Siemens Micromaster 420 As Motor Controller

[Moko]

I saw this article over on TNT about using a Siemens Micromaster 420 as a motor controller for a Garrard 401 [Review] Siemens Micromaster 420 - [English]

I was wondering if anyone here is using a similar set up and can answer a few questions, and comment on any sound improvements over the standard 401?

Thanks in advance

 

[Zen Mod]

if Twogoodears said it's worthwhile improvement , just chill

I'm planing to buy one for my EMT , but I'm not in a hurry , having new phono section as primary goal

 

[Moko]

A couple of things that the article does not mention is whether with the MicroMaster you can dispense with the Eddy Brake on the 401 as the controller would set the speed? Apparently Loricraft always reckoned that removing the Eddy Brake improved the sound of the 401.

Also do you adjust the speed of the deck 33/45 with the controller or does it still require the pulley to be moved as on the original deck?

 

[Osvaldo de Banfield]

NO!

I work repairing such stuff, and I surely can suggest not to use this AC speed for audio. It works with rectangular waveforms unfiltered, and PWM modulated in a 3-4KHz frequency. This, near a magnetic cartridge is synonymous of lots of noise in the audio system.

 

[Moko]

But could you not put the MicroMaster a good distance from the cartridge and use shielded cable then the cartridge would not pick up any noise from the unit.

I am not very experienced in electronics so forgive my ignorance.

 

[Osvaldo de Banfield]

The strong HF magnetic field arround the motor coils and rotor can reach the magnetic pickup generating a signal of both low rectangular waveforms and the PMW to control the current.

Also the output of this stuff is intended for 3 phase motors, running usually at 380V. So applying this voltage to the motor will blow the coil. Also, if the motor if of the phase split type, there will be no severe malfunction, but the motor uses a capacitor to run, the cap will overload the driver outputs possibly damaging the cap, the motor and the driver. Also, the PWM carrier (again, in the order of 3-4KHz ussually) may cause a overheating in the iron core because of the eddy currents generated at so high frequencies.

 

[Bksabath]

I use those at work (hundreds of them) and just this morning I was programming a couple of 440 I hate Siemens stuff is so complicated 300 + pages installation manual and a further 340+ pages parameter manual. If you get one make sure you price all the bits you need as Siemens charges for everything For example you will need the programming unit.
IMO I like Mitsubishi and those are easier to use

I am pretty sure they can do the job but I would worry (see Osvaldo posts) about the noise they may introduce on a domestic mains which will find is way to your Pre/ amplifier is not going to be just magnetic field and you may nedd a few bobs for EMC filters and such

The idea is quite interesting and if you need help Just PM
One needs to set P0003 to 3 to gain access and P0004 to the required data set even before you start

I wonder if the cash lay out would be justified as one can use a DC motor and any dedicated supply already in use on TT

 

[Osvaldo de Banfield]

Of course. No Siemens stuff is easy to program and use. Old DC thyristor controlled DC rectifiers has more than 1000 inter-dependent parameters, like the Simovert and Simoreg. I hate them!

 

[Bksabath]

About the puley you can use a pot to set the speed and if the motor got one a taco can monitor the speed
Use to have same of those to Stop a 24 tones crane traveling at 24 M/minute to a fraction of an inch to the required position

 

[Moko]

I found this article with a search http://www.diyaudio.com/forums/anal...aster-420-emt-930st-converting-60hz-50hz.html

It seems that it can be done, but there does seem a lot to overcome

 

[Bksabath]

Yes it can be done as I said if you need help just ask EG there are better cheaper easier ones than Siemens.

I am Not sure how it will sound but...