Alembic Guitars Club
Alembic products => Owning an Alembic => Troubleshooting => Topic started by: Notachemist on April 03, 2025, 08:54:05 AM
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Odd title, and I apologize for sounding like an absolute novice (which I probably am), but since the last few days I have noticed my Alembic sounding a lot more bass and midrange dominant, compared to a week ago, and I'm struggling to figure out exactly why this happened, in the first place. First thought was the strings being the culprit, but they are Elixir Nanowebs, and they don't look worn, and still have that "twang" when digging in a bit, so I tried swapping out the 9V battery, but nothing changed. I have been trying to adjust the pickup height, but although I can dial in something thats a bit less midrange-dominant, the bass pickup still overpowers the treble pickup by a fair bit, even if i lower the bass pickup till the point where the two visible screws won't go further down, on the bass pickup. I could use the trim pots to adjust the gain, but before doing so, it would be nice to know what changed, since I'm at a bit of a loss here. I will add, that I also notice less fret noise, but measuring the relief shows that not much has changed in the last few months, so I assume that, at least in part, rules out seasonal changes affecting the neck relief.
Bass is a MKD with signature electronics, and I normally play with the pan split 50/50 between neck and bridge pickup. Panning between both pickups, does in fact indicate that the bass pickup is louder than the neck pickup, even with aforementioned adjustments.
Anyone who has experienced something similar, or have any advice, to point me in the right direction :o?
Edit: Substitute the word "bass pickup" for bridge pickup.
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Sorry to ask a really obvious question here, but you didn't mention anything about the filters. What do you notice if you open the filters all the way and then slowly turn them back down? Does it seem like you're getting full treble content when they are wide open?
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Sorry to ask a really obvious question here, but you didn't mention anything about the filters. What do you notice if you open the filters all the way and then slowly turn them back down? Does it seem like you're getting full treble content when they are wide open?
:) A great question, and yes, the filters have been exercised around 50-60 times to no avail, and are fully open with both Q-switches enabled as well, but I stupidly forgot to mention it. Both of them have always been played wide open, but now, even with both of them wide open, I notice the lack of treble content. Dialing them down just seems to behave like the low pass filters usually operate.
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dunno if this helps. i string my MKD with fresh roto rounds and run the filters wide open thru a bi-amped rig. i generally beat the crud outta my strings fingerstyle when i play. given the amount i've been playing lately (at least 2 hrs/day on non-band days, >3 hrs at rehearsal twice a week) they lose their edge after about a month. i get similar results outta the SII which is also in the rotation except due to the hi-fi nature of that bass it gets noticible sooner. boiling the strings helps. except for the SII :-(
when i listen to playbacks from our band the sound of dulling strings is pretty obvious even to my 69-year-old ears. it gets boomy and indistinct. it's not a mystery to me why the big leaguers change strings before every show.
so maybe try a fresh set of strings? i go thru a lotta strings and every now and agin i get a loser.
cheers!
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dunno if this helps. i string my MKD with fresh roto rounds and run the filters wide open thru a bi-amped rig. i generally beat the crud outta my strings fingerstyle when i play. given the amount i've been playing lately (at least 2 hrs/day on non-band days, >3 hrs at rehearsal twice a week) they lose their edge after about a month. i get similar results outta the SII which is also in the rotation except due to the hi-fi nature of that bass it gets noticible sooner. boiling the strings helps. except for the SII :-(
when i listen to playbacks from our band the sound of dulling strings is pretty obvious even to my 69-year-old ears. it gets boomy and indistinct. it's not a mystery to me why the big leaguers change strings before every show.
so maybe try a fresh set of strings? i go thru a lotta strings and every now and agin i get a loser.
cheers!
I also forgot to mention, that I play directly through a sound card through a DAW, but that sounds about normal for rotosounds, but I do find it odd if Elixir strings would go dull after a few months, since longevity is one of their main selling points, and it seems they can last for around half a year, on average, which to be honest, does sound a bit optimistic ;D. I tried GHS Boomers, but they barely lasted half a month, before a significant decrease in tone, although I liked the feel and sound of them, fresh out of the box. Then again, boomy and indistinct is a good way of describing the change in sound I am experiencing, so maybe they are getting dull, after all. Not sure if dull strings translate into a reduction in fret noise, which I would assume is a sound, independent from the sound of the string.
