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By deverett
I previously had an MP3 trigger I bought 5 years ago in a project which stopped working a few months ago. I bought a replacement but the maximum volume seems to be half of what it was before.

I checked I am sending max volume to the unit, but I can't get close to the old volume. Has there been a change to the firmware that might affect this?

If so can that be modified. The output is now to low to trigger other circuits which rely on a reasonable level of volume.

Dave Everett
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By robertsonics
I assume you're playing the same files on both the old and new unit, and that it's not just the level of your mp3 file... What do you mean when you say "I am sending max volume to the unit"? How and what are you sending?
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By robertsonics
Also, the hardware has changed since you purchased your original unit. Specifically, an option was added to provide a true line-level output circuit with DC blocking caps and a reference to the board GND, making it compatible with grounded external equipment with line-level inputs. This option is now the default. You can restore the original output (direct from the VLSI chip) via the solder jumpers SJ2, SJ3 and SJ4. Please refer to the schematics.

And to answer your original question, the firmware has not changed.
By deverett
Thanks, that is great, I will try modifying the output and see how that goes. I am using the same SD card of files as on the old unit, I also checked the gain of all files and they are about maximum.

When I say I am setting max volume I am sending volume commands from an arduino which has a pot connected. I can see the data that is being sent and it does affect the volume so I'm confident that this is still working as it always did.

Thanks again,