Hello GE community!

It's been a long time since I posted as I have been enjoying my T1's in my reference system since 2015.

However, as a result of a tt/cart upgrade, I am now getting horrendous bass feedback. Only happens with the tt/vinyl. No issues with SACD/CD/Hi rez music files played through USB DAC.

My previous tt is a vpi classic 3, which I bought to resolve this same problem, and it worked perfectly. FYI: My tt/cart is about 2.5 ft from the bass radiators. The bass volume level in each T1 has been changed from 12-1 oclock to 8 oclock, depending on music being played. My bass jones has been left wanting. (I'm a bassist too... ouch. Gotta have my bass! One of the big benefits of owning the T1's.)

Since I have made such a sizable purchase to upgrade my tt to allow both mono and stereo cartridges to be mounted and used when needed, a solution is mandatory. I have two placement options in my mancave that may resolve this.

1. Move the rack into a dormer/vestibule area which is currently occupied by my work desk and computer. This would allow me to place the t1's out front and to the side of the tt/cart. The bad thing is the t1's will be sticking out in space and will make it difficult to get to the window in the dormer.

2. Move or remove a home recording studio desk and associated gear in another corner of the room. I could get as much as 5.5ft of distance from the T1's and the tt/cart this way, but they would be in line with each other, as they are now.

The first question I probably should have asked is if anyone members have had this issue with their t1/cart/tt combo and what did they do to resolve this. How far did you have to move the t1's from the tt to eliminate the bass feedback completely?

I look forwad to all input.
happy listening!
RS1506 (gus)

Hi there,

2.5 feet from the turntable could definitely cause issues depending how loud the speakers are playing.

Another thing that can cause your system to be more vulnerable to feedback is if there might be a mismatch of the cartridge compliance and arm mass giving you a non-optimal resonance. You can check here: www.vinylengine.com/cartridge_resonance_evaluator.php

Enter your arm's effective mass and then submit. Scroll down for a chart that cross references the mass with the cartridge's dynamic compliance. If you're in the 8-11 Hz resonance range that's good.

Does your phono preamp, receiver, amp, etc. offer a "rumble" filter? Switching that on will help, too.

Hello Moderator,
Thank you for your prompt response.

The effective Mass of the VPI JMW 12" 3DR(eference) tonearm is 10.5 grams. Compliance is 10 µm/mN. I looked at the table that came up but I'm not sure how this compliance specification relates to the vertical graduations marked as 10 -6 cm/dyne.

Perhaps you are on to something as the Classic 3 had the metal JMW 10" arm.. perhaps a metal tonearm is a better match for a moving iron cartridge. I haven't a clue. All I know is I spent a whole lot of $ for my new tt that costs nearly 4 times the msrp (not what I paid) of the classic 3 can't reject the bass feedback that the classic 3 did with ease.

btw: I reached out to Richard Mak, distributor of the Analog Magik cartridge setup software, which I used in conjunction with the Smartractor. I gave him all of the test numbers and described how his AM kit performed. Aside from the horrible bass feedback, the new Zephyr cart is crisp, clear and revealing without a hint of harshness (perhaps due to the fine GE T1's?). I played the Weezer Teal album as my first LP after completing all testing and making adjustments when/if required. I heard tidbits of guitar and keyboard I missed with the old faithful Classic 3/original zephyr cart, so I believe perhaps this new cart is far more sensitive than the old one, and/or the avenger plinth is not nearly as damped as the Classic 3, OR, as you mentioned, perhaps there is a mismatch of the 3DR tonearm and the Soundsmith cart. Very frustrating....

Even if there is some sort of mismatch, how the heck would you correct it??? Azimuth, anti-skate, loading, VTA, and speed pass with flying colors. Oddly, there was an odd "climbing" of the resonance tests, which should be between 8 and 12 hz. I questioned Mr. Mak about this since his video tutorial shows the number climbing as well, but the test is stopped after 20 seconds. I ran mine for a full minute, with final resonance numbers pushing 20-22 hz. A failure by any measurement but perhaps I ran the test too long. Unfortunately, the instructions do not specify a data collection time frame limit. I should have an answer from Richard after the holiday. He is very responsive to inquiries.

btw: I should mention the classic 3 had a run of the mill JMW 10" metal tonearm.. never ever gave me a whisper of trouble in the 3 years I've had it, although I have probably put barely 150 hours on the tt as I have been dabbling in Reel to reel tapes and SACD's. No feedback there, with the bass pots on the T1's at 12-1 oclock. Bass is amazing, as always.

If it turns out the avenger is not as well damped as the classic 3, and the new zephyr cart is more sensitive, then my only option may be to distance the tt from the T1's, but since I'm stuck at the cape in a hotel for work, I have nothing better to do (unless work calls me in) to research the fix. I hope and pray I didn't ruin my system for the sake of adding both a mono and stereo tonearm/cartridge capability to my system. I will try to come up with a basic floor plan showing system placement options.

Thank you for your time.
best
RS (gus)

Hi RS1506!

I have to admit I'm a 100% digital guy with no vinyl, and I know next to nothing about it. HOWEVER, I have read where feedback problems have been solved using isolators under the turntable. If your feedback is being caused by your rack or tt support resonating, then isolators might help.

Just a thought,

Charlie

Hi Charlie,
Thanks for the response.

Certainly something one must think about, but the rack/shelving system is by Adona Corporation. I have two towers of the signature series with 5 mdf/granite hybrid shelves.

www.adonacorporation.com/av45dw4.html

In conjunction with my previous (keeping it though) tt, the VPI classic 3, JMW classic 10" (metal) tonearm and the original soundsmith Zephyr/VPI cart, never ever a problem with bass feedback, even though the tt is only 2.5 feet from the right triton 1.

Nope, it's not isolation. Either the avenger is not properly damped like the Classic 3, the Zephyr Mkiii ES cart is more sensitive than the original model, or a combination of the two.

What would be most helpful is if someone who may have experienced this conundrum could tell me the optimum/minimum distance the T1's should be from such a sensitive/under damped tt/cart combo before I start moving heavy gear and furniture around.

with that in mind, I spent the day using the free floor plan app, Roomle to draw up current and proposed floor plans. I wish I could leave everything as is, and maybe there is another fix, but I doubt it. The two proposals get the T1's a minimum of 4'4" away from the cartridge/avenger. nearly double the current distance. I will try to post the 3 floor plans on the forum today or tomorrow for review..perhaps we will hit upon the magic bullet.

I think I will reach out to VPI directly as well, but they are observing the holiday, like everyone should be... not fools like me that are working.

Thanks for taking the time to offer a solution Charlie. Appreciated.
Best
gus

Does your phono preamp offer a high-pass filter? That can help a lot. They're sometimes called rumble filters and they are designed to attenuate very low frequencies, mostly outside of what we hear.