2. analog
  3. 192655-151312

Rumbly feedback

Hello fellow A'goners. About a year ago I set up a wand 10.3 on the pedestal they sell as my turntable (brinkmann bardo) does not have an option for a second tonearm. Overall, I'm extremely satisfied with the performance. It has an ortofon Winfeld Ti mounted on it and the detail of the cartridge mates to the musicality of The tone arm is a truly magical match. Recently though, I've been listening to a bit more bass, heavy music and a couple of recordings that are mastered at very low levels. When I play these recordings at moderate volumes I get an intermittent bassy rumble that seems to come through. If I turn the volume down it dissipates and additionally, if I place my first two fingers on the pedestal, it goes away immediately. This rumble does not occur if I use my other tone arm which is the brinkman 10.1 with a custom vas cartridge mounted on it. I'm wondering if anybody has any ideas on how I could dampen the pedestal some to try and avoid this feedback. 

rmdmoore
rmdmoore OP
170 posts
 

@mulveling I think I have pics of my system in my virtual system. It don’t have a big tall rack. I have a lower solid walnut custom piece that weighs a ton. I dont thing it’s flapping from that and, as I mentioned, it’s only the tonearm/cartridge combination mounted on the pedestal, the tonearm attached to the turntable does not have this problem. I’m wondering if bracing the pedista to the HRS platform might solve it since when I press on it it goes away. I just ordered some very long Velcro straps to do this. We’ll see what happens!

lewm
13,371 posts
 

The Bardo tonearm is well coupled to the plinth, the platter, the bearing, So if the TT as a whole entity is disturbed by acoustic feedback, there is little to no aberrant motion of the stylus with respect to the LP. Hence no low frequency noise. The pod is a separate entity from the TT. Hence when it is disturbed by the same amount of acoustic energy, the cartridge mounted on it is much freer to move independently with respect to the LP. That creates the LF noise you hear. You need to move your rig away from your speakers and/or the speakers away from your rack. I disagree with Mulveling’s advice to fasten or lean the rack against the wall, because the wall may also be vibrating. So you might make matters worse. The root cause of your noise is the TT and the pod being separated entities.

mulveling's avatar
mulveling
2,043 posts
 

Yes, the separate arm pod is not a variable I’ve dealt with before. That itself might well be the culprit here. Hopefully so, becasue if not, good luck - the hum / rumble types of feedback were the most obnoxious of all gremlins I’ve dealt with. Many times I thought it was finally put to rest, only to come back again. The tables I had the problem with - VPIs - were large enough to not lend themselves easily to spring platforms that could perfectly break the feedback.

The rack bracing advice was aimed specifically at subsonic feeback (non-audible) which causes woofer flapping. I say non-audible, but it can cause chuffing or doppler artifacts because the amplitude is so large. But it won’t transmit through a wall at the necessary amplitudes. However, the wall could contribute to the audible feedback frequencies.

More to discover