Popping Sound from Brand New LGB RhB Glacier Express Locomotive

LGB333

Active Member
I recently sold a customer a brand new LGB 28446 Class Ge 4/4 II locomotive with the Marklin mfx/dcc sound decoder. It was produced from the Marklin factory's recent production run of these locomotives. When my customer tested the locomotive on his roller wheels test track using his Massoth 12 Amp Command Station/Massoth 12 Amp Power Supply and Massoth wireless 2.4GHz Navigator, he's getting some low background popping noise. This issue has been referred to the Marklin factory for a response. In the meantime, I'm wondering if any other hobbyists have experienced this popping sound coming out through the sound system with recent production LGB locomotives with their factory mfx/dcc sound decoders.
 

idlemarvel

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13 Jul 2015
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All I can think of is to turn mfx off in the decoder to make it DCC only, set CV 50 to zero, or two if they may want to use it on analog DC layouts as well.
 
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LGB333

Active Member
All I can think of is to turn mfx off in the decoder to make it DCC only, set CV 50 to zero, or two if they may want to use it on analog DC layouts as well.
Dave - My customer has already set the decoder as you suggested and the popping sound continues:

CV50=0 All protocols off except DCC; CV29=34 28/128 steps, 4 digit address, analog off.

In the Massoth Loco config I set: 28D for speed steps, Parallel functions.

Marklin Inc USA has requested he ship the locomotive to them to check out but I expect they'll have to return it to he Marklin Factory for repair.
 

Diesel2000

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I'm the owner of the 28446 in question that Tom posted about. I was able to determine that the CV50 setting is the cause of the popping/crackling sound.

I reset the decoder CV8=8 to factory defaults and tested the sound and the popping stopped. I then performed the same setting changes again to CV50 and CV29 and the popping noise came back! So then I tested sound after each CV change and started with setting CV50=0 for DCC only and the popping sound was there again.

I then started testing through the CV50 values. On 2 I still had the popping, on 7 it seemed to be far less, and at the default 15 it stopped. So my determination is there is something going on with the multi protocol setting when you turn off mfx, which has a bit value of 8.

I have several other MLGB decoder-equipped locos and they have a default setting of 10 for CV50 and only offer DCC, DC, and mfx protocols. I never heard the popping sound with the operating sounds on those when turning off mfx and only having DCC mode enabled.

This 28446 decoder has DCC, AC, DC, MM, and mfx protocols and the value combinations for CV50 have changed as a result.
 
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dunnyrail

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I'm the owner of the 28446 in question that Tom posted about. I was able to determine that the CV50 setting is the cause of the popping/crackling sound.

I reset the decoder CV8=8 to factory defaults and tested the sound and the popping stopped. I then performed the same setting changes again to CV50 and CV29 and the popping noise came back! So then I tested sound after each CV change and started with setting CV50=0 for DCC only and the popping sound was there again.

I then started testing through the CV50 values. On 2 I still had the popping, on 7 it seemed to be far less, and at the default 15 it stopped. So my determination is there is something going on with the multi protocol setting when you turn off mfx, which has a bit value of 8.

I have several other MLGB decoder-equipped locos and they have a default setting of 10 for CV50 and only offer DCC, DC, and mfx protocols. I never heard the popping sound with the operating sounds on those when turning off mfx and only having DCC mode enabled.

This 28446 decoder has DCC, AC, DC, MM, and mfx protocols and the value combinations for CV50 have changed as a result.
Glad you got it sorted, indeed the wonders of DCC can be confusing at times. The slightest change can sometimes bring out unforeseen circumstances, moral of this story is to go back to factory and do as you did changing things one at a time. What a pain!
 

JimmyB

Semi-Retired; more time for trains.
It sounds far to confusing for me, even the thought of all these CVs was bad enough, but these issues make me glad I stayed away from DCC, this is not to say those of who have and love DCC are wrong, if just its not for me - ever :)
 

Greg Elmassian

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Tom or Diesel2000, what does the manual define for CV50 exactly? i.e. what bits for what.... I'd be interested...

pretty smart stepping through combinations until it worked, what a pain though..

Greg
 

Diesel2000

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Tom or Diesel2000, what does the manual define for CV50 exactly? i.e. what bits for what.... I'd be interested...

pretty smart stepping through combinations until it worked, what a pain though..

Greg

Here are the CV50 bit values from the 28446 decoder manual

28446_CV50.jpg

Here the values from my Napa F7 20580 from 2019

20580_CV50.JPG
 

Greg Elmassian

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Thanks! I assume MM means Motorola Mode ?

So CV 50 = 15 seems to be all bits on which would enable everything... I'm a bit confused...

That's what worked? if so, that is plenty weird... (perhaps factory testing was only in that mode(s)?)

Greg
 

Diesel2000

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Thanks! I assume MM means Motorola Mode ?

So CV 50 = 15 seems to be all bits on which would enable everything... I'm a bit confused...

That's what worked? if so, that is plenty weird... (perhaps factory testing was only in that mode(s)?)

Greg

Correct, CV50=15 is the default value, which is all protocols enabled. In my initial configuration I was setting CV50=0, which is all modes except DCC disabled. Interim values of 2,3,7 all produced a popping/crackling noise when operating sounds are turned on. Only with all protocols enabled does it go away.

It could be something specific to this decoder, thats why Tom was posting here to see if anyone else who recently got the loco had the same issue.

My only recourse is to send it back to Marklin and if it goes to Germany it might as well be many months before I'd see it again.
 

Greg Elmassian

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I would have done the same thing instinctively, turn off all the protocols I did not want, usually it helps minimize problems.

Also, it's funny, in that from a computer point of view, turning off extra processing usually lets things run faster, but in this case it was not helpful.

Are there any side effects that are giving you grief from having all these protocols enabled?

Greg
 

Diesel2000

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Exactly, in fact the manual even says to turn off the protocols you do not use because they can influence each other!

So far no issues with keeping them all on, but I havent been able to run it on my outdoor layout yet as its been buried under 2.5ft of snow for the past 4 weeks.

protocols.JPG
 

Greg Elmassian

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Funny, you got in trouble following the instructions. Hopefully they should be able to duplicate this problem at the factory and fix it.

Maybe a firmware update?

Thanks for all the info, a good learning experience and warning to many!

Greg