mydeadblues Posted December 22, 2010 Share Posted December 22, 2010 So I just purchased a used reissue Epiphone Rivoli and it's pretty noisy. It hums when I plug it into my bass amp and stops humming when I roll the volume knob back. I know it's not the amp because I've tried other basses and I've never had this problem. I was also trying to record with the Rivoli but it makes a lot of noise on my computer too. Would it be the input jack or maybe the pots? Any feedback would be appreciated. Thank you! Link to comment Share on other sites More sharing options...
RaSTuS Posted December 22, 2010 Share Posted December 22, 2010 Would it be the input jack or maybe the pots? It could be either, or does the hum lessen when you hold the strings, if so, it may also be a grounding issue. One of the first mods most people on this forum do is to upgrade the pots to CTS pots, and the switch and jack to switchcraft, probably the weakest area for Epi guitars are the electronics. Link to comment Share on other sites More sharing options...
bigneil Posted December 22, 2010 Share Posted December 22, 2010 It could be either, or does the hum lessen when you hold the strings, if so, it may also be a grounding issue. One of the first mods most people on this forum do is to upgrade the pots to CTS pots, and the switch and jack to switchcraft, probably the weakest area for Epi guitars are the electronics. +1 Link to comment Share on other sites More sharing options...
mydeadblues Posted December 22, 2010 Author Share Posted December 22, 2010 I'm pretty comfortable switching the jack but I am pretty clueless with the pots haha. Should I have my guitar tech do it when I get it set up? Or is there a good how to somewhere on this forum or around the web, I do like learning how to do these things so I don't have to rely on techs. Link to comment Share on other sites More sharing options...
mydeadblues Posted December 22, 2010 Author Share Posted December 22, 2010 Oh and It doesn't lessen when I hold the strings. Link to comment Share on other sites More sharing options...
RaSTuS Posted December 22, 2010 Share Posted December 22, 2010 I'm pretty comfortable switching the jack but I am pretty clueless with the pots haha. Should I have my guitar tech do it when I get it set up? Or is there a good how to somewhere on this forum or around the web, I do like learning how to do these things so I don't have to rely on techs. There's a permanent DIY thread at the top of the Epi Lounge section, it has heaps of tips and info for most any mod or repair you're ever likely to encounter, it's a great resource compiled by member 'animalfarm', kudos to him. It's not that difficult job, as long as you can wield a soldering iron it should be reasonably painless. If you're worried about it, take a few pics first so you have a reference point to return to. Link to comment Share on other sites More sharing options...
animalfarm Posted December 22, 2010 Share Posted December 22, 2010 I'm pretty comfortable switching the jack but I am pretty clueless with the pots. Should I have my guitar tech do it when I get it set up? Or is there a good how to somewhere on this forum or around the web, I do like learning how to do these things so I don't have to rely on techs. There's a permanent DIY thread at the top of the Epi Lounge section, it has heaps of tips and info for most any mod or repair you're ever likely to encounter, it's a great resource compiled by member 'animalfarm', "" to him. I modded your quote! RaSTuS - Thx for the mention, but also KUDOS to all who have helped contribute ideas and threads for the "Do-it-Yourself! Ok, "M.D.B" (well, it's better that Abbreviating it to "dead"....) - Touch Strings, no change. Sounds like Bridge/Tailpiece ground is ok. Is your output jack located on TOP or Side? If on side, remove screws, gently pull out to look at the 2 wires connected to it. Sometimes the jack gets loose, spins, and VIOLA!, broken wire or wire with barely ANY strands connected. Also possible Jack is corroded internally - would cause cr@ppy connections/ground. The inside of the jack barrel IS the ground connection. To clean, Wrap FINE grit sandpaper around a pencil/stick, push into jack while turning, then spin pencil/sandpaper around a few times to clean inside of barrel and the jack tip. There ARE other things, but I'll wait for your response, and perhaps one of our BASS PLAYAs can chime in, too! I found a RIVOLI SCHEMATIC in the DIY Sticky, looks like your Bass has a "Bass Boost" Pushbutton near the bridge? Is THIS what you have? http://www.youtube.com/watch?v=UL3jtA8JdjU Link to comment Share on other sites More sharing options...
