Muse Model 2 DAC with optional Bessel Filter. The Muse has a 1-volt output. So, unless you have a preamp; i.e., if you are using a passive volume control instead, you will need to get a 2-volt version of the Muse (which is rare) or have Muse upgrade it to 2-volts for you. They are still doing the upgrade and it is $165 plus shipping.