semi-off topic, but now that i started using L-series batts on my zoom, i wouldnt hesitate to use them on the mixpre instead of the 8-AA sled. (i really dont consider the 4-AA sled all that useful except for as a backup power source
considering 8-AAs are around 5000 mA at 5V, almost any decent pair of L-series batts in the 2600-3000 mAh range should match or beat them on run time, and they are hot swappable unlike the AAs. and they make some big honkin ones as well, upwards of 10000 mAh, which could easily replace a usb-c battery without the cable fears
we'll be testing a bunch over here:
https://taperssection.com/index.php?topic=193221ill circle back with recs, but i no longer have a mixpre. if anybody has an L-series mount i can pass a pair of known-good batts along to try, in a bit.