Official Fix for Pro-ject Turntable rumble now available

TheAppleChap

New Member
The "S/E Upgrade Kit" from Pro-ject has now been launched that will put to bed, once and for all, any problems with low level rumble noise on affected Pro-ject turntables.

The kit comprising a replacement pulley and belt and rubber isolating grommets and screws costs £25 and is available from Henley Designs in the UK. It may also be available from your local Pro-ject supplier.

I was given access to the kit two days ago and the installation was simple, taking less than ten minutes and should be easily doable for anyone able to wield a screwdriver.

I have written an instruction guide and posted a full review on my blog at :

http://www.theapplechap.com/TheAppl...ion_set_on_a_deck_with_50_&_100Hz_rumble.html

Henley Designs describe the fix as "These simple additions help decouple (isolate) the motor from the turntable plinth. By doing this, unwanted vibrations from the motor are dramatically reduced, allowing the sub-platter to spin truer, and the tonearm to transmit the sound signal better."

Enough to say that on my turntable there was a complete removal of ALL low level rumble, shoring up the bass, making it deeper and more controlled.

I would thoroughly recommend this kit to all Pro-ject owners with compatible turntables.

I'm grateful to Henley Designs for agreeing to lend me the necessary parts and let me review them and post the article on my blog. I have no professional relationship with Henley Designs and had a free hand to write the article. Therefore all errors and omissions are mine and mine alone.

Cheers

Alan
 
Can't help feeling Pro-ject have come very late to this and it has done some damage to their reputation.

I sold on my Debut III some years ago because of the high level of motor noise, as I suspect others have too, and have been recommending against the cheaper Pro-jects since. I also think it's expensive since the problem was a design fault - if it were an automobile, this would have been done in a recall for free.

Is this now a standard modification for all their cheaper decks?
 
Can't help feeling Pro-ject have come very late to this and it has done some damage to their reputation.

I agree. But is this even officially from Pro-Ject?

Even my RM-5 has this issue when played at 45rpm. I didn't notice it for a long time because it's not that loud, and I don't often play records at that speed. I'll probably look into this kit, the sonic strengths of the RM-5 make it well-worth keeping, and spending an extra $25 or so.
 
Personally while I feel Pro-Ject should be offering this as a FREE retrofit for all existing owners, two blobs of sticky tack rendered mine silent. Nice work BTW Applechap!
 
Personally while I feel Pro-Ject should be offering this as a FREE retrofit for all existing owners, two blobs of sticky tack rendered mine silent. Nice work BTW Applechap!

Hmm, I tried silencing mine with some extra Herbie's db Neutralizer material, and it didn't seem to help at all.

I've just set up my RM-5 for the first time in about one and half years. Listening with headphones, a little bit of the rumble/surface noise is audible even at 33 rpm. My Thorens has it beat in that department, but in detail, refinement, resolution, and natural sound, the Pro-Ject wins (same cartridge being used btw).
 
Whoops - just realized a minute ago I forgot to level the tt. :yikes: That got right of a good portion of the hum/noise.
 
A little late on this one!

Too late for me.
I unloaded my Project TT awhile back because of the motor hum issue. This was the most annoying piece of audio equipment I’ve ever purchased.
I lost all respect for Project gear and Sumiko, the most worthless distributor of product I’ve ever been involved with.
 
Too late for me.
I unloaded my Project TT awhile back because of the motor hum issue. This was the most annoying piece of audio equipment I’ve ever purchased.
I lost all respect for Project gear and Sumiko, the most worthless distributor of product I’ve ever been involved with.

I'm going to ignore that comment (just kidding :) ). Remind us which Pro-Ject turntable you had?
 
I wonder if this would help out Music Hall's MMF5?
I believe they share components with the Projects

This fix is for the turntables with the motor suspended on a resilient ring, which would not include the MMF-5. I once owned an MMF-5 and it didn't have this particular problem, which made me wonder if Pro-Ject wouldn't be better off mounting that motor the same way Music Hall did.
 
I would guess this fix could be accomplished with a few silicone grommets and no special kit. You could put two silicone grommets under the flanges of the motor, put two more grommets and maybe two washers on top of the flanges, re-install the transport screws (not too tight). The round belt and alternate pulley might be a slight upgrade, but don't look essential. Cost of a small pack of grommets would probably be under $5.
 
I had an Xpression lll.
I noticed the hum after about six weeks. I couldn't get it out of my head after that.
It was really annoying listening to classical music..... Bulgarian death metal...not so much. :D
 
Well if you take a look at my thread in the link, I explain how I've pretty much eliminated the hum entirely with proper isolation of the turntable.
 
Permanent Fix for Pro-Ject Rumble

Fixing the suspension of the Pro-ject RM6-SB elevated the sound of the turntable to a different level (in my system). I upgraded to the Pro-ject from a Thorens, but after a couple of weeks began to notice the rumble. I started googling for answers with hum, noise, rumble searches. Found a bunch of postings of customers complaining and also looking for answers. I went the route many Pro-ject owners suggested by isolating the TT. I mounted the TT on a shelf attached to a wall. Then I placed a mat between the subplatter and platter, and between the cartridge and headshell, and between the platter and the record. Then I purchased a set of threaded brass footers, then a silicone dot above the spindle (between the subplatter and platter). Each fix helped improve the sound of the turntable. The greatest improvement was the footers. Coupling each 5 pound "threaded" brass footer to the plinth made the biggest noticeable improvement. I recommend that upgrade to all Pro-ject owners. But even adding the additional 15 pounds of mass coupled to the plinth did not get rid of the rumble because I later discovered that the source of the rumble was from the vibration in the motor being transferred to the plinth. Thanks to the Applechap, I discovered the answer was simply and inexpensively to isolate the resonance caused by the motor vibration. What really convinced me were his before and after graphs; evidence that it worked.

I did not use the Henley fix, instead took Applechap's theory to further develop his original idea, which I felt was almost but not quite there at reducing vibration coming from the motor. I ordered a packet of grommets (http://www.grainger.com/Grainger/Rubber-Grommet-3MRT4) which cost a total of $8 including shipping (I have about 40 grommets leftover). Purchased a round belt from Turntablesneedles.com for $19. The theory behind using the round belt instead of a flat one is because it is stiffer and there is less surface area touching the sub-platter to transfer resonance.
Installed the four grommets around the collar of the suspension screws. Then two more grommets, one above and one and below each of the two packing screws (I used a longer screw). The eight grommet method seems do the most to isolate the motor from having direct contact with the plinth (in my TT). I then attached the suspension o-ring belt between the lips around each of the four grommets (suspension belt must not touch the screws directly or the motor will continue to channel its vibration onto plinth).
The source of the rumble in these Pro-ject suspended motor turntables come from the four screws attached to the plinth having direct contact with the o-ring band. Some including the Henley aftermarket kit, have only used two grommets where the packing screws hold the motor in place to stabilize the motor, but that alone will NOT fix the problem. The two grommet method helps, but it will not achieve the potential of this fix.
All motor-borne rumble disappeared, microdetails now appeared, soundstage improved with greater clarity, warmth moved to more neutral, excessive woofer movement disappeared. In my system it worked, but I'm disappointed in Pro-ject.
Make the fix and keep your table.
Cheers!
 
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Sounds like a fix has been found. Good. I love the modern look of the Pro-Ject tables...and may own one some day...but there is a black mark on Pro-Ject for not even considering the problem was in their engineering. But its just like the rest of the worlds problems. Those with big money will care less about those less fortunate who buy their product as long as we keep spending. Shame on you Pro-Ject! I hope you at least acknowledge that you made an engineering error and now an improved product is on its way.
 
Pictures of Fix

Grommets saved this turntable.You can see how there are grommets isolating the motor from the plinth.
Discovered one more effective resonance reducing method for the RM or RPM 6 series turntable. As you know the plinth transmits vibration to the tonearm from the motor. The tonearm assembly is connected to a recessed section of the the plinth with only three screws. You can remove the screws and install a square piece of rubber that fits into the recessed area, or use the grommets to isolate the tonearm plinth. The rubber square I used was 2 1/2 x 2 1/2 by 1/8 thick. Be careful holding the tonearm at the removal of the last screw as the cartridge will be exposed.
You will need to adjust the VTF and the tonearm lift the same height as the thickness of the rubber square. Easy to do with two smaller allen wrenches. Installing the rubber square was less than 10 minutes and getting the VTF and tonearm hold adjusted was another 10 minutes. In my system, it continued to significantly improve all the elements of the soundstage already mentioned.
 

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Not to buzz kill but....you can go to your local hardware store and purchase medium firm rubber washers for a few cents each and they work just as well. I've used this fix on a number of Pro-Ject and MMF turntables.

Matt
 

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