Hi, sorry I misunderstood your original post. Glad you found a solution, but it stll seems odd to me that such a thing would be required, and there may be some side-effects to operating the EQ in such a manner. The Beomaster phono preamp gives a solid 40dB gain and should be able to drive most any consumer line-level input just on it's own.
I take it you're using the RCA "tape 2" outputs? Another possibility would be to remove the U-jumpers and use the "line out" . . . this is before the volume control as well. If this works better (and if you're using it as a receiver as well) you could use Y-cables to restore the jumper connection and still use the line-out. Or if you're not, there's always the preamp-out connection, which would then allow you to get some more gain by operating the volume control.