So I connected everything the other day through the preamp front left and right and I do receive sound from the yamaha receiver. Unfortunently it seems that only the right speaker connected to the yamaha is producing sound and the quality is very bad. I completely rotated the RCA's to ensure it wasn't a bad RCA cable and the problem stayed on the left, which leads me to believe there is something strange with the left channel in this type of configuration. Any suggestions?
Almost forget to mention I also tried the CDR and the quality was unbareable.
Hmmm. Some suggestions for you (which you may have tried):
1. Try playing another source (e.g. tuner, CD player) on the Yamaha and check if any sound is coming out of the left speaker. Also check the sound quality.
2. If the left speaker works and everything sounds good when you do the above, do this (if not done as part of 1): Connect another source (e.g. CD player) to the same inputs on the Yamaha as you are using with the Denon and again check if the left speaker produces sound and if the quality is good.
3. If #1 sounds good, and #2 sounds bad, try another input on the Yamaha if available and do the same checks.
These checks are intended to determine if the issue is local to the Yamaha and not related to the Denon or the RCA cables that you ran between the two. If you still have the same issues, then it is with the Yamaha, the speakers, and/or how they are connected to each other.
If you don't have the same issues, then it's caused by either the Denon or the RCA cables. So, I would then do the following: disconnect the RCA cables from the Denon, connect a CD player (or some other source with left/right audio outputs) to those RCA cables, and try to play that source through the Yamaha. If you have the same problems as before, then the issue is with the RCA cables. If you don't, then the issue is with the Denon.
We can help you troubleshoot some more or try to help you fix whatever is wrong once you (and then we) know better what the source of the problems is.
Adam