because of no thermal connection
which supposedly could cause DC instability
question is ?
what happens if you lift amp with hands on heatsinks
if using two seperate heatsinks per channel
and they are elctrically isolated
then semis can be mounted directly only using grease, and no insulator
I do know some say NO this, because of no thermal connection
which supposedly could cause DC instability
question is ?
what happens if you lift amp with hands on heatsinks
Using this schematic
http://i374.photobucket.com/albums/oo189/Tripmaster_photo/F5PSUGround.jpg
What would happen if you omitted R9 and R10?
http://i374.photobucket.com/albums/oo189/Tripmaster_photo/F5PSUGround.jpg
What would happen if you omitted R9 and R10?
Why there was no "High Voltage Capacitor" parallel with the Power Switch to prevent "Spark" abd "Pop Sound" when On/Off ?
Thanks Nelson, thats what I thought but I wanted to be sure. I was going to leave them out because I didn't think I had the right resistors but it turns out that I did have them.
After a bunch of power supply issues I now have my F5 playing with it's own power supply, in it's own chassis. On the bench supply everything sounded too far away, sort of like an artificial depth. That is now gone and things sound much more natural. At first hookup I had some terrible buzzing from the speakers. Turns out that my ground wires were way to close to the transformer and it was inducing noise, that is now fixed. I do have a small amount of noise when you put your ear to the speaker but you cannot hear it from the listening position. I am not sure if this is due to my cheap bridge rectifiers or internal wiring. I am going to listen to it for a week or two before I put the cover on and call it a finished project. This has been a very trying and rewarding experience. I have wanted to build an amp for over 8 years and now I have done it, and my background is in business. For anyone who wants to build an F5, being able to buy the boards from this site, the components from Techdiy and a case and transformer from Antek makes this a very good first amp to build. You don't have to understand the whole design to build an amp. Build it and then worry about figuring out how it works. Also realize you are going to make mistakes and burn up some stuff in the process of learning unless you get lucky or just have knack for building amps.
One of the next things I want to build is an F5 for the HLCDs I just put in my car. If I get around to it, it will be the first with such an amp in car. For a newbie I sure do like to make things hard for myself
Quick Q: What would happen if you encased a toroid in a copper cover? Would that shield other components from it's EMI?
After a bunch of power supply issues I now have my F5 playing with it's own power supply, in it's own chassis. On the bench supply everything sounded too far away, sort of like an artificial depth. That is now gone and things sound much more natural. At first hookup I had some terrible buzzing from the speakers. Turns out that my ground wires were way to close to the transformer and it was inducing noise, that is now fixed. I do have a small amount of noise when you put your ear to the speaker but you cannot hear it from the listening position. I am not sure if this is due to my cheap bridge rectifiers or internal wiring. I am going to listen to it for a week or two before I put the cover on and call it a finished project. This has been a very trying and rewarding experience. I have wanted to build an amp for over 8 years and now I have done it, and my background is in business. For anyone who wants to build an F5, being able to buy the boards from this site, the components from Techdiy and a case and transformer from Antek makes this a very good first amp to build. You don't have to understand the whole design to build an amp. Build it and then worry about figuring out how it works. Also realize you are going to make mistakes and burn up some stuff in the process of learning unless you get lucky or just have knack for building amps.
One of the next things I want to build is an F5 for the HLCDs I just put in my car. If I get around to it, it will be the first with such an amp in car. For a newbie I sure do like to make things hard for myself
Quick Q: What would happen if you encased a toroid in a copper cover? Would that shield other components from it's EMI?
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Sorry to but in I may have quick and easy answer..
I love cooper no mistery about that but is not magnetic so maybe it will be beter to use same othet metal.
Now for the easy answer why not try a biscuit tin ?
Attachments
Hi Bksabath,
You don't necessarily need a magnetic material to shield for electromagnetic fields. You only need a conducting plate or mesh, as long as the holes in it are smaller then the wavelenght of the expected magnetic field. The electromagnetic field induces current or forces in the conductor. Just google for electromagnatic shielding, or "eddy currents". De buzz caused by a transformer, a few posts ago seems more like an earth loop to me, dc on the mains, or harmonic distortion of the mains induced in the toroid. The magnetic field outside a toroid is very,very small due to it's construction!!
Have fun!!
Forgot to mention, don't "short" a toroid with the shielding and it's mounting bolt. If you create a current path through the surrounding shielding and the centre bolt you create a magnetic short-circuit.
BTW strange transformer you have with the two mounting holes, both offcentre... Not the best place to have conducting bolts; offcentre = magnetic flux.
BTW strange transformer you have with the two mounting holes, both offcentre... Not the best place to have conducting bolts; offcentre = magnetic flux.
