sALuT
Thank you for purchasing this Xaoc Devices
product. Tallin is a dual voltage controlled
amplifier (VCA) with overdrive, offering some
unusual control features and a range of at-
tractive tonal characteristics. Each of the two
identical channels offers two simultaneously
available inputs for voltage control over sig-
nal attenuation or gain, with linear and expo-
nential response to CV. Volume control knobs
offer manual gain settings ranging from fully
closed (-80dB) up to +18dB. A color LED indi-
cator displays output signal levels. A soft-clip
circuit avoids harsh clipping distortion, while
a switchable overdrive circuit offers two care-
fully crafted distortion responses, simulating
the sound of classic tube amplifiers.
Since both CV inputs are simultaneously
active, they can be jointly exploited within
patches featuring more complex volume con-
trol that otherwise would require using two
traditional VCAs in series. As the signal path
is DC-coupled, Tallin can also be used for han-
dling the control voltages.
INsTALLATION
The module requires 6hp worth of free space
in the eurorack cabinet. The ribbon type pow-
er cable must be plugged into the bus board,
paying close attention to polarity orientation.
The red stripe indicates the negative 12V
rail and is supposed to match the dot, –12V,
or red stripe marks on both the unit and
the bus board. The module itself is secured
against reversed power connection, however,
reversing the 16-pin header
may cause seri-
ous damage
to other components of your sys-
tem, because it will short-circuit the +12V and
+5V power rails. The module should be fas-
tened by mounting the supplied screws before
powering up. To better understand the device,
we strongly advise reading through the entire
manual before using the module.
mOduLe OVerVIeW
Tallin consists of two completely independent
but functionally identical channels, a and b
(fig. 1). Each channel is built around a “mod-
ern vintage” discrete VCA core with a matched
transistor pair and multiple feedback topolo-
gy. This gives Tallin a specific character not
present in other VCAs that use mathemati-
cally precise and sonically pure integrated
gain cell VCA chips. With Tallin, we opted for a
discrete core, to provide a thick and charming
sound that reflects Xaoc’s tonal idiosyncrasy.
The signal inputs
1
accept Eurorack signal
levels (typically 10Vpp, but capable of handling
up to 20Vpp). They can also accept normal
studio level (+4dBu) signals which can be am-
plified to the modular levels, thanks to the gain
reserve of up to +18dB. The knobs
2
control
the attenuation or gain by scaling the corre-
sponding control voltages. Thus, in a min posi-
tion, they fully silence the channel, regardless of
whatever control voltage is applied to the VCA.
Turning a knob up will gradually open the VCA,
offering a significant boost when above the 12
o’clock position (depending on the control volt-
age patched in).
There are two CV inputs in each channel, re-
spectively featuring an exponential
3
and
linear
4
control response. Both controls
are available simultaneously, and they jointly
determine the gain of the VCA. A CV of 0V at
2
module
explained