RobinTheHood Posted December 22, 2010 Share Posted December 22, 2010 Sounds like a bad wire to me...or a bad boost switch. I dont recall any of my potentiometers or input jacks ever making a consistent buzzing sound. They tend to crackle and pop when they are dirty or going bad. Now, a bad or loose wire to the input jack will cause buzzing similar to a 60 cycle hum, for sure. I assume there is no access panel on this bass, so the hard part is going to be getting at the wiring. This is a used bass, correct? Its possible that someone else did some work to it that just isnt holding up. Another thing to check for would be cold solder joints...especially on the backs of the pots. Potentiometers are particularily difficult to solder and result in cold solder joints if done incorrectly. If any of the solder is a dull gray in color , it needs to be redone. Link to comment Share on other sites More sharing options...
animalfarm Posted December 25, 2010 Share Posted December 25, 2010 BUMP! Senor Blues, we HAVEN'T forgotten! DO realize the time of year, so you may be busy! interested in update when time permits.... Link to comment Share on other sites More sharing options...
mydeadblues Posted January 6, 2011 Author Share Posted January 6, 2011 Sorry for the delay guys! I actually took it to get set up with Rotosound flatwound strings and asked my tech if he could figure out the humming problem as well. I just got it back yesterday and it still hums a bit but significantly less. He said he sprayed the pots down with contact cleaner. It's a hollow body bass so I guess it's prone to feedback hum especially when the baritone switch is activated. I'm also playing in a rather small room at the moment so being close to my amp is a likely culprit. When I turn away from the amp the hum lessens a bit. I plan to change the input jack eventually to see if that helps. I'll also see if it's quieter next time I try recording. But I'm content, at least for now... I just got it back so it could be that I'm just excited to play it and I am in the puppy love state as it is still a new instrument to me haha. Thanks for all the input guys! Everyone on this forum is always such a great help! Link to comment Share on other sites More sharing options...
mydeadblues Posted January 6, 2011 Author Share Posted January 6, 2011 I modded your quote! RaSTuS - Thx for the mention, but also KUDOS to all who have helped contribute ideas and threads for the "Do-it-Yourself! Ok, "M.D.B" (well, it's better that Abbreviating it to "dead"....) - Touch Strings, no change. Sounds like Bridge/Tailpiece ground is ok. Is your output jack located on TOP or Side? If on side, remove screws, gently pull out to look at the 2 wires connected to it. Sometimes the jack gets loose, spins, and VIOLA!, broken wire or wire with barely ANY strands connected. Also possible Jack is corroded internally - would cause cr@ppy connections/ground. The inside of the jack barrel IS the ground connection. To clean, Wrap FINE grit sandpaper around a pencil/stick, push into jack while turning, then spin pencil/sandpaper around a few times to clean inside of barrel and the jack tip. There ARE other things, but I'll wait for your response, and perhaps one of our BASS PLAYAs can chime in, too! I found a RIVOLI SCHEMATIC in the DIY Sticky, looks like your Bass has a "Bass Boost" Pushbutton near the bridge? Is THIS what you have? http://www.youtube.com/watch?v=UL3jtA8JdjU Oh ya, and yes that is my bass! I will give the output jack trick a try, but I think I might order a new one from Musicians Friend. I love how they don't have a minimum for shipping right now, I keep buying strings, jacks, and other inexpensive items :). Link to comment Share on other sites More sharing options...
mydeadblues Posted January 7, 2011 Author Share Posted January 7, 2011 Are these the pots everyone usually upgrades to? If not, can you please send me a link. :) Also, what's the difference between 500k, 250k, and 1 meg ohms? Which would I need for a volume controller on the Rivoli bass? http://accessories.musiciansfriend.com/product/DiMarzio-250K-Custom-Taper-Split-Shaft-Pot?sku=364665 Thank you! Link to comment Share on other sites More sharing options...
