Hello. I incounter myself with a big problem. Im trying to use a voltage elevator like the Klon Centaur in a JRC4558 that is in a Ts-808 (protoboard)
The problem is that using this configuration creates a very High frecuency thats pears the ears. I think is like 9 or 10k but it really hurts
Is there a way to prevent that high frecuency?
I left the settings in the picture
thanks
(https://i.postimg.cc/3y5hFYMb/18.png) (https://postimg.cc/3y5hFYMb)
Is your chip a 7660SCPA?
If so, do you have pins 1 and 8 jumpered? (schematic does not show pin 1, this implies you are using the 7660A.)
The SCPA version is "super" in that connecting 1 to power (or jumper to 8, power+) doubles the frequency into ultra sonic.
For pedals you pretty much need the SCPA version. Maybe there is also 7660S that is ok.
Quote from: idy on April 02, 2022, 09:46:12 PM
Is your chip a 7660SCPA?
If so, do you have pins 1 and 8 jumpered? (schematic does not show pin 1, this implies you are using the 7660A.)
The SCPA version is "super" in that connecting 1 to power (or jumper to 8, power+) doubles the frequency into ultra sonic.
For pedals you pretty much need the SCPA version. Maybe there is also 7660S that is ok.
Just to piggyback on this comment: In addition you can use the TC1044SCPA or TC7662B as a sub, and both require pins 1 and 8 to be tied together to push the operating frequency out of the audio range. However, the MAX1044CPA is also the equivalent of both of those (no "S") and is another good alternative.
If you have a high frequency device, follow what the others have said,
https://datasheets.maximintegrated.com/en/ds/ICL7660-MAX1044.pdf
https://www.renesas.com/us/en/document/dst/icl7660s-icl7660a-datasheet
If you have a low frequency device then you would be best to change it.
For a low frequency device you can reduce noise by increasing the caps:
- C2 and C5 to 47uF to 100uF
- C1 to maybe to 100uF.
- C4 and C4 47uF to 100uF (optional)
All the caps need to be located close to the IC.
While it helps, it's not great advice since a high gain pedal with a the low frequency switcher will inevitably cause the switcher noise to be audible to some degree.
wuoooo thats brillant l..l,!!! thanks for the reply Im learning a lot
Im using the 7660S (you can see it in the picture)... when you say "jumpered" you mean that I need to connect Pin1 with Pin 8?
(https://i.postimg.cc/FYP05S07/IMG-20220403-075620.jpg) (https://postimg.cc/FYP05S07)
Yes, you jumper pin 1 and 8, connect them.
There are lots of examples out there. MadBean's road rage shows a circuit with a switch that allows you to choose whether your chip needs this or not.
You can also use caps with a low ESR (equivalent series resistance) for C3 and C4 (your schematic). It can make the charge pump operation a tiny bit more efficient. FWIW.
Wuooooo thats cool!!!
How can I do or use that ESR (equivalent series resistance) for C3 and C4 ?? it sounds interesting
Quote from: bean on April 03, 2022, 04:36:26 PM
You can also use caps with a low ESR (equivalent series resistance) for C3 and C4 (your schematic). It can make the charge pump operation a tiny bit more efficient. FWIW.
broooo thanks!! it works l..l,!!!!! you are the best
Quote from: Yoshi on April 03, 2022, 06:08:07 PM
Wuooooo thats cool!!!
How can I do or use that ESR (equivalent series resistance) for C3 and C4 ?? it sounds interesting
It's just a matter of finding the part with low ESR. IOW, it's a manufacturing spec.
Here's an example - 47uF cap with a practically negligible ESR: https://www.mouser.com/ProductDetail/667-EEU-FR1E470
This is another one, although it's scheduled for obselence. This is the one used in all the VFE pedals (which are typically +/-9v operation): https://www.mouser.com/ProductDetail/Nichicon/UMF1C470MDD?qs=STYa3Y5G4R67hN8%252BYHc2xg%3D%3D
Peter (the VFE guy) clued me into using this spec with charge pumps.