You need a preamp with a processor bypass loop. Many of the newer preamps have this feature.
4 responses Add your response
I have an old, beautiful 2 ch. tube preamp and a Lexicon DC-1. I run my CD player direct into the preamp for no-compromise straight audio. For HT, I run the DVD's digital output into the Lexicon and the Lexicon's L & R analog output into the Aux input on the preamp, same as any other source. To balance the channels, I set the volume on the preamp at exactly noon (pick anything you want) and use the Lexicon's internal noise sequencer. When I switch to HT viewing I put the volume back to that spot, change the input to Aux, and then everything is controlled through the Lexicon. To listen to CD I switch the input to CD and adjust the volume where I want. HT listening is (very) slightly compromised by this setup, but 2 channel is glorious.
Seth has the right idea. I have gone even one step further by using a passive attenuator (instead of an active preamp) with multipal inputs, one of which is connected to the front left & front right outputs of a Cal Audio SSP-2500 surround processor / preamp. You keep your 2-channel system pristine, and get awesome results for HT.
Actually, I've done a number of 2/5 channel combo set-ups in my system. You can use some of the newer more current tube preamps with "processor bypass" (i.e, Audio research LS16 or Sonic Frontiers LIne 1, or similar), and simply loop the 2 channels through that way. Or, I've also tried what I currently use, wich is a passive/active Pass Labs preamp, and simply put the output of the right/left channel out of the Lexicon into one of the auxilary inputs on the preamp, and do the "12 oclock" thing on the preamp,and adjust the volumes accordingly. REallly, this works just fine! You'll play around with it for a while, and you'll get it, I'm sure.