billtee Posted July 31, 2012 Share Posted July 31, 2012 I have purchased the Bachmann class 55 Deltic with sound chip fitted. Loco goes well except for one thing: The sound does not match the locomotive movement. That is, when I accelerate the locomotive from stop, the loco moves off quietly and smoothly, but the engine revs don't begin until the vehicle is moving quite quickly. I have an idea that the problem is caused by ESU 3.5 sound files being used on a v.4 chip. I took the model down to Howes of Oxford to see if they could 'reblow' the files in a v.4 format, but they do not have "good enough" sound files (their words, not mine!). I have encountered this same problem on other Bachmann sound chipped models, and Howes could reblow them. Can anyone suggest a company who can reblow the Deltic? Many thanks for any suggestions. Bill Link to post Share on other sites More sharing options...
Guest 838rapid Posted July 31, 2012 Share Posted July 31, 2012 There are few places you can send the loco to, The problem with the Deltic sounds is getting the bass for the deep sounds. I would reccomend South West Digital for reblowing it. They do the original sounds for Bachmann but set them to the requirements that Bachmann request. I have had their sounds in my OO deltic and the were better,have now used them for my O Deltic and it operates just as it should. No connection over than a satisfied customer. Link to post Share on other sites More sharing options...
HLT 0109 Posted July 31, 2012 Share Posted July 31, 2012 Bill, Olivias in Sheffield will reblow the Bachmann Deltic. I had mine done some time ago so it is 3.5 version files on a 3.5 version decoder but it may be worth speaking to them if you want an alternative to SWD. Mine certainly revs up well in advance of moving off. Harold. Link to post Share on other sites More sharing options...
billtee Posted August 2, 2012 Author Share Posted August 2, 2012 Sent the chip from Deltic down to SWD and they are putting on their own 'multi-start' sound files which are for v.4 ESU chip, so should be better. I'm not going to get that real deep growl of the Deltic because I would need a MUCH larger speaker and there's no room (is there?) to fit one. I took my Bachmann 25 and 45 down to Howes for a re-blow, and Brian did a fantastic job. They now sound brilliant, especially the little class 25, and i am very pleased with them. Thank you, gentlemen, for your help. Bill Link to post Share on other sites More sharing options...
nimbamoss Posted August 2, 2012 Share Posted August 2, 2012 Hi Bill, You could always fit a 58mm x 22mm bass reflex speaker in the fuel tank area and run in parallel with the standard Bachmann speaker. Takes a bit of work but well worth it. Ian Link to post Share on other sites More sharing options...
billtee Posted August 4, 2012 Author Share Posted August 4, 2012 Received my Deltic sound chip back from South-West-Digital, and I am very, very pleased indeed. I purchased the 'multi-start' version of their Deltic sound files, and I am delighted with it (er, them?). The extra £10 or so is well worth the extra cost, and the chip was returned very promptly indeed. I can thoroughly recommend S-W-D, as a very satisfied customer. All the best, Bill Link to post Share on other sites More sharing options...
billtee Posted August 4, 2012 Author Share Posted August 4, 2012 Nimbamoss, your suggestion re a bass reflex speaker in the Deltic fuel tank sounds like a good idea - I will give it serious consideration. Would I have to use a 4-Ohm speaker or some other value (100 Ohms?) to run in parallel with Bachmann's little speaker? I'm not very technical when it comes to electronics, but I think components in parallel usually HALVE the resistance, don't they? Thank you for your suggestion. All the best, Bill Link to post Share on other sites More sharing options...
nimbamoss Posted August 5, 2012 Share Posted August 5, 2012 HI Bill, If you do a search in this forum I am sure you will find some detailed instructions how to fit the bass reflex in the tanks. http://www.rmweb.co....tion#entry47215 Here's one to start, I used 838Rapid's way op installing. Ian Edited to remove false information, Apologies to Pauiliebanger and Bill. Link to post Share on other sites More sharing options...
pauliebanger Posted August 5, 2012 Share Posted August 5, 2012 HI Bill, If you do in parallel the resistance stays the same only when they go in series does the impedence change. Ian Bill, Ian, Whoops, that's not correct, and could put your decoder in danger. Resistors/impedance in Series is the simple addition of all the values. eg 4 ohms and 8 ohms gives a total of 12 ohms. This will not cause a problem to your Lok V4.0 but perceived volume will be reduced a little. In parallel it's a bit more complicated, since you have to work with the reciprocals. 1/Total Resistance = 1/R1 + 1/R2 + 1/R3 etc where R1, R2, R3 etc are the resistance/inpedence values. When there are only two resistors, you can use a more convenient calculation, called ''Product over Sum'' Total Resistance = (R1 X R2) divided by the total of (R1 plus R2). To use the example above, Total Resistance = (4 x 8 ) divided by (4 + 8 ) = 32 divided by 12 = 2.67 Ohms = disaster! (this is far too low a value). A point to remember: When a number of resistances are connected in parallel, the total resistance will always be lower than the smallest resistor value. Bill refered to parallel 'halving impedence'. That is only correct when there are two resistances of equal value. ie., 2 x 8 Ohms speakers in parallel will produce a total load of 4 Ohms Do not use a 4 Ohms and an 8 Ohms speaker in parallel when using a Lok V4.0, you will almost certainly kill the decoder's output amplifier. Obviously, if the original speaker is 4 Ohms, adding another 4 Ohms speaker in parallel would give only 2 Ohms - even worse. (whilst 2 x 4 Ohms in series would give 8 Ohms total will and be perfectly safe for a Lok V4.0, but not a Lok V3.5). The most efficient load for the lok V4 is 4Ohms, so 2 x 8 Ohms in parallel is the best combination of two speakers. Kind regards, Paul Link to post Share on other sites More sharing options...
billtee Posted August 8, 2012 Author Share Posted August 8, 2012 Thank you Pauliebanger for your explanation of resistances. I have (up to now) only ever used (resistors) in parallel or series, and when in parallel they have always been of the same resistance. I have filed your resistance in parallel explanation away in my "Need to Know" book! Thank you all, Bill Link to post Share on other sites More sharing options...
silverlink Posted August 14, 2012 Share Posted August 14, 2012 Bill, I have a few Deltics on my exhibition layout which I have modified sound wise in fact, I did an article around two years ago for Railway Modeller. You don,t need the speaker in the roof as you fit a bass reflex in the fuel tanks. Before anyone says 'not in the fuel tank' it works fine with no sound drop off what so ever in fact I have to turn the sound down even at a show. Not sure of the ohms rating for the V4 so would suggest contacting Neil Bishop at 'Olivias Trains' as all my sounds came from him. Cheers Ian Link to post Share on other sites More sharing options...
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