I'm using a TDA7265 chip amplifier I bought on Amazon, and an ICL7660 charge pump inverter circuit I designed myself (in KiCad, from a schematic someone else made) and had PCB's made for it (thank you OSH Park!), to make one 9V battery power the TDA7265 chip amp, which requires a dual DC supply (+, -, and Ground). It worked perfectly! Er, well... not exactly.
You see, I was noticing some distortion in one of my music files and then, to check to make sure it wasn't my song file, I decided to play "Dolphin Dance" from Tangerine Dream. I consider that my reference test song, because I like it so much. Anyways, about 15-20 seconds into the song, when the "highs" start, the distortion was quite noticeable. I thought maybe it was the 9V battery I was using. So I grabbed a brand new 9V Rayovac. Same thing. To make sure the song (on YouTube) wasn't bad, I plugged my headphones into another amp I've used and listened to the song. No distortion at all. Cranked up the volume. Same diff. No distortion. So I knew it had something to do with the amp I bought from Amazon. But it's not the chip, because it's the same chip as in the other amp I just tested with (which runs off of AC, so power requirement isn't an issue), which means it has something to do with the power.
So, question is... is it the 9V battery, itself, or the single to dual supply module I designed? Is the battery unable to supply enough power (voltage and/or current (mA)) or is the ICL7660 unable to give the amplifier the power it needs, even if the 9V battery can supply it?
I'm only powering a pair of Drop + HiFiMan HE-X4 headphones, not external speakers, so I wouldn't imagine they're demanding that much power from the amp. since they're 25 Ohms.
You see, I was noticing some distortion in one of my music files and then, to check to make sure it wasn't my song file, I decided to play "Dolphin Dance" from Tangerine Dream. I consider that my reference test song, because I like it so much. Anyways, about 15-20 seconds into the song, when the "highs" start, the distortion was quite noticeable. I thought maybe it was the 9V battery I was using. So I grabbed a brand new 9V Rayovac. Same thing. To make sure the song (on YouTube) wasn't bad, I plugged my headphones into another amp I've used and listened to the song. No distortion at all. Cranked up the volume. Same diff. No distortion. So I knew it had something to do with the amp I bought from Amazon. But it's not the chip, because it's the same chip as in the other amp I just tested with (which runs off of AC, so power requirement isn't an issue), which means it has something to do with the power.
So, question is... is it the 9V battery, itself, or the single to dual supply module I designed? Is the battery unable to supply enough power (voltage and/or current (mA)) or is the ICL7660 unable to give the amplifier the power it needs, even if the 9V battery can supply it?
I'm only powering a pair of Drop + HiFiMan HE-X4 headphones, not external speakers, so I wouldn't imagine they're demanding that much power from the amp. since they're 25 Ohms.