Hey,
I have an old sennheiser md421 flying around, which I would love to use with the OG-1. since it’s a 200Ohms dynamic mic I would presumably need a kind of portable preamp. But would my attempt be worth at all? Would OP1 and the 421 be a suitable combination, or just don’t match for their specs?
what wouldn’t “match”?.. it’s a mic… as long as you got a pre amp or interface to go into the op1 i don’t see why anything would be an issue… Not sure what you mean by “suitable combination”…
it’s just a large diaphragm mic… or am i missing something?
No, you’re missing nothing. It was just my question. technic-wise.
@Fab.t @Erlik_Khan if you wanted to skip the preamp it might work but it depends on the ratio of output impedance of the mic and input impedance of the op-1. i think the op1-field has a very high input impedance (i dont know the specs off hand) but OG op1 i dont know. the higher the input impedance the better. in the field, i dont need a preamp for my dynamic mic that doesnt require phantom power.
the biggest issue in plugging in mics is just making sure you do not send phantom power to anything that does not support it, like the op1, a mic, etc.
heck yea then you’re good to go if you have some sort of interface/preamp, 
i don’t think i’d want to run the dynamic mic straight into the op1, it won’t need phantom power but it will have a balanced xlr output so i think for best sound, lowest noise and least EMF interference i’d go : MIC → Interface-> into OP1 line input.
and to reduce ground loop noise i wouldn’t have the two devices powered by the same power supply. For example, if you had a USB powered XLR preamp, i wouldn’t plug both it and the OP1 into a 2 socket USB power wall wart. You will prob get ground loop noise, hum, or hiss.
When mobile music making, i really love ANKER brand USB power supplies. They claim to have all this advanced circuitry and it seems to work wonders. I have equipment that will get ground loop noise with 10 dif usb Wall warts but will be fine if all 3 of the devices are plugged into my single 3 port anker USB brick. Super clean audio that way. No hum, no interference.
Using a mobile XLR recording interface, like Zoom or Tascam, has advantages over pluggin straight into the op1 mic input. You get better preamps, better gain staging, more control, plus things like auto limiters, compressors, and other helpful stuff the OP-1 doesn’t have on the Mic input. And you can be recording a clean, pre-OP1 track of the Mic so you can always double back and sample something into the op1 later 
Hey,
Thanks for the insight:) yea, bypassing a preamp would be convenient.I could imagine that OG’s input impedance is lower than the field… which mic do you actually you use?
Thanks for that input Erlik 
,
Ok, that’s nice to know. Also the tips about groundloop. Have to dig into that.
A zoom would be a good compromise for mobile use, which is what I’m after.
Do you guys know any further portable and small preamps?
i use a peluso r14
absolutely happy to help anytime.
Nice! Seems to have a pretty warm sound character due to the ribbon?
its an amazing mic. yeah really warm. i record guitar primarily and it gives a really fat tone. highly recommend.
Sounds like a good combination I love OP1 with further acoustic instruments also. It suits well somehow! To me OP is like a whole little recording studio.