Alembic Guitars Club
Alembic products => Owning an Alembic => Troubleshooting => Topic started by: Dm1 on March 13, 2017, 10:18:22 PM
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My Excel has developed some hissing lately and last saturday it started distorting.
I've put in a new battery - it distorted even more, like a damaged speaker
Hissing goes away when closing the highs.
I've checked and ressoldered the input jack. And tested in 3 different amps.
Edit: Reducing the volume pot makes it worse.
Where should I look next? I have a gig on friday and no other basses :(
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Well, I don't know for sure what the reason for the hissing is but one of the things you can do first is to exercise the knobs. That means rotate them fully open and closed about 50 times for each one. They are self cleaning pots and this will clear any gunk that may have accumulated during use.
http://club.alembic.com/index.php?topic=220.0
Other than that it might be an idea to do a search on hissing or wait for one of the more knowledgeable members to chip in. I hope you get it sorted before your gig.
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Also, check inside the electronics cavity to make sure none of the circuit boards are contacting the shielding paint, or each other. ;)
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I found this with a quick search:
http://club.alembic.com/index.php?topic=4538.msg54493#msg54493 (http://club.alembic.com/index.php?topic=4538.msg54493#msg54493)
If you have a gig on Friday, you might want to take it to a local repair shop and see what they think.
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Well, I don't know for sure what the reason for the hissing is but one of the things you can do first is to exercise the knobs. That means rotate them fully open and closed about 50 times for each one. They are self cleaning pots and this will clear any gunk that may have accumulated during use.
http://club.alembic.com/index.php?topic=220.0
Other than that it might be an idea to do a search on hissing or wait for one of the more knowledgeable members to chip in. I hope you get it sorted before your gig.
I've done that when I bought the bass. The pots don't crackle anymore. Its like EM interference or something
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I found this with a quick search:
http://club.alembic.com/index.php?topic=4538.msg54493#msg54493
If you have a gig on Friday, you might want to take it to a local repair shop a and see what they think.
Yeah, I looked through that thread, bu he's got different electronics than I, and some mods too. The Excel is a simpler bass.
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Also, check inside the electronics cavity to make sure none of the circuit boards are contacting the shielding paint, or each other. ;)
Good idea. Just did a quick check, and nothing is touching anything it isn't supposed to.
ps: is there a multi quote option here in the forum? Thank you all for your suggestions.
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Double check that "new" battery to make sure it's got juice. Try another cable / amp input / amp...
Jimmy J
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Maybe some other things to consider. Have you recently changed the light bulbs in the area you play to the new LED's, or have you installed a digital solar panel/charger/inverter system? Those 2 things increased hiss in my system.
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Double check that "new" battery to make sure it's got juice. Try another cable / amp input / amp...
Jimmy J
Done. Problem still persists
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Maybe some other things to consider. Have you recently changed the light bulbs in the area you play to the new LED's, or have you installed a digital solar panel/charger/inverter system? Those 2 things increased hiss in my system.
No, nothing changed at home. The problem started at the venue I was playing at. The worst of it is the distortion coming from the bass that makes it unplayable.
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Have you checked the wires from the battery and the part the battery clips onto to make sure nothing is damaged and that there is no short at the junction of the battery leads and electronics?
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ps: is there a multi quote option here in the forum? Thank you all for your suggestions.
Actually there is. When you click the REPLY button, it takes you to the Post Reply page with the edit window on top, and the posts in reverse order under Topic Summary. For each post listed there, you should find an "Insert Quote" button. You can insert the quotes as you write your response.
Happy quoting!
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8)
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Have you checked the wires from the battery and the part the battery clips onto to make sure nothing is damaged and that there is no short at the junction of the battery leads and electronics?
Thank you!Have you checked the wires from the battery and the part the battery clips onto to make sure nothing is damaged and that there is no short at the junction of the battery leads and electronics?
I did. My luthier just cleared out some time for me to bring it in. I will be back with answers. Thank you everyone.
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Update. Problem fixed.
I feel a bit embarassed to post this. I took the Excel to the luthier and the problem in my preamp was an output level thingy that rattled its way to the max, so the output was coming too hot. :-[
My previous basses circuits were all epoxied out, so I didn't even think of checking this kind of thing. I hope my experience here can help someone else with the same issue.
Cheers.
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I'm glad that's fixed but I'm a bit confused as to how that creeped up to max and caused that kind of distortion. I think all my basses have the pre-amp settings at maximum via the internal trim pots and they work fine on my bass rigs. On other amps at rehearsal rooms and backline provided gigs sometimes the bass has been too hot at my normal volume settings but that can is easily remedied. The issue of hissing for that reason would concern me. So how did the gig go did it go fine with no sound concerns?
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I'm glad that's fixed but I'm a bit confused as to how that creeped up to max and caused that kind of distortion. I think all my basses have the pre-amp settings at maximum via the internal trim pots and they work fine on my bass rigs. On other amps at rehearsal rooms and backline provided gigs sometimes the bass has been too hot at my normal volume settings but that can is easily remedied. The issue of hissing for that reason would concern me. So how did the gig go did it go fine with no sound concerns?
Wait, all your internal trimpots are set to the max? The gig was cancelled last minute so I only managed to test it briefly on the studio. I think it sounded a bit dull, and planned to raise the trimpot a bit back up.
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Hmmm, I've never heard of those trimpots rattling up. Is it possible they were just set there when you got the bass? If you have too much gain it can cause distortion for certain amps, it really depends.
If you have downtime and want to send the electronics in for testing, there's no charge for us to see what's going on (except return freight). If there is something wonky we'll let you know.
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Hmmm, I've never heard of those trimpots rattling up. Is it possible they were just set there when you got the bass? If you have too much gain it can cause distortion for certain amps, it really depends.
If you have downtime and want to send the electronics in for testing, there's no charge for us to see what's going on (except return freight). If there is something wonky we'll let you know.
Yeah there is still something wrong here. Most distortion and hissing went away now fidgeting with the trimpot, even when close to max, but now the volume pot is mute until the last 1/3 of turn. I'm stumped. :(
If I were anywhere else in the world I'd send it over, but my packages always seem to go missing in the brazilian mail system :(
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was the volume pot replaced? that is sounding like a linear taper pot instead of an audio taper.
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was the volume pot replaced? that is sounding like a linear taper pot instead of an audio taper.
Nope, it is still the original. Board says alembic.
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Daniel, a close shot pic could be helpfull to Mica realize what is going on. I can understand distortion if the preamp is too hot, but that doesn't explain hissing.
Does it have the magnet beads? Alembic PU can be really picky about RF interference and AC magnetic fields, and as we have no rigid control over radio transmission bands in Brazil (you know, all those church pirate radio stations...), they are essential. Until I realize that just one PU was passing trough the bead I suffered for sometime with my Rogue since I play a lot near TV and Radio antennas.
Are you really sure volume pot is original? Because it seems the tapper is wrong (behaves like linear and not logaritmic, as it should), can you spot any letter writen on it (as LOG or A)?
ps. If you want, contact me inbox and I will give you my personal phone number to talk in person and in portuguese (don't know about you, but to me is always a little struggling write in english).
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Daniel, a close shot pic could be helpfull to Mica realize what is going on. I can understand distortion if the preamp is too hot, but that doesn't explain hissing.
Does it have the magnet beads? Alembic PU can be really picky about RF interference and AC magnetic fields, and as we have no rigid control over radio transmission bands in Brazil (you know, all those church pirate radio stations...), they are essential. Until I realize that just one PU was passing trough the bead I suffered for sometime with my Rogue since I play a lot near TV and Radio antennas.
Are you really sure volume pot is original? Because it seems the tapper is wrong (behaves like linear and not logaritmic, as it should), can you spot any letter writen on it (as LOG or A)?
ps. If you want, contact me inbox and I will give you my personal phone number to talk in person and in portuguese (don't know about you, but to me is always a little struggling write in english).
Yeah, I'm sure it is an alembic. it worked fine before. Distortion is fixed, but hissing persists. I apparently bought a bad batch of batteries, two brand new out of the package duracells reading 5 volts. duh.
Do you wanna speak on facebook mario? That would be better for me. Thanks
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And per suggestions, pics of the electronics