Build Your Own Clone Message Board

Check the datasheet for same series as the other low profile caps you're already using. Or you can use 2 x 100uF in parallel. That's probably close enough. But more importantly, I'm willing to bet that's nothing more than a power filter cap. If you're using a battery or a decent filtered/regulated power supply, it's not really as critical as something like the power filter caps in an amp. You can substitute it with a 100uF or 47uF and I'm sure you won't notice any difference. You could just leave it out and I doubt you'd notice it was gone.

Since that’s probably the power supply filter cap, sometimes I leave them off the board and solder them across the lugs of the 9v jack. Or, do a 100uf low profile on the board, and another 100uf on the jack (in parallel). You’d want to look at the schematic though and make sure they’re the same point electrically - no 100ohm resistor in line before the cap, etc. Hope that made sense

I didn't realize that was being used in a charge pump, so you actually do need that cap, but it doesn't need to be that big. You can use a 100uF, 47uF. FYI, the TC7660SCPA is a less expensive, pin-for-pin alternative to the MAX1044 in case you don't already know.

... I'm not sure what you would do with that much voltage ...

Run a tube?

https://www.mouser.com/datasheet/2/268/21467B-1180369.pdf
https://www.mouser.com/datasheet/2/256/ ... 514385.pdf

According to the datasheets, the MAX1044 has a maximum input voltage of 10VDC while the 7660 has a maximum of 12VDC. However, the 1044 has a current output of 100mA while the 7660 is only about 50mA. So in hindsight, you may need to stick with the 1044 depending on your current draw needs. You probably already know about the LT1054. It's costs a little more, but it has a 15v max input and has 100mA output if you're needing higher voltage. You can also run the negative converter as a doubler as well, so you could potentially get +30V and -30V output for a 60V differential. I'm not sure what you would do with that much voltage since most op amps can only handle +/-18V, but it's still pretty cool.

I'm not sure if you can run the 1044 or 7660 as negative voltage doublers. I'm never actually tried it. Only with the 1054. It doesn't say anything about that configuration in their datasheets. The 7660 shows the positive double with negative (like the configuration in the Klon or the BYOC 27V Boost), but nothing about negative voltage doubling unless you run multiple chips in series.

There's almost nothing in a power supply circuit where 100uF won't work as a sub for 220uF. And, 100uF is readily available in low profile. It's actually the only kind I use!