Motor - CT's usual excellent motor control features

Sound - 3 channel output; ~170seconds 16-bit; 16 aux sound effects; highly configurable lots of options to play with; 8ohm speaker max 3W; native 'stay-alive'

Function - 8 outputs (4 pre-wired, 4 solder pads); many effects; highly configurable; excellent support for coupling devices; extended function mapping

Comments - YouChoos' favourite sound decoder, with plenty of power for any OO loco, lots of options for flexible programming and remarkably small - certainly the smallest combi-decoder of this spec and output.

Cost: £70-£80 (blank or with default CT sounds)

Motor - Zimo's excellent motor control (possibly even better than CT)

Sound - 4 channel output; ~180seconds 8-bit; many aux sound effects; highly configurable lots of options to play with; 8/4ohm speaker; native 'stay-alive'

Function - 10 outputs (4 pre-wired, 6 solder pads); many effects; highly configurable; excellent support for coupling devices; extended function mapping

Comments - Marginally bigger than CT's SL51-4, arguably better specced. Perhaps better for steam sounds, but not so good for diesel sounds (arguably). Zimo are not far off being offering the best sound decoders around. Very impressive.

Cost: £75-£85 (blank or with default Zimo sounds)

Motor - excellent motor control features

Sound - 4 channel output; 16-bit; 16 aux sound effects; highly configurable lots of options to play with; 100ohm speaker max 3W

Function - 4 outputs; many effects; highly configurable; fully mappable

Comments - much larger than CT's SL51-4, but better specced. Only 4 function outputs is a bit limiting, but flexible programmability is the best. This is the industry leader, and most popular combi-decoder.

The V4 is a similar size, has 4 function outputs, 8-channel sound and a massive 32Mb memory to store sounds.

Cost: £85-£115

Same features as CT SL51-4, but lower power output and 4 functions instead of 8

Comments - the best solution for N scale sound, and just about powerful enough for some OO. This decoder is identical to the SL51-4 except for max motor power and number of function outputs.

Cost: £70-£80

Same features as Zimo MX645 but 4 function outputs instead of 10 and lower power output capability. No native 'Stay-Alive'.

Comments - Marginally bigger than CT's SL75. Same comments as for MX645. Great for N.

Cost: £75-£85 (blank or with default Zimo sounds)

Smaller version of Zimo MX646 but 6 function outputs instead of 4.

Comments - Very exciting for N - seriously small and top-spec too - much shorter than MX646 making it the smallest sound/motor decoder around!

Cost: £75-£85 (blank or with default Zimo sounds)

Same features as LokSound 3.5, but lower power output

Comments - baby brother to LokSound 3.5. Quite small, but not nearly as small as CT's SL75, with the expected max power reduction.

The V4 Micro is a little smaller than then 3.5, still with only 4 function outputs, but sports 8-channel sound and a massive 32Mb memory to store sounds.

Cost: £85-£115

A sound-only version of the SL75, CT's GE75 is a great way to add DCC sound without it needing to cost a fortune. Identical in dimension and functionality to the SL75 except without the motor control, and just 2 function outputs.

Cost: £45-£65

Motor - basic features including Back-EMF on/off

Function - basic 3 outputs; no effects; no mapping; output high enough to power a Seuthe smoke unit from a single function

Comments - provides good basic functionality for the price, but don't expect to be able to do too much with it. A good choice if you are converting a large number of locos to DCC. Quite large dimensions.

Cost: £8-£12

Motor - basic features

Function - basic 4 outputs; no effects; no mapping; output NOT high enough to power a Seuthe smoke unit

Comments - very small, but otherwise only a basic spec. Not enough power for a smoke unit from a single function output. Good cheap price though. A good choice is you are limited for space or have lots of locos to fit DCC to. It's 'ok'.

Cost: £7-£12

Motor - CT's usual excellent motor control features

Function - 7 outputs (4 pre-wired, 3 solder pads); many effects; highly configurable; excellent support for coupling devices; extended function mapping

Comments - arguably the best motor/function decoder available. It has everything going for it - very small, lots of functions, and hugely configurable. Actually not that expensive either.

Cost: £25-£30

Motor - probably the best there is

Function - 6 outputs (4 pre-wired, 2 solder pads); many effects; highly configurable; excellent support for coupling devices; extended function mapping

Comments - better specced than CT's DCX70-2, but a bit bigger. Includes native 'stay-alive' capability - works incredibly well.

Cost: £25-£30

Motor - CT's usual excellent motor control features

Function - 2 outputs; many effects; highly configurable; excellent support for coupling devices; extended function mapping

Comments - the smaller decoder available in terms of width/length, although it is double-sided so not as thin as CT's sibling DCX75. Stunning motor control. Perfect for the tightest of installs.

CT also produce a slightly larger version, the DCX74zV, which has 4 function outputs - also superb, and competes directly with Zimo's MX621.

Cost: £30-£40

Motor - CT's usual excellent motor control features

Function - 2 outputs; many effects; highly configurable; excellent support for coupling devices; extended function mapping

Comments - similar to CT's DCX74z, perhaps slightly better motor output, but the same great configurability. Although a tiny bit longer, this is incredibly thin being single-sided.

Cost: £30-£40

Motor - perhaps the best in this size

Function - 4 outputs (2 wired, 2 solder pads); many effects; highly configurable; excellent support for coupling devices; extended function mapping

Comments - equivalent of CT's DCX74zV, better performing for motor control, but only just. Bigger, but suitable for most installs in N anyway.

Cost: £30-£40

Motor - reasonable motor control, with some configuration for Back-EMF

Function - 2 outputs; excellent effects; configurable

Comments - good entry-level micro decoder. Reasonable features including some great lighting effects. Pretty small, but not in the same league as the CT micro-decoders, and nowhere near as many programming options. Great price though.

Cost: £15-£20

Motor - good motor control, with some configuration for Back-EMF

Function - 2 outputs; good effects; configurable

Comments - thinner but longer than DigiTrax's DZ125, and comes with the good feeling that always comes with using Lenz equipment - they are after all the masters of DCC! The Silver Mini+ is pretty small, suitably thin and has average spec. For this money though it is not as well featured as the small CT decoders.

Cost: £30-£35

Basic 4 outputs; good choice of lighting effects; NMRA function mapping; output high enough to power a Seuthe smoke unit; outputs NOT dimmable

Comments - fabulous entry-level function-only decoder. Plenty of power to each output, full NMRA function mapping, and some great lighting effects. It is also very small, so for the price makes for a very sensible choice for kitting out wagons and coaches. The only thing missing is the ability to dim the outputs.

Cost: £12-£15 (often available in a 5-pack which helps reduce the cost further)

8 outputs (4 pre-wired, 4 solder pads); many effects; highly configurable; excellent support for coupling devices; extended function mapping; high power; native 'stay-alive'

Comments - this has got to be the best of the bunch, with a tiny footprint as well as being single-sided, it is the smallest. Lots of outputs, and the usual excellent CT programmability. Not as cheap as the TCS FL4, but then again it is much better specced.

Cost: £20-£30

5 outputs; very basic effects; not mappable; high power (1 output at a huge 500mA)

Comments - Good power output, and the extra output compared to some others is very useful. However, it is not very programmable - no function mapping, and very basic lighting effects, make it unsuitable for all but the most simple uses. It is also quite thick. However, this is now an old model, so it may well be worthwhile taking a look at the later versions which sport much better programming potential.

Cost: £15-£20

4 outputs; basic effects; basic mapping

Comments - now an old model, this is rather on the large side, with very little in the way of programming options. Still, good and reliable and the new versions look really very excellent.

Cost: £12-£20