4:1 Compressor at 18 volts?

[brucer]

Hi all.

I'm just boxing up a MB 4:1 compressor and the way my board is shaping up I either need another tap on my 9-volt daisy chain or to use the 18-volt outlet on my VL ISO-5. 

Can the 4:1 compressor be run at at 18 volts?  Is there an upside (more headroom?) or downside (more noise?) doing that?

My google-fu is not strong, but I did find a site that suggests it's fine if your caps are rated high enough (mine are): https://atomiumamps.tumblr.com/post/158891400886/hollis-flatline-compressor-modsupdates-ive-built

Any guidance would be appreciated.

Thanks!

[Drew Hallenbeck]

Ratings on your caps are important but you'll also need to check the datasheets for any of your active/semiconductor components as well. Transistors, ICs, etc.
I just looked at the datasheet for a TL072CP available from Mouser (they're the ones I usually stock up on) and it's max operating voltage is 36 volts. Shouldn't be an issue!
You may want to consider using a slightly higher value for the Current limiting resistor for the indicator LED too. I've built a few pedals that can run at 18v and haven't had any problems with my typical CLR/LED combos. Then again, I like to use a lot of bright/clear LEDs and typically use pretty high value CLRs to keep em from being "laser beam in the eyes" bright.
That being said, I'm not sure if the circuit will work/sound any better or worse.....
But you should be fairly safe as far as not letting any magic smoke out of the components!

[brucer]

Thanks Drew!
Good tips. I'll do as you suggested.
Much appreciated.