Super rare, these 1U monoblock VTL-built Equalizer Line Preamplifiers were first prototyped in 1989 or 1990. A handful, or maybe just these two units, were built as mono units with the Manley brand. Later a VTL-branded model called the Ultimate Line Equalizer was put into production into the existing 3RU short Ultimate chassis along with an additional 12AU7 stage ahead of volume and balance controls. This first stage was interesting as  it was a common cathode phase splitter with two capacitor coupled anode outputs providing a balanced output at that point in the circuit which is how the Polarity Invert was achieved. The BASS and TREBLE R-C shelf circuits lived in the feedback loop of the second gain stage, and I'm pretty sure the Marantz 7 preamplifier was the inspiration for this part of circuit. The TILT EQ section was a passive R-C circuit after the 12AT7 EQ stage and before the final paralleled 12AT7 Cathode Follower output buffer. I remember referencing the TILT circuit when I was David Manley's design and prototyping assistant, but I can't quite remember where he got the TILT circuit from. It was lifted from some earlier classic circuit. He did not originate this design either. Perhaps 25 or 30 VTL Ultimate Line Equalizer Stereo Preamplifier units were sold into the audiophile market in the first few years of the 1990's. As they carry the VTL brand, please contact VTL about them, not us!

If you come across any more of these MANLEY-branded 1U monoblock Equalizer Line Preamplifiers, that's what this page is all about and we can help you with them.