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Best tonerarm match for Acutex M320 III STR cartridge

I have lately been having feedback problems with using the bespoken Acutex cartridge in my Dynavector 501 arm. It sounds spectacular until the feedback sets in.Usable information on what tonearm might be a good (or bad), match is not easily found. The tonearm is mounted on my heavy plinth, with my Garrard 401 'table. It sits on a wall mount stand, Brightstar BigRock 2 sandbox, with Edensound large brass footers, that are six pounds each. 

My phono stage is a Modwright SWP 9.0, that has a resistor installed to cut low frequencies. One other factor is a 15" subwoofer that is about 10 feet away, that might be a factor.

Any information would be greatly appreciated.

Thanks, and regards,
Dan
Ag insider logo xs@2xislandmandan
uberwaltz's avatar
uberwaltz
13,381 posts
 
Dan
A lot more gain could certainly contribute.
Do you know what gain?
I run 44db gain most of the time on my Nova 3 although not had the acutex mounted for a while and not with the Nova. Last time I used it was with a Chinook at 40db gain.
The 320str has over 3mv output so really should not need any more than 40db gain IMHO.
Is it possible to reduce the gain at the Phonostage?
Yes you would then need more preamp volume to bring you back to the volume level you decide but if it is Phonostage gain related you may have your answer.
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islandmandan OP
1,260 posts
 
Uberwaltz, I have not changed phono stages, just the line stage. In any case, the MM gain is 50db, and MC gain is 66db.The gain provided by the line stage is 15db.

I've been using the same Modwright SWP 9.0 SE Phono Stage for around six or seven years now, this seems to be a new issue I don't remember encountering before. I remounted the Acutex again today, I'll try and sleuth out the problem some more. I'll get back to 'ya.

Thanks, and Happy New Year,
Dan
ct0517's avatar
ct0517
2,041 posts
 
Happy New Year Guys.

Dan

The signal has a "fluttery" sound, or like a vibrato.

Is this sound heard through your sub and your main speakers ? 
What HZ does your sub kick in at ?  
What happens if you turn off the sub ?

Cheers Chris

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islandmandan OP
1,260 posts
 
Hi Chris, et al,

The sub is rolled off at 60HZ. When I finally got to listening, I tried first with the sub off. There was no feedback issue, using my SET 300B amp. I then turned the sub on, and there was no feedback at all.

I don't remember which of my three amps I was using when the feedback occurred. It may be the 845 amp, but I would have to swap out amps to be sure. So the problem must be amp-dependent. I will do further testing and get back to you. 

Thanks, and Happy New Year,
Dan 
ct0517's avatar
ct0517
2,041 posts
 
Sounds amp related Dan. Easy to check out.
Also as your sub is crossed at 60 hz you have an opportunity to use it in near field, placed beside your listening chair.  This results in the Sub  db level being used at probably 1/4 of the level it is at now. This results in better bass and a much less stressed out sub. My subs in the Quad room are placed on either side of the listening couch.   
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