??Quality Vol.Control for between Transport&DtoA ?

I have mono amps with DAC included. So input to mono amps can be selected as standard analog or digital from a transport etc. Goldmund and maybe others make a digital preamp..but the $$,$$$!!! Any suggestions on a volume control for between the transport and the DAC in the amp. I don't want to throw away half the digital signal as I understand is the situation in digital volume controls. Thanks for your reply.
Look into a used Z system home unit or their current z-q2 or z-qualizer. If the amps have 24 bit dacs and if you don't need a high amount of attenuation you'll get great sound plus a pre that has EQ's that work great or can be bypassed just by setting the EQ level to zero