McIntosh reference preamp C12000

On my C12000 I can’t hear a difference between the Tube and Solid State settings as used through the RCA main out.  When I set it up through balanced XLRs then I can hear a difference.  
 

C12000 owners can you help me?  I am wondering

if my unit is defective or if this is normal??  
 

Thanks in advance for any insight!

bernardwilliams, So you are not using the MEN220 before C12000 preamp in your system? 

On the C-12000 remote the input on the left side of the remote.  On the read out on the control unit, depress until you get to the desired input be it tube in input 2 or solid state input 4. You can label inputs as well

Any hi fi product labeled as " reference " should be avoided...

farne230 On the C-12000 the bottom row of inputs are tubes the top row solid state. I am not sure for the MEN-220 you can only use the fixed rca out. Ask for Chuck in service at the 1-800 number at mcintosh he can help with any question.

bernaardwilliams are you cabling btw the MEN220 and C12000. If so how did you hook up balance connection/RCA to allow the preamp remote switch btw Tube (T) & Solid State (SS)? 

I am using MC611 mono-amps, MEN220, C12000 and HIFI Rose 150B as only source. 

I have the C-12000 and you can switch between tube or solid state by using your remote control or switch by turning the knob on the control unit to the desired input. so far the solid state will run rings around the C-53 which is a good pre-amp as well. The tube section is fantastic it keeps me up at night.

I have the unit below this, the C 1100 and I thought that you had to set up separate systems completely. One through the tube preamp and one through the solid-state preamp. I wasn’t aware of being able to switch. I might be wrong.