Rumble is just another word for low frequency noises. But first of all, I think it is important for you to figure out the source of the rumble. So, you can add that function to any phono stage, via the KAB filter which you apparently already own. And finally, the outboard KAB filter is really no different from what you would get if it were built into a phono stage. The lack of a rumble filter on modern phono stages is partly a symptom of laziness among manufacturers, and their desire to cut costs while also raising prices. American products from around the 1970s maybe up to the 1990s also can have rumble filters built-in. So if you really want that feature, find one of those. Many older phono stage designs, especially from japan, DID incorporate a rumble filter. Louis, with whom are you arguing? None of us is against the idea. The only negative I have with the KAB is that another set of interconnects is needed. I use my KAB rumble filter, with no loss of sonics, so I want a phono preamp with this included. There are just too many factors that create rumble or acoustic feedback (still don't understand the difference), and there are too many people that experience this problem. I am not trying to be combative with what you are saying, I just believe that these items that you mention can be dealt with in an effective manner. I just don't believe that any of the things you mention can't be done with no loss of performance, or ultimate cost (1-another switch in this signal path.how many switches/connections are already in the signal path, are you saying one more switch is going to degrade the sonics to the point where it's so audible that it is going to degrade the sound of your system to a point of dissatisfaction? 2-, after all, in a phono preamp costing several or more thousand dollars, how much more can a 'high-quality capicator' add to the final cost of a product? 3-a change in the circuit design.ok.I agree with that.

These all affect 'ultimate' transparency, and are design choices. If not, what's the rumble filter may be a band aide, however, when engaged, I notice no loss of anything (transparency, detail, staging, etc) other than the pumping of my so in the purist form, inserting a filter in the circuit may not be 100% kosher, however, if your traveling down that avenue, why do designers use crossovers in their speakers rather then design them cross-overless, why use a speaker cable with connectors on each end (rather then use bare wire, and solder it directly to the amp/speaker), why do designers of electronics use IEC connectors for the power cable, rather then hard wiring it (as some do) on and on. However, thank you for reminding me that it's time to do that again.Īlso, isn't acoustic feedback the same as rumble.

Been maybe a year since I have lubricated the main bearing, but when I did, I didn't notice any change.

Inline subsonic filter