M-AUDIO TAMPA - Manual (Page 2)

TAMPA, simplified block-diagram:
The perception of warmth comes from a phenomenon called soft clipping, where
desirable distortion increases with internal signal level. As shown in the following
diagram, TAMPA’s soft clipping exhibits a non-linear property: The majority of the
increase in distortion only comes into play at the higher end of the gain range. TAMPA’s
OUTPUT LEVEL METER displays internal signal level and is therefore a good indicator of
soft clipping.
Input Matching
2400/1200/600/300
Select
Balanced Preamp
Gain: 6dB - 40dB
80 Hz
Highpass
Phase
Reverse
Compression
Ratio Adjust Attack
&
Release
Adjust Antilog
Amplifier Compression Meter
Logarithmic
Amplifer
Threshold
Adjust
Select
S/PDIF and
AES/EBU
Outputs
Clip LED
Dual Optical Servo
VCA
Attenuation:
0dB to 22.5dB Buffer
Inverter
Gain: 6dB
A/D
Converter Sample
Rate
Select
Phantom Power
Output Meter
Phone Input
XLR Input
X10
Gain: 20dB 20 dB
Pad
Compressor
On / Off
XLR & Phone
Outputs
Compressor Section
24-bit Digital Section
alignment found in nature. (The industry has only even had the technology to measure
this temporal distortion for the past decade or two.)
Tubes, on the other hand, induce harmonics that are temporally aligned with the
fundamental—at least in the mid-range where most featured content lives. (In the lows
and highs, tube harmonics are temporally misaligned just as with solid-state.) Further,
harmonics produced by tubes exhibit fairly high amplitude. That combination produces
the perception of “warm” tonality. Nonetheless, tube sound is colored as opposed to
transparent.
Conventional attempts to simulate tubes consider the amount of harmonics generated, but
not their timing. Unlike any other preamp—solid state or tube— TAMPA exhibits proper
harmonic temporal relationships at all frequencies. And because we’ve intentionally
designed TAMPA to have low THD, it does not necessarily have the same amplitude of
harmonics as does tube equipment. Instead, the design allows harmonic energy to vary
with signal level. The hotter the internal signal level, the greater the amplitude of the
harmonics and the perception of “warmth”. The result of this versatile design is sonic
transparency across the entire audio range with the ability to add warmth as desired.
About TAMPA’s Compressor
Most compressors, including many high-end models, exhibit very high distortion that
gives them a particular sonic signature. TAMPA’s compressor stage, on the other hand,
has very low distortion that further contributes to the unit’s transparent audio quality.
Inexpensive compressors utilize VCA technology exhibiting problematic distortion,
noise and accuracy. Most professional-class compressors utilize servo-controlled
optical resistor technology instead. While this design is quieter and more accurate, the
servo system used to stabilize the optical resistor introduces considerable distortion into
the optical device. TAMPA’s design avoids this by using a matched pair of optical
resistors. The servo system stabilizes one of the optical devices, yet audio is only
passed through the other optical device. This dual-optical servo design completely
eliminates the servo-induced distortion. As with the rest of TAMPA’s gain stages, this
means that you will experience a very transparent sound when using the compressor.
Setting TAMPA Properly
As we’ve established, TAMPA’s Temporal Harmonic Alignment is designed to do
something that no other preamp can do—deliver transparent sound. While that is its
primary design criterion, a sophisticated series of gain stages also yield the ability to add
tube-like “warmth” at higher signal levels. The real key to getting the results that you
want from TAMPA, therefore, is understanding how to use those gain stages—both
within TAMPA and in relation to your other gear. TAMPA’s meters and pads play a
significant role in this process.
TAMPA is capable of delivering up to 66dB of gain. As shown in the following block
diagram, TAMPA’s output gain is determined by the interaction of the GAIN control,
+20dB switch, compressor settings and (in the case of analog output) the 20dB PAD.