Conrad Johnson phono stages

The TEA1 Series 3 triode equalization amplifier is a stand-alone vacuum-tube phono stage designed to satisfy the expectations of the most demanding music lovers. 

The TEA1s3 features a zero loop feedback circuit with passive RIAA equalization. It offers two phono inputs, one with switch selectable resistive and capacitive loading allowing the user to fine-tune performance to the chosen phono cartridge. The other input is fitted with premium wide-bandwidth audio transformers installed on the PHONO 1 input to provide the higher gain and very low noise required by low output moving coil cartridges. TEA1s3 is using step-up transformers.

The circuit is a zero-feedback design, to eliminate the temporal inaccuracies that negative feedback introduces. RIAA equalization is established by a passive network between the two gain stages. This network has been carefully designed and has been implemented with precision (1% tolerance) parts to precisely track the prescribed RIAA equalization curve assuring absolute tonal accuracy. A high-current MOSFET buffer stage follows the second gain stage to achieve a low output impedance (less than 200 Ohms).

The TEA2 is available in high-gain (55 dB) and low gain (40 dB) versions to match a wide range of modern phono cartridges. THe SE version are upgraded with CJD Teflon capacitors and upgraded AC cord.