cmcguire
Active Member
I'm hoping someone will have some experience with this issue. I very recently overhauled a somewhat tampered with TD 135 and made a modest sized slate plinth for it to nest in. The plinth weighs about 30 lbs and is a slate-plywood-slate sandwich which I have resting on abut 20 lbs of ceramic tile that's sitting on a barely inflated inner tube. Even with all this weight and isolation I'm getting a very audible low frequency rumble that seems to be caused by acoustic feedback from my top ported speakers. I have a small living room so the speakers are only about four feet from the turntable and are level with it. I was thinking of getting a subsonic filter but I recently got a screamin' deal on a very nice Technics SL 1600 mk2 and instaled the same cartridge, an Ortofon 2M Bronze on it. Guess what? There's no speaker flutter! No subsonic rumble at all!
Now I'm thinking there could be a few issues with this; the Technics being a suspended design could definitely be a factor but the plinth/inner tube setup should really take care of a lot of vibration from the floor and speakers on the Thorens TD 135. This has led me to beleive the metal chassis of the 135 could be resonating and causing feedback. Maybe bolting it to the plinth would take care of this? I'd have to modify the plinth design somewhat but it's definitely doable. I'm also wondering whether I'm experiencing a tonearm-cartridge mismatch. The table is equipped with the simple yet a little clunky TP 14. To tell you the truth, I never really understood the nuances of matching cartridges with tonearms so I admit that this might very well be the case.
As a side note, I really love the old 135 but am really enjoying the simplicity of the Technics table! It just kind of does what it's asked to perfectly every time. It's nice after spending almost 100 hours to get the other setup working the way I'd (almost) like it to. Dont get me wrong- the time spent on the the table was totally worth it!
Now I'm thinking there could be a few issues with this; the Technics being a suspended design could definitely be a factor but the plinth/inner tube setup should really take care of a lot of vibration from the floor and speakers on the Thorens TD 135. This has led me to beleive the metal chassis of the 135 could be resonating and causing feedback. Maybe bolting it to the plinth would take care of this? I'd have to modify the plinth design somewhat but it's definitely doable. I'm also wondering whether I'm experiencing a tonearm-cartridge mismatch. The table is equipped with the simple yet a little clunky TP 14. To tell you the truth, I never really understood the nuances of matching cartridges with tonearms so I admit that this might very well be the case.
As a side note, I really love the old 135 but am really enjoying the simplicity of the Technics table! It just kind of does what it's asked to perfectly every time. It's nice after spending almost 100 hours to get the other setup working the way I'd (almost) like it to. Dont get me wrong- the time spent on the the table was totally worth it!
