Jump to content
 

Bass reflex speakers. (now updated)


kevpeo

Recommended Posts

Sorry for the late reply, I am intending to use the Zimo 21pin which I beleive has more functions free.......anyone familar with that decoder?

 

BB

 

Good choice, the Zimo MX644 is the one you need, about £79, and you don't need to shell out for other decoders or adapters if you want more than 4 functions. The Zimo has 8 'normal' function outputs and 2 low voltage outputs in addition, so 10 in all as standard.

 

You will need to have separate return (negative) feeds from each pair of lamps (remember to fit resistors to protect your LEDs if you wire 'off-board').

 

The rest is done with CVs. If you go for the Class 37 Multi-Drive from Digitrains, it is already set up for Bachmann models to have independant and directional white and red lamps, and directional cab lights. All this uses only the normal lighting F0 and two other F keys, (F7 and F8 from memory). Just as well really when there are so many sounds on board that use up a lot of F keys.

 

And you will have choice of 3 driving styles, 'normal' linear with coasting control, full manual notching, or Thrash drive with coast control, and two sub classes of each, 37/0 and 37/4 each with different horns and radiator fans. That's six permutations all available on one decoder just by changing one CV. (CV265).

 

Bargain!

 

Good luck,

 

Paul

Link to post
Share on other sites

  • 5 months later...

Thanks for the show and tell on DCC sound surgery, much learning gained, many mistakes avoided, particularly for a DCC newbie - I now have one of Bif's chips fitted and I am very satisfied driving up and down, up and down ...

Link to post
Share on other sites

  • 5 months later...

Today I just got started on a '37/0  with the  Legomannbiffo Loksound V4. It's not the first sound conversion I've done (did a Class 55 3 years ago ) but this particular Bachmann had terrible soldering joints - just about  every joint failed just by looking at it,  and wires fell off left, right and centre !! ...and all before everything had been completely documented.

 

Has anyone got a wiring attchment diagram of this type of Class 37 PCB to help me reconstruct the wiring  attachments? It's a late type 21-pin with switches like shown above. 

Link to post
Share on other sites

Hi David. If no one has a suitable photo/diagram for you I'll have to take one to pieces and have a look. But it will not be for a few days, if only you'd asked a couple of days ago! From memory I thought all the wires were ''plug in'', not soldered on the 21 pin PCB, or is that only the ones to the switches? Kev.

Link to post
Share on other sites

Hi Kev, 

 

 M+ve  and -ve , Pickups +ve and -ve,    the plug-on wires (1-6) to the switch in the tank had been documented already before being taken off, however all the soldered joints at the front and back of the PCB (LED lighting)  just fell off later (brittle solder,  I guess). Unfortunately my Class 55 is an earlier model, so it doesn't suit my purpose. I called Bachmann Service from Germany this afternoon  - they said they don't have diagrams (!!) in Britain but will send me a digital photo. 

 

BTW - I take it the tank switches are now redundant as the decoder takes over the switching according to loco direction? David

Link to post
Share on other sites

That’s nice of them David.  At least I won’t have to take mine to bits!  As for the ex-switched outputs, as you say the cab lights are taken over by the decoder, but the taillights remain rubbish. Why they switched to 21 pin decoders but didn’t mod the wiring at the same time is beyond me!!  :banghead:   Kev.

Link to post
Share on other sites

David has had a reply from Bachmann which has produced the goods, so I'll stick it up here for future reference!

 

 

''Thank you for your enquiry. Looking at the PCB with the printed lettering the right way up the wires are:

LH end
 

 

LED-    black
A        brown
+        red cab light
B        orange
LED+  red


Top

1         orange  )
2         orange  ) switch
6         green
M+      orange to motor
R         red pickup

Bottom

3         yellow   ) switch
4         yellow   )
5         green   
M-       brown to motor
L         black pickup

RH end
 

 

A         brown
+         red
B         orange
 
Mit freundlichen Grüßen / Best regards''

It may come in handy for folks.  ;)  HTH, Kev.

