If I connect my turntable to the HD6 will it be necessary to purchase a phono preamp or can I simply connect the turntable directly to the HD6 input?

Some turntables will need a preamp before being connected and others may have one built-in. With that in mind, it is best to check the turntable manufacturer’s website, the turntable’s user manual, or you can even try your turntable without the preamp first to see how it operates.