LGB Uintah/Sumpter Valley sound decoder

T

Tim Brien

Registered
I always liked the original factory sound on my Sumpter Valley Mallett (when I had it????) and when the opportunity arose to obtain a sound unit for my non-sound Uintah Mallett, I purchased a kit of parts to upgrade the non-sound Mallett to a factory sound version using all original LGB parts. The kit included both boards, clocking device (Hall sensor and axle), bell/whistle reed switch and speaker.

The sound board is marked LGB #20892 which is the Sumpter Valley board (the sound version Uintah board is #20882). The board is set up for MTS. Now my question is what decoder do I fit. At the time I believe a small MTS decoder plus booster decoder was used (circa-2000's). Would a type 3 LGB #55027 or a Massoth XL be suitable utilising the original sound board as just purchased? Where on the board is the decoder installed?

As the original sound was 'serial' (pre parallel upgrade) then I assume multiple function button operations will be needed to get a particular sound function.

First photograph shows the sound board. Second photo is the main circuit board.

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I assume that the blue six pin plug receptacle in the main circuit board in the second photo above is the interface for the LGB #55026 Interface cable. This should then handle lights and motor operation (piggyback on the two sets of motor connectors I assume). After reading it seems the Massoth XL is an easier option than a type 3 LGB decoder #55027 which is more intended for a ten-pin decoder interface factory installation on later models from LGB.

Sound wiring leaves me a little in the dark. I can easily break into the wiring for the bell/whistle reed switch to digitally operate the bell and whistle but as for other sounds I am a little in the dark (unless they are automatic sounds and not controllable).
 
I cannot edit the above posting as 20 minutes has elapsed since posting. Forget the reference to piggybacking the motor leads as the interface connection handles this. There is a six wire umbilical chord connecting the sound board to the main board. Does this carry the decoder signal for selectable sound functions when a decoder is installed?
 
Hi Tim
I am not sure if the following is any help....
I know that you are installing the boards into their correct loco but when I installed the 'analogue' LGB sumpter sound boards in my Annie tenders I had to work out the wiring for the non-LGB hall sensor system that I fixed up and the triggers and this is what I found.

I run the boards of track voltage from the loco via the rear light plug. This can be DC or DCC, the board just works from either power source as they have a rectifier for the power input. Apart form the triggered bell or horn, the sounds are automatic. I don't know if the later DCC equipped Sumpter locos had the options for selecting brake squeal, coal shoveling etc from a DCC handset.
The two three pin sockets on the sound board are, one for the hall sensor and the other for the horn/bell. There is a label printed on the circuit board next to the horn/bell one. The two outer pins are for the horn/bell trigger wire and the middle pin is the common. But if you have the correct cables, I expect that you know this already.
But just in case....
1) The Sound trigger connector (top black 3 way connector), connect 2 reeds, one to each to outer pin and centre pin (GND).
2) The Chuff sensor connector (lower black 3 way connector). Top is +12v, Centre is CLK and lower is GND.

Here is the links to the thread of my installation with photos
http://www.gscalecentral.net/tm?m=217711&high=sumpter+sound < Link To http://www.forum.gscalece...amp;high=sumpter+sound
 
Being an analogue/MTS compatible board (decoder interface) I am hoping the installation will be simplified, plus the 'kit' comes with all fittings except the speaker wires and connector.

The LGB Sumpter loco instructions state that installing an LGB decoder (#55020 and #55030 booster - both no longer available) using the decoder interface cable, #55026, will give all sounds in MTS. Surely a Massoth XL should give the same result.

Now, one assumes that the dual drive block wires plus their mating circuit board connections will need to be connected to the decoder. This will be a lot of wires so will need to be simplified with maybe a 'chocolate block' connector.

Am I on the right track here or missing something?
 
Well a little grey cell energising and I think that I have it cracked. The original board was made when 3 amp decoders were not even envisaged so two decoder installs were normal for a twin motor install. The second photo above shows two sets of track/motor pin sets on the left side of the main board. These two sets of pins are independent of each other so that independent control/programming of each motor block was possible.

For my decoder install I will use the six pin decoder interface cable #55026 to sort out lights, smoke and sounds and then connect the eight track/motor pins (two sets of four pins each) to the decoder track/motor terminals. All very simple one would think (hopefully????). The stock connectors from each motor block are left untouched and remain attached to the main board.
 
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You need to set A1 (F1) to Fast pulse string so that the decoder can tell the sound board what sounds to play.
 
Mark,
many thanks. I assume that I simply duplicate the motor/track terminals on the main board to the decoder motor/track terminals.

When you say set 'A1' to fast pulse, I presume you are referring to CV49 setting fast pulse string bit (CV49=11). I remember you telling me a couple of years ago on another LGB factory sound installation that I did.
 
This whole saga has left me a little peeved. The original main board appeared to have a short circuit. As soon as power was applied the power supply would trip. I reinstalled the original board and operation was normal. The seller in the U.S. organised a replacement board from Germany which arrived today.

I installed the new board and immediately the board tripped my power supply. I decided to check continuity on the new board and found that the track power pins on both front and rear motor block connections on the board had continuity indicating a short circuit. The pins were not only shorting on the front block but also interconnected and shorting with the rear block pin connections as well. The old board orginally sourced with the sound board also did this. It seems odd that two new boards could be faulty. I did check the motor blocks to ensure no problem with them. This was a new Uintah Mallett purchased about ten years ago but never used.

After consultation with a friend we think that we can hardwire the individual motor blocks to the decoder bypassing the main board track/motor block connections. Power will then be applied to the board using the two DCC interface track power pin connections at the front of the board. I temporarily powered the board using these two pins after DCCing the board by setting the DIP switches to the 'OFF' position and selecting #1 DIP switch on the sound board to 'OFF' (I believe this isolates the capacitors on the board). I ran the sound for 90 minutes with no tripping occurring, occasionally manually moving the loco backwards/forwards to initiate starting sounds and chuff. The reed switch also worked the bell/whistle as required. Hopefully this may solve my problem with the board. I will use the decoder to trigger lights and smoke rather than the decoder interface connections on the main board.

Now I need to source a decoder and hope it all works out.
 
were the Sumpter and Uintah sounds different?
if so, if you could be so kind as to elaborate, as I would have presumed otherwise
 
Steve,
the Uintah sound board was a one piece analogue board combining all light/smoke functions plus the analogue sound file. It had provision for axle synched chuff and reed switch triggered bell and whistle.

The Sumpter Valley board was a digital sound board designed for MTS operation. It was a two piece board comprising a sound board and a separate main board. It was designed for fitting a decoder using a decoder interface, something the analogue Uintah board could not (within reason).

Edit: the sound files are the same, but the digital Sumpter Valley board allows independent control over sound files when decoder fitted. The analogue Uintah board is very limited in the control of individual sounds.
 
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