Popping Sound from Brand New LGB RhB Glacier Express Locomotive

LGB333

LGB333

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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.
 
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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idlemarvel said:
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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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.
 
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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Diesel2000 said:
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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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!
 
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 said:
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
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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 said:
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
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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.
 
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
 
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
 
Tim - That's for updating the forum users with your detailed procedures for finding the correct "unconvential fix" to eliminate the operating noise distortion.
 
I have dabbled with Mfx decoders and they do some odd things. I do not consider them fully DCC compatible. That said, I have not encountered this popping problem.
I have turned off Mfx in all my MFX decoder as as I use Massoth. Without turning this off I have experienced runaways following a stutter over a bit of dirty track. One big issue with Mfx is using other makes of programmers, these frequently change several CVs for you such as when changing to a high digit address code (CV17, 18, 23 etc). The sprog and the Massoth system set CV18 to zero rather than 127 (I think - was a while ago) This is not a problem with any other make of decoder - only the Marklin MFX.
I work out what what I want and change each CV individually - this works. I suggest you read and write down each CV before changing.
I don't like the Marklin Mfx, it is not completely DCC compatible. I invite Marklin to correct me.
 
Thanks Stockers, I agree with you on those points about the mfx protocol. Since I have a Massoth system and do not have a CS I have to adjust each CV. At present I only have this one loco that has an MLGB decoder. I've had some previously, but I converted them to ESU Loksound 5 XL decoders. Those decoders also have multi-CV settings, but a Lokprogrammer handles this easily and is much cheaper than investing in a CS. I find the sound capability to be far superior with these decoders and they operate very well without any issues. You can get a lokprogrammer and 3 5 XL decoders for the price of the CS.
 
Diesel2000 said:
Thanks Stockers, I agree with you on those points about the mfx protocol. Since I have a Massoth system and do not have a CS I have to adjust each CV. At present I only have this one loco that has an MLGB decoder. I've had some previously, but I converted them to ESU Loksound 5 XL decoders. Those decoders also have multi-CV settings, but a Lokprogrammer handles this easily and is much cheaper than investing in a CS. I find the sound capability to be far superior with these decoders and they operate very well without any issues. You can get a lokprogrammer and 3 5 XL decoders for the price of the CS.
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I'm another fan of the ESU v5XL's and its smaller cousins. So much so, I now stock them in my webstore. (www.amazinglittletrains.com) I've been looking at pulling out the factory MFX decoder from my LGB 50 year GE4/4 and putting in an ESU decoder. As you say, they also speak all of the different protocols and have no issues with having to have unused formats turned off. I'm actually looking at getting one of the 28446 locos as the next big purchase so will look out for any weird popping noises.
What I don't get is part of the manual tells you it looks for the track protocol as a tier system, starting at MFX and working down, all automatically, but then it tells you to turn off the unneeded formats?
 
I know its been some months since this thread started, but I have recently picked up my own 28446 loco and can report when changing cv50 to value 6 (DC analogue with DCC), I also get a faint random popping noise which is noticeable when the running sounds (F6) are on and the loco is stationary. Putting cv50 back to value 15 (all formats enabled), the popping goes away. If it makes a difference, the changes were made 'on the main' using a Massoth 12amp system with wireless navigator.
Hopefully the weather will improve this week so I can get the full Glacier set out in the garden :)
 
andyspencer said:
I'm another fan of the ESU v5XL's and its smaller cousins. So much so, I now stock them in my webstore. (www.amazinglittletrains.com) I've been looking at pulling out the factory MFX decoder from my LGB 50 year GE4/4 and putting in an ESU decoder. As you say, they also speak all of the different protocols and have no issues with having to have unused formats turned off. I'm actually looking at getting one of the 28446 locos as the next big purchase so will look out for any weird popping noises.
What I don't get is part of the manual tells you it looks for the track protocol as a tier system, starting at MFX and working down, all automatically, but then it tells you to turn off the unneeded formats?
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Andy - The LGB User Guides for these multi-technology mfx/dcc/analog decoders, and now they've added ac analog, recommend to turn off the technologies not used to preclude any conflict between them. So, if you don't use mfx, turn it off. Or, if you use mfx, turn off dcc and analog. The decoder is designed to first seek to use mfx, if none, then dcc, and lastly, dc analog. But the recommendation still applies, turn off what you don't use to help prevent, or perhaps, reduce the potential, for internal conflicts when all technologies are active.
 
LGB333 said:
Andy - The LGB User Guides for these multi-technology mfx/dcc/analog decoders, and now they've added ac analog, recommend to turn off the technologies not used to preclude any conflict between them. So, if you don't use mfx, turn it off. Or, if you use mfx, turn off dcc and analog. The decoder is designed to first seek to use mfx, if none, then dcc, and lastly, dc analog. But the recommendation still applies, turn off what you don't use to help prevent, or perhaps, reduce the potential, for internal conflicts when all technologies are active.
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Turning off what I didn't need was my plan, but that's when the popping occurred. Having all formats on so far has not given any issues. It was happy to accept cv changes to cv29, 17&18 on the Massoth programming track and has been tested on the rollers ok so far. Once it stops raining, it'll get a proper run outside.
This is my third factory DCC/MFX loco. The Heidi has MFX turned off and has a short address. The LGB 50 year GE4/4 has all formats enabled and running a long address. Apart from a stupidly noisy smoke unit, both of these locos have been ok running on a Massoth system.
 
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