Flat speaker sound/preamp the culprit?/external EQ needed?


Hi, I have a Rogue Audio tube amp, which I love, a U-Turn turntable and an NAD phono preamp. Here's my issue: on many recordings the bass can really drown out the rest of the record. In general things sound muddy. When I plug my iPhone directly into the amp, I dont have this problem. So I think the premp is the culprit. (It has no EQ controls.) Can someone recommend a reasonably priced solution to this? An external EQ? Something else? (Someone recommended a Schiit Loki.) Many thanks in advance!
ineedhelpwithcables
@ineedhelpwithcables From the link you posted I would consider a more expensive phono section, perhaps one with tubes.


This does not sound like a feedback issue to me.
@ineedhelpwithcables  You're not answering our questions, and without that basic information we can't help.

We need a precise description of your system, with make and model of each component, and how you're hooking it all up.
Do you have the MC/MM switch set correctly? plugged into the correct MC/MM connection? A high output MC would go into MM side (I think). 
So this did it! I switched the preamp to MM and the muddiness went away. I looked up Uturn's website and all their cartridges are MM. 

Thank you all!

I would still be interested in preamp recommendations where you can adjust the bass, if such things exist.  Would the Schiit Loki do that?