If I can't fix it I will scrap it and before I will take it apart take pictures and post them here. I want too to understand.
Hi everybody,
The situation is very new and I must confirm but I think that I should share this with you.
I can't believe my ears but the sound of the amp has improved significantly
.
I have replaced C1(470pF styroflex) by a 560pF. I have also ordered some additionnal values 580pF, 600pF, 620pF. I will make some tries and will be back to give details (if you wish). At the moment I do not want to scrap this amp anymore!
The situation is very new and I must confirm but I think that I should share this with you.
I can't believe my ears but the sound of the amp has improved significantly
.I have replaced C1(470pF styroflex) by a 560pF. I have also ordered some additionnal values 580pF, 600pF, 620pF. I will make some tries and will be back to give details (if you wish). At the moment I do not want to scrap this amp anymore!
many might be wondering why this worked, like i did at first. The answer is when you increased the value of C1, it basically grounded the high frequencies, thus making a very very simple tone control circuit. Increase the cap size more and you can reach a point where only bass can be heard.
I also faced such problem with pre-built kit (a transistor cheap kit)
I also faced such problem with pre-built kit (a transistor cheap kit)
This amp shows 4u7F followed by 1k5 and 10k to signal return.
That is 11k5 + 4u7F
What is your definition of high?
I'm sure AndrewT refers to the schematic for the ancient and best forgotten ETI 480.
I don't know that it's always going to be a problem but sure, the OP's design TL071 input is floating and unless direct coupled to a grounded resistive source, needs to be ground referenced somewhere. Assuming a preamp. or source is <10k, that might be ok but most have capacitor outputs with various or no shunt resistance, even feedback loops. I think its unwise to have such a floating input for a universal device like an amplifier.
I don't know that it's always going to be a problem but sure, the OP's design TL071 input is floating and unless direct coupled to a grounded resistive source, needs to be ground referenced somewhere. Assuming a preamp. or source is <10k, that might be ok but most have capacitor outputs with various or no shunt resistance, even feedback loops. I think its unwise to have such a floating input for a universal device like an amplifier.
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