animalfarm Posted January 7, 2011 Share Posted January 7, 2011 1. Are these the pots everyone usually upgrades to? If not, can you please send me a link. :) http://accessories.musiciansfriend.com/product/DiMarzio-250K-Custom-Taper-Split-Shaft-Pot?sku=364665 2. Also, what's the difference between 500k, 250k, and 1 meg ohms? 3. Which would I need for a volume controller on the Rivoli bass? Other than #1, ALL Answers were obtained from the reference links in the EPI LOUNGE "Do-it-Yourself Thread". I mention this just to get folks used to the idea of using it. A little research, and - "Badda Boom, Badda Bing" - ANSWERS!!! #1 - The choice of Potentiometer Brand is up to you, will depend on the $$$ you wish to spend. Alpha and CTS are very popular, Alpha is the less expensive of the two. I've always used Alpha, I'm a cheap-@zz, and have never had problems. Alpha Pots also have the "Coarse Splines" on top that fit the "Import" knobs that EPI uses. Do not know what length you would need, you'll have to actually measure the shaft to confirm. I buy mine from guitarfetish: http://www.guitarfetish.com/Guitar-Electrical-Components_c_14.html #2 - ***POTENTIOMETER and CAPACITOR INFO: "Frequently Asked Questions" http://www.hoaglandbrothers.com/pages/FAQ.htm "Pot Values and HOW they affect TONE" http://www.stewmac.com/freeinfo/Electronics/Pots/w101-controlpots.html #3 - ***CROSS-REFERENCE/COMPARISON GUIDES: VINTAGE GUITAR/BASSES/AMP/EFFECTS Specs and Data (Many, many, many!) Rivoli Bass: http://www.vintageguitars.org.uk/epiphoneRivoli.php Now, it mentions that Gibson's Equivalent to the Rivoli was the "EB-2 Bass". Soooooo, Let's head off to the EB-2 Schematic to see what pots were used.... ***GUITAR WIRING DIAGRAMS: "GIBSON and EPIPHONE Instrument and Amplifier Schematic Library" http://www.gibson.com/Files/schematics/EB2.PDF And there you have it - 500K for Volume, 250K for Tone. Hope this helped! Link to comment Share on other sites More sharing options...
mydeadblues Posted January 7, 2011 Author Share Posted January 7, 2011 Thanks animalfarm, Very helpful! Link to comment Share on other sites More sharing options...
mydeadblues Posted February 22, 2011 Author Share Posted February 22, 2011 So the Rivoli's been in the shop for the last 2 weeks. I installed a new output jack a month back and it didn't help so I brought it to the shop so they could check the wiring and pots. They said it was fixed so I picked it up and brought it home. When I played the bass it was dead silent with no extra noise/humming but as I began to roll the volume knob down, the noise came back . I brought it back to the shop and they just installed a new volume pot but they're still getting the same problem (silent when the volume pot is all the way up or all the way down but noisy anywhere in between). Any ideas on what would make this happen?? This is what I brought them last month Link to comment Share on other sites More sharing options...
mydeadblues Posted February 26, 2011 Author Share Posted February 26, 2011 Anyone? So the Rivoli's been in the shop for the last 2 weeks. I installed a new output jack a month back and it didn't help so I brought it to the shop so they could check the wiring and pots. They said it was fixed so I picked it up and brought it home. When I played the bass it was dead silent with no extra noise/humming but as I began to roll the volume knob down, the noise came back . I brought it back to the shop and they just installed a new volume pot but they're still getting the same problem (silent when the volume pot is all the way up or all the way down but noisy anywhere in between). Any ideas on what would make this happen?? This is what I brought them last month Link to comment Share on other sites More sharing options...
