PauBass Posted July 24, 2012 Share Posted July 24, 2012 I'm trying to find a couple of 50K pots with center detent for my bass preamp but I can't locate them anywhere. Aguilar seems to sell them but their shipping charges are quite high, $50 and the pots cost $11 I have tried with Allparts, Doctorweek and a few other places but no luck so far....Any ideas, please Thanks in advance for your help! Quote Link to comment Share on other sites More sharing options...
PauBass Posted July 24, 2012 Author Share Posted July 24, 2012 [quote name='Johnston' timestamp='1343138403' post='1745899'] Mouser maybe IIRC the delivery is $15 though. [/quote] Thanks! I have checked with Mouser and they don't have them...I can't find IIRC on the web, do you have a link by any chance, please? Quote Link to comment Share on other sites More sharing options...
PauBass Posted July 24, 2012 Author Share Posted July 24, 2012 [quote name='Johnston' timestamp='1343144601' post='1746015'] IIRC = If I Recall Correctly [/quote] I need to get some sleep...I thought that was another shop! Quote Link to comment Share on other sites More sharing options...
icastle Posted July 24, 2012 Share Posted July 24, 2012 50KΩ is not a preferred value. Try sourcing a 47KΩ and adding 3x1KΩ resistors in series with one of the outer connections if you need to. HTH Quote Link to comment Share on other sites More sharing options...
Big_Stu Posted July 24, 2012 Share Posted July 24, 2012 [quote name='PauBass' timestamp='1343137118' post='1745852'] I'm trying to find a couple of 50K pots with center detent for my bass preamp but I can't locate them anywhere. Aguilar seems to sell them but their shipping charges are quite high, $50 and the pots cost $11 I have tried with Allparts, Doctorweek and a few other places but no luck so far....Any ideas, please Thanks in advance for your help! [/quote]Have you tried WD? they're not on their website at 50k but they may be able to source - and they're UK based. They were recommended to me by JayDee which was as good a recommendation as I could wish for. Quote Link to comment Share on other sites More sharing options...
PauBass Posted July 24, 2012 Author Share Posted July 24, 2012 [quote name='icastle' timestamp='1343160317' post='1746436'] 50KΩ is not a preferred value. Try sourcing a 47KΩ and adding 3x1KΩ resistors in series with one of the outer connections if you need to. HTH [/quote] I don't know much about electronics, the pots on my Bartolini preamp are 50K so that's why I'm looking for those. [quote name='Big_Stu' timestamp='1343163710' post='1746535'] Have you tried WD? they're not on their website at 50k but they may be able to source - and they're UK based. They were recommended to me by JayDee which was as good a recommendation as I could wish for. [/quote] Thanks I'll get in touch with them. Quote Link to comment Share on other sites More sharing options...
flyfisher Posted July 24, 2012 Share Posted July 24, 2012 Farnell has 65 different types of 50k single-turn potentiometers: http://uk.farnell.com/jsp/search/browse.jsp?N=2031+204275+110167408+110190129&Ntk=gensearch&Ntt=potentiometer&Ntx=mode+matchallpartial&No=0&getResults=true&appliedparametrics=true&locale=en_UK&divisionLocale=en_UK&catalogId=&skipManufacturer=false&skipParametricAttributeId=&prevNValues=2031+204275&mm=1002553||,1002571||,&filtersHidden=false&appliedHidden=false&autoApply=false&originalQueryURL=%2Fjsp%2Fsearch%2Fbrowse.jsp%3FN%3D2031%2B204275%26Ntk%3Dgensearch%26Ntt%3Dpotentiometer%26Ntx%3Dmode%2Bmatchallpartial%26No%3D0%26getResults%3Dtrue%26appliedparametrics%3Dtrue%26locale%3Den_UK%26divisionLocale%3Den_UK%26catalogId%3D%26skipManufacturer%3Dfalse%26skipParametricAttributeId%3D%26prevNValues%3D2031%2B204275 Quote Link to comment Share on other sites More sharing options...
icastle Posted July 24, 2012 Share Posted July 24, 2012 [quote name='PauBass' timestamp='1343165259' post='1746567'] I don't know much about electronics, the pots on my Bartolini preamp are 50K so that's why I'm looking for those. [/quote] Ok. Quick crash course for you without the techie jargon just in case you can't get hold of the 50K ones. Resistors come in lots of values but it isn't sensible for a manufacturer to make every possible value. The manufacturers have therefore come up with a set range of values and 50K is an oddity which isn't one of those values (these are called 'preferred values'). The way a pot works is a 'wiper' (connected to the centre contact of the pot) moves around a curved track of carbon and the closer the 'wiper' gets to one end of the track, the lower the resistance gets. The resistance of the entire track (which is between the two outer contacts of the pot) is used to describe the value of the pot. So, in your case - measuring the resistance of the track would equal something close to 50K. The usual trick if you can't get the exact value you're after, is to take the closest lower 'preferred' value (which is 47K in your case) and to add a few resistors to the end of the track, a bit like adding an 'extension'. By doing that, when the pot is set at it's lowest level (and you are making the maximum possible resistance because you're using the entire length of the track) you're adding 3K to the 'track' - so 47K (your pot value) + 3K (your 'extension') = 50K. The other thing to bear in mind is that a pot is never going to be the exact value it is supposed to be - there's a +/- 10% error margin in there - so despite what it says on your 50K pot, it 'could' be anything from 45K to 55K... HTH Quote Link to comment Share on other sites More sharing options...
