Rane SM82 Eight Channel Stereo Line Mixer
Last Update 05-26-2025
This is probably the briefest webpage I have written, not much to
write about line mixers. Line mixers are designed for devices with
line level outputs - every keyboard and module I own has line level
outputs. I don't need mic preamps with 60dB of gain or EQ with them.
I started my MIDI studio with a Rane SM82 which fit the bill
perfectly. Line mixers are simple circuits that can be built with
just opamps, no discrete circuits. There is almost nothing circuit
wise that can degrade the tone of anything. What goes in is what
goes out.
Rane built high quality professional audio accessories until a new
owner purchased them, who proceeded to discontinue all the
professional audio products and replace them with DJ products. These
mixers were a popular product which are easy to find used. The
closest new product today is the Ashly LX-308B.
The SM82 is a 1U rackmount compact stereo line mixer with eight
stereo or mono input channels, with stereo or mono effects buss and
send levels for each channel. Each channel has a balance control
(pan for mono signals), level control, and overload LED. The inputs
and effects send/return are unbalanced, the main outputs are
balanced. Effects and main output have balance and level controls.
Also included are expand in/out jacks, which allow expansion by
adding more SM82 mixers without consuming a channel (you must use
expansion cables 18 inches or shorter to prevent noise). You simply
chain multiple SM82 mixers with an expansion cable. That's it,
simple and sweet. Compact, easy to expand, and I don't need a
large console to mix my keyboards/modules. A common malfunction is
the main output level control; when they start to fail, the audio
output will be intermittent. I have been unable to source a direct
replacement pot, and Rane no longer stocks spare parts for legacy
products. So today I leave the main level controls alone and
control the main output to my monitors using a stepped attenuator
that I built from a circuit in the excellent book "Audio Cyclopedia"
(Howard Tremaine, 1978 second edition seventh printing ISBN
0-672-20675-7). If I do need to record any of them to my multitrack,
I use a Countryman Type
10 DI box.
As my arsenal grew, I added SM82 mixers. I now have five of them,
three in the studio and
two in my stage MIDI system. They
were made in grey face and black face panels, there is no circuit
difference in them. If you buy an SM82, you must make sure the sale
includes the remote power supply ("lump in the middle") as the SM82
does not have an internal power supply. There is no direct
replacement for the Rane remote power supplies. Rane did make
an SM82S model that has an internal switching power supply.
Well, that's it. Told you there wasn't much to write about!

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