Sound Performance Lab 2595 - Manual (Page 9)

9
Passeq
Lundahl Transformers
The Swedish firm of Lundahl is recognized world wide for the superior sonic qualities of its
hand made transformers. SPL has used Lundahl transformers for many years, typically for
optional in- and output stages of various products. In the case of the Passeq, there is no
question of whether solid state or transformer-based input and output stages are the better
choice: Because of their excellent and similar sonic qualities, Lundahl transformers are a clear
choice to complement to the Passeq’s EQ circuitry.
I/O transformers are classical analog components in many “vintage” machines. In addition
to increased operational safety due to the isolation from incidental I/O electrical interference
they offer, transformers also introduce their own element of sonic “warmth” that is today too
often inadequately attributed solely to tube circuitry.
The sonic quality from Passeq’s Lundahl transformers may be described in comparison to
straight electronic I/O circuitry as: Bass and fundamentals are rounder, fuller, and exhibit
more “punch”, while higher frequencies and harmonics sound silkier and more present, yet
without leaving the impression of being overly emphasized or singled out. Moreover, they add
the subtle impression that mix elements are better localized.
The reasons for this are the tendency of transformers to reduce uneven harmonics (which
often give the impression of harshness in a sonic canvas) and to act with some latency
compared to electronically balanced stages. In particular, fundamentals and low frequencies
benefit from this.
Other Features
XLR contacts from Switchcraft serve as In and Output connections, while controls and switches
are from the manufacturers Elma and ALPS (including ALPS’ “Big Blue” with 41 steps). The
internal, fully analog power supply features a generously proportioned toroidal transformer
that offers switchable, 110-120 Volt/60 Hz or 220-240Volt/50 Hz functions.
Conclusion
The Passeq represents the most powerful passive EQ system to date and fulfills the highest
expectations in all areas of audio processing, from recording through mixing to mastering.
Introduction