I have done some scope checks on the amp and its almost completely free from ringing, despite not having a single bypass cap, only the lytics.
Either way this amp is way cleaner than the other one with the TL494.
Either way this amp is way cleaner than the other one with the TL494.
I designed it for subwoofer use so with fullrange speakers theres a faint beep that sound like 5khz or so, not visible on scope due to the sinewave @ 2v around 300khz.
As a sub amp it has enough power to bottom out my 2ohm sub, and it clips mutch better than the TL494 thing.
For those who the links wors for, heres some pics: http://user.faktiskt.se/Tekko_Tubeamp/D-amp project/opamp_comp_pwm/
How do your diy ucd (it was ucd, right ?) sound, Chris ?
As a sub amp it has enough power to bottom out my 2ohm sub, and it clips mutch better than the TL494 thing.
For those who the links wors for, heres some pics: http://user.faktiskt.se/Tekko_Tubeamp/D-amp project/opamp_comp_pwm/
How do your diy ucd (it was ucd, right ?) sound, Chris ?
Hi Tekko
Congratulation. Looks quite good 🙂
What is your supply voltage?
Could you post the "final" schematic?
Congratulation. Looks quite good 🙂
What is your supply voltage?
Could you post the "final" schematic?
Tekko said:
Perhaps you can now modify it for full range? It would be far more rewarding I think.
Yes it is UCD, and it's extraordinary 🙂
As i recall yours was on protoboard too, hows the ringing and over/under-shoot, ever checked ?
My amp despite no bypass caps near the ic´s is very close to clean, almost no riging at all.
My amp despite no bypass caps near the ic´s is very close to clean, almost no riging at all.
Tekko, what is your switching frequency?
If your output filter is optimised for 2 Ohm the cap should be 4.7 uF rather than 0.47 .. that would correspond to corner freq of 25 kHz. Try this LC designer
Altering to full range should be easy, by just changing the sawtooth freq.
Chris: What's the extraordinary part of your design?
😀
And btw, glad to see that there are still DIY'ers that creates their own constructions, though it is realy not that easy to make a class-d work 😉
If your output filter is optimised for 2 Ohm the cap should be 4.7 uF rather than 0.47 .. that would correspond to corner freq of 25 kHz. Try this LC designer
Altering to full range should be easy, by just changing the sawtooth freq.
Chris: What's the extraordinary part of your design?
😀
And btw, glad to see that there are still DIY'ers that creates their own constructions, though it is realy not that easy to make a class-d work 😉
Its running at the highest freq TL074 allows, dunno what the freq is tho. I don´t have a freq meter.
The op filter cap is 1µF, not 0.47. The amp is not designed for any special output load.
The op filter cap is 1µF, not 0.47. The amp is not designed for any special output load.
No freq meter huh? Man, I hate it when a scope comes without one of those.
Baldin, that it both works and sounds the way it does, and it's never seen a scope yet. 😀
Baldin, that it both works and sounds the way it does, and it's never seen a scope yet. 😀
Can't you just read it of your Scope?
You should make sure that the switching frequency is well above the filter corner freq. which is of course dependant of the load.
You should make sure that the switching frequency is well above the filter corner freq. which is of course dependant of the load.
Hi Chris
Is it build around one of the schematics you have posted using only discrete components?
How huch output have you got?
😎
Is it build around one of the schematics you have posted using only discrete components?
How huch output have you got?
😎
Baldy, I just saw your SODA, very comprehensive. Welcome to the DIY D club 🙂 Wish I had seen that around here before. Are you still trying to perfect it?
Yes I believe it is built around the one I re-posted in this thread. Simple as possible, single ended, no input stage, works like a charm. Of course I only built it on a breadboard and in P2P so the hiss is expected from it. All the same, excellent detail, tons of air, very neutral and lifelike.
I figured ~35 watts, 4ohm load, speaker was 102dB efficient so it was great fun.
One of my other posted circuits "my diy ucd" I believe the thread is called, was built by an MIT student virtually unchanged.... but with a SMPS 🙂 I had only simulated it.
I figured ~35 watts, 4ohm load, speaker was 102dB efficient so it was great fun.
One of my other posted circuits "my diy ucd" I believe the thread is called, was built by an MIT student virtually unchanged.... but with a SMPS 🙂 I had only simulated it.
Yes, and I'm pretty much there. (the diagram on my page is not totally up to date .... some is written in the "Noise problems in non-d ...." threat and some in Snickers-is's "Distortion ... " thread.
Next thing is to make a protection circuit. And then finally I'll make a new PCB with all the changes and using smd components for the most parts. ....... still a long way to go 😉
... also need to try out a more permanent PSU.
It is intended for my sub, which you can also see on my homepage ... filter, and bas eq + one band parametric eq. is already waiting for the amp 😀
Next thing is to make a protection circuit. And then finally I'll make a new PCB with all the changes and using smd components for the most parts. ....... still a long way to go 😉
... also need to try out a more permanent PSU.
It is intended for my sub, which you can also see on my homepage ... filter, and bas eq + one band parametric eq. is already waiting for the amp 😀
the sub is on the new projects page using a peerless XLS driver
The mini-sub was just a first try intended for my PC .... never really finished
The mini-sub was just a first try intended for my PC .... never really finished
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