Early Bachmann 8 Pin Class 25 Chassis sound Fitting

[drgj]

I have not got sound fitted into any of my locos and would like to have a go. I thought that the Legoman "Drive Lock" type might be a good choice but is there a good sounding speaker that would sit on top of the old 8 pin Bachmann class 25 chassis block? On the DC Kits site they have the chips and a choice of speakers. Is the 8 pin socket a stumbling block?

 

Thanks

Dave

Edited June 13, 2017 by drgj

[CloggyDog]

I know I've done at least 1 8-pin Bachmann 25 (and/or 24) to add sound. While there is some space atop the chassis block for a speaker (you might need to remove the fan and trim the fan mount), I found a better bet was to fit the speaker facing downwards in the battery-boxes (removing the small cast weight - it's held in with a screw, so quite easy to do) and drilling a series of holes in the base to let the flavour flood out.

 

I used Loksound 8-pin decoders bought from SWD, though I've since had at least one reblown by Coastal DCC.

[SRman]

The 8-pin socket isn't a stumbling block at all. I have fitted sound to an 8-pin Bachmann class 24 in the past (chassis all but identical to the 25). Finding space for speakers is not s easy but can be done. In the 24 I fitted a rectangular bass-enhanced speaker on top of the chassis block at one end, with a round 20mm speaker at the other end - this had to have the sound chamber cut down considerably to fit inside the body shell. If I was doing this one nowadays, I would use a sugar cube speaker instead of the round one, or possibly I would have used a 'dumbo' set up with a pair of sugar cubes in a specially designed enclosure in place of both in the previous setup.

It may take a bit of experimentation to get the best sound possible, but speakers are relatively cheap to buy. Either ESU LokSound v4 or Zimo decoders could be used.

 

p.s. As Cloggy Dog suggested, I did have to remove the fan assembly.

Edited June 13, 2017 by SRman

[drgj]

Thanks for the replies. The loco I'm thinking of doing is in fact a class 24 but on a Bachmann 25 chassis. It was the Non boiler tanks type that I changed to look like a 24 battery/ tank set so will have to check the space inside there.

 

If you use more than one speaker I suppose you have to check the impedance of the speakers used. I'm not up on electronics but I am thinking that two speakers would be wired in parallel.

 

Dave

[Mark Forrest]

On my non-boiler 25s, I've removed the fan, putting the decoder in its place and mounting the speaker at the other end, where the chassis block is slightly lower.

 

For comparison, the larger battery boxes and tanks of a 24 make a good location for a larger speaker.

[drgj]

Thanks for those excellent pictures, Mark.  I see you have sealed around the round speaker. Are both speaker types in some kind of enclosure? How does your set up compare with an off the shelf Bachmann loco fitted with sound?

Dave

Edited June 13, 2017 by drgj

[Mark Forrest]

From memory, the factory fitted ones have a different chassis block with a recess for a speaker, think I have one of those in the box, I'll take another photo later.

 

The round speaker in my 25 above is sealed to a square of plastic with some blu-tack. A bit crude, but it does the job.

[Phil Bullock]

Mark's blue tak tip will improve sound 100%!

 

Phil

[drgj]

That is one thing I have read in your posts before, phil.  Certainly seems a good  idea from you and mark.

 

Dave

[Mark Forrest]

Here are a few more...

Top is a 21 pin chassis, with the speaker recess at number 1 end. I temporarily fitted a standard round speaker that came with the decoder (more blu-tack), intention was to replace this with a bass enhanced one, but never got round to it.

Middle is a factory sound 24, with the standard speaker replaced with a bass enhanced one (DCC Supplies, I think) same one as I showed previously in the tanks of the other 24.

Bottom is a 8 pin chassis, as before the decoder is at number 1 end and the speaker at number 2. I made up a plasticard enclosure for a rectangular speaker this time.

 

Hard to say which sounds best, to be honest I don't listen to them much! I do like that they all sound slightly different though.

[drgj]

Thanks again, Mark. Very useful pic for me to study. Also, thanks for taking the time to dismantle your locos.

 

dave

Edited June 14, 2017 by drgj

[drgj]

The SLW class 24 has an extra element to the engine sound that I can't hear on other similar sound fitted locos. Can I buy the same chip?

Thanks

Dave

[RAF96]

If you don't have an enclosure for a 28mm round speaker a Humbrol plastic paint pot with the lid cut off is a perfect fit with a bit of 'tak' to bed it in. The height of the pot wall can be adjusted as required to suit your space limited.

[drgj]

Will need a controller and I thought of getting either the Bachmann Dynamis or the Gaugemaster Prodigy Express. There doesn't seem much between them.

 

dave

Edited June 20, 2017 by drgj

[CloggyDog]

The SLW class 24 has an extra element to the engine sound that I can't hear on other similar sound fitted locos. Can I buy the same chip?

Thanks

Dave

 

Dave,

 

the SLW 24's sound decoder is specific to the model and, for obvious reasons neither it, or the sound files thereon, are available separately.

 

Imho, the next best available 'baby Sulzer' sound chips are a toss-up between Legomanbiffos (via dckits) and the CoastalDCC one, either combined with a decent speaker give very good results.

[9C85]

On 13/06/2017 at 17:10, Mark Forrest said:

On my non-boiler 25s, I've removed the fan, putting the decoder in its place and mounting the speaker at the other end, where the chassis block is slightly lower.

 

For comparison, the larger battery boxes and tanks of a 24 make a good location for a larger speaker.

These are very useful pictures. 

 

I have an 8-pin Bachmann class 25 to which I would like to add sound.  It has the larger tanks/ boxes arrangement as shown in the second picture above. 

I have a few questions:

1) How do you get the speaker wires from inside the roof to outside the chassis?

2) Do you have to drill a hole in the chassis?

3) Do you have to desolder the speaker/wires and refit them after passing through the chassis, or do they 'clip in' to the circuit board?

4) How do you remove the boxes/tanks?

As you may have guessed, I am fairly new to this game and I try to get as much information as possible before trying something beyond my skill set.

Thanks in advance. 

Stu

[Mark Forrest]

I agree with @Richard Croft, there is a wider choice of speakers available now than when I did those, in fact the 25 pictured has recently had a new speaker fitted - I used the 25 x 25 x 7 mega bass as suggested.

 

Regarding modifying the the tanks and battery boxes, if you drop the bogies out you'll see 4 small screws holding the plastic moulding to the metal chassis.  With that removed you can cut and hack at the tanks much more easily. If you are going down that route on a 25, it's worth seeking out Jim Smith-Wright's article on how to improve the chassis (think it's on his P4 New Street site).

 

[9C85]

53 minutes ago, Richard Croft said:

You might find that as speaker technology has moved on theres better speakers which fit inside the model and will save you a lot of work as well as giving better sound.

 

This model has a 25x25x7 megabass speaker under the non fan end where the chassis is a bit lower and the decoder sits across the pcb, this style of speaker gives a bit more bass than some other types of speaker https://www.roads-and-rails.co.uk/collections/most-popular/products/25x25x7mm-square-megabass-speaker-4-ohm

 

The speaker is available as a free upgrade with the decoder if ordered from me.

 

 

Richard

Thanks again Richard and Mark,

 

Richard, I know I keep putting you off, and thank you for your patience, but if it will fit inside my loco without too much plastic surgery then I feel that even I can have a go.

 

I will take the body off my loco this evening and post some photos in order to check if (and where) things will fit.

 

Thanks again,

Stu

[9C85]

 

 

 

These are the photos of my loco as it is now.

 

I was slightly confused by the fact that the 'non-fan end' chassis is lower - I assumed that the space was there for the fan.

 

Since the photos, and given my wrong assumptions, I have put the bodyshell back on the wrong way round.  I will go and swap it back immediately (I even noticed that the cab floors weren't sitting snugly at the buffer beams  but assumed that I had not clipped it back together properly).

 

Makes me wonder if I will be able to put a chip in the correct way 

[9C85]

Thanks for the info.  I am entering negotiations with the finance department 

[tarifa]

Many moons ago I fitted sound and lights to the Bachmann 8 pin 25.  A couple of photos might help.  The picture quality is not good (just rushed off) but they may give you some ideas for your project.

 

1st picture shows the chassis modified to accept a 23mm diameter or 25mm square speaker.

2nd picture shows the square speaker in place.

3rd picture shows a speaker located in the tank, this is how I fitted the speaker.  Back in the day we only had the 23mm speakers.

 

Edited March 15, 2021 by tarifa
Spelling correction

[Phil Bullock]

The loudest and rortiest 25 in our fleet is D5234 with a 23mm round speaker in a Blu-tac housing, Ear defenders required....

Edited March 15, 2021 by Phil Bullock