AHere we have a great sounding preamplifier, the Audible Illusions Modulus IID all tube preamp with a fine phono section. We acquired this unit from its original owner who purchased the unit in 1990. There are some small scratches on the top cover around some of the allen screw holes and some fading on the black anodizing on the top right rear vent slots. The unit as a whole presents itself very well and the faceplate is in great shape.
This is a highly regarded preamp and is known as a giant killer. This is the 4th iteration of the 2nd generation of the Modulus. We prefer these attenuators over the stepped attenuators in the later models. The unit has individual left/right volume controls which double as balance controls, high quality gold plated RCA jacks, and component quality selection found in preamps three times this price. This build quality on the unit is superb.
The unit was cleaned, and a new phono/hi level switch was installed that we acquired from Audible Illusions. When we put the unit on the bench for testing there was a noticeable hiss with the volume turned down. The unit still sounded great when the volume was up even just a little bit, but we still felt the need to try new tubes. We installed a full set of new ECC 88 6DJ8 Tesla tubes and the hiss disappeared. We ran the unit for a few days in one of our systems and it performed flawlessly. We will include the original set of Russian 6H23 tubes just in case the new owner wants to experiment with them.
Frequency response: 2Hz to 100kHz
Total harmonic distortion: 0.15%
Gain: 28dB (MM), 30dB (line)
Signal to noise ratio: 74dB (MM), 85dB (line)
Output: 2V (Pre out)
Valve complement: 4 x 6DJ8/ECC88