Link to post
Share on other sites

  • 3 weeks later...

hi there I have just orderd a dcc sound decoder for a deltic from swd aso orderd a bass reflex speaker for the fuel tanks and I was wondering where do you wire the bass reflex speaker to is it the same wires as the 23mm speaker is attached to? also do you use both the speaker and the reflex speaker im a bit new to this and would like some help as I don't want to do something wrong and blow it up many thanks for any help

 

mike

The most often asked question when exhibiting our layouts is where is it and how do you get it in! Many thanks to Richard Foster at Model Rail and Andy Y for allowing me to reproduce my article from last year here. The following are the steps taken to fit sound and a 58mm x 22mm bass-reflex speaker into the 8 pin socket version of a Bachman 37. This procedure can also be followed to upgrade the factory sound fitted 21 pin 37's, just miss out steps 15 & 16.

Photo 1attachicon.gifphoto 1.JPG

The ingredients! One Bachman 37, a bass-reflex speaker, an ESU soundchip and a spare bogie (optional! don't ask!).

Photo 2attachicon.gifphoto 2.JPG

Firstly remove the six retaining screws, under the red marks , be careful with the ones under the buffers though as they can break off the buffer shanks on the way out. I've done it!

Photo 3attachicon.gifphoto 3.JPG

Unsolder the red and black wires from the pick-ups marked R & L on the PCB (or unplug them on the latest 21 pin versions)and the three wires to the lights, marked in red at each end, but make a note of where they go first. Or just unplug the two pin connector on the really early ones! You can then remove the bogie retaining screw and gently pull the bogie and carden shaft forward and down to release them, trying not to damage the wires though as they pull through the chassis.

Photo 4attachicon.gifphoto 4.JPG

Remove the four short retaining screws, marked in red, to remove the plastic chassis. While the bogie's are out of the chassis, now is a good time to check, adjust, and paint the pickups to make them work and look better.

If your model is the latest version with these switches-

Photo 4aattachicon.gifnew 37 chassis 001.jpg

The blue, orange and yellow wires on the PCB marked 1 to 6 will also need unplugging-

Photo 4battachicon.gifnew 37 chassis 002.jpg

The red and black wires seen in the photo are the disconnected speaker wires.

Photo 5attachicon.gifphoto 5.JPG
or
Photo 5aattachicon.gifnew 37 chassis 003.jpg

Remove the retaining screws that hold the metal weight in and discard all, the weights do come in handy on my work bench though, so I save them.

Photo 6attachicon.gifphoto 6.JPG


You can either snip off the plastic columns now or drill them out at a later stage.

Photo 7attachicon.gifphoto 7.JPG

Using a razor saw remove just enough of the protruding plastic at the insides of the tanks to allow the speaker in.

Photo 8attachicon.gifphoto 8.JPG
Photo 9attachicon.gifphoto 9.JPG

Drill as much of of the the central rib out as possible before snipping and cutting out the remainder. This allows the speaker to sit as low as possible.

Photo 10attachicon.gifphoto 10.JPG

Once the inside of the tanks are cleaned up you need to decide which way round the speaker is going to go in. You'll need a lot of holes in one tank with just two groups of four in the other.

Photo 11attachicon.gifphoto 11.JPG

You may get the holes straighter than me! Its a longer job than just chopping the base of the tanks out, but it does help to protect the delicate speaker.

Photo 12attachicon.gifphoto 12.JPG

The speaker should now squeeze in nicely with the wires sticking out to the side. I also put a sticky pad on the back of the speaker, without removing the second backing paper. This stops any movement of the speaker which can cause distortion.

Photo 13attachicon.gifphoto 13.JPG

The plastic chassis moulding can now be reattached to the motor block, taking care not to trap the speaker wires. At this point I glued a small piece of copperclad sleeper strip with an insulating slot cut into the copper onto the side of the motor. This allows the brown wires from the chip to be soldered or unsoldered from the speaker wires in the future if needed without the need to remove the speaker. The alternative to this is too drill through the chassis block and connect the speaker wires to the SP + and SP- points on the 21 pin chassis PCP.

