Alembic Guitars Club
Alembic products => Owning an Alembic => Troubleshooting => Topic started by: Dazza53 on December 22, 2018, 02:44:29 AM
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Hi everyone .... hope you can help ! This is my first post to the Forum, and I've recently moved from the UK to live in Bulgaria.
I own an Alembic Series I - registration date 8-17-84, and serial number 843263 - which I bought about 18 months ago via Reverb from the Craig Brody dealership in Fort Lauderdale, Florida.
The original pale blue DS-5 power supply failed for me just before my move, so (after arriving in Bulgaria) I've subsequently tried to get the guitar to work by using 9v batteries.
But absolutely nothing now works .... zero, zilch, nada! The guitar is dead as a dodo !!
I've contacted Station Music in Germany to ask for advice, but all they've suggested is for me to ship the guitar to them to have a look at. Not too keen on this suggestion, as the shipping cost would be high and I've no guarantee as to what the outcome would be. They do sell new DS-5's, but I obviously don't want to purchase one if there is something more fundamentally wrong with the guitar.
As you might expect, I'm pretty upset and cut up about this situation, so I do hope someone can provide sensible advice for me to follow.
Kind regards,
Darryl Wetherall.
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Sorry to hear that Dazza53. If your bass's previous owner was like me, someone who never uses the batteries in the bass, then I would check for damage caused to the wiring if the battery had in the past leaked and caused corrosion of connections. It's not un heard of. Failing that I'd suggest taking some pictures of the inside of the control cavities especially around the battery compartment and jack socket in case there is something we can see that has gone astray.
The other thing you could try is exercising the jack socket. The alembic (switchcraft jacks) are self cleaning so you should push a jack cable in and out of it about 50 times to clean them up.
Also that bass may be one of the ones with the stereo jack so you would only get the neck pickup with a mono jack, so you would only get an output using batteries from the neck and both pickup positions of the switch.
Another thing you can try is plugging stereo headphones into the jack socket. I belive the pre-amp can power headphones although I have never tried it.
I hope there is someone closer who has a DS-5 box you can try.
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Hey Darryl,
Sorry to hear you're having problems but you've come to the right place for troubleshooting...
I presume you already know that the batteries only work when you have a cable plugged into the 1/4" jack? The 5-pin cable is not meant to be used at the same time. That 1/4" jack has a switch built in which connects the battery power. As Jazzeyvee suggested, the first thing to do is inspect the battery connectors to be sure they're not corroded. Next would be to exercise that 1/4" jack many times in case the battery switch contacts need some convincing. Then the headphone test. Sound may not be good with phones because of the impedance mismatch, but if you hear any sound - in either ear - we can go to the next step.
We also want to help you revive your DS5. How did that fail? It's likely a 120V model so you'd need a small step down power transformer. But the instrument doesn't draw much current so it wouldn't need to be a large one.
Let's get that thing working!
Jimmy J
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Hey, many thanks for your suggestions, guys !!
I'll try pushing the 1/4" jack in & out about 50 times, and also see if there's any sound when connecting my Phil Jones headphones.
Hopefully, one or both of these actions will result in success - if not, then I'll post some photos of the battery compartment, with and without my Duracell batteries.
BTW, I don't still have the original DS-5 - it was the 120v version, and it just decided to lie down & die one day. Mind you, it was 34 years old, so I guess I really can't complain too much. That's why I mentioned possibly ordering a new DS-5, but there's no point if there's something else fundamentally wrong with my guitar.
Watch this space for updates ....
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OK .... success (of sorts) !
With the 9v batteries connected, I inserted a 1/4" jack about 50 times as suggested - but nothing came out of my amplifier.
I then plugged in my Phil Jones headphones. This time, there was output !!!
The sound was only coming out of one headphone, and only the treble pickup appeared to be working.
However, I'm really grateful to you both for your suggestions. The thing is ... what does this all mean, and what should be my next steps? (Buy a new DS-5, presumably?)
Best wishes,
Darryl.
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Darryl,
Good to hear the instrument is producing some audio, that's a step in the right direction. However, the mono signal should have been the bass pickup only. Can you tell us which switch positions produce that sound? Furthest counter-clockwise is "Standby", next position (if everything is correct) should be Treble p/u only, next should be Both, last position should be Bass p/u only. Answer that and we can go to the next step.
Also, it would be great if you could open the electronics cavity and post some pics of the harness, 1/4" jack, and the preamp board.
We'd also like to try to repair your DS5. I can describe a couple possible issues there... First being the power cable itself as it enters the box through the strain relief. Eventually, this point gets bent back and forth so many times that the wire can stop passing current. You may be able to get it to work intermittently by moving the wire around at that point. If that's the problem, it means popping out that strain relief grommet, shortening the wire by a few cm and remounting it. (Not actually as easy as it sounds, but a fairly simple repair.) The 2nd thing is, the power passes through a small thermal protection type of fuse before getting to the transformer itself. It's possible that component has failed - though I'm not sure how likely that is.
You'll still need a small 220 to 110 external power transformer to run this US model DS5...
Keep going! We've gotta get this axe back online!
Jimmy J
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I can also vouch for that thermal protection diode going out. I had one fail from it being left in a hot car.
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Hi again JimmyJ,
Seasonal greetings to you & your family !
I don't actually have my original DS-5 any more - after it died on me, a dealer in the UK (Bass Direct) offered me £200 for it as they thought they might even be able to fix it. I was well into the process of emigrating at that time, so I took the money (and ran, courtesy Steve Miller). That's why I do need to get a new one ASAP - probably from Station Music in Germany, as I've found import taxes into Bulgaria from the US are way too prohibitive.
Anyway ... I've taken lots of photos which will hopefully help you to diagnose the next steps needed to 'repair' the guitar. Unless I'm misunderstanding the your advice (and the diagrams, which I admit is quite possible), I still think that it's only the treble pickup that's currently working. I've included photos of the 2 positions where I can hear sound from the guitar, along with the original documentation from 1984 and also pics of the preamp section. Hope they can all fit in this post - if the size limit is reached, then I'll just add further post(s).
Many thanks again.
Darryl a.k.a Dazza
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Here's my remaining photo ....
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Can you take please the whole back of your bass? Where are the trim pots located?
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Hi Dazza53,
Do you have a photo of the back plate where the colored wires and the pickup wires connect to the circuit board? Check those connections to make sure they are correct and tight. I would think that stereo headphones should have produced stereo output.
-Rob
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Hey Darryl,
Thanks for the post. That instrument looks brand new!
OK, I understand about the DS5 and hope you can track down another one. Sometimes (though rare) they come up for sale in your part of the world. Or, if you or any of your friends can solder, you could build one! (With something like this: https://www.mouser.com/ProductDetail/Delta-Electronics/AA30D1515C?qs=sGAEpiMZZMs2%252bVrH5rwl1rQXvzNrCTAMH7ymmoJZGnmxQMWIKoYJ3A%3d%3d (https://www.mouser.com/ProductDetail/Delta-Electronics/AA30D1515C?qs=sGAEpiMZZMs2%252bVrH5rwl1rQXvzNrCTAMH7ymmoJZGnmxQMWIKoYJ3A%3d%3d) )
Now about your photos:
#1. I'm happy to see it's a bass we're talking about. :) Just kidding.
#2. You'll need to take one more pic of your selector switch in "standby" (furthest anti-clockwise, or like turning a volume knob all the way down). That knob can be set to point in any direction so we need a starting point to see what position the switch is in.
#3. Your 1/4" jack appears to have the original stereo wiring so you will need either a stereo to mono summing cable, a stereo cable with two outputs (running into two amp inputs), or you can modify the bass itself to sum to mono (more soldering).
#4. As the other posters suggest, we need one more picture of the preamp board which is mounted to the underside of the other brass back plate. That will help us see if the pickups are plugged in correctly.
We're getting closer! Keep the info coming!
Jimmy J
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Hi again,
Here's some more photos - selector switch in 'standby', preamp board (above & below), battery compartment & combined preamp/battery.
Thank you all so much for your patience - didn't realise that there was so much to check, but it'll all be worth it when the guitar is working correctly again!
Looking forward to hearing from you again ....
Darryl.
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Hey Darryl,
Thanks for the new pics. Here's my new theory... Ahem!!
If we call "Standby" on the pickup selector "position zero", then as your info sheet explains "position 1" is treble pickup only, "position 2" is both, and "position 3" is bass pickup only. Since you report hearing sound in your headphones from the bridge pickup in positions 1 and 2 (I'm going to bet that it was in the right headphone channel?) then I think the treble pickup is working correctly and only the bass pickup output is not yet there.
The first thing to do is to exercise the bass pickup volume control (the knob closest to the pickups). You need to spin that back and forth about 50 times. While you're at it I suggest doing that to each knob and each of the Q switches. If they haven't been moved for a very long time they can get noisy, but the fix is simply to sweep the pots and switch the switches several times.
After you've done that, do the headphone check again to see if the bass channel has come alive.
Let us know!
Jimmy J
PS: to look at your preamp board it's not necessary to remove all 8 screws from that small brass plate. With only the 4 outer screws removed you should be able to gently swing the panel out like in the picture below. If your bass is still open, how about one more picture of the component side of your preamp board just for good measure?
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Hi Jimmy,
As requested, here's a couple of photos of the component side of the preamp board ....
Hopefully, you're now getting closer towards an explanation for my Series One 'quirks' - apart from you playing a 5 string, I eventually hope to be able to emulate your sound from the James Taylor live album .... :)
Thanks again, and best wishes for 2019.
Darryl a.k.a Dazza53
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Hmmm...everything looks so clean! Maybe check the gray and light colored wires where they connect to the maroon plastic connectors and make sure those wires are intact and not frayed and coming apart and breaking the connection. The light one in the middle should be your hum canceler, so make sure that is not running to the bridge or neck pickup. Maybe follow all of those wires and make sure they are going to the proper pickups. Then take a look at where the wires connect to the neck and bridge pickups and make sure they are not damaged (you have to remove the pickups to do this).
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Darryl (or Dazza if you prefer),
Thanks for the new pictures. And for the comment about the JT Live record - engineer George Massenburg and producers James and Don Grolnick took good care of the bass tone on that one!
As Rob said, your whole bass looks super clean, like new! I don't think that instrument has seen much playing so it's up to YOU to put some mileage on it. Ha!
Troubleshooting:
1. First try my simple suggestion of exercising all the pots and switches to see if your bass pickup comes alive.
2. Rob's suggestion; follow the pickup wires into the cavity to make sure each is plugged into the correct spot on the preamp board (see your modified pic below).
3. Try turning up the bass pickup trimpot (see below) and check the headphones again.
4. Swap the Bass and Treble connectors at the preamp board and see what happens in the headphones. Report back if you try this.
I see you're missing the small plastic "C-clamp" that holds the ribbon cable connector in place. Not a big deal (I think one of mine was gone too) just be sure the ribbon cable stays firmly seated as you move the board around during these operations.
We're getting closer. Gotta get that bass running properly so you can enjoy the tones!
Jimmy J
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Hi everyone,
Well ..... the trimpots do appear to be working as expected, but turning both of them up full still has no effect i.e. only the treble pickup is operating.
I'm only using a mono lead to test everything out (as I don't have a stereo lead!), and I just noticed on the Alembic operating guide that it says 'Inserting plug turns on internal batteries. If you use a mono cord you will only get one pickup'.
Which is what is actually happening .... but only through my headphones ! There's still S.F.A coming out of my Genz Benz amp, when I connect the mono lead to it.
Does this mean that I won't get sound through my amp if I only use batteries? Conversely, does it mean that everything will be OK if I get a new DC5 and special lead?
Many thanks,
Darryl a.k.a Confused of Bulgaria ... :)
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Hi Darryl,
Happy NewYear!
I just checked it out on my Series I Bass.
1. With a mono 1/4” cable you should get sound through your amp from the neck pickup only. If you are getting sound from the bridge pickup only, check the connection at the preamp board, they my be connected backwards. If you are not getting any sound check the cable and the amp, they may be the source of the problem. Also, install two new batteries in the bass and see if that helps.
2. With stereo headphones you should get sound from each pickup individually in separate ears, and in both ears when selecting both pickups. The sound will not be loud. If this is not the case, check the connections at the preamp board to make sure they are tight and connected properly.
3. Exercise all pots and jacks to clean out the contacts and see if that resolves the issue.
4. If none of that resolves the issue, then it may be time to bring it down to your local tech to evaluate. You may have a faulty 1/4” jack or some other issue that they should be able to identify.
Good luck and let us know how it goes!
Rob
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Hey Darryl,
Happy '19!
I believe you're hearing the treble pickup in your RIGHT headphone (??) which means half of your bass is working correctly. The RIGHT headphone is the "ring" of the 1/4" stereo jack. The "tip" of the 1/4" jack should be the bass pickup, but it's not yet producing sound. That's why when you plug in a mono cable and connect to your amp you've got nothing. Does that make sense?
So as Rob and I have been saying - your very first move should be to exercise all the pots and switches, back and forth on the switches and full sweeps of the pots, like 20 times each. (Not the trimpots, leave those alone for now.)
The next test is to swap the two pickup connectors at the preamp board and see what happens. For instance, if that results in you hearing the bass pickup only - through your RIGHT headphone - then we need to look into troubleshooting the board itself and the wiring harness. But if the treble pickup moves to your LEFT headphone and you get that sound through your mono cable and amp, that points to an issue with your bass pickup.
The fact that the bass is making any sound at all means that your batteries are correctly powering the board when you plug into the 1/4" jack. I do not believe a DS5 would make any difference at this point and you'd still only have output from the treble pickup. If you can, try the two things above and let us know what happens and we can help figure out your next move... Sorry for the frustration, thanks for your patients.
Jimmy J
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Wow - thank you everyone for helping this member out. It truly warms my heart that you are so generous with your time assisting eachother. I'll wait to hear Darryl's pickup report and then we can see what parts he needs to get his bass up and roaring again :)
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Hi again everyone,
I'm gradually losing the will to live with my Series One problem ....
I'm not technical at all, and certainly don't want to start messing around with swapping connections, soldering, etc, etc - I'll probably just end up making a bad situation even worse!
Much as it grieves me to say so .... I think I need to get the guitar into an Alembic dealership to be sorted out properly (or to a luthier who knows the workings of this model well). Not sure where the nearest reputable place to Bulgaria would be for me - maybe even Station Music in Germany, but that would necessitate a plane trip ....
Many thanks to everyone for their help, patience & guidance - but I feel this is something that I just can't correct via the Internet !!
Kind regards,
Darryl a.k.a Dazza53
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Darryl,
I understand that if you're not a wire-head (like me) it can be a bit overwhelming to try to troubleshoot this electronics package. There's a lot more going on here than on a Fender bass! But we're all sad your bass isn't working properly and would love to help you get it going. After all, you've gone to the trouble of acquiring this great instrument, which is very rare in your current part of the world, and this community here in this forum would like to see you enjoying it and playing it to its full potential... It's like we're concerned for one of our children. Ha!!
I understand you are new to that area but start asking around for an electronics shop that might have a repair guy. Could even be a stereo store. Or if you meet any musicians playing electric instruments, see if they know of a shop or if they do any wiring themselves and would be willing to lend you a hand. Then if you find somebody, have them log in here and we can talk them through the procedures.
You should also send your mailing address to Mica*at*Alembic.com in case you need parts...
In the meantime, keep playing that bass "acoustically" to keep your fingers moving!
What I haven't asked is; did the bass ever work properly with the original DS5??
And Darryl ... EXERCISE THE POTS AND SWITCHES. You haven't confirmed that you've tried that yet and it is by far the simplest fix. :)
Jimmy J
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Hey Darryl... Understand feeling intimidated by the thought of poking around at the electronics but suggest you at least swap the pickup connectors before throwing in the towel and taking the bass to a repair facility. I am terrible with a soldering iron but the connectors on the pickups are modular and really easy to disconnect and swap, no tools other than fingers required. Even I can do it! If one of the pickups is dead you will need to get a new one from Alembic so better to figure that out first. If one pickup needs replacing you could have a tech do that once you have the new pickup.
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You understood that there is no soldering involved, right? Is just for swaping conectors and exercise potentiometers, can't get easier. Exercising pots can solve many noise/distortion/low level issues and swaping conectors can show if problem is in the PU or in circuit. There is no expertise needed, just will to find and solve a (eventualy easy) problem before going to a repair shop or givin up a superior gear...
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Hi again everyone,
Sorry for the delay in rejoining the thread ....
Jimmy - I can confirm that I've exercised the pots (ad nauseum), and still no joy.
Just to reiterate - I get no output at all from the guitar through my Genz Benz Shuttle amp, but do get one channel when connecting up to my Phil Jones headphones.
I'm not a techie in any sense of the word (and have no intention to be, either) - think I need to take the guitar to my nearest 'kosher' dealer (Station Music in Germany ?), or even take the guitar back to a London dealer on my next trip back to the UK.
Thanks again
Dazza
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Great to hear the instrument is creating some sound, that is a positive development. Be that as it may, the mono sign ought to have been the bass pickup as it were. Would you be able to disclose to us which switch positions produce that sound?
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I know I'm not helping with this thread but I've got to say daaaammmn! Your electronics compartment is so neat! My '79 is a rat's nest of wires and a ribbon to the circuit board. Best of luck on your issue though. You can get a wiring diagram from Mica if need be. Say, a question though. Did your DS-5 die catastrophically while playing? Maybe some kind of power surge/short/?? from that event?