Bass reflex speakers. (now updated)
Posted 29 March 2011 - 18:53
The ingredients! One Bachman 37, a bass-reflex speaker, an ESU soundchip and a spare bogie (optional! don't ask!).
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!
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.
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-
The blue, orange and yellow wires on the PCB marked 1 to 6 will also need unplugging-
The red and black wires seen in the photo are the disconnected speaker wires.
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.
You can either snip off the plastic columns now or drill them out at a later stage.
Using a razor saw remove just enough of the protruding plastic at the insides of the tanks to allow the speaker in.
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.
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.
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.
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.
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.
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.
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.
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.
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!) , 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.
Posted 29 March 2011 - 19:08
On a side note I want one of those locos. I really really do. I must have seen it around four times a day when I was young. One sold on Ebay a week or two ago (brand new) for about Â£44 probably to someone on here. My computer crashed as I put my bid in and gutted I missed out (I'm almost sure I would have won it).
Anyway, thanks for a great thread.
Posted 13 April 2011 - 16:02
Like you I have done a lot of these tanks chops, weights out jobs and with some success. I have recently gone to fitting the bass enhanced 20 x 40 under the fans in 37s in the same space as Bachy speaker would be. Hadn't been a convert until Bryan's latest 37/0 and 37 refurb sounds came out. The concensus amongst the highly critical Airthrey Park crew was that this combination of decoder and speaker is the best 37 yet. Saves a lot of grief too. The only loco I fit bass reflex to is the 60. Verdict seems to be speakers to suit loco racket? Tried bass reflex in a 56 and compromised the top end too much, likewise 58.
Incidentally how many Loksound 4.0s have you guys done yet? I have done a Duff with a 28mm round which is awesome and a Peak (20x40 normal) (both Howes/Bryan) Something has changed. Cannot put finger on it, but would say sound quality has improved a step and they seem louder and clearer than before. Alternative speakers are becoming available too. 28mm and 20x40 already. Bass enhanced/reflex next?
Posted 13 April 2011 - 16:32
Funnily enough the 60 is one of the few loco's we don't use a bass speaker on (the others are mainly 20's and Sprinters) We tended to find the higher pitched sounds suit a well sealed std speaker better! ho hum. Only done one v4 so far, a mates SWD 47. Sounds ok, just need to figure out the new software so I can move the function assignments around. Then we can compare it to a v3.5 in a 'taste' test. DCC Supplies have already announced a 4 Ohm bass-reflex. I hope a 8 ohm works too, cos I've already got two! see you soon, kev.
Posted 12 June 2011 - 08:40
I did mine slightly differently, mine had the cab and directional light switches in the tanks also, here's how I reconnected my lights, as you will know there are six wires going to the switches, after removing the weight in the tanks, I unsoldered the wires from the switches then removed and discarded the switches.
I didn't drill any holes in the underside of the fuel tanks, instead, I removed the bottom completely, of course the downside to that is always making sure that nothing can damage the bass speaker and making sure that no debris is attracted to the speaker.
The switch wires were joined as follows, the two Green or Blue wires are joined together, the two dark Yellow wires are joined together then the two light Yellow coloured wires are joined together, the wires I joined up were all insulated with some 1/16 heat shrink tubing then the loco reassembled.
Sound and lights all working fine.
Posted 16 June 2011 - 11:47
Posted 20 June 2011 - 10:41
Now I've chopped up my shiny new 37 049(!) I've added to and updated the original post at the top of the page with the relevant photo's and details for the version with on/off switches in the tanks. Have fun. Kev.
Hi Kev. Can I just check that 049 gets the same treatment as 410?
Did I miss where you said you got the new speaker?
Cheers, Phil @ 36E
Posted 20 June 2011 - 17:22
Posted 25 June 2011 - 22:27
Only one problem, I have no lights!
Can you tell me which of the numbered tabs on the pcb I need to connect to get the lights back?
Thanks in advance,
Posted 26 June 2011 - 09:27
Posted 26 June 2011 - 12:29
Hi nimbermoss, cool name by the way, are you missing all the lights? As mentioned above you do lose the tail/cab lights by taking out the switches but these can easily be restored by connecting the numbered tabs the wires came out of back together again. 1&2 for no2 end taillights, 3&4 for no1 end taillights and 5&6 for the cab lights. If the headlamp/marker lights are not working are you sure you connected the three end wires back on in the correct order? The red wire should be in the middle with (looking head on toward the buffers) the brown on the left and orange on the right. hth, Kev.
I guess the origins of the user name are quite apparent,
When I removed the pcb for access and then disconnected the 1 thru 6 to remove the switches it didn't occur to me to note numbers down as to where they came from!
The three at each end are correct as I took some pice during their removal but not of the 6 tabs for the switch connection (DOH)!
Thanks for the advice, it does sound great gently thrashing on the rolling road, I have even tried the notching settings mmmm brings back memories of the Santon's at Barnetby and Brocklesby with double tractors at the head......
Posted 19 January 2012 - 19:11
how do i wire it so i get main lights one end, and tail lights the opposite end as normal.
just installed a chip in 37506 sounds great, i have main lights on now and the cab lights, i disconected the wire that connects terminal 1 and 2 together,
please help almost there. cheers rob
Posted 20 January 2012 - 11:42
just waiting to pop the body on a run her, cant wait please help cheers rob
Posted 20 January 2012 - 13:04
jeessee must be me, i have had a lack of sleep , thats the excuse anyhow,
no matter 37506 lives and is thrashing with the amazing zimo multidrive chip,
Posted 20 January 2012 - 18:58
Glad you got it sorted rob, you had me panicking and reaching for 37 033 to pull to bits there!!!!! kev.
well im really sorry about that mate, i cant understand it, as i followed everything you said but at first it didnt work second time it did, ive done loads of instals before but this one didnt go as easy as the others, ill put it down to me being overtired and suffering having a stupid moment,
one thing ive learned is i dont like that bloody switch they have put in, though i understand its beneficial for dc users, which i still am for most my stock, but only till i can dcc everything, however that will take a fair few pay packets and theres other locos i want to buy etc.
ever so sorry for the trouble and i forgot to mention in my earlier post thanks for the excellent tutorial.
cheers rob (holds face in hands embarressed)
Posted 27 January 2012 - 19:10
I am proposing to fit out my 37003 with sound and wondered what connections I would need to complete to make the taillights and cab light independantly controlled from the chip/DCC?
Is there a straight forward way or too much hassle?
The wiring for the lights will require altering to provide separate circuits. Having F button controlled inde tail lights uses up all 4 functions on the decoder. To also have F button controlled Cab lights, either together, or each cab switched separately, will require a second function only decoder, or an ESU 21pin adaptor plate which gives access to a further 2 Aux functions when used with the sound decoder.
Edited by tractor_37260, 27 January 2012 - 19:11 .