2 of my 4 AT440MLa's have forgotten the words. Hummmmmmmmmmmmmmmmmm

Wayner · « **on:** 1 May 2008, 10:33 pm »

The long mystery is finally over for the baffling hum from the AT440MLa on my new Technics SL-1200 MK II. This story has 2 trails. First, apparently when I bought my last 2 carts, they were from a bad batch (which AT will gracefully replace). I heard about this from a contributor on AC. I can't remember your name, but I must thank you. Of course, I didn't think I had one of those, that my troubles were from some other source...bad Technics.

This afternoon, (lazy as I sometimes get), I decided to swap out the AT that I had in the VPI. This cart was very quite and if I was going to prove to myself that I had a bad cart, this was the way to do it. So, in about 15 minutes, I had that cart out of the VPI and into the headshell of the Technics.

Now there is zero hum. That is with the preamp volume at full blast. If I might release some anger here.....@*!!!?%~8****f'n.........

There, I feel better now.

I also notice that I can induce a slight hum by OVER TIGHTENING THE HEADSHELL NUT. Turn it snug, then back a crack. Clean as a whistle.

Saturday, 2 carts are going back to AT for replacement.

I know Jazz Vinyl bought an AT and had hum issues....here you go buddy. Go get a new one.

I have held my head in shame since Christmas as the AT440MLa pimp, but now I might be able to hold my head up high once again.

Wayner

TheChairGuy · « **Reply #1 on:** 2 May 2008, 12:17 am »

Ha! ATPimp is back!!!

ChairSpud · « **Reply #2 on:** 4 May 2008, 04:48 pm »

Quote from: Wayner on 1 May 2008, 10:33 pm

The long mystery is finally over for the baffling hum from the AT440MLa on my new Technics SL-1200 MK II. This story has 2 trails. First, apparently when I bought my last 2 carts, they were from a bad batch (which AT will gracefully replace). I heard about this from a contributor on AC. I can't remember your name, but I must thank you.

Wayner

Your very welcome, am glad AT is going to make things right for you, I was stuck with two of the bad hummers. Just want to know, does this make me an AT440MLa pimp too?

Jampot · « **Reply #3 on:** 4 May 2008, 05:11 pm »

Quote

does this make me an AT440MLa pimp too?

Ohhhh no, sorry 'spud - IIRC it was I who bestowed the honour on Wayner. He has pages and pages of posts dedicated to the AT 440 Mla.

Quite a turn up, Wayner, pleased you got it sorted.
I guess mine was quite a bit older than your recent purchases, and I didn't have the problem.

Mind I don't have a Technics either

Jim

Wayner · « **Reply #4 on:** 4 May 2008, 05:33 pm »

Thanks Jampot, your my hero!

ChairSpud, you can pimp all you want. Just remember whos street corner your on.

Wayner

ChairSpud · « **Reply #5 on:** 4 May 2008, 08:18 pm »

Wayner and Jampot, thanks for the friendly welcome. I pop in here infrequently so have missed all but one of your AT440MLa posts. Wayner, for some reason I thought you were using a Rega not a Technics, never mind I'll have to go back and look at those pages and pages of posts.

Wayner · « **Reply #6 on:** 4 May 2008, 10:55 pm »

I have many TT's. Rega, Empire, Technics, AR, VPI.

Wayner

TheChairGuy · « **Reply #7 on:** 4 May 2008, 11:22 pm »

Great moniker, ChairSpud

John / TheChairGuy

ChairSpud · « **Reply #8 on:** 6 May 2008, 11:08 pm »

Thanks John, the compliment means a lot especially from another chair guy! In real life I go by Dave, I'm retired and have been into HiFi as a hobby for quite a while.

Wayner, Now I know who to ask if I have a question about my Technics or Rega clone. Some great stuff you guys have archived in this forum, still have a lot more to read. The Grado Green thread was of particular interest to me as I'm trying to tweak the sibilance out of a Gold.

Almost forgot, jampot, I promise not to AT440MLa pimp on this board without your proper blessing.

ChairSpud

TheChairGuy · « **Reply #9 on:** 6 May 2008, 11:28 pm »

Quote from: ChairSpud on 6 May 2008, 11:08 pm

Some great stuff you guys have archived in this forum, still have a lot more to read. The Grado Green thread was of particular interest to me as I'm trying to tweak the sibilance out of a Gold.

ChairSpud

Dave/Spud,

Due to the prior pimp's untimely passing, I have taken on the Grado pimp duties around here of late.

