I bought the last six Jaycar LM833 dual OPAMP based MM phono stage kits. This is the very last. Two were resold and four assembled and three sold so far. Where the previous “Player” was enclosed in an expensive Hammond extruded anodised Al enclosure this one cleverly hides in a strayed plastic enclosure. Colour is Iron Stone and thus the name for this final build. The paint is durable epoxy enamel on an etching primer.
The last two builds are powered by an external 12VAC wall wart. There is excellent power filtering and +/- 12V regulators on board to ensure a dead quiet MM phono stage. The RIAA EQ is a mix of passive and active plus there us a buffer gain stage. The front knob controls gain not volume though more gain means more volume. Input impedance is 47K. Internal components are most NP caps and metal film resistors. The inside of the enclosure is heavily lined with bituminised Al foil which is earthed. The foil shields the inside from stray electrical interference and the bitumen damps any resonances.
Overall the sound is transit quick, very clean and extremely detailed. The LM833 OPAMPs have bipolars transistors throughout which provides a rich warm tone though any similar OPAMP can be used. For example an OPA2134 can be dropped in. I find this FET/bipolar OPAMP not as warm and the bass not as full. Im staying with the LM833.
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