Photo 14attachicon.gifphoto14.JPG

At this point the speaker wires were cut back and soldered to the copperclad and the chassis reassembled. The red and black pick-up wires can now be reconnected and the chassis given a good run on DC power, just to make sure it all bedded back in nicely with no short circuits. If yours is the latest chassis type that had the switches disconnected you will find that the tail lights and cab lights no longer work. If you wish to reconnect them connect contacts 1&2 together for the tail lights at the no 2 end. 3&4 together for the tail lights at the no 1 end, and 5&6 together for the cab lights.

Photo 15attachicon.gifphoto 15.JPG

Next I fitted a 25mm square piece of thin black plastic-card over the wires at the end furthest from the 8-pin socket. This tidies the wires out of the way and makes doubly sure the chip cannot touch any part of the metal chassis block. Another sticky pad is used to hold the chip in place.

Photo 16attachicon.gifphoto 16.JPG

The chip fitted to the sticky pad with the 23mm standard speaker still attached. If its a 21 pin chip the speaker will be a 40mm x 20mm rectangular one. Make sure the chip is clear of the contacts for the cab lights.

Photo 17attachicon.gifphoto 17.JPG

The wires are unsoldered from the standard speaker and attached to the copperclad strip. As you can see I use blue-tack to tidy up the wires and make sure they don't get where they shouldn't be. I also cut any exposed core from the violet wire and cover the end with insulating tape.

Now the chassis is ready for its DCC test run (thrash!) wink.gif , after checking it first on the programming track of course! Hope this is of some help, quite a few said they'd used it when it was published! Kev.

Link to post
Share on other sites

hi there I have just orderd a dcc sound decoder for a deltic from swd aso orderd a bass reflex speaker for the fuel tanks and I was wondering where do you wire the bass reflex speaker to is it the same wires as the 23mm speaker is attached to? also do you use both the speaker and the reflex speaker im a bit new to this and would like some help as I don't want to do something wrong and blow it up many thanks for any help

 

mike

 

The bass refex speaker replaces the 23mm one supplied. You could wire the two speakers in series but the volume will be reduced. Not good on  a Deltic!

 

I have assumed that since the chip was supplied by SWD that it is a Loksound and that it is a version 4 decoder with a 4 ohm speaker attached. If it is 21 pin the speaker will be attached to the PCB in the loco. I have also assumed that the bass reflex speaker is also 4 ohms.

 

If any of these assumptions are incorrect please return to this thread and ask again.

Link to post
Share on other sites

  • 1 month later...

hi just to say that i have just finished one of my sound class 37 using your advice and photos , and the difference is  realy good much better than before, now i have to do my other class,  37 with the on and off switches underneath, well done for a very good advice

Link to post
Share on other sites

I am asking if you can help me  I have converted one class 37 with sound as per your instructions, and  the sound has increased well, so I did my second class 37  the same but the sound has not increased at all this is the one with the switches under the fuel tanks. the speaker is the same type as on the first class 37. I have checked the cv setting and it is 63 with vol of  64. have I done something wrong, if you can help me

Link to post
Share on other sites

From that description it sounds like a v4 decoder with a 100ohm speaker. The v3.5 decoders used 100 ohm ones and had a max volume of 64 in cv 63. The v4 decoder uses a 4 ohm speaker and has a max volume of 192 in cv63. Check the ohm value on the back of the speaker. If you fit a v4 with the wrong speaker it will be quiet. If you fit a v3.5 with the wrong speaker, don't!!!!!!!!! hth, kev.

Link to post
Share on other sites

From that description it sounds like a v4 decoder with a 100ohm speaker. The v3.5 decoders used 100 ohm ones and had a max volume of 64 in cv 63. The v4 decoder uses a 4 ohm speaker and has a max volume of 192 in cv63. Check the ohm value on the back of the speaker. If you fit a v4 with the wrong speaker it will be quiet. If you fit a v3.5 with the wrong speaker, don't!!!!!!!!! hth, kev.

many thanks for reply checked the old speaker and was a 4 ohm speaker my mistake as I thought the class 37,s decoder was a v3,5 so I fitted a 100 ohm. so now waiting for a bass reflex  4 ohm speaker to fitt

Link to post
Share on other sites

  • 11 months later...
  • RMweb Gold

Just to drop in on this topic, I'm currently working with Paul Chetter to mod a class 37 (are you reading this Richard?) setting up the lights etc and the MX644D decoder to provide directional cab lights on F19 and directional red tail lights on F20. The cab lights will also auto extinguish when the loco moves. Speaker will be an ABS-229-RC in the tanks.