The sibilance doesn't go 100% away until you mount a shibata or line stylus to the Grado....but you can dial out most of it with the following things:

1. 1.6 gram tracking force and approximately half that in anti-skating

2. Longhorn stabilizer a la van Alstine (do a search for 'longhorn' in Vinyl Circle and you'll find along topic on it)

3. Fluid damped tonearm (damps the inherently underdamped nature of the cartridge). If you don't have this go to #4 as partial solution to damping.

4. A squidge of modelling clay, rubber, wood sliver or other medium in between plastic cartridge body and headshell will tame some of the mechanical energy that's causing sibilance.

John

Jampot · « **Reply #10 on:** 7 May 2008, 05:30 am »

Quote

Almost forgot, jampot, I promise not to AT440MLa pimp

Anyone and everyone can (and very often does

) pimp. But there can only be one 'Pimp' if you see what I mean

What part of the world are you in Dave?

Jim

ChairSpud · « **Reply #11 on:** 8 May 2008, 01:26 pm »

I get it now, thanks Jim.

I live in Maryland USA, a mile south of the Pennsylvania line. I'm way out in the country surrounded by alfalfa, timothy grass, corn and cows. I know I have to update my profile.

Dave/ChairSpud

Wayner · « **Reply #12 on:** 12 May 2008, 10:44 pm »

The UPS truck just pulled up and delivered 2 brand spankin' new AT440MLa's!!!!!!!!!

What a company. Stuff happens, but it's nice when they set it right.

Wayner

Wayner · « **Reply #13 on:** 13 May 2008, 01:17 pm »

Problem is not fixed. I do not know what they (Audio Technica) have done to this cartridge. The new one is ultra quite......when the turntable ground screw is off! Need I say "ground loop"! I just can't figure out how there is ground loop, cartridge has plastic body.

More tonight when I get home.

Wayner

ChairSpud · « **Reply #14 on:** 13 May 2008, 02:21 pm »

For what its worth, I've not heard of this problem from anyone else who received replacement AT440MLa cartridges. Hope its something simple.

Dave

Wayner · « **Reply #15 on:** 13 May 2008, 02:59 pm »

I didn't have a lot of time to monkey with it last night, but I have been thinking about it. There is no way a ground loop could be made unless the cartridge body is made of metal and somehow, the negative terminals and the body are connected. With trustly MMC I will do some signal tracing. Perhaps AT has changed the cartridge material to metal. I thought it was always plastic. If that's the case, I should get continuity between the body and the ground screw. If that is the case, the fix is a very thin piece of nomex between the cartridge body and the tone arm and nylon cartridge mounting screws. That will isolate the cartridge. This is almost the exact same thing that happened when I mounted a new AT into my Technics. Now same results with the VPI.

ChairSpud · « **Reply #16 on:** 13 May 2008, 05:32 pm »

On my older 440MLa, the right ground terminal is strapped to the metal cartridge body, but then there's the plastic housing over that which has the mounting slots. No continuity to the headshell here, but as you suggested they could have changed things to cure the original hum problem. Can't wait to hear what you find.

Dave

Wayner · « **Reply #17 on:** 13 May 2008, 10:26 pm »

Dave,

Did you ever have one of them days when you have the Midas touch and everything goes to shit? Well, that was yesterday. Today we have vinyl Nirvana!

Yes, Dave, I'm getting old, the old eyes aren't what they used to be and I'm always in a hurry. The hum was caused by too long of mounting screws, barely stopping the stylus assembly from completely sitting in the cartridge.

All is well. Now I have to email Jim at Audio Technica and try to be real humble (and not look like an idiot, too late), and tell him all is well.

Now I have 4 killer tables with zero hum! I will spend the evening listening to LP's (the wife is out) and think of more tweaks.

Wayner aa

ChairSpud · « **Reply #18 on:** 13 May 2008, 11:00 pm »

Yup, sure have, tell Jim it was my fault. Actually he'll probably be happy not to have another problem on his hands.

That's not fair, I've only got three tables. My friends say I'm the only guy has a turntable on the hamper in the bathroom. Well I gotta put one somewhere while the other table is playing. My wife just shakes her head.

Glad you got things worked out and enjoy.

Dave

Wayner · « **Reply #19 on:** 14 May 2008, 12:14 am »

By the way, any properly set up belt drive table can equal any direct drive. Rhythm, pace and dynamics all equal. At least VPI = Techincs. If not, you have other problems.

W