FAQ
I hear hum through the headphones, what do I do?
It’s most likely a ground loop. To fix a ground loop, try a GFCI outlet or a
ground loop isolator.
Hey, the amp just clicked and I get no sound. What gives?
Mjolnir has sophisticated internal protection for overcurrent and DC—did
you just try to connect your unbalanced headphones? Or did you try to drive
speakers with the amp? If so, you hit the protection. Unplug the headphones
and turn the amp back on. The protection will reset and allow you to use
balanced headphones as intended.
There’s no sound for a while after I turn Mjolnir on. Why?
That’s perfectly normal. Mjolnir delays the headphone output for 20 seconds
after you first turn the amp on to protect against turn-on thumps. A minor
click is normal when the relay is engaging.
Can I leave Mjolnir on all the time?
You can, but we really recommend you power down the amp if you aren’t
going to use it for an hour or more. Mjolnir uses a reasonable amount of
power, and runs pretty warm.
Can I power speakers with Mjolnir?
That’s not a great idea—speakers require more current than headphones,
and you may trigger Mjolnir’s internal protection.
It doesn’t turn on, what do I do?
Plug it in to a different AC socket. Ensure you are not currently in a blackout.
Then call us if it still doesn’t turn on.
Hey, you know this amp runs pretty warm?
Yep.
What do I do if my headphones don’t have balanced connectors?
Many headphones with detachable cables offer optional balanced cables
from the manufacturer. Contact them and see if they offer balanced cables,
or check with the aftermarket cable manufacturers.
What if my cables are attached to my headphones?
Then you’d better get a screwdriver and soldering iron if you want to use
them with Mjolnir. Some headphones are relatively easy to re-cable, because
they already have 4-conductor cables. However, we don’t have an exhaustive
list of these, so please contact the headphone manufacturer for details.
Hey, once I re-terminate my headphones with balanced connectors, how
do I use them with single-ended amps?
There are tons of adapters for converting 4-pin XLR to 3-pin TRS jacks—and
they are totally safe to use. It’s the other way around that gets messy.
Why don’t you have a single-ended output as well as balanced?
Unlike other “balanced” amps, Mjolnir isn’t just two of the same amps in a
box with one run inverted, or a single-ended amp connected to a 4-pin XLR
jack for looks. It’s an inherently balanced topology that cannot be unbalanced
without heroics like summing the outputs together (additional circuitry) or
having a completely separate gain stage. We wanted to maximize perfor-
mance for balanced output, so we stuck to balanced-only.
