L78L05 (100 mA) for powering Daisy Seed — is it sufficient?

Hardware Development
1

Hi all,

I’ve been looking at different Daisy Seed pedal/module designs (for example the Terrarium from PedalPCB and the Hothouse), and I noticed they use an L78L05 regulator to step down 9V to 5V.

From the Daisy Seed specs, the Seed itself seems to draw around 120 mA typical, not counting external circuitry like pots/switches/OLEDs. Since the L78L05 is only rated for 100 mA max output, I’m wondering:

  • How are these designs getting away with it?

  • Is the Seed’s actual current draw often lower in practice, or is the L78L05 able to source more than 100 mA in reality?

  • Are there potential stability or thermal issues when running above the rated current?

  • Would it be safer to use a higher-current regulator (like a 7805, a modern low-noise 500 mA LDO or maybe a buck converter)?

Curious what others have found in practice — is the L78L05 a safe choice for Daisy Seed designs?

Thanks!

2

The Terrarium and Hothouse only use the 78L05 to power the op amps.

3

Ah, thanks for clarifying. Looking at the BOM and schematic, though, the Terrarium uses TL072 op-amps for the I/O buffers. If the Terrarium uses a 78L05 to power the TL072 op-amps, how does that work given the TL072 needs at least ±3 V (6 V total) to operate, and even more voltage to operate with sufficient headroom?

4

Obviously, tl072 doesn’t require +/-3 to operate, just to operate optimally. I suspect the usual guitar signal is small enough that it doesn’t hit the rails. I built a Terrarium way back (sold it), didn’t test to see how it behaved with a hot input. It sounded fine for electric guitar.