Schiit Mjolnir SCH-05 User manual

headphone amps
and dacs
ITEM
FOR
MODEL NO
OWNER’S MANUAL
SCH-05
balanced cROSSFETTM headphone amplifierDESCRIPTION
NOTES
REVISION bRANDOM NUMBER 110110111
mjolnir is thor’s hammer in norse mythology.
ours is a little less clunky than the one in the movie.
and a lot more musical.
but we think it’s a good name, given 8w into 32 ohms.
just don’t try to use it to pound in any nails.
that would void the warranty.

THIS IS A BALANCED HEADPHONE AMP.
It requires balanced headphones.
USING adapters to connect unbalanced headphones will short two active
outputs together, and you will trigger the internal protection.
The following is required by the roughly 9,542 government agencies and regulations we have to comply with. If you have some common sense, they should seem pretty
straightforward. In any case, read these instructions before proceeding farther, follow all instructions, and heed all warnings. Or else!
1. If you don’t know how to install audio devices, get a qualified professional to help.
2. Never use this device near water, and clean only with a dry cloth.
3. Assure adequate ventilation, do not block any ventilation openings, or place near heat sources.
4. Use only the supplied power cord or suitable replacement. Route cords away from traffic areas and protect them from being pinched. Unplug the cord from the outlet if the apparatus
is unused for a long period of time.
5. To prevent electric shock, do not use the plug with an extension cord, receptacle, or outlet unless blades can be fully inserted.
6. Refer all servicing to qualified service personnel. Service is required when the device has been damaged, including cord or plug damage, liquid has been spilled or objects have fallen
into the device, the device has been exposed to rain or moisture, does not operate normally, or has been dropped.
WARNING: TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK, DO NOT EXPOSE THIS DEVICE TO RAIN OR MOISTURE.
safety instructions
Application for Council Directives 72/23/EEC
Conformity declared for EN60065, EN50082-1

welcome to mjolnir!
Mjolnir is Thor’s hammer. You know, the ultimate weapon to crush your
enemies. Or something like that. We’re from the USA, so we may not be up
on all the Norse mythology, unless we saw it in a movie or something.
But back to Mjolnir. Don’t use our Mjolnir to crush your enemies, use it to
take control of the hardest-to-drive headphones on the planet. Or to add
new life to ultra-sensitive cans. Because even though Mjolnir is stout
(delivering 8W RMS into 32 ohms), it’s also quiet enough to be used with
efficient headphones as well.
Why? Thank Mjolnir’s Crossfet™ circlotron-style output stage. It’s unique in
the headphone amp world, and it delivers both excellent performance and low
noise. High-voltage JFETs provide voltage gain, while MOSFETs make up the
Crossfet output stage for current gain.
Yeah, we know, we’re swinging too hard into engineeringland here, but bear
with us. The main thing is: this is one seriously cool headphone amp, not just
two of the same amps in a chassis, or a single-ended amp with balanced
connectors, or a balanced-to-single-ended-to-balanced converting amp with
tons of extra circuitry.
Take a look through the top vents, and you may be surprised by how simple
Mjolnir is. Or you may just want to look at the pretty lights. Which aren’t just
pretty lights. They’re actually voltage references for the front-end current
source.
Yeah. Engineering. It’s fun. Tell your kids. And enjoy your time with Mjolnir.
ONE
Mjolnir headphone amplifier
ONE
Power cord (for, like, well duh)
ZERO
Stick-on feet (because the amp already has screw-in feet—you’ve
reached the big leagues now, guys)
IN THE BOX
GETTING STARTED
1. Choose an input and connect your source. Mjolnir provides both
balanced XLR and single-ended RCA inputs, but you can only use one at a
time. Choose the one you want and connect your source.
2. Plug in your amplifier and turn it on. Some amber lights will glow inside
the chassis and the power on LED will light. After 20 seconds, you’ll hear a
click as the relay engages the headphone outputs.
3. Plug in your balanced headphones. You can use 4-pin or dual 3-pin XLR
connectors. You can run two sets of headphones at once. You can even plug
them in before you turn the amp on, too.
And, in case you missed it: BALANCED headphones. Not single-ended with a
balanced adapter. That’s a bad day. You’ll trigger the internal protection of the
amp and you won’t get any sound.
4. Press play. And enjoy your music!

2 Power On LED.
When this is lit, the
power is on. When it’s
not lit ... well, you get
the picture here. Mjolnir
delays the output for
20 seconds when first
turned on to protect
against turn-on thumps.
FRONT PANEL
1 Volume Knob. Turn
it to the right to make
the music louder. Stop
before smoke comes out
of your cans. Seriously.
3 Four-Pin XLR
Headphone Jack. This
is where you plug your
balanced headphones in,
using a standard 4-pin
XLR connector. In case
you missed it, DO NOT
use any adapters for
single-ended head-
phones. They short the
outputs together. Boom.
Well, not boom but
click. That’s the internal
protection saving you
from frying the amp.
12
34 5
4 and 5 Three-Pin
XLR Headphone
Jacks. Alternately, you
can connect balanced
headphones connected
with two 3-pin XLRs
here. Right side is the
right channel, left side
is the left channel. And
yes, you can run these
outputs simultaneously
with the 4-pin jack.
6 Top Vents. Mjolnir
runs plenty warm, and
needs the airflow out of
these vents to keep its
cool. Don’t block them
by stacking other
equipment on top. If
you want to stack, put
the DAC on the bottom.
6

