LaChapell Audio 583e 500 Series Tube Pre with EQ - DEMO, from LaChapell

The Model 583E features the same amplifier stage found on the 583S including the Jensen JT-115k input transformer coupled with an ultra-clean transformer-less three-band EQ section with fully sweeping frequency controls and cut/boost settings of +/- 8dB. The EQ can run as an integrated EQ serving the preamplifier or separate as its own autonomous module where both units run independently.

Preamplifier:

Gain: 0 to 70dB
Instrument: 0 to 51dB
THD+N: 0.25% (50dB gain)
Tube: (1) 12AX7/ECC83
Frequency Response: 12hz to 70khz (-3dB)
Max Output: >26dBu (1% THD+N)
Typical EIN: -120dB (22hz to 20khz~Rg=150ohm)
Input Impedance: 1.5kohm; Instrument: 40kohm
Output Impedance: 50ohm


EQ Section:

3 Band EQ with fully sweeping frequency control; fixed 'Q' value of 1 with very low phase deviation
Input/Output Type: Transformer-less; Ultra clean with minimal harmonic signature
Input: 40k
Output: 50ohm
Bands:
    Low 30hz - 400hz
    Mid: 325hz - 5khz
    High: 2.5khz - 20khz
Cut/Boost: +/- 8dB
Max Input: +24dBu
Max Output: +26dBu
Self Noise: -93dB
THD+N: 0.012% (with +8dBu input signal)