User Guide / Owners Manual

7
Frontliner
Special technical features
• Threeseparate,individuallyoptimizedinputsformicrophones,linesignalsandinstruments.
• Discrete semiconductor/tube hybrid preamplifier to combine the advantages – high
dynamic range and low noise operation of semiconductors with the musical qualities of
tube sounds (appealing top end, beautiful spacial impression). Discrete construction is
based upon single transistors instead of integrated circuits (ICs) from industrial production
and ensures a higher level of optimization.
• 250voltstubecircuitsinthepreamplifierandfortubesaturationstages.
• High-gradeoperationalamplifiersfromBurr-Brownatcriticalpositions.
• The SPL De-Esser applies the method of phase cancellation for reducing sibilants. This
innovative approach works much more neutral than traditional compression methods – a
unique method for unobtrusive results and extremely fast operation.
• ThecompressorisoperatedbySPL’sdoubleVCAdrivecircuitry.Adifferentialstageelimi-
nates side effects and the half load per VCA dramatically reduces THD.
• The operational amplifiers for the compressor circuitry meet military specifications.
Therefore the regulating voltages are extremely precise – a precondition for high signal
processing quality.
• SelectedcondensersfortheEQfilterswithpleasantsoundcharacteristics.Especiallywith
vocals, amplified frequencies are not sounding too bright, and on the other hand reduc-
tions can tame harsh sounds without sounding dull.
• Central star ground wiring scheme minimizes influences that could affect the ground paths.
The audio ground is separated from the ground of the remaining equipment. This leads, in
the truest sense of the word ”clean”, to considerably improved tonal quality.
• Thepowersupplyisbuiltaroundtwotoroidaltransformers,onefortheaudiovoltagesand
one for the other supply voltages (tube heating, LEDs, micro controller etc.) Mutual inter-
ferences are excluded and lavishly over-dimensioned capacities ensure absolutely stable
supplies for all audio circuitries.
Options
• Lundahlinputtransformerforthemicrophoneinput.Theinputtransformersaddca.14dB
gain (depending on the microphone). This must be added to the scaled values. The addi-
tional passive gain relieves the preamplifier electronics at any gain level. Microphone input
transformers are highly recommended for ribbon microphones, as they are demanding a lot
of amplification.
• OUT1fromtheMAINOUTPUTScanoptionallybeequippedwithanoutputtransformerfrom
Lundahl.
• The Frontliner can optionally be equipped with a digital output AD converter card. The
Frontliner is a mono channel strip. An additional socket at the rear panel (AD Input 2) allows
to feed the dual-channel converter with feed a second signal source.
• Refertopage27forfurtherinformationontheoptionalequipment.
Introduction