That's what I did.
I read, found a PCB layout which according to someone that responded here was; "perfect enough ...." and when I did the exact same thing it was considered to be "Absolutely terrible, its a disaster."
That's ok, but if none of you are giving me hints on where the issues are I'm stuck.
I read, found a PCB layout which according to someone that responded here was; "perfect enough ...." and when I did the exact same thing it was considered to be "Absolutely terrible, its a disaster."
That's ok, but if none of you are giving me hints on where the issues are I'm stuck.
For an idea about nice board designs, check out the work by AlexMM and MikeB, i think thats their forum names.
This seems a matter of looking in the right places. Books and papers are the right place when forum one-liner opinions just lead to
misunderstanding and personal issues. This requires systematic learning because there are so many constraints from electronics
theory to know before you can easily understand and apply generalised rules to PCB design.
Your plan to put the PSU.on the amplifier board is a good indication of what you may not know yet. Here is just one basic course to
introduce concepts, It's not slick or impressive but the ideas are there with appropriate references. Unfortunately, no one is likely to
tailor a course here with only your immediate interests in mind
misunderstanding and personal issues. This requires systematic learning because there are so many constraints from electronics
theory to know before you can easily understand and apply generalised rules to PCB design.
Your plan to put the PSU.on the amplifier board is a good indication of what you may not know yet. Here is just one basic course to
introduce concepts, It's not slick or impressive but the ideas are there with appropriate references. Unfortunately, no one is likely to
tailor a course here with only your immediate interests in mind
How does this look? I know, the wires are not thick but how does the distribution of components look?
http://imageshack.us/photo/my-images/846/comebacka.png/
http://imageshack.us/photo/my-images/846/comebacka.png/
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SuperR, your principles and understanding of the layout is fine. Fix the track-widths for the expected currents and let us have another look.
Since this has a CFP o/p stage, wouldn't Q9 be better as a TO126 mounted directly onto Q5?
Brian.
Brian.
Use 1.27mm traces for most of the parts, apart from the power tracks to the output transistors, and the output tracks - use at least 2.54mm for those.
Keep the decoupling capacitors near the output transistors.
Keep the decoupling capacitors near the output transistors.
D
Deleted member 148505
like this one...
An externally hosted image should be here but it was not working when we last tested it.
If you don't want to move Q9, you could mount a thin aluminium sheet across all three (Q5, Q9, Q6).Insulated, of course.
D
Deleted member 148505
is this one better?
An externally hosted image should be here but it was not working when we last tested it.
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My layout looks a lot like Jlester's layout. I will etch tomorrow when the new pcb's get here. Stay tuned.
I like that layout jlester. Your Zobel components will work just fine if you put them across the speaker terminals instead - with the speaker ground returned straight to your power supply.
Mine is up and running! Still in prototype-style but so far so good. No weird pops and clicks, no strange tone. No hiss or humm.
Next job, figuring out how to "measure" the amplfiers performance.
Next job, figuring out how to "measure" the amplfiers performance.
I have made a THD+N measurement. So far so good, but is there a way of damping the noise? I will try and borrow a lab supply to check if the psu is the problem, but I am not sure if that's the problem. The 0.04%-area THD+N is ok according to Elliotts specs
An externally hosted image should be here but it was not working when we last tested it.
D
Deleted member 148505
What equipment did you use for measurements? If you used an onboard soundcard, that could add noise...
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