Music Hall MMF-5 Modifications

mgalusha · « **on:** 30 Dec 2002, 04:31 am »

All,

I have owned a Music Hall MMF-5 for quite some time now and while it's not a bad turntable (in fact, very good for the money), it's not a great turntable either.

I decided to take a look and see if there was any way to economically improve the performance of this table.

The obvious: the job of a turntable is convert minute groove modulations (mechanical energy) into an electrical signal. Since it's designed to handle minute modulations, the stylus/cartridge assembly is very sensitive to vibration.

Goal: improve vibration damping if possible to lower the influence from external (and internal) sources.

Actions taken:

Remove or cover the stylus!

You did protect the stylus right?

Disassemble the table. This is actually very easy. Begin by lifting off the platter and removing the belt.

Remove the two screws clamping the signal cable to the bottom plinth.

Lift the top plinth off of the motorboard/bottom plinth. No fasteners, it just sits there. You will need to guide the signal wires through the hole.

Remove the two screws holding the arm to the plinth. Lift the arm from the board, guiding the cables through the hole. Set aside somewhere safe.

To remove the sub platter you need to remove the bottom cover of the spindle bearing and remove the C clip you will find there. A good sized adjustable wrench works well.

Add damping compound to underside of top plinth. Most of the underside of the top plinth was covered with Dynamat Xtreme. Other damping sheet materials are available and should work well. I just happened to have a roll of Dynamat on hand. Of course you don't want to cover the dimples where it contacts the bottom plinth supports or the arm and motor holes.

Add damping compound to underside of sub platter. The sub platter on an MMF-5 is just a plastic casting about 6 inches (15cm) in diameter with 12 radial ribs. I cut a piece of Dynamat and applied it between each rib.

When re-assembling the sub platter I used some moly grease on the shaft. This was chosen because it was on hand and was originally designed for applications requiring a shear resistant lubricant. I *believe* it will help rotational stability since it's fairly viscous.

Reverse the above steps to re-assemble. Adjust tracking weight, cartridge alignment, VTA and anti skate.

Results: While I don't have a second MMF-5 to compare against I am quite familiar with the sound of this TT. IMO the additional damping material made a substantial improvement in the sound. It seems cleaner from top to bottom. The highs could be somewhat harsh especially when playing a higher volume levels. They are now clean and clear. Bass has tightened up and sound stage depth improved. I had the overall impression of cleaning a window or lens. Improved transparency across the board.

There are photos of this in the Gallery. One photo shows the location of the azimuth adjustment screw and of the VTA adjustment screws. The azimuth screw cannot be accessed without removing the anti-skate post from the gimbal. Hopefully you won't have to adjust it.

IMO this was very worthwhile. The cost is minimal, about $5.00 or $10.00; it is easily removed if you don't care for the results, and is simple enough that most anyone could do it.

Mike

TheChairGuy · « **Reply #1 on:** 30 Dec 2002, 07:59 pm »

Mike,

Yeah, I bet you did get a nice result damping the platter.

I used Mortite caulking compound on an old JVC belt drive INSIDE and OUTSIDE (not the platter though). The sound was amazingly improved.

That was 20 years ago with an awful S-shape tonearm that eventually broke...and I traded up to a Thorens TD-316. After the JVC broke, my dealer displayed my mortite masterpiece in his store for a few years until he had a fire! It was sin ugly, but hilarious looking.

I've since moritit-ed the bottom plate of my Thorens - though the top is suspended so I can't add there. I've damped the platter with some vinyl amping sheets from Parts Express and cheapo tonearm wrap from Music Direct. Sum total maybe $25.00 and, also, a very worthwhile improvement.

You may have gotten better results with damping your platter as (I think) the MMF-5 is solid plinth design and benefits greater from damping than suspended designs.

As for spindle oil, I use slick 50 (teflon based) and heard a fair decrease in noise levels. Stan Warren recommends Linn oil - seems the stuff fills in the microscopic spaces in the metal shaft and cylinder and adds mini ball bearings beween the metals for decreased noise levels. He uses a pretty substatial MapleKnoll rig.

Mathew_M · « **Reply #2 on:** 30 Dec 2002, 08:47 pm »

Can damping compound be found at your local Home Depot or Lowes? Where would I purchase the Dynamat? This sounds like an extremely inexpensive upgrade. Mike, do you notice a sibilance problem with this table. It's not so bad on mine with some exceptions. I figure it's mistracking on the stock goldring's part. I was looking at upgrading to the Shure cartridge.

