totally get it. I am prototyping a dual power supply atm. Methods I discovered to rid noise on the output lines, you covered here. Great vid. Great to know I am on the right track, by just what you were saying. I find the most challenging area in electronics design, is those blasted ground plane areas, loops and star points. The ultimate secret to high performance. Thanks for sharing this info :)
Nice tutorial, I always think if you can get it to sound ok on breadboard it's going to sound so much better on a PCB especially if you follow your advice.....cheers.
Thank you John. You are one of the main channels I check out whilst I am teaching myself electronics. I have to kind of reverse engineer your fixes though as I am interested in guitar effects and I want distortion and clipping :-D. Also a fan of The Strawbs, even seen them .
My Phase linear amp 400II I get a Perfect SQ wave but when the speaker relay kicks in, The speaker output going into a dummy load and a Parallel 1uf and 5 ohm resistor to ground I get a terrible Sq Wave I took the dummy load off and added a Non-inducted 8 ohm resistor and 1- it helped going to add another capacitor main supply rails to the + Bus and - Buss (8vdc and -80vdc ) it has a .31uf to ground do you think a higher value would would better? what would the Max be?
2- Add a stopper Resistor? what value? 100 Ohm? it has a Pre-driver (also added 40pf cap to the Base to Collector) and it goes to a to the output Bootstrap driver? 3- Will add a .1uf across the Op-amp LM351 power pins.
Is it oscillating on both channels? If both check power supply throughout. If one channel, check where oscillation is coming from and find the failing component. Test all transistors. You shouldn't need to modify the circuit, just fix. And you don't need to put 1uf and 5 ohm across the dummy... Test it again without.
"It'll ring" I said "no it won't" he said "it's only 5mm of track" 20 minutes of this back and forth. He had given me the prototype on vero board to fix, and I had, it was all in the earth layout. so I gave up trying to convince him and he sent the PCB of to be manufactured. One week later. I got a phone call, "it's ringing and I can't work out why"... I told him what I thought ( he was the wise designer), he said I was wrong. After another twenty or so of this I lost it and then bet him "IT WOULD WORK", "cut the track and run another earth. Five minuets later I got another phone call "it works". NEVER underestimate layout, NEVER! 5mm. that's all, 5mm
I have trouble almost every audio circuit. I suspect it's line and switching noise. I need to start using my isolation transformer. I have to find a box to put it in then I can build a linear supply off my variac
Finally with your video I have a clear understanding of what "star ground" means and its importance. Thanks so much! 👍
The layout is very important. Great Video John!
Tda2030/40/50 are the kings of oscillation! If the layout isn't perfect, they are prone to oscillation.
Thanks, John. I was just wanting a new JAT video today and here it is. Hope that you're doing well.
Always interesting and always relevant.
I love your channel, mate. Great d I y content.
I have been tinkering with audio electronics for 45 years. Great fun!
Love the Cilla Black impression.
Hey man really like these vids, helps me alot with ampilifers!
totally get it. I am prototyping a dual power supply atm. Methods I discovered to rid noise on the output lines, you covered here. Great vid. Great to know I am on the right track, by just what you were saying. I find the most challenging area in electronics design, is those blasted ground plane areas, loops and star points. The ultimate secret to high performance. Thanks for sharing this info :)
Nice tutorial, I always think if you can get it to sound ok on breadboard it's going to sound so much better on a PCB especially if you follow your advice.....cheers.
Thank you John. You are one of the main channels I check out whilst I am teaching myself electronics. I have to kind of reverse engineer your fixes though as I am interested in guitar effects and I want distortion and clipping :-D. Also a fan of The Strawbs, even seen them .
Great video, as always keep them coming
Great video, thank you!
As usual sir, another great video, thank you very much.
New video. Love your videos. They are great.
Good demo. Thank you.
very good video thank you.
My Phase linear amp 400II I get a Perfect SQ wave but when the speaker relay kicks in, The speaker output going into a dummy load and a Parallel 1uf and 5 ohm resistor to ground I get a terrible Sq Wave I took the dummy load off and added a Non-inducted 8 ohm resistor and 1- it helped going to add another capacitor main supply rails to the + Bus and - Buss (8vdc and -80vdc ) it has a .31uf to ground do you think a higher value would would better? what would the Max be?
2- Add a stopper Resistor? what value? 100 Ohm? it has a Pre-driver (also added 40pf cap to the Base to Collector) and it goes to a to the output Bootstrap driver? 3- Will add a .1uf across the Op-amp LM351 power pins.
Is it oscillating on both channels? If both check power supply throughout.
If one channel, check where oscillation is coming from and find the failing component. Test all transistors. You shouldn't need to modify the circuit, just fix. And you don't need to put 1uf and 5 ohm across the dummy... Test it again without.
Layout matters.
"It'll ring" I said
"no it won't" he said "it's only 5mm of track"
20 minutes of this back and forth. He had given me the prototype on vero board to fix, and I had, it was all in the earth layout. so I gave up trying to convince him and he sent the PCB of to be manufactured.
One week later.
I got a phone call, "it's ringing and I can't work out why"...
I told him what I thought ( he was the wise designer), he said I was wrong.
After another twenty or so of this I lost it and then bet him "IT WOULD WORK", "cut the track and run another earth.
Five minuets later I got another phone call "it works".
NEVER underestimate layout, NEVER!
5mm. that's all, 5mm
Good topic. You forget how sensitive a scope can be and how it can show you what's going on in a circuit.
Hi John, how are you? What's the best way to convert line level stereo into mono?
I'd mix down the L and R channels through two resistors.
I have trouble almost every audio circuit. I suspect it's line and switching noise. I need to start using my isolation transformer. I have to find a box to put it in then I can build a linear supply off my variac
It's sure strange that neatness doesn't really mean much in electronics - neater looking layout was the most horrible interference wise😂
Yep, the most beautiful looking amp can sound like rubbish !.....cheers.