whatlep
Registered
Summary
This is a short review of Massoth's latest power buffer (cat no. 8151601), introduced in 2012. It's a device I've found to be an excellent way of overcoming "dead track", especially for short wheelbase locomotives. The review includes a step-by-step guide to installation, details of the wiring connections needed (easy!) and CV settings required. Don't let the reference to CVs put you off if you're still using 19th century analogue technology. You can also use the power buffer on analogue lines, but a decoder is still required. Massoth are also gradually introducing new versions of their decoders which support use on either DCC or analogue lines seamlessly.
For proof of operation, see my YouTube video here: http://www.youtube.com/watch?v=TRWcr34MzRs
The Problem
Any model railway in any scale will periodically have problems with locos failing to pick up current. In G scale, the problems are made worse by running outdoors and the common use of "dead frog" points. Track is also affected by natural ground movements and deterioration of connectors. In short, maintaining good electrical contact between rail and wheels requires effort. The smaller the loco, the more likely problems are to happen, but given the size (and price!) of G scale stock, small locos tend to be popular.
How then to solve the problem? Extending the wheel/rail contact area by using LGB's accessory socket is an easy way. The same goes for connecting two small locos permanently together. Neither answer is ideal: the first means effectively using a "trail car", so the loco can't be used for light engine movements, nor run round a train without some "hand of God" shunting; the second means shelling out on a second loco (one loco for the price of two!).
A more radical solution is to go for battery power and that certainly is a viable option with today's technology. However, good quality battery conversions aren't cheap and you need to be able to fit enough battery "oomph" into your loco to make it useful. Trouble is that the smaller the loco, the less space there is for batteries, receivers and the necessary switches and charging sockets. I've seen some very creative solutions to "packing it all in", but generally not work for the fainthearted or those - like me - whose hamfistedness with a soldering iron is the stuff of legend. The only practical alternative for many smaller locos, including LGB's iconic Stainz, is to use a "trail car" and we're back with the limitations that brings.
The Solution
A far more elegant means of coping with lack of rail/wheel contact is to fit a power buffer. Effectively a standby battery carried on the loco which can instantly supply power if the track supply is lost for any reason. When the loco has good electrical contact with the rails, the power buffer receives and stores charge: the longer contact is maintained and the higher the track voltage, the quicker and higher charge is stored, up to the maximum capacity of the device. Power buffers are particularly suited to DCC layouts since power is constantly supplied at a relatively high voltage (nominally 18 volts). Electrically, the buffer is one or more capacitors with a controlling circuit which checks that the unit is not overcharged and ensures a smooth outflow of current when required. Examples have been around for many years - both home grown for those with enough electrical engineering knowledge not to destroy either components or loco and commercially produced.
Massoth's latest power buffer is the third in their range of offerings. The trio's characteristics are as follows (prices quoted are from Garden Rail Outlet, UK as at Sept 2012):
8151001 - power buffer: 1 amp continuous output for max 2 seconds (3 amp peak); £22
8151601 - Powercap micro: 1 amp continuous output for max 30 seconds (3 amp peak); £44
8151501 - Goldcap power buffer: 3 amps continuous output for max 60 seconds; £67
The new device, highlighted in bold fills a big hole in Massoth's range. Simply, the smallest buffer is too small to be of much help, while the largest is both expensive and intended for locos drawing a lot of power: typically two-motor locos, but they are less likely to suffer from poor pickup in the first place.
Expensive or cheap?
Reading the last section, you may have instantly thought that £44 is too high a price. Yet do the maths and it may well be cheaper than the alternatives. Consider too the following: fit a Powercap micro and you may well be able to make use of smaller locos than you thought possible. Smaller locos are generally cheaper and readily available too, especially the ubiquitous Stainz and LGB's Schoema shunter. What you spend on a buffer, you may well more than save on the purchase costs of locos. On top of that, you now have a true locomotive: no trail cars, no battery charging, no hassle.
Fitting the Powercap Micro
Fitting the Powercap micro is pretty simple, but please note that these notes are not a substitute for reading the manual and also the manual for your choice of DCC decoder. Once out of its plastic bag, you should have something looking like this:
The buffer modules are roughly 25x25x12mm, separated by 150mm of wiring to enable each module to be placed in small spaces all over your loco if really necessary. In my experience, there is plenty of room for all three modules taped together even in the smallest LGB locos (though I haven't tried a Feldbahn one yet!). See, for example, the buffer elements in my "Kleine Dicke", neatly tucked in behind the boiler backplate, leaving lots of lovely room for additional lead weight!
The switch is supplied solely to enable the discharge function to be switched off when changing CVs in older DCC decoders after the buffer is installed. By older decoders, I mean those which do not support "buffer control" in their CV settings. As may be expected, all Massoth's current decoders (and quite a few older ones from the mid-2000s onwards) support buffer control. Even if your decoder doesn't support buffer control, you probably don't need the switch wired in. After all, how many times do you alter your decoder CVs after installation?
There are five possible types of installation:
1) Attach to decoder with dedicated buffer control terminal (marked BC) - currently Massoth XLS & LS only
2) Attach to decoder with buffer control via output A5 - all other current Massoth decoders, plus many older ones except older XLSs - they use output A4
3) Attach to decoder without buffer control, or to avoid soldering to A5 output, or unable to set CV118/ CV116
4) Attach to decoder without dedicated terminals for buffer attachment (no +22 volt/ GND terminals) - experts only!
5) Installation for analogue control only (not for use with DCC)
Important - only methods 1 & 5 allows power buffer operation on analogue layouts. Methods 2-4 require analogue support to be turned off via CV29.
Method 1 installation:
1 - Connect black buffer wire to GND terminal (decoder 22v negative); red wire to decoder positive and white wire to BC. That's it. All done!
Method 2 installation:
1 - BEFORE connecting power buffer, set CV29 to either zero (14 speed steps, analogue operation blocked) or 2 (28 speed steps, analogue operation blocked) and set CV118 to 31 (CV116 to 31 on Massoth XLS decoders without BC connector)
2 - Connect black buffer wire to GND terminal (decoder 22v negative); red wire to decoder positive and white wire to A5. The last step requires soldering on the Massoth LS. All three wires require soldering on a Massoth M decoder.
Method 3 installation:
1 - BEFORE connecting power buffer, set CV29 to either zero (14 speed steps, analogue operation blocked) or 2 (28 speed steps, analogue operation blocked)
2 - Connect both black and white buffer wires to GND terminal (decoder 22v negative); red wire to decoder positive. On Massoth M decoder, soldering required!
Method 3 can be used with older decoders such as the LGB 55020/55021 by using the appropriate pins in the F1 row of three, as pictured below. Should it ever be necessary to reprogram the decoder's CVs , the black/white buffer connection can simply be disconnected to allow reprogramming.
Method 4 installation:
1 - Locate the decoder's 22 volt positive and negative locations (electrically after the AC rectifier) - I can provide locations for LGB onboard decoders, or see picture below.
2 - Convince yourself that you can solder the wires onto the designated places without destroying your decoder!
3 - BEFORE soldering power buffer wires, set CV29 to either zero (14 speed steps, analogue operation blocked) or 2 (28 speed steps, analogue operation blocked)
4 - Connect both black and white buffer wires to GND terminal (decoder 22v negative); red wire to decoder positive.
The picture below shows one of my LGB onboard decoders with buffer wires soldered on by another GSCer. I would not dare try soldering to such delicate components!
Method 5 installation (ONLY for use on analogue layouts):
1 - Connect both black and white buffer wires to GND terminal (decoder 22v negative); red wire to decoder positive. On Massoth M decoder and LGB onboard decoders, soldering required!
NOTE - if a loco is converted in this manner - without changing CV29 - it will be uncontrollable if used on a DCC layout!
In conclusion
Whichever method you used, you should now have a loco which will happily ignore bits of dirty or uneven track and laugh in the face of dead frog points. As in the picture below, one rail may be electrically dead over several feet, but the lights will stay on and the loco keeps on rolling. Happy buffering!

This is a short review of Massoth's latest power buffer (cat no. 8151601), introduced in 2012. It's a device I've found to be an excellent way of overcoming "dead track", especially for short wheelbase locomotives. The review includes a step-by-step guide to installation, details of the wiring connections needed (easy!) and CV settings required. Don't let the reference to CVs put you off if you're still using 19th century analogue technology. You can also use the power buffer on analogue lines, but a decoder is still required. Massoth are also gradually introducing new versions of their decoders which support use on either DCC or analogue lines seamlessly.
For proof of operation, see my YouTube video here: http://www.youtube.com/watch?v=TRWcr34MzRs
The Problem
Any model railway in any scale will periodically have problems with locos failing to pick up current. In G scale, the problems are made worse by running outdoors and the common use of "dead frog" points. Track is also affected by natural ground movements and deterioration of connectors. In short, maintaining good electrical contact between rail and wheels requires effort. The smaller the loco, the more likely problems are to happen, but given the size (and price!) of G scale stock, small locos tend to be popular.
How then to solve the problem? Extending the wheel/rail contact area by using LGB's accessory socket is an easy way. The same goes for connecting two small locos permanently together. Neither answer is ideal: the first means effectively using a "trail car", so the loco can't be used for light engine movements, nor run round a train without some "hand of God" shunting; the second means shelling out on a second loco (one loco for the price of two!).
A more radical solution is to go for battery power and that certainly is a viable option with today's technology. However, good quality battery conversions aren't cheap and you need to be able to fit enough battery "oomph" into your loco to make it useful. Trouble is that the smaller the loco, the less space there is for batteries, receivers and the necessary switches and charging sockets. I've seen some very creative solutions to "packing it all in", but generally not work for the fainthearted or those - like me - whose hamfistedness with a soldering iron is the stuff of legend. The only practical alternative for many smaller locos, including LGB's iconic Stainz, is to use a "trail car" and we're back with the limitations that brings.
The Solution
A far more elegant means of coping with lack of rail/wheel contact is to fit a power buffer. Effectively a standby battery carried on the loco which can instantly supply power if the track supply is lost for any reason. When the loco has good electrical contact with the rails, the power buffer receives and stores charge: the longer contact is maintained and the higher the track voltage, the quicker and higher charge is stored, up to the maximum capacity of the device. Power buffers are particularly suited to DCC layouts since power is constantly supplied at a relatively high voltage (nominally 18 volts). Electrically, the buffer is one or more capacitors with a controlling circuit which checks that the unit is not overcharged and ensures a smooth outflow of current when required. Examples have been around for many years - both home grown for those with enough electrical engineering knowledge not to destroy either components or loco and commercially produced.
Massoth's latest power buffer is the third in their range of offerings. The trio's characteristics are as follows (prices quoted are from Garden Rail Outlet, UK as at Sept 2012):
8151001 - power buffer: 1 amp continuous output for max 2 seconds (3 amp peak); £22
8151601 - Powercap micro: 1 amp continuous output for max 30 seconds (3 amp peak); £44
8151501 - Goldcap power buffer: 3 amps continuous output for max 60 seconds; £67
The new device, highlighted in bold fills a big hole in Massoth's range. Simply, the smallest buffer is too small to be of much help, while the largest is both expensive and intended for locos drawing a lot of power: typically two-motor locos, but they are less likely to suffer from poor pickup in the first place.
Expensive or cheap?
Reading the last section, you may have instantly thought that £44 is too high a price. Yet do the maths and it may well be cheaper than the alternatives. Consider too the following: fit a Powercap micro and you may well be able to make use of smaller locos than you thought possible. Smaller locos are generally cheaper and readily available too, especially the ubiquitous Stainz and LGB's Schoema shunter. What you spend on a buffer, you may well more than save on the purchase costs of locos. On top of that, you now have a true locomotive: no trail cars, no battery charging, no hassle.
Fitting the Powercap Micro
Fitting the Powercap micro is pretty simple, but please note that these notes are not a substitute for reading the manual and also the manual for your choice of DCC decoder. Once out of its plastic bag, you should have something looking like this:

The buffer modules are roughly 25x25x12mm, separated by 150mm of wiring to enable each module to be placed in small spaces all over your loco if really necessary. In my experience, there is plenty of room for all three modules taped together even in the smallest LGB locos (though I haven't tried a Feldbahn one yet!). See, for example, the buffer elements in my "Kleine Dicke", neatly tucked in behind the boiler backplate, leaving lots of lovely room for additional lead weight!

The switch is supplied solely to enable the discharge function to be switched off when changing CVs in older DCC decoders after the buffer is installed. By older decoders, I mean those which do not support "buffer control" in their CV settings. As may be expected, all Massoth's current decoders (and quite a few older ones from the mid-2000s onwards) support buffer control. Even if your decoder doesn't support buffer control, you probably don't need the switch wired in. After all, how many times do you alter your decoder CVs after installation?
There are five possible types of installation:
1) Attach to decoder with dedicated buffer control terminal (marked BC) - currently Massoth XLS & LS only
2) Attach to decoder with buffer control via output A5 - all other current Massoth decoders, plus many older ones except older XLSs - they use output A4
3) Attach to decoder without buffer control, or to avoid soldering to A5 output, or unable to set CV118/ CV116
4) Attach to decoder without dedicated terminals for buffer attachment (no +22 volt/ GND terminals) - experts only!
5) Installation for analogue control only (not for use with DCC)
Important - only methods 1 & 5 allows power buffer operation on analogue layouts. Methods 2-4 require analogue support to be turned off via CV29.
Method 1 installation:
1 - Connect black buffer wire to GND terminal (decoder 22v negative); red wire to decoder positive and white wire to BC. That's it. All done!
Method 2 installation:
1 - BEFORE connecting power buffer, set CV29 to either zero (14 speed steps, analogue operation blocked) or 2 (28 speed steps, analogue operation blocked) and set CV118 to 31 (CV116 to 31 on Massoth XLS decoders without BC connector)
2 - Connect black buffer wire to GND terminal (decoder 22v negative); red wire to decoder positive and white wire to A5. The last step requires soldering on the Massoth LS. All three wires require soldering on a Massoth M decoder.
Method 3 installation:
1 - BEFORE connecting power buffer, set CV29 to either zero (14 speed steps, analogue operation blocked) or 2 (28 speed steps, analogue operation blocked)
2 - Connect both black and white buffer wires to GND terminal (decoder 22v negative); red wire to decoder positive. On Massoth M decoder, soldering required!
Method 3 can be used with older decoders such as the LGB 55020/55021 by using the appropriate pins in the F1 row of three, as pictured below. Should it ever be necessary to reprogram the decoder's CVs , the black/white buffer connection can simply be disconnected to allow reprogramming.

Method 4 installation:
1 - Locate the decoder's 22 volt positive and negative locations (electrically after the AC rectifier) - I can provide locations for LGB onboard decoders, or see picture below.
2 - Convince yourself that you can solder the wires onto the designated places without destroying your decoder!
3 - BEFORE soldering power buffer wires, set CV29 to either zero (14 speed steps, analogue operation blocked) or 2 (28 speed steps, analogue operation blocked)
4 - Connect both black and white buffer wires to GND terminal (decoder 22v negative); red wire to decoder positive.
The picture below shows one of my LGB onboard decoders with buffer wires soldered on by another GSCer. I would not dare try soldering to such delicate components!

Method 5 installation (ONLY for use on analogue layouts):
1 - Connect both black and white buffer wires to GND terminal (decoder 22v negative); red wire to decoder positive. On Massoth M decoder and LGB onboard decoders, soldering required!
NOTE - if a loco is converted in this manner - without changing CV29 - it will be uncontrollable if used on a DCC layout!
In conclusion
Whichever method you used, you should now have a loco which will happily ignore bits of dirty or uneven track and laugh in the face of dead frog points. As in the picture below, one rail may be electrically dead over several feet, but the lights will stay on and the loco keeps on rolling. Happy buffering!
