Dave Tholen

I had assumed that Zoom's insistence on using only the AD-19 adapter (going so far as to include a separate warning sheet about the possibility of death) had to do with current capability of the AC adapter. Try driving eight microphones that need 10 mA of current at 48 volts for phantom power, and the microphones alone would be drawing almost 4 watts of power. I didn't think about the tolerance on the voltage. The Hirose power input has 9 to 18 volts silkscreened right next to the connector. That's a pretty wide tolerance. Zoom says nothing about the voltage tolerance on the barrel connector, but the AD-19 puts out 12 volts. I figured an external battery that delivers 12 volts and at least 1 amp would work via the barrel connector, but battery voltage isn't nearly as flat as an AC adapter's voltage. Thanks for the heads-up on that. My experience so far is that a set of eight relatively new Panasonic Pro Eneloops (2500 mAh per, or a total of 24 Wh) can power the F8n for about 5.5 hours with two microphones drawing 10 mA of phantom power at 48 volts, with four channels being recorded at 24-bit and 44.1 kHz (stereo, with dual recording at a different gain level), though I've gotten nervous because the battery gauge turns orange quite quickly, probably because the discharge curve for NiMH battery chemistry flattens out at 1.2 volts pretty quickly, so the Zoom stays in the orange voltage range for a fairly long time. I'd feel a lot more comfortable, especially as the Eneloops age, with an external battery that can supply 72 Wh, which the Talentcell can apparently do. That way I can use more than two microphones that need phantom power and not have to worry about the batteries becoming exhausted during the recording session. The first time I used the Zoom F8n, I wound up swapping batteries at intermission over concern about the battery gauge turning orange. That's when I started looking at external battery power solutions, and a Google search led me to this forum. It's nice that the F8n will automatically switch power sources if one becomes exhausted, so between a 72 Wh Talentcell and 24 Wh internal batteries, that's 96 Wh of power, and I could always swap in a second Talentcell while the internal batteries are powering the unit for virtually unlimited recording time. But it sounds like I should purchase both the Talentcell and the DHC-1, rather than using the barrel connector with the Talentcell. The outer diameter of the barrel connector on the AD-19 appears to be 5.0 mm, while the inner diameter is a little harder to measure in low light, but is around 2 mm.

After a bit more web surfing, I see that Zoom included the DHC-1 cable with the F4, but not with the F8n. Fortunately, the DHC-1 is available for purchase. Curiously, the Zoom web page about the F4 and DHC-1 shows the AD-19 adapter as being used with the DHC-1, making one wonder why not just use the separate DC input and avoid using the DHC-1 cable. Yes, I can understand how some users like the idea of a connector that can't get accidentally yanked from the device. But it's beginning to look like the Talentcell solution could be used both via the DC input and via the Hirose input, if the DHC-1 cable is used. Does the power cable included with the Talentcell have the correct inner and outer diameters on the plug to fit in the F8n DC input and/or the DHC-1? In the video above about the Fotodiox solution, the point was made about the DC in and DC out connectors having different sizes. The Talentcell linked above says 12 volts and 6000 mAh. That's 72 Wh, comparable to laptop batteries that sell for several times the price, and also comparable to some of the NP mount battery solutions that also sell for several times the price (and do not include a charger), which makes me a little suspicious. Can others vouch for the quality of the Talentcell power banks?

I assume the F8n is comparable to the F8. Am I correct in assuming that the Talentcell solution would connect to the F8 (and hopefully the F8n) via the same connector as the AC adapter and NOT via the 4-pin Hirose connector?