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If you are playing through a DAW, are you perhaps listening through headphones? Mind the volume, ear fatigue is a thing (as is hearing damage, of course). On the other hand, can you test using a regular bass amp? Earwax build-up is another thing that presents itself as a loss of brightness.
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If you are playing through a DAW, are you perhaps listening through headphones? Mind the volume, ear fatigue is a thing (as is hearing damage, of course). On the other hand, can you test using a regular bass amp? Earwax build-up is another thing that presents itself as a loss of brightness.
Yes I am playing through headphones, but I am being quite cautious in regards to volume. Perhaps it could be ear-wax buildup, but I doubt it, since there's nothing inbetween my two ears 8). I don't own an amp anymore, so no immediate chance of trying it out on another amplifier, sadly. The thing that caught my attention was not having played for a few days, and noticing the loss in clarity, pretty much immediately. First I was unsure if it was a problem with the electronics, since the strings look fine, but after having considered the matter of worn out strings, brought up by Beendown, it does sense that they might actually just be worn out, since they are about 3 months old, at this point - I might have had unrealistic expectations, in regards to string longevity. The loss in clarity just seemed very sudden and stark, but perhaps that usually happens with nickel-plated Elixir Nanoweb strings (it is, after all, my first time trying these strings). GHS Boomers just seemed to very gradually lose their top end, whereas these strings, if this theory proves to be true, just go from 100 to 5, all of a sudden, which seemed a bit odd to me.
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Your personal body chemistry can affect how quickly strings go dead. A friend of mine used to help luthier Jimmy D’Aquisto around his shop and when Jimmy finished an arch-top he would ask Marty to play it so he could better hear what it sounded like. Something in Marty’s body chemisrty would interact with the strings (most likley D’Addario) and kill the tone of the new strings quickly, Jimmy commented about it every time. It may be that the Elixer Nanoweb strings don’t interact well with whatever natural oils your hands extrude. You could put a new set of Boomers on since they worked for you previously and see it the problem persists.
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Just to clear up some ambiguity for me, the bass pickup is the neck pickup, and the treble pickup is the bridge pickup. It sounds like you're saying the bridge pickup is louder than the neck pickup with this statement "bass pickup is louder than the neck pickup," and "Edit: Substitute the word "bass pickup" for bridge pickup"
Because what is expected is that the bass (neck) pickup to be louder than the treble (bridge) pickup, but with normal factory presets on the preamps we balance them to be about the same.
Anyway, please clear this up for me so I can think straight, thanks!
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Just to clear up some ambiguity for me, the bass pickup is the neck pickup, and the treble pickup is the bridge pickup. It sounds like you're saying the bridge pickup is louder than the neck pickup with this statement "bass pickup is louder than the neck pickup," and "Edit: Substitute the word "bass pickup" for bridge pickup"
Because what is expected is that the bass (neck) pickup to be louder than the treble (bridge) pickup, but with normal factory presets on the preamps we balance them to be about the same.
Anyway, please clear this up for me so I can think straight, thanks!
;D I understand how confusing it must be, in hindsight. When I mention the neck pickup, and I will try to be more precise here, I am talking about the pickup closest to the neck, and when talking about the "bass" pickup, I am indeed referring to the bridge pickup, as in the pickup closest to the bridge. I probably used these terms incorrectly, after having read your instructions on how you regarded the pan between neck and bridge pickup, as a choice between more treble or bass, when talking about signature electronics.
But what I am in fact experiencing, is that the bridge pickup is quite a bit more louder than the neck pickup, which I found to be a bit unusual. If I pluck an open D and pan from the neck towards the bridge pickup, the sound gets louder when fully panned towards the bridge pickup. And if I start with the pan split 50/50, and then pan the line on the knob fully towards the neck pickup (as in to the left, looking down from the top of bass, in seated position), the tone is quite trebly and "nasal", whereas panning it towards the bridge pickup, results in an almost overpowering bassy tone. I should note, that the bridge pickup is positioned higher than the neck pickup, as per instructions I found somewhere on this website. I am 99% certain that the trim pots on each preamp were both centered in the middle, while I was changing the 9v battery.
