I have a fishman loundbox mini amp but it doesn't have a headphones output and only has a mic level D.I. output. I'm happy with the amp but would like to monitor my singing and guitar. What should I do in order to monitor my vocals and guitar through the amp. I saw somewhere that I need to use a mixer (connected to the DI out of the amp) with headphones out to do that. That makes sense to me but would like to know if I have any other options? Can I use a headphones amp (where I plug my headphones for monitoring) with the DI out? what is the best option?
A mic level input requires a mic preamp to bring it up to line level before it could be fed into a headphone amp. You could buy a separate mic pre and headphone amp, but getting a little mixer is a good idea since it's a nice tool to have around and you'll probably spend less on a mixer.
The one other option would be to get a computer audio interface that features on-board mixing (often called "low latency monitoring") so you can route the mic pre input right to the headphone output. The downside to this is that you have to have a computer around any time you want to use it.
According to the circuit diagram in the Fishman book the mic channel has a preamp before the channel controls and effects. The DI out is post both channels and pre master vol and main amp. This suggests to me it's not mic level and more line level. If so a headphone amp should suffice. I'm wanting to do same thing and considering a 'UK Topping TP NX2 Portable Headphone Amplifier' running off its own USB rechargable battery, £30 off ebay.