tubes and analog

Csmithbarc,

1. The AES's output impedance might be a mismatch for the Prima Luna.

2. The AES's output level might be too high for the Prima Luna, causing overload distortion.

Either of these is a more likely answer to your question than tubes vs. solid state.

Can you describe, in audiophile terms, HOW the Graham Slee sounds better than the AES? That might help those interested in offering helpful diagnoses or suggestions.

Best,
Doug

Csmithbarc,

Mab33's discovery re: the Prima Luna's input sensitivity mirrors what I found (but didn't post, since I wanted someone else to verify it - thanks, Mab33!). There's a case to be made that it's so low that many phono preamps will overdrive it. This can lead to all sorts of audio nasties, and their character will undoubtedly depend on the source doing the overdriving. How to tell? If the sound is especially distorted or unpleasing on dynamic peaks or strong, sustained vocals, your Prima Luna's input sensitivity is probably overloaded.

On "punchy" vs. "muddy" bass...

Have you tried different tubes in the AES? You've got a 12au7 regulating the power supply (I think) and 6SJ7's as signal tubes. Rolling different tubes into either of these locations will provide substantially different sounds. "Muddy" bass is characteristic of some tubes more than others. I don't have any specific recommendations for the tube types your AES uses, but as a rough guideline, look for tubes whose internal structures appear especially robust and "stable", in an architectural sort of way. Tubes built like this tend to have tighter bass than tubes with less solid internal structures.

Best,
Doug

Some Herbie's Audio Labs tube dampers would be a great tweak to try...they will help with your "muddy" bass, as well as "clean up" the sound a bit allowing the low level detail to come through.

Excellent suggestion, and a very quick and easy way to determine if overly microphonic tubes are to blame for the muddy bass.