As I have discussed with other members in this thread, the strings might just be worn, but with them being nickel-alloy strings, I find it a bit peculiar that they suddenly went from sounding normally "Alembic-like", to being very midrange and "boomy and indistinct", out of pretty much nowhere - I wouldn't be surprised if they were stainless steel strings, since that seems to be common with that type of string.
If I am still being unclear, I apologize, and please let me know, so I can try to clarify anything that might be confusing.
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The trimpots are there so you can compensate for the relative output of both pickups at the physical height that you set them (which one typically does to make them sound hotter, or less hot) to the point where your balance pot lets you blend the two signals to your liiking. The trimpots are not meant for always sitting at the halfway point, unless that should happen to be what works for you. If the bridge pickup is too loud for your application, either turn up the neck trimpot, or turn down the bridge trimpot.
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As adraan said, there is no "standard" position for the trim pots. They're meant to be a way to set the balance as you prefer for when your pan pot is centered.
That said, it's possible you have an issue with your neck channel. Alembic gear is extremely robust but sometimes components do fail and that could be what has caused the change in your sound.
I say that because you describe the neck pickup (nearest the fingerboard) as being thin and hollow while the bridge pickup has a huge bass-heavy tone. Both pickups should have a huge sound! The bridge pickup simply picks up more overtones which means it contains more high frequency info while the neck pickup reads more of the fundamental.
Can you test to be sure your pan pot is operating the way you think it is? Pan all the way to one pickup and use paper clip or small screwdriver to tap on that pickup to be sure you are hearing the one you think you are hearing.
The next test would be to swap the pickup connectors in the electronics cavity. If you do that the pan pot should work in reverse - but you could determine if the thin and hollow sound moves with the pickup or stays on the same side. If you know what I mean.
Keep testing and hopefully we can help you get to the bottom of it.
Jimmy J
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So I have been doing some testing and listenting, and the results, so far, are interesting. I have an old Gallien & Krueger MB150 that didn't work properly for a long time, but after doing some research I managed to get it going again, by simply turning the gain and volume to 11 and then bonking it back into life. Since I normally play through headphones via. a USB audio interface, I am not able to make a completely surefire statement, but it did sound more like it's "former self", as in sounding more balanced and less boomy and indistinct. :P
Another interesting thing I discovered, is that when seated in playing position and panning between the bridge and neck pickup, gently tapping the pickups with a paper clip like Jimmy suggested, shows that panning to the left, away from the input jack, in playing position, means the bridge pickup is active, and panning to the right, towards the input jack, means the neck pickup is active - isn't it supposed to be the other way around? Also, I actually noticed that one of the Q-switches have been turned 45 degrees (?), meaning it operates horizontally, whereas the other Q-switch operates vertically (which, if I recall correctly, is how the good people at Alembic normally set it up to operate).
The paper clip trick did show that the neck pickup is in fact the loudest and most fundamentally sounding pickup, whereas the bridge pickup is the one that sounds more high-frequency dominant, which seems to be in accordance with how they usually operate.
So, now I am wondering if there is some sort of signal interference between the audio interface and the computer it's connected to. Sadly, the audio interface is so old (a Steinberg CI1 that I bought over 10 years ago), I cannot connect it to an isolated power outlet, like a wall socket, since it requires an ancient software driver, to even turn on.
The plot thickens...
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Ain't nuthin' quite so satisfying as turnin' sumthin' up to 11, givin' it a good bonkin'... and it works. I had a Crate amp like that... still got it.
*you can switch the pickup leads on your pan module so that the pan function is intuitively L/R as you, the player sees it... and while you're in there, straighten up that Q-switch. The nut takes a 5/16" wrench, IIRC.
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well we still haven't come up with a band name, but i think i found it here:
boomy and indisitinct
gonna run it up the flagpole at next rehearsal and see who salutes 8)
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Hahaha! Well played - at least you have a very good reason to save money on frequent string changes, then. ;D
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🤔 Now that I think about it, if that sideways Q-switch is loose, this may actually be causing some of your issue. It could certainly cause some noise if the switch isn't making solid contact with the shielding paint.
