http://www.parttimeprojects.com/audio/diy/F5.php
There have been many, many, happy builders of the F5, but, this guy really didn't get on with it.
I've not built one, I'm happy with my Aleph 4.
The F5 is very easy to build and is fairly cheap. The Alephs require a little more expense and attention to detail.
The Alephs raise the output above the 25W of the F5. This comes at a cost of course in Heatsinks and Transformers.
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Karajak, what are your values over the source resistors? I have 0.556v.
I tried to measure r5 but my probes cant reach it... the bottom of the pcb is mounted, also unreachable... also measure the transistors C to E, as mentioned prior..
Hang in there my friend, don`t give up. We are the Aleph clan.
I tried to measure r5 but my probes cant reach it... the bottom of the pcb is mounted, also unreachable... also measure the transistors C to E, as mentioned prior..
Hang in there my friend, don`t give up. We are the Aleph clan.
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Nrg, thanks.
Karajak, 244mV is low nrg is correct should have .5V.
Now here is my problem I've kinda forgot what we where doing. Sorry I've got a short attntion span.
Let me refresh myself and get back to you with some questions to put me on the same page as you.
But we will get it.
Nrg, how is she sounding?
Karajak, 244mV is low nrg is correct should have .5V.
Now here is my problem I've kinda forgot what we where doing. Sorry I've got a short attntion span.
Let me refresh myself and get back to you with some questions to put me on the same page as you.
But we will get it.
Nrg, how is she sounding?
I still have my amp on the bench, all opened up, so I haven't done much listening. My next task is to drill/tap holes to secure the 244's. I'm waiting for proper tools to arrive. I can't wait to finish it off but it will be a couple more weeks. Thanks for your help with Karajak's build. It's very helpful for me to read it, I'm learning tons of things.
Ahh, the tapping of the sinks. I don't miss that.
Don't forget to countersink the holes just a bit, if you are using the holes in the fets to mount them.
I also recall you using thermal tape correct? You might be better off removing that before drilling and tapping, to prevent stuff ending up under the fets.
The goal is to have a perfectly flat plate that has a perfectly flat fet mounted to it.
100% of the die (the silver plate on the back of the fet) touching the sink.
You use thermal compound, or your sticky tape to fill in the little gaps.
As far as KJ and me helping, I'm learning too.
And like I said, ill do what I can.
Karajak, I'm going to be in a fiberoptic class today (boring) so ill bring my laptop and go over this fourm And make my list of questions.
If anyone else has any sujestions, please pop up.
I have no pride to be hurt. I'm learning too.
Don't forget to countersink the holes just a bit, if you are using the holes in the fets to mount them.
I also recall you using thermal tape correct? You might be better off removing that before drilling and tapping, to prevent stuff ending up under the fets.
The goal is to have a perfectly flat plate that has a perfectly flat fet mounted to it.
100% of the die (the silver plate on the back of the fet) touching the sink.
You use thermal compound, or your sticky tape to fill in the little gaps.
As far as KJ and me helping, I'm learning too.
And like I said, ill do what I can.
Karajak, I'm going to be in a fiberoptic class today (boring) so ill bring my laptop and go over this fourm And make my list of questions.
If anyone else has any sujestions, please pop up.
I have no pride to be hurt. I'm learning too.
well. i think this guy is way out there. i bet he had very low or no gain in his preamp.
lack of bass? i have not felt that. my F5 is better than my aleph2's in low frequences
and regards to the power. it's no problem building it as 200W pr.ch
exept of heat and money problems
You say better in low Fq's, how about the rest?
I've been thinking about a F5.
Your thoughts.... Please?
I get the power diffrence but witch do you enjoy listing to more?
Can you rate them?
Like a overall 1-10 on the aleph
And a 1-10 on F5?
I would be greatful if anyone else has a opnion.
I have aleph 1.2 running paradigm S6's
Should I bother with a semi turbo F5?
Make VERY SURE that the MOS-FETs are mounted tightly against the heatsink and that there is no swarf underneath them. DON'T OVERTIGHTEN the fixing bolts either, as you stand the chance of cracking the MOS-FET.
I lap the holes with a fine file after drilling and tapping to ensure that everything is flat.
If the MOS-FETs aren't closely coupled to the sink they will rapidly fail, similarly any swarf will cause rapid destruction.
Ensure that you use only enough heatsink compound to fill in the gaps between the MOS-FETs and the sink. It is a complete falicy that you need toothpaste sized quantities of the stuff. Too much and you actually end up insulating the devices from their heatsink.
I lap the holes with a fine file after drilling and tapping to ensure that everything is flat.
If the MOS-FETs aren't closely coupled to the sink they will rapidly fail, similarly any swarf will cause rapid destruction.
Ensure that you use only enough heatsink compound to fill in the gaps between the MOS-FETs and the sink. It is a complete falicy that you need toothpaste sized quantities of the stuff. Too much and you actually end up insulating the devices from their heatsink.
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