Thanks

Mathew_M · « **Reply #3 on:** 30 Dec 2002, 08:48 pm »

Can damping compound be found at your local Home Depot or Lowes? Where would I purchase the Dynamat? This sounds like an extremely inexpensive upgrade. Mike, do you notice a sibilance problem with this table. It's not so bad on mine with some exceptions. I figure it's mistracking on the stock goldring's part. I was looking at upgrading to the Shure cartridge.

Thanks

mgalusha · « **Reply #4 on:** 30 Dec 2002, 10:39 pm »

Chair Guy,

Sounds like you had very similar results. I bought the mmf-5 to replace a Thorens TD-166 that I ownen for about 20 years. I finally wore it out.

Truly amazing what can be accomplished with a bit for effort for very little cost.

Matthew - You can buy Dynamat at auto sound stores. I picked it up from Car Toys (which I really don't like) when they had a tent sale. It was about $30 for a 4 sqft. roll. I believe parts express sells advesive backed damping material as well. Some auto parts stores carry similar stuff. You can try asking for door damping material.

I think Home Depot and Lowes carry some asphalt based products. I have not used them.

I have not really noticed a sibilance problem. Do you have any tools for aligning the cartridge? Having it mis aligned will seriously impact the sound quality. You might want to visit AA. There are some good articles in the FAQ section on setting up your TT. To be honest I adjusted the cartridge alignment when I received the table, so I never listened to it in as delivered configuration.

If you don't already have one, a good stylus force gauge is needed. The markings on the counterweight on this table are not accurate. I also have a DB Protractor. This allows you to set the overhang and cartridge angle very accurately.

Mike

Mike

TheChairGuy · « **Reply #5 on:** 31 Dec 2002, 12:50 am »

Mike,

Whaddya' think of the MMF-5 vs. ye' ol' Thorens? I'm pretty sure I like the more stable imaging and tighter bass of the solid plinth designs, but ya'know, my TD-316 is paid for many times over now. Not anxious to spend more on vinyl-related stuff - the MMF's seem to be great value for little moola' if I'm antsy to try something.

About 15 years ago I had a (original) Townsend Rock TT with Helius Silver tonearm and modded Grado - man, was that sweet music. Solid bass like digital. Had to sell it for wedding money a couple years later - I got a good deal. On my wife, that is - hehe.

mgalusha · « **Reply #6 on:** 31 Dec 2002, 04:01 am »

I think the Thorens was warmer sounding. I had a V15 Type V in the Thorens, so that probably accounted for much of the differance. The main thing that was toast on the '166 was that the platter spindle bearing was very worn. The platter had developed a wobble which of course did not sound good. I have some CD's I recorded off of the Thorens. Perhaps one of these days I will burn another disk using the mmf-5 and do a comparison. That should prove interesting. One thing for sure, the mmf-5 has quite a bit less rumble than ye olde Thorens.

Mike

TheChairGuy · « **Reply #7 on:** 31 Dec 2002, 06:18 pm »

I have the newest V15 in the TD-316, but it doesn't seem warm to me at all. Pinpoint, not flowery or overly romantic this version of the cartridge is. I vaccillate between loving it and only liking it. Maybe the upgrade in the construction in the newest version removed some cartridge body shakes that lead to that warm groove the old version gave off.

I had a Grace in there before - until my nephew bent the cantilever to death. THAT was warm, but no where near as accurate sounding to my ears. But, as a 20 year old design, the 'warmth' was probably poorer body assembly back then. Still, it was pleasant with the solid state gear I had then.

I think the Thorens, or any suspended table, would sound more romantic, less dynamic. But, nowadays we have some many good physical isolation devices and tweeks (discs, cones, platforms with air, sand, lead, better equipment racks, ball bearings - all work to some degree) that I am not sure a suspended design is needed. Sounds to me that your MMF is more accurate (read as dynamic, ballsy, bass loving) than ye' ol' Thorens of yore as most solid plinth designs may be today given the better isolation products we can use underneath them.

God, I hope I just didn't offend any Linnies on AudioCircle with that commentary!

- I love this emoticon. Good one Borg!

Brad · « **Reply #8 on:** 3 Jan 2003, 07:29 pm »

Has anyone with an MMF looked into replacing the fantastic quality factory RCA's?

bunnyma357 · « **Reply #9 on:** 12 Apr 2009, 05:26 pm »

Bumping an old thread as I just did these mods today to my MMF-5. I had been itching to get a new cartridge, and decided to spend a little time on double checking set up and searching for some low cost DIY mods before spending the extra cash.

I had similar results, everything just seemed to tighten up, and there seems to be a little more ease in the presentation. Very easy and worthwhile to do. Thanks Mike for the write up and photos, otherwise I probably wouldn't have tried this.

Jim C