NO USER SERVICEABLE PARTS INSIDE
CIRCLOFET™
BALANCED HIGH-OUTPUT
HEADPHONE AMPLIFIER
bal in pre out
sE IN
bal
SE
SCH05A
000001
230VAC 45W
caution: risk of electric
shock— do not open. no user
serviceable
parts inside
2 RCA Single-Ended
Inputs. If you have a
single-ended source,
don’t despair. Mjolnir’s
inherently balanced
amplification stage
converts every input to
balanced output. But be
sure to hit the switch
(see #3.)
1 XLR Balanced
Inputs. Connect your
balanced source here for
best sound. Mjolnir does
not convert balanced to
single-ended and back
again.
BACK PANEL
3 Single-Ended
Grounding Switch.
Your single-ended inputs
sometimes appreciate
a ground reference for
lowest noise. Some-
times they don’t. Down
grounds the RCAs, up
lets them float.
Important: connect
only one pair of inputs
at a time (RCA or XLR).
The inputs are shared,
so you’re shorting them
together if you connect
both RCA and XLR.
4 XLR Balanced
Preamp Outputs.
Mjolnir can be used as
a high-quality balanced
preamp. Outputs are
muted for 20 seconds
when the amp turns on,
and whenever the amp
is in protection mode.
12
3
4
5
5 On-Off Switch.
Up is on. Down is off.
Pretty simple here. We
recommend turning off
Mjolnir when you’re not
wielding...er,using...it.
6 AC Input. Plug the
power cord in here.
Plug the other end into a
wall outlet of the correct
voltage. Trying to run a
115V unit on 230V will
result in a blown fuse,
no music, and a void
warranty.
7 Disclaimer. No,
seriously. Don’t take
this apart. Don’t stick
paperclips through the
holes on the top or side.
There are dangerous
voltages inside, and we
don’t want you to die.
6
7

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.

Headphone Impedance: 8-600 ohms
Speaker impedance: not recommended for speaker use
Frequency Response: 20-20 kHz, -0.2dB, 2Hz-400KHz, -3dB
Maximum Output: 45V P-P into 32 ohms
THD: Less than 0.008%, 20Hz-20KHz, at 1V RMS
S/N Ratio: >100dB referenced to 1VRMS
Output Impedance: <1.5 ohms
Topology: Balanced Crossfet™ circlotron-style topology
Protection: 20 second delay on start-up, DC sense, and overcurrent sense
Power Consumption: 45W
Size: 16 x 8 x 2.25”
Weight: 12 lbs
Schiit Audio warrants to the original purchaser that the product shall be free from defects in
material and workmanship for five (5) years from the date of purchase. Exceptions: Tubes.
Tubes are covered by a 90-day limited warranty with the same terms. If a defect covered by
this warranty occurs during this warranty period, Schiit Audio will repair the defective product,
free of charge. Date of purchase will be based on customer-submitted receipts, otherwise date
of manufacturing will be used to determine warranty period.
If you believe you need warranty service, CONTACT US first. There may be a simple
solution to your problem. Schiit Audio products sent back to us without a RETURN
AUTHORIZATION (RA) will be returned to the sender without repair. To contact us and obtain
an RA, call [phone] or email [email protected]. We will respond quickly to either
phone or email messages.
WARRANTY LIMITATIONS
THIS WARRANTY SHALL NOT APPLY IF THIS PRODUCT: (a) IS MODIFIED OR TAMPERED
WITH; (b) IS DAMAGED BY NEGLIGENCE, ACCIDENT, UNREASONABLE USE, COFFEE, OR BY
OTHER CAUSES UNRELATED TO DEFECTIVE MATERIALS OR WORKMANSHIP; OR (c) HAS
HAD THE SERIAL NUMBER ALTERED, DEFACED OR REMOVED.
ANY APPLICABLE IMPLIED WARRANTIES, INCLUDING WARRANTIES OF MERCHANTABILITY
AND FITNESS FOR A PARTICULAR PURPOSE, ARE HEREBY LIMITED IN DURATION TO
THE WARRANTY PERIOD (5 YEARS). IN NO EVENT SHALL SCHIIT AUDIO BE LIABLE FOR
CONSEQUENTIAL OR INCIDENTAL DAMAGES RESULTING FROM THE BREACH OF ANY
IMPLIED OR EXPRESS WARRANTIES. SOME STATES DO NOT ALLOW LIMITATIONS ON HOW
LONG AN IMPLIED WARRANTY LASTS OR EXCLUSION OF CONSEQUENTIAL OR INCIDENTAL
DAMAGES, SO THE ABOVE LIMITATIONS MAY NOT APPLY TO YOU.
This warranty gives you specific legal rights. You may also have other rights which vary from
state to state or province to province.
Schiit Audio’s address is: Schiit Audio, 22508 Market Street, Newhall CA 91321 USA.
5-year limited warranty
SPECS

everything else ain’t.
ITEM OWNER’S MANUAL BACK COVER
GRAPHIC FOR THE BACK COVER OF THE MANUALDESCRIPTION
NOTES
YES, ALL SCHITT PRODUCTS ARE MADE IN THE USA.
YES, PRIMARILY OF US-SOURCED COMPONENTS.
YES, IT’S PRONOUNCED EXACTLY LIKE YOU THINK.
NO, WE ARE NOT ON FACEBOOK.
NO, WE’RE NOT ON TWITTER.
And no, we’re not on youtube.
SCHIIT AUDIO
22508 MARKET STREET
NEWHALL, CA 91381 USA
PHONE [phone]
WWW.SCHIIT.COM