Pop the hood on that MK and see if it's worked loose and may be touching something it shouldn't.
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When reading your post where you said when panned towards the neck the sound got nasaly and when panned towards the bridge it got boomy the first thing that came to mind is the pickups were connected backwards on the pan pot. It looks like you confirmed that. Since the connectors are not connected as I would expect them to be it might be worthwhile reseating all of the connectors in case someone was in there and caused the connectors to not be fully seated. A loose connector might be a cause of the issue you are seeing and is easily eliminated.
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Thanks for the suggestions. I will check up on the Q-switch and pan tomorrow. It has been mentioned that the Q-switch is tightened with a wrench at the nut, but how do you switch the pickup leads on the pan operator? Is it done by swapping two connectors (one for each pre-amp)? When I was switching the 9V battery, there were quite a lot of cables, so I would appreciate, to be 100% certain I'm not fiddling with the wrong cable(s).
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Thanks for the suggestions. I will check up on the Q-switch and pan tomorrow. It has been mentioned that the Q-switch is tightened with a wrench at the nut, but how do you switch the pickup leads on the pan operator? Is it done by swapping two connectors (one for each pre-amp)? When I was switching the 9V battery, there were quite a lot of cables, so I would appreciate, to be 100% certain I'm not fiddling with the wrong cable(s).
Yes, that simple. Should be a brown or possibly white modular connector for each pickup; just switch them where they are plugged-in. Don't flip them, as in the orientation of the plugs-to the pins they plug into, as this will flip the polarity. (ask me how I know...) Plug each pickup back in the same direction as before, just on the opposite output.
If you can, post us a picture of your electronics cavity and we'll point you to this. Signature can be a little bit crowded in there, but it's just two wires, and they are coming from your pickup leads... easier to trace.
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Here are a couple pics of electronics I've borrowed from the Interweb. I believe these are Signature packages of differing ages. Arrows point to the pickup connectors which can be swapped between the two locations. As edwardof... said, don't rotate these connectors - if these pics are right, the correct polarity leaves the white wire of the pickup cable visible at the connector when it's plugged into the circuit board.
BUT ... as you can also see by these two pics there is not much allowance for a Q-switch to rotate! I'm gonna go out on a limb here and suggest that if you have a spun Q-switch, THAT is the cause of your change of sound. I think you'll find either a lead to that switch is shorting to another terminal or you've lost one of the leads coming out of that capacitor (the small can between the board and the switch).
Open that puppy up and show us what you find!
Jimmy J
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Is there any sort of indication on the connector, as to make sure I am not accidentially going to flip them, aside from the color of the wire on each pickup cable? If I recall correctly, it had one white housing and one brown housing on each connector.
I think it would be most wise for me, to proceed cautiously, and take a couple of photos of the electronics in the cavity, before I start tinkering. I do recognize the ferrite bead and what I assume to be both preamps from the photos that Jimmy posted, but although I am not sure if it is of any help, I will note that the bass sounded fine for almost half a year with the spun Q-switch, before it recently started to sound different. But I want to stress, that I really appreciate the input, that you guys are taking the time, to offer.
I will also add, that I have noticed a sort of hum, when the bass is plugged into the audio interface, which gets louder, the more i turn up the gain - the hum is pretty faint at full gain, but audible if you pay attention - I am not sure if this hum started at the same time, as the tone started to change, but it's possible. Turning the gain knob to 0 on the bass, makes the hum go away, and switching cables just makes the hum louder or quieter, depending on the quality of the cable. I have been doing a bit of reading online, and it seems that humming is decently common with USB audio interfaces, due to the many internal components in a pc, working and interferring at the same time as the audio interface, but in my experience, troubleshooting things like this, can be a real headache, so it's important to note that it sounded more "normal" through a bass amplifier. I wonder if this hum contributes to the "boomy" sound I am hearing, all of a sudden, since it is operating in the same area of frequencies, if that makes sense.
Anyways: Pictures coming up tomorrow, nevertheless.
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Is there any sort of indication on the connector, as to make sure I am not accidentially going to flip them, aside from the color of the wire on each pickup cable? If I recall correctly, it had one white housing and one brown housing on each connector.