 

Some details still to sort out but once complete I'll post some photos and list of CVs etc

Link to post
Share on other sites

Sounds interesting. As an aside I've just fitted another one for a friend. I thought I'd count up the discarded weights to see how many I'd done. The total - 22!!

Not including rebuilds to fit v4/4ohm replacements. I should charge! Kev.

Link to post
Share on other sites

  • RMweb Gold

Still waiting for  new fine tip for my soldering iron to add the extra function wires to the PCB, but one update is that I had to cut down the 229 speaker as I didn't realise it was too tall for the loco, I split it at the original join then cut 4mm off the back (back to the chamfer) then after applying lots of Plastic Magic I squeezed the two halves together in a vice, this made a good seal :)

Link to post
Share on other sites

Sounds interesting. As an aside I've just fitted another one for a friend. I thought I'd count up the discarded weights to see how many I'd done. The total - 22!!

Not including rebuilds to fit v4/4ohm replacements. I should charge! Kev.

 

Kev,

 

At your current rates, I've got a few I can send for you to pass the time with. Lol

 

Paul

Link to post
Share on other sites

  • RMweb Gold

OK, here's the details of the mods to a Bachmann class 37 to provide F button switch-able cab lights and red tail lights (both directional) when fitting a Zimo MX644D sound chip.

 

This is useful if you need to junk the under tank switches when fitting a bass reflex speaker as described earlier in this topic, or if you just want to improve the functionality under DCC.

 

First disconnect the wires from the pads marked 1 to 6 on the pcb. Next unsolder the black wire that runs from the separate cab lighting pcb at the #1 end.

 

Now using a new bit of wire connect pads 5 and 6 together, this makes the rear (#2 end) cab light on all the time, then solder two wires (I used red) from pad 2 to pin 4 of the 21 pin connector on the pcb and from pad 3 to pin 13. I used a very fine cone pointed bit in my soldering iron and an Optivisor so I could see what I was doing! Extreme care is needed to ensure nothing is shorting on the PCB.

 

Finally I soldered a black wire to pin 14 and joined it to the black wire from the #1 end cab lighting pcb.

 

post-6717-0-06709900-1400483133.png

 

Note in the above the extra wires are attached to the decoder, I decided that it would be best to solder to the Bachmann PCB as stuffing up a 90 quid chip didn't appeal :lol:

 

Here's a photo of the PCB following the mods

 

post-6717-0-38984900-1400483153_thumb.jpg

 

Now for the CVs

 

to remap the four function outputs that we have connected to the lights:

 

cv430 = 21 - F21 for the cab lights

cv432 = 2

cv434 = 1

 

cv436 = 20 - F20 for the tail lights

cv438 = 4

cv440 = 3

 

and for extra finesse cv 127 and 128 to 60 makes the cab lights extinguish when the loco moves :)

 

Thanks to Paul Chetter for helping me with the cvs etc. I'm going to open up my LMS10000 to see if the same arrangement cab be made :)

Link to post
Share on other sites

  • RMweb Gold

Another update - I noticed that Paul had originally used F8 for the cab lights (should have checked this first!) so:
 
CV430, 432 and 434 back to 0
 
CV42 =12
CV127 = 62
CV128 = 61
 
gives the directional cab lighting with the auto extinguish when moving on F8 instead of F21 :)
 
thanks again Paul for your assistance

Link to post
Share on other sites

  • 4 months later...

Hi Redgate, and all,

 

I'be been following this and a couple of other threads with interest as I'm about to rehash my own Bachy 37, probably with Biffo's project, or maybe PaulieBangers, but I would like some advice re soldering.

 

I have an Antex CS 18 which has served me quite well, with both needle and wedge tips, and I'm reasonably ok with most stuff (including SMD LEDs) but wonder what kit you'd recommend for connections to the motherboard as per your last photo above.

 

My Bachy has the same motherboard and your wiring looks very neat!

 

Regards,

 

Alan

Link to post
Share on other sites

Archived

This topic is now archived and is closed to further replies.


×
×
  • Create New...