icastle Posted July 24, 2012 Share Posted July 24, 2012 [quote name='flyfisher' timestamp='1343165836' post='1746573'] Farnell has 65 different types of 50k single-turn potentiometers: [url="http://uk.farnell.com/jsp/search/browse.jsp?N=2031+204275+110167408+110190129&Ntk=gensearch&Ntt=potentiometer&Ntx=mode+matchallpartial&No=0&getResults=true&appliedparametrics=true&locale=en_UK&divisionLocale=en_UK&catalogId=&skipManufacturer=false&skipParametricAttributeId=&prevNValues=2031+204275&mm=1002553||,1002571||,&filtersHidden=false&appliedHidden=false&autoApply=false&originalQueryURL=%2Fjsp%2Fsearch%2Fbrowse.jsp%3FN%3D2031%2B204275%26Ntk%3Dgensearch%26Ntt%3Dpotentiometer%26Ntx%3Dmode%2Bmatchallpartial%26No%3D0%26getResults%3Dtrue%26appliedparametrics%3Dtrue%26locale%3Den_UK%26divisionLocale%3Den_UK%26catalogId%3D%26skipManufacturer%3Dfalse%26skipParametricAttributeId%3D%26prevNValues%3D2031%2B204275"]http://uk.farnell.co...3D2031%2B204275[/url] [/quote] The only panel mount pot they supply with a centre detent is an industrial style one with a 6mm shaft, has a metal film conductor that handles 30VAC and costs £21.75. Quote Link to comment Share on other sites More sharing options...
flyfisher Posted July 24, 2012 Share Posted July 24, 2012 How important is the centre detent? Still, ALPS is a quality manufacturer. Quote Link to comment Share on other sites More sharing options...
PauBass Posted July 24, 2012 Author Share Posted July 24, 2012 [quote name='icastle' timestamp='1343167037' post='1746591'] Ok. Quick crash course for you without the techie jargon just in case you can't get hold of the 50K ones. Resistors come in lots of values but it isn't sensible for a manufacturer to make every possible value. The manufacturers have therefore come up with a set range of values and 50K is an oddity which isn't one of those values (these are called 'preferred values'). The way a pot works is a 'wiper' (connected to the centre contact of the pot) moves around a curved track of carbon and the closer the 'wiper' gets to one end of the track, the lower the resistance gets. The resistance of the entire track (which is between the two outer contacts of the pot) is used to describe the value of the pot. So, in your case - measuring the resistance of the track would equal something close to 50K. The usual trick if you can't get the exact value you're after, is to take the closest lower 'preferred' value (which is 47K in your case) and to add a few resistors to the end of the track, a bit like adding an 'extension'. By doing that, when the pot is set at it's lowest level (and you are making the maximum possible resistance because you're using the entire length of the track) you're adding 3K to the 'track' - so 47K (your pot value) + 3K (your 'extension') = 50K. The other thing to bear in mind is that a pot is never going to be the exact value it is supposed to be - there's a +/- 10% error margin in there - so despite what it says on your 50K pot, it 'could' be anything from 45K to 55K... HTH [/quote] Thanks for all that info!... But I wouldn't know how to do that myself [quote name='icastle' timestamp='1343167551' post='1746599'] The only panel mount pot they supply with a centre detent is an industrial style one with a 6mm shaft, has a metal film conductor that handles 30VAC and costs £21.75. [/quote] It doesn't sound like what I need. [quote name='flyfisher' timestamp='1343167901' post='1746607'] How important is the centre detent? Still, ALPS is a quality manufacturer. [/quote] Quite important since it's a 2 band preamp with cut and boost. Quote Link to comment Share on other sites More sharing options...
icastle Posted July 25, 2012 Share Posted July 25, 2012 [quote name='PauBass' timestamp='1343168741' post='1746622'] Thanks for all that info!... But I wouldn't know how to do that myself [/quote] It's really not much harder than soldering a new pot in. If you don't have any luck finding your 50K pot then shout and I'll draw you a little diagram of how to do it. Quote Link to comment Share on other sites More sharing options...
PauBass Posted August 8, 2012 Author Share Posted August 8, 2012 [quote name='icastle' timestamp='1343238228' post='1747612'] It's really not much harder than soldering a new pot in. If you don't have any luck finding your 50K pot then shout and I'll draw you a little diagram of how to do it. [/quote] Thanks for your help and to everyone that contributed n this thread. I have know found the right pots in the States, couldn't find them anywhere in the UK. Quote Link to comment Share on other sites More sharing options...
JimBobTTD Posted August 10, 2012 Share Posted August 10, 2012 [quote name='PauBass' timestamp='1344408428' post='1763905'] Thanks for your help and to everyone that contributed n this thread. I have know found the right pots in the States, couldn't find them anywhere in the UK. [/quote] Link or more info? There will be someone else looking one day who will find this thread! Quote Link to comment Share on other sites More sharing options...
PauBass Posted August 10, 2012 Author Share Posted August 10, 2012 [quote name='JimBobTTD' timestamp='1344574978' post='1766575'] Link or more info? There will be someone else looking one day who will find this thread! [/quote] Sorry I thought I had added the link to my post Got them from [url="http://www.bestbassgear.com/"]http://www.bestbassgear.com/[/url] It will take a few weeks for them to arrive but they have cost me only £9 including shipping! Quote Link to comment Share on other sites More sharing options...
icastle Posted August 10, 2012 Share Posted August 10, 2012 [quote name='PauBass' timestamp='1344604889' post='1767006'] Sorry I thought I had added the link to my post Got them from [url="http://www.bestbassgear.com/"]http://www.bestbassgear.com/[/url] It will take a few weeks for them to arrive but they have cost me only £9 including shipping! [/quote] Crikey! That's a good price. Quote Link to comment Share on other sites More sharing options...
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