mydeadblues Posted March 22, 2011 Author Share Posted March 22, 2011 I just brought it to another guitar tech and he replaced both pots, the output jack (again), and rewired it back to factory schematics. According to him there were some extra unnecessary wires I guess the previous tech put in that differed from the original wiring diagram. I just went in there today hoping to pick it up but the humm is still there! He said he's going to replace the resistor but he can't figure out what is going on with it. The volume pot works better now; the volume is more gradual but the humm increases as the volume increases. It's noisy the entire way through now (unlike before when at full volume the humm diminished). The tech initially thought it was some kind of ground issue but now we're both unsure what it could be. I think the only variables left to eliminate are the resistor, baritone push button, and the pickup but I could be wrong . Any more help would be appreciated! Thank you! Link to comment Share on other sites More sharing options...
RaSTuS Posted March 22, 2011 Share Posted March 22, 2011 Considering the electronics have been swapped out twice seems to point to a problem pickup IMO. Link to comment Share on other sites More sharing options...
mydeadblues Posted March 22, 2011 Author Share Posted March 22, 2011 Considering the electronics have been swapped out twice seems to point to a problem pickup IMO. Ya I just bought a dimarzio dp120 bass humbucker off ebay so hopefully that does the trick. This bass is beginning to look like a money pit ! Link to comment Share on other sites More sharing options...
mydeadblues Posted March 23, 2011 Author Share Posted March 23, 2011 I just found this schematic on another site, it looks different than the one provided by gibson. Is the circuitry the same though? Also, what are the .02 referring to? Thanks guys! Link to comment Share on other sites More sharing options...
RaSTuS Posted March 23, 2011 Share Posted March 23, 2011 I just found this schematic on another site, it looks different than the one provided by gibson. Is the circuitry the same though? Also, what are the .02 referring to? Thanks guys! The .02 refers to .022uf capacitors, as for the differences, I can't say, I haven't seen the other diagram you're referring to. EDIT: my bad, just scrolled up and saw it, sorry but I can't read the first one, my failing eyes can't make it out clearly. Link to comment Share on other sites More sharing options...
mydeadblues Posted March 23, 2011 Author Share Posted March 23, 2011 The .02 refers to .022uf capacitors, as for the differences, I can't say, I haven't seen the other diagram you're referring to. EDIT: my bad, just scrolled up and saw it, sorry but I can't read the first one, my failing eyes can't make it out clearly. Is there somewhere in particular I should get these capacitors from other than like a radio shack? Also, is there a suggested voltage these should be at? I've never really done circuitry work before so I just want to make sure I have the right parts. Thank you! Link to comment Share on other sites More sharing options...
RaSTuS Posted March 24, 2011 Share Posted March 24, 2011 Is there somewhere in particular I should get these capacitors from other than like a radio shack? Also, is there a suggested voltage these should be at? I've never really done circuitry work before so I just want to make sure I have the right parts. Thank you! I usually use Orange Drop caps in the 400-600V range, but the voltages in guitars are rather low, I think anything above 200V should be fine. They are available all over the place, check eBay for the best prices. Link to comment Share on other sites More sharing options...
mydeadblues Posted March 24, 2011 Author Share Posted March 24, 2011 I usually use Orange Drop caps in the 400-600V range, but the voltages in guitars are rather low, I think anything above 200V should be fine. They are available all over the place, check eBay for the best prices. Awesome thank you! Same deal with the 220k capacitor? 400-600v? Link to comment Share on other sites More sharing options...
RaSTuS Posted March 24, 2011 Share Posted March 24, 2011 Awesome thank you! Same deal with the 220k capacitor? 400-600v? That 220k doodad is a resistor, not a capacitor. I've never had to replace any of them, but I would guess the same voltage ranges would apply. Remember I'm not technically savvy in the true sense, basically just a self taught hack, so hopefully someone with more technical leanings can chime in and confirm or refute my advice. Link to comment Share on other sites More sharing options...
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