I think it would be most wise for me, to proceed cautiously, and take a couple of photos of the electronics in the cavity, before I start tinkering. I do recognize the ferrite bead and what I assume to be both preamps from the photos that Jimmy posted, but although I am not sure if it is of any help, I will note that the bass sounded fine for almost half a year with the spun Q-switch, before it recently started to sound different. But I want to stress, that I really appreciate the input, that you guys are taking the time, to offer.
I will also add, that I have noticed a sort of hum, when the bass is plugged into the audio interface, which gets louder, the more i turn up the gain - the hum is pretty faint at full gain, but audible if you pay attention - I am not sure if this hum started at the same time, as the tone started to change, but it's possible. Turning the gain knob to 0 on the bass, makes the hum go away, and switching cables just makes the hum louder or quieter, depending on the quality of the cable. I have been doing a bit of reading online, and it seems that humming is decently common with USB audio interfaces, due to the many internal components in a pc, working and interferring at the same time as the audio interface, but in my experience, troubleshooting things like this, can be a real headache, so it's important to note that it sounded more "normal" through a bass amplifier. I wonder if this hum contributes to the "boomy" sound I am hearing, all of a sudden, since it is operating in the same area of frequencies, if that makes sense.
Anyways: Pictures coming up tomorrow, nevertheless.
Now we're getting somewhere. If you're getting a hum, this a a symptom that something is likely loose from the shielding, and it sounds like from what you're describing, the Q-switch is suspect. Humming, buzzing and sometimes crackling are often heard as the contact is intermittent.
Study on Jimmy J's borrowed pics there, and you should be able to trace your pickup leads down. The two wires looped through the ferrite bead should be the pickup leads.
To answer your other question (I've bolded it in the quote) yes, just study the modular plug. They are oriented to plug in a specific direction, but it is possible to reverse them. It's very easy to correct. Stay on target and keep us posted.
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Yes, there is a friction lock on the connectors. If you are really concerned you might put the connector on incorrectly, you can add a little mark with a pen so you know you have the right direction when you swap besides the locking mechanism in fact being locked.
IMPORTANT: do not pull on the wires when unplugging. Handle the plastic housing only. You may need to unmount the control to access the connectors, or use needle nose pliers. If you pull the wires, you can dislodge the crimp, and that can cause a host of issues from hum to signal loss.
Hum is a very specific frequency, in the US it's 60Hz. Are you certain you are hearing hum? Could it be a higher frequency?
Also, just how close to your PC are you? Does the noise you are hearing diminish when you get farther away?
One more time on pickup nomenclature: - The bass pickup is neck pickup
- The treble pickup is the bridge pickup
For clear communication, I'd stick with using either bass/treble OR neck/bridge.
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dunno if this helps, here's a pic of my 2018 MKD cavity all lit up and everything 8)
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https://imgur.com/a/jB8s0Bq
As promised, I have uploaded a few photos for you to take a look at. the spun Q-switch is the one in the top of the cavity, besides the 9V battery, if memory serves me right. I also noticed that the cavity has a piece of foam attached the non-visible side (the side that faces the electronics) - I assume that's normal.
Mica, the pen suggestion is great - thank you. So the friction lock means it's kept in place by a plastic lock, if you understand what I mean? Is it the type of connector where you have to "wiggle" them, or should it just slide off, when unlocked?
In regards to the hum: The best way I can describe the sound I faintly hear, is the sound you hear, when touching a surface with an instrument cable, that is connected to an amplifier, that's turned on, and it sounds like low frequency to my ears.
And I am sitting at around 80-90 centimeters (0.3937 inches) from my PC, and the noise stays the same if I move closer or further away from the PC. From now on, I will refer to the pickups as being neck and bridge pickups.
To everyone so far: Thank you very much for the continued help, and I hope these pictures can be of help.
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Okay, having looked at the pics... wow, that's a tangle. Seriously, it's not too bad. How handy are you? This isn't too bad, but you'll have be somewhat patient and tool-sy to do it.
If I were going to perform this operation, I'd -
1. Take a picture. (you already did)
2 .Take the battery out.
3. Unplug the pickup leads. (note which one is bridge and which is neck... good opportunity to mark them)
4. Lift the ferrite bead with leads and the battery wires out of the way so you can access the Q-switch.
5. Determine if it's loose. It's probably semi-tightened up in a slightly rotated position.
6. Put the bass in your lap so you can hold the switch with one hand. Loosen the 5/16" nut with the box end of a wrench. No need to take it off, just loosen a thread or two. Hold the switch while doing this. Do not let it twist the wire leads to it.
7. Gently turn the switch back to the direction it belongs with your fingers, and hold it in place while you snug the 5/16" nut. Just snug it, don't overtighten.
8. Switch those pickup leads to the opposite points of where they were in your picture so your pan function will be intuitively like you imagine from the player's perspective... L/R.
9. Ease the ferrite bead back in place. Usually that foam piece you mentioned lines up with it... keeps it in place and from clacking against the backplate.
10. Reinstall the battery. (I'd put a new one in, just because...)
11. Because it goes to eleven... Seal up the backplate and give it a run. Don't forget to give that amp a good bonk. ;)
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I've marked where the friction locks are with green circles in one of your images. It's really easy to see how it works with the one that is the original brown color and newer "natural" color. You can pull the connector straight out provided you are holding on the plastic housing only, but a little wiggle can be helpful to get it going.
We generally recommend being at least 1 meter away from an amplifier or computer, and you're close to that. When you say it doesn't change when you are closer or farther away, what kind of distance are we talking about? What about when you are twice the distance away?
The foam is to keep the ferrite bead from rattling.
For high frequency noise there is an upgrade where you replace the 8-pin ICs on the filter boards (and ideally the pan control as well) with a new tiny circuit card that has the IC and other components to take care of the high frequency noise filtering. None of this is what you are observing in your situation, but it's something that should be done at some point.
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@Edward:
Oh no, it doesn't sound good when you describe it as being a tangle - the pictures were taken very close to the cavity, so maybe it looks more crowded, than it really is.
I would think of myself as being better at handling books than handling tools, if that makes sense :). But really, in this specific case, I am usually not fond of tinkering with my Alembic, due to the fact that I live several thousand kilometers away from the factory itself, so any mistake made, is going to be costly and time-consuming to fix. As an example, Jimmy was very kind to assist me in adjusting the truss rods when I first got my Alembic (first time I ever encountered the dual truss rod system), but I am still not very comfortable adjusting them. I would say that I am so far comfortable doing pretty basic stuff like height adjustments and changing strings etc.
Swapping the pickup leads sounds manageable to me, but the Q-switch operation sounds more demanding, especially on my own, which is pretty unfortunate, as that is probably most likely to be the source of any unwanted noise, in relation to the instrument itself. I will say, that I spend 99.9% of my time playing with the pan centered, so unless it could be a possible cause for the change in sound, I would rather leave it alone.
@Mica:
I will try to double the distance, and see if anything improves. I tried using my backup bass (a Sandberg with active electronics :o) with the same PC and Audio Interface, and I actually noticed that it was very noisy as well (more than the Alembic) - I even experienced noise changing just by hovering my hand over the tone controls, leading me to believe that all of this could be caused by either the PC or the audio interface - but I will try doubling the distance, and report back with my findings.
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Well, I promised Mica an update on my findings when increasing the distance, and I think I have found the cause of the problem: The metal casing of my PC and worn strings.
I tried connecting the Audio Interface to a PC made of carbon fiber plastic, and pretty much all noise was gone immediately upon connecting both basses to the audio interface. Interestingly enough, the switch doesn't seem to cause any unwanted noise when connected to the other PC, so I think the switch still in contact with the silver in the cavity area @Edward.
So, if anyone reads this at some point in time, trying to figure out a sudden onset of noise while playing through a USB audio interface, try switching to a PC made of a materal that isn't conductive to noise, and change those strings! :)
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👍🏼
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Greg is on another level of restoration! I’m from the sophomore school of fill a hole with a toothpick and glue. My idea was wood “toothpicks” from the battery compartment (neck woods) and glue. This is all theoretical as I wouldn’t have the cojones to take on a full Series 1 restoration! This is shaping up to be a primo thread. As Greg pointed out 76 412 seems to be an internet orphan and it looks like this frog might be a prince soon!