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jazzyvee
Senior Member
Username: jazzyvee

Post Number: 2976
Registered: 6-2002
Posted on Monday, June 25, 2012 - 5:44 am:   Edit Post

Hi I have had this problem for a while now, since 2009, and I really want to get to the point where it's gone so that I can use my instruments in the away they were designed to be used…..with the PSU.

I would really appreciate some knowledgeable help on this I've been through it before with my series guitar and thought it was down to my amp because the noise went away for a while but alas not for long so I got frustrated by it and basically gave up just tried to live with the problem and as a result have only used the guitar at home apart from 2 outings.,

Now I have a major gig in just under a months time at the Symphony hall in Birmingham for one of the Olympic Games parties that is happening here. Both the Jamaican and USA teams are going to be based here and in the city so begin a high profile gig I really want to take my Series II bass to it. But this problem is going too make it difficult for me to take it.


With Series II bass or series I guitar the situation is exactly the same so I doubt if it is a problem with the instruments as that would indicate a design fault which I very much doubt.

Right.
I have two PSU's one which came with my Series I guitar and one that came with the series II bass. The only one that works is the one that came with the Series I guitar. The one that came with the series bass, I changed the voltage selector to 240v and plugged in and it gave some signal for a few seconds then stopped and has not worked ever since. It's now on the pile of objects to take for electronic repair or bin depending on my mood at the time. :-(


I have two rigs. One with F1-x, SF2, QSC amp and mesa cabs, the other is a Mesa walkabout head and mesa cabs. and again the situation is exactly the same on both rigs and guitar rigs, Fender Twin and Roland JC120.

Anyway here is the situation when using the remaining working PSU.

(1) When I plug in the series cable into the PSU and and take a signal from any output on it into my rig.
Result: Great bass sound but on top of that there is high frequency hiss, ( like frying breakfast).
Not mains hum.

(2) Now if I remove the series cable from the bass and the psu, and plug a standard jack cable from the bass into either rig using battery power only for the bass.
Result: No Noise just great bass sound.

(3) Plug the series cable into the bass and leave the other end free and disconnected using the battery to power the bass and standard jack connected between bass and rig.
Result: Great bass sound no noise.

(4) Plug the series cable into the bass and PSU to power the bass, remove the audio jack cable from PSU, plug standard jack connected between bass and rig.
Result: Great bass sound and noise.

(5)Plug the series cable into the bass and PSU, turn off mains power to psu and unplug mains connector, plug audio cable from PSU to rig.
Result: No bass sound only noise.

(6)Plug the series cable into the bass and PSU, turn off mains power to psu and unplug mains connector, a standard jack connected to rig from bass.
Result: Great bass sound and noise.

(7) plug standard jack cable into rig without connection to anything else
Result: No Bass sound (obviously) but Mains Hum, NO high frequency hiss as described above..


(8) Remove Series Cable from bass and PSU, and remove Standard Jack cable from bass and bass rig.
Result: No bass sound, No Noise. :-)


As I said earlier, I tried the above scenario's on both bass and guitar and they are exactly the same.

I cannot begin to describe how annoying this is……….

Jazzyvee
dfung60
Senior Member
Username: dfung60

Post Number: 554
Registered: 5-2002
Posted on Monday, June 25, 2012 - 6:01 am:   Edit Post

Jazzyvee -

Looks like your "working" power supply isn't working. There are two cables involved here, so there are a few things to check out.

1) You probably have two 5-pin cables. Is the problem exactly the same with either cables?

2) Try a different, known-good jumper cable from the power supply audio output to your amp. The best way to do this is to take the 1/4" cable that you were getting good bass sound with when plugged