Official Pro-Ject Fix For Turntable Rumble Now Launched

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geminideos
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Re: Official Pro-Ject Fix For Turntable Rumble Now Launched

Post by geminideos » 02 Jul 2015 01:46

johnmath wrote:
geminideos wrote:I wish I'd visited this forum before buying a Debut III Special Edition when I travelled to London. Definitely a bad move, because this model is 50Hz and I live in Brazil, which is 60Hz. I haven't even turned it on yet, because it will run faster. I read the this whole thread, and it was very helpful.

So I'm thinking about buying a 60Hz pulley, although Henly didn't recommend using it with the rounded belt that came with the TT.

I'd like to ask you for some feedback about this configuration in the long term (rounded belt + standard 60hz pulley). Should I consider buying the standard flat belt too?

I suggest you buy the Pro-Ject Speed Box S with an appropriate plug-pack supply for your region (18 volts DC) then you can use the existing pulley. The Speed Box generates it's own crystal locked 50Hz and is much more stable than the mains frequency used in simple setups. Plus the Speed Box allows speed change to 45rpm by pushbutton by outputting 67.5Hz when you select 45rpm. Just make sure your Debut III has the 16 volt AC motor to be sure it is compatible with the Speed Box.
Thank you. That's something I hadn't thought of. The only problem is getting the 50Hz model here..... (I believe I have to buy the 50Hz speedbox because of the output voltage).

johnmath
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Re: Official Pro-Ject Fix For Turntable Rumble Now Launched

Post by johnmath » 02 Jul 2015 01:52

geminideos wrote:Thank you. That's something I hadn't thought of. The only problem is getting the 50Hz model here.....
The Speed Box is independent of mains frequency because it uses an external 18 volt DC plug pack. All you need to ensure is that you have a plug-pack to suit your country's voltage (220?) and with sufficient output at 18 volts DC, namely 500 mA. See:

http://www.project-audio.com/main.php?p ... es&lang=en

geminideos
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Re: Official Pro-Ject Fix For Turntable Rumble Now Launched

Post by geminideos » 02 Jul 2015 02:13

johnmath wrote:
geminideos wrote:Thank you. That's something I hadn't thought of. The only problem is getting the 50Hz model here.....
The Speed Box is independent of mains frequency because it uses an external 18 volt DC plug pack. All you need to ensure is that you have a plug-pack to suit your country's voltage (220?) and with sufficient output at 18 volts DC, namely 500 mA. See:

http://www.project-audio.com/main.php?p ... es&lang=en
But what about the voltage provided by the Speed Box? It is AC. The manual and specification don't mention this, but I believe there must be both 50 and 60 hz versions.

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Re: Official Pro-Ject Fix For Turntable Rumble Now Launched

Post by johnmath » 02 Jul 2015 02:56

geminideos wrote:But what about the voltage provided by the Speed Box? It is AC. The manual and specification don't mention this, but I believe there must be both 50 and 60 hz versions.
I think the Speed Box is normally supplied for the mains frequency of the country it is supplied in. Therefore, buy one from a 50 Hz country like the UK, but ask first.

geminideos
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Re: Official Pro-Ject Fix For Turntable Rumble Now Launched

Post by geminideos » 02 Jul 2015 03:10

johnmath wrote:I think the Speed Box is normally supplied for the mains frequency of the country it is supplied in. Therefore, buy one from a 50 Hz country like the UK, but ask first.
ok!

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Re: Official Pro-Ject Fix For Turntable Rumble Now Launched

Post by Doubleplay » 03 Nov 2015 18:02

Interesting read from Pro-ject:

http://www.project-audio.com/main.php?i ... ang=en#a14
Is it necessary to remove motor transportation screws?
a Usually best results are achieved by removing the transport screws! So the motor is hanging free and the vibrations are decoupled by the O-ring, which works like a subchassis. Unfortunately in reality it is not that easy! Because of different quality and cleanness of AC power, Motors react different strong in their vibration behaviour. Although we select the motors according to their vibration pattern, not every motor is the same! Also the used power supply influences the vibrating of the motor significantly. So there are differences by using 110V or 220/30 power supply .There are lot of combinations possible which are impossible to foresee.

In worst case, motor starts to vibrate in a certain frequency area so strong, that the free mounting makes it even worse. So in some cases it is better to fix the motor with transportation screws! If you decide to re-mount transportation screws, it is very important not to tight the screws too hard on the plinth as this will eliminate the damping ability of the mounting! Right strength of screw fixing can be judged by try and error only. If there is no hum noise coming out of the speakers when tracking a groove without signal, you achieved the correct adjustment!

Since some time we are using high-tech Thermo Elasto Plastimer (TPE) dampers on each mounting point additionally. These dampers avoid motor vibration transmitted to the plinth in addition.

Attention!

Please do not mix up this “motor hum” with electrical ground noise caused by bad or no grounding. If there is a hum noticeable while the needle is NOT placed in the groove, something is wrong with grounding. This has nothing to do with the correct motor fixing. You can find this also by touching the plinth with your fingers. A hardly noticeable vibration on the plinth is the correct adjustment!

Please note that Pro-Ject Audio Systems offers a modification Kit for older Debut, 1Xpression and RPM-5.1 turntables, which includes new and better O-rings and a set of Thermo Elasto Plastimer (TPE) dampers.
In my opinion the big issue here are the o-rings. They are getting stretched over time. Mine is so stretched that the motor virtually hits the bottom of the motor well, so i have fixed the motor to two hard rubber grommets.

And i have the SE Upgrade kit, but it obviously cannot fix this.

Does anybody know about the o-ring and TPE damper kit?

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Re: Official Pro-Ject Fix For Turntable Rumble Now Launched

Post by muziekfreak » 01 Sep 2019 18:20

I realise this is an old thread but I'm wondering if this hum issues also occur in the R(P)M1 and 3 models.
In this models the motor is decoupled from the plint so I hope this issue is not / less present in the models. Who has experience with this?
TheAppleChap wrote:
29 Jul 2011 11:46
I have written an instruction guide and posted a full review on my blog at :
http://www.theapplechap.com/TheAppleCha ... umble.html
It's a pity this website isn't online anymore. Has the info been transferred elsewhere?

johnmath
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Re: Official Pro-Ject Fix For Turntable Rumble Now Launched

Post by johnmath » 06 Sep 2019 09:08

The RPM series motor is mounted quite differently and the fix detailed above is irrelevant. In my dozens of service notes for Pro-Ject turntables I have none specifically about mechanical hum from motors picked up by cartridges in the RPM series. Despite that the possibility exists for some mechanical conduction of vibration from the motor to the plinth and consequently to the cartridge though it can't be as big an issue as for other models.

muziekfreak
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Re: Official Pro-Ject Fix For Turntable Rumble Now Launched

Post by muziekfreak » 06 Sep 2019 19:47

johnmath wrote:
06 Sep 2019 09:08
The RPM series motor is mounted quite differently and the fix detailed above is irrelevant.
I don't understand. The R(P)M 4 where this fix is for is still one of the RPM series.
I argee with you that the current free standing motor setup of the RPM 1, 3 and new 5 is different then the old 5. Maybe that is what you mean?

johnmath
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Re: Official Pro-Ject Fix For Turntable Rumble Now Launched

Post by johnmath » 07 Sep 2019 10:23

My mistake, I only checked the RPM 1 and RPM 3 user manuals for the motor configuration, as they were the models you asked about, and falsely assumed all the RPM series had outboard motors but the 4 doesn't.

Earlier in this thread I brought up another hum issue I've found to afflict some Pro-Ject turntables even with an isolated motor. https://www.vinylengine.com/turntable_f ... pm#p637842

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