legomanbiffo

Does this mean I have to record a 380 now.....?! I suspect the majority of sounds will be the same as a 350 though, which I've done already. Anyone know of any audible differences?

Bif

I wouldn't normally announce such things here, but as the question was asked in the thread I will; my Ruston 37 is now ready.

Dave,

You've guilt-tripped me into picking up the Ruston project again! I had some spare time today and made quite a bit of progress. Still a little way to go but I've broken the back of it now.

Bif

I'm afraid not Dave. As well as the day job I've been doing the APT-E for Rapido and the 68 for Dapol, in between recording sessions and something has to give. The Ruston recordings are not mine and weren't made with DCC sound in mind, and have been harder work than I anticipated.

Bif

Hello Gents,

 

Are you going to Perth this year? I missed Glasgow sadly.

 

Regards

 

Roy

Yes we are Roy. I will be doing the sound seminar again. I'm open to suggestions on what to talk about this year (within the subject of DCC Sound of course).

Bif

Anyone know where we can record sounds for an APTe?????

Relax Charlie, it's under control :-)

Not quite ready yet Dave, sorry. Shouldn't be too long now though, it's aproximately half-finished.

That low-profile chamber is more suited to the other type of Bachmann speaker fit. You shouldn't need it here - try the glue / Blu-Tac first.

Bif

Sandy,

Your speaker fit wasn't the one I had visualised so different advice applies.

In this configuration the body of the loco is acting as the speaker enclosure. The success of such a configuration depends upon all of the sound radiating from the front of the cone going out through the radiator grille, and all of the sound raditing from the back of the cone staying inside the loco. Any leakage from the front of the cone into the loco body will defeat this, and Bachmann's speaker mount is inherently leaky.

To fix this, remove the speaker and the plastic plate it's attached to. Apply Evo-Stik or Blu-Tac all around the plate (where it meets the roof) and refit. Block any remaining gaps you can see with more glue or Blu-Tac. The interface between roof and plate must be airtight. Then carefully apply a very thin bead of glue or very thinly rolled Blu-Tac around the speaker cone and refit to the plate. Don't apply so much that movement of the speaker cone is impeded. Again the interface between speaker and plate must be airtight.

That's all there is to it. Louder, fuller sound for little or no expense.

Bif

A loudspeaker needs to be in airtight box for best results. Whilst you can craft these out of plasticard this is often tricky in Bachmann locos as sound is something of an afterthought for them. This is where blu-tac comes into its own; just use it to help you form an airtight chamber behind the speaker cone using the recess in the top of the Bachmann chassis. The bigger you can make the chamber the better. Don't obstruct the free movement of the cone and make sure no wires can touch it or they will rattle and sound awful. You'll gain 40-50% in volume and it will sound a lot less tinny if you get it right.

Volume control (CV63) is minimum 0, maximum 64 on the v3.5, but maximum 192 on the v4. That is one easy way to tell which chip you have; set the volume to 64 and listen, then set to 192 and listen again. If it gets louder it's a v4. If it stays the same it's a v3.5. Another way is to see what's written on the speaker. If you can see 100 it's probably a v3.5, whereas 4 is likely to be a v4.

Bif

The question posed as we packed up at Warley was quite straightforward; Charlie, do you need my demo locos for any more shows before Stafford? Answer from Charlie: No.

In that case I'll take them all home for maintenance / updating with the latest versions / playing trains over Christmas. You'd have thought he'd be able to think 7 days ahead. Mind you he's knocking on a bit now and you have to make allowances :-)

Bif (hard at work doing his 'real' job this weekend and not just playing trains) :-)

Legoman is now ready for his trip to Perth! He's just waiting for his hat to be finished.

Apologies, I didn't spot big Dave Adam's post. All of my sounds that were originally created for the v3.5 chip are still available as reblows. When v4 came along it became clear that it was not straightforward to backdate the sophisticated v4 projects to load onto the v3.5 chip, plus there was the issue of space (the v3.5 having only half the memory of the v4). I decided that my time was better spent creating better v4 projects instead of 'dumbing them down' to fit on 'old' chips. In short, everything I do is available on v4 but only the earlier projects are available on v3.5. There are quite a few of these early projects though. A full list is available on request.

Hope this helps,

Bif

I won't repeat the joke about the Grand Canyon being started by a Scotsman (or Yorkshireman) who dropped 50p in a ditch :-)

My 37 sounds use the full four minutes of space so they will only fit onto a v4 chip unfortunately, but thanks for the recommendation Phaeton.

It sounds like your enclosure might not be completely airtight. From experience of building four I found that the slightest leak made a big difference. Check seams and corners carefully and apply extra liquid-poly or sealant if necessary. The best way to check is to put the reflex port to your mouth and gently apply breath pressure and see if it leaks away. Gentle breath pressure in and out should move the speaker cone up and down. If it doesn't move very much, or not at all, you probably have a leak. You can check where air is leaking by dampening the back of your fingers and feeling all round for cold air whilst you blow gently into the reflex tube. If the model is reassembled it's difficult to get a seal around the hole with your mouth so put a short length of tube (eg the middle of a ballpoint pen) into the hole and seal all around it with blu-tac to try. This all sounds a bit Heath-Robinson but believe me it does work.

Those coaches are shaping up really nicely. It's great to see someone taking the initiative and producing something completely new.

I don't know if it's of interest but I have a full set of recordings of a Class 442, made at Railcare Wolverton a couple of years ago. I haven't done anything with them to date as there was no model to the best of my knowledge, but if you were after a DCC sound chip let me know...

Bif

I love the synchronised smoke, very nice.

Thanks Bill. That might be worth a try too. I know that some people have managed to fit a bass speaker between the bogies, which really appeals. The only problem is that I don't want to destroy the superb underframe detail on my 26s/27s. Some action is definitely needed though, as I'm not happy with the current sound. It sounds much too "tinnie" to my ears.

I will shortly be releasing a resin part to make this job much easier. The part will replace the centre moulding of the Heljan tanks and incorporate a sealed chamber for a 20x40 rectangular speaker. The tank-sides will then be a simple clip-fit onto the outside, so none of your detail will be lost. Experience shows that this configuration sounds infinitely better than unsealed speakers in the roof space facing up. There will be versions for the 26, 27 and 33. In the fullness of time I'll see what can be done with the locos that have had their boiler water tanks removed.

BIf

V3.5 chips use 100 ohm speakers and V4's use 4 ohm ones, so one way to tell is by the number printed on the speaker (ie 100 or 4).

Another way to tell is as follows;

Set the master volume control (CV63) to 64 and see how loud the sounds are. Then set the volume to 192 and try the sounds again. If they are louder you have a v4. If they stay the same you have a v3.5.

CV63 on the v3.5 can be set to any value from 0 (minimum volume) to 64 (maximum)

CV63 on the v4 can be set to any value from 0 (minimum volume) to 192 (maximum)

Bif

My lawyers have been informed :-)

Bif

Jamie,

You can hear them in our 7mm demo loco which often has people grinning so something must be right. All of the 4mm ones I did were a pal's so I don't actually have one in 4mm to demo.

Bif

In this one I didn't remove the entire tanks but in later ones (as the method matured) I removed most of them leaving only the cosmetic sides and the ends. To an extent it's the end result that's important, not how you get there. The end result should be a big sealed box with a long tube to the outside air.

Bif

I had two opportunities to photograph the APT-P in service. The first time at Hartshill we didn't hear it coming and it was going so fast the shot was completely missed. A couple of years later I took another shot of it at Bletchley with no film in the camera.

I also dropped a Mamiya 645 from my backpack onto the pavement and miraculously the only damage was to the skylight filter which hit the ground first. I can still remember the gasps from the onlookers.

In the days when you sent your slides off to Kodak to get processed I lost a complete film in the post. Glorious summer shots taken in NSE days at West Drayton. I got about three shots that day from the next film but the loss has scarred me ever since.

Whatever you do in life, you have to learn all the different ways of cocking-up first.

This article details a loudspeaker design which will significantly improve the sound from your Bachmann Deltic regardless of whose version of Deltic sounds you use (mine, Howes, SWD etc). Of the four different speaker designs I tried, this one performed the best by some margin. Photographs of the prototype design follow the text. The article is offered in good faith for the common good. No responsibility is accepted if you destroy your model trying!

Aim;

To construct an airtight chamber in the underframe fuel tank area of the Bachmann Deltic, with a long reflex tube, open to the air at one end, and using the drive unit from a bass reflex speaker. The reflex tube acts like an organ pipe; resonating at, and reinforcing the lower frequencies that are needed to produce a convincing Deltic sound. In the finished article, the open end of the tube and the loudspeaker drive unit will be at the same end of the loco, such that the distance the sound has to travel to the outside air is as large as possible.

You will need;

A length of Evergreen StripStyrene number 258 (rectangular tube 4.8 x 7.9mm / 0.187 x 0.312”) or similar

Some plasticard sheet, 30 thou or thereabouts for the bottom (next to the track), and something thinner for the top (next to the motor)

A 21 x 57 x 9mm bass reflex speaker

Method;

1. Read the method in full before starting work!
2. Remove the body, desolder the connections to the pickups at both ends, remove the bogie screws and drop the bogies.
3. Unclip the underframe moulding and set the casting to one side.
4. Use a disc cutter in a dremel to carefully cut out the central section of the underframe, leaving the two ends and the cosmetic fuel tank sides in place. Tidy up with a file and sandpaper so that the long internal sides are completely flat (you’ll need all the width you can get at this stage) .
5. Cut a piece of the rectangular  tube section to the length of the tanks plus 10mm or so initially. Make a flush cap for one end and glue in place, then cut the tube to the match the overall length of the tanks.  Make sure the cap is airtight. In the finished article one end of the tube will be open to the air and visible on one side of the loco, but painted black will be largely unnoticeable.
6. Take the bass reflex speaker and using a razor saw, cut off the end with the hole such that the length is reduced to around 44mm long. The actual length is not critical, but it looks better if you keep it symmetrical. Carefully split the speaker enclosure in half along the seam and discard the back. The drive unit remains in place in the other half in the final design.
7. Carry out a dry run and see if the tube and the remaining speaker  assembly will fit side by side in the tanks. Remove plastic carefully until they will. It is quite a tight fit.
8. Take the underframe moulding and place it the right way up on the bench. Use the thinner plasticard to construct a ‘lid’ for the tanks. It needs to be completely airtight, and must not protrude upwards too far or you won’t be able to clip the moulding back onto the casting. Carry out a dry run after glueing to make sure you can clip it back on before leaving things to dry.
9. Loosely fit thetube section into the tanks along one side and mark a rectangular hole in its side, at the same end as the cap. The hole must be open to the inside of the sealed chamber and approximately the same size as the cross-sectional area of the tube (it should be around 3mm x 6mm). Only cut into the side of the tube, not the top or bottom.
10. Desolder the red and black wires from the speaker and carefully pull them away from the glue at the end of the speaker. Remove any residual glue and sand the ends flat in readiness for reconstruction. Replace the speaker wires with thinner ones of sufficient length to run back to the chip.
11. Place the reflex tube and speaker assembly side by side such that the open end of the tube is at the same end of the loco as the loudspeaker drive unit. Drill two tiny holes in the ‘lid’ of the enclosure and pass the speaker wires through. Glue tube and speaker in place and use a square across the bottom to ensure they remain flush whilst drying.
12. Gently pull the speaker wires through so there isn’t too much slack inside the chamber and nothing is touching the speaker cone. Use Evo Stik or something similar to seal around the speaker wires where they pass through the ‘lid’, to make sure the holes are airtight.
13. Once dry, close any remaining gaps at the speaker end of the tank assembly using plasticard or filler, such that the finished enclosure can be completely airtight.
12. Using the thicker plasticard, cut out a rectangle to form the final part of the sealed chamber and glue in place, taking care not to obstruct the hole cut in the reflex tube. Use filler to block any remaining holes in the completed enclosure and tidy up cosmetically.
13. When dry, confirm that the enclosure is completely airtight by sealing your lips around the open end of the reflex tube and gently sucking and blowing. If the speaker cone moves up and down significantly then all is well. If not, seek out and fill any leaks (dampen the backs of your fingers and feel for cold air around the seams etc whilst blowing into the reflex tube).
14. Paint the underframe assembly including the inside of the reflex tube where it will be seen, allow to dry, then reassemble and test.

The overall concept. The reflex tube is on the right, with the hole at the corner furthest from the camera

A view from the opposite end showing the drive unit and reflex hole

A close-up of the reflex hole, which is not noticeable in normal operation