Helios Type 69 Mic Pre / EQ

The Helios Type 69 is a faithful remanufacture of the legendary mic pre and three-band EQ used in Olympic Studios from the 1960’s.

The Helios Type 69 has been updated for modern applications and now features a custom Sowter 8666x input transformer based on the much sought-after Lustraphone transformer found in the original Olympic Studios units. In addition, this recreation is built with military grade components offering much improved reliability and quality. Other updates include 30Hz and 16kHz frequencies in the EQ section in order to meet with modern full bandwidth productions and a polarity reversal switch.

True to the original, the preamp section boasts a five position mic and line input gain ranging from 20dB all the way up to 70dB in 10dB steps. The microphone input section works at a fixed impedance of 1200 Ohms and 10k Ohms for the Line level. The input section also includes a -20dB position of the 3-way toggle switch.

The three-band EQ uses the same passive design found in the original with a unique combination of RC and LC tone circuits. The HF band features a static 6dB-per-octave, 10kHz shelf with a +/- 10dB gain. The LF band is more complex with five selectable peaking frequencies (30Hz, 80Hz, 120Hz, 240Hz and 400Hz) with a 15dB boost and cut. Turning the Elma switch further selects a 70Hz fixed frequency, 6dB-per-octave shelving filter with 3, 6, 9, 12 or 15dB roll-off. When in peaking mode, an additional switch activates an additional 12dB-per-octave High-pass filter with selectable 40Hz or 80Hz frequencies. The LF can be deactivated entirely for a more transparent performance. The MF band offers a wide range of frequencies including 700Hz, 1kHz, 1.4kHz, 2kHz, 2.8kHz, 3.5kHz, 4.5kHz, 6kHz and the newly added 16kHz with a Peak / Trough (cut) toggle switch and 15dB boost/cut with proportionate Q. At its widest the Q is a wide three octaves at 700Hz and 2 Octaves from 6kHz. As the boost/cut is increased the Q narrows.

The Helios Type 69 delivers an incredibly open sound with sweet high frequencies and mids and pultec-style lows. The Helios 69 module works with an external PSU available in a 1U rack with two slots or a mono vertical module slot.

Helios Type 69 mic preamp and three-band EQ Overview:

• Faithful Recreation of Olympic Studios legendary mic pre and EQ module
• Custom Sowter 8666x input transformer based on original Lustraphone design
• Improved manufacture with military grade components
• Added 30Hz and 16kHz frequencies for modern full bandwidth recordings
• Five position 10dB stepped gain
• Added polarity switch
• Three-band passive EQ with fixed 10kHz HF Shelving
• Extensive range of midrange frequencies: 700Hz, 1kHz, 1.4kHz, 2kHz, 2.8kHz, 3.5kHz, 4.5kHz, 6kHz and the newly added 16kHz
• Unique LF EQ design with selectable Peaking and Shelving frequencies
• 15dB cut/boost on LF and MF bands, 10dB on HF
• External PSU Required
• 1U dual slot or single vertical PSU available (sold separately)