Heritage Audio Symph EQ
Features:
- Individually tuned Carnhill Oxford transformers
- Class A operation
- High-precision rotary switches with 0.5 dB steps
- HP/LP filtering, Bypass function
Historical Update
The Baxandall equalizer typology, introduced to the public by Peter Baxandall in 1952, was a very original way of obtaining high and low shelves with the ability to boost and cut without the need for expensive rotary switches. This cost-effective scheme was soon embraced by hi-fi and PRO Audio manufacturers for its simplicity, eliminating the need for parametric options.
Heritage Audio successfully replaced the Baxandall typology with a more musical functional equivalent - implemented as a master bus/mastering device with a single rack space.
The stereo asymptotic equalizer, known as Symph EQ, got its name from the shape of its shelf curves, where the amplification or attenuation increases until reaching an asymptotic value, providing consistent control and sub-bass values.
Its sound can be characterized as dense, pleasant, and natural, with the use of parallel equalization to achieve desired response curves resulting in extremely low phase deviations and artifacts.
High Precision with 0.5 dB Steps
The carefully designed connection scheme provides a maximum boost/cut of 10.5 dB with 0.5 dB steps. The main rotary switch sets the step at 1 dB, with a 0.5 button adding half a dB to the main reading. The "CUT" button transforms the boost value into a cut value. There are six strategically selected frequencies for each range (8, 10, 12, 15, 20, and 24 kHz on the upper shelf, and 20, 60, 110, 220, 360, and 470 Hz on the lower shelf).
2-pole High and Low Pass Filters
To control the content of low and ultra-high frequencies, additional high and low pass filters have been added on two concentric rotary switches with a 12 dB/octave frequency. Each has 5 frequency options plus OFF (10, 12, 18, 22, and 30 kHz for low frequencies and 15, 20, 47, 82, and 160 Hz for high frequencies).
The Symph EQ, as described above, could be an amazing tool for sculpting, but it becomes a masterpiece with the following three additions:
- It uses the same exclusive Carnhill input transformers made in Oxford as its predecessor.
- Its outputs are driven by Class A 73 type output amplifiers, using the same Carnhill St Ives output transformers as other devices in the family.
- Most importantly, here is where Symph EQ truly shines - with its built-in M/S capabilities.
Package includes:
- Equalizer
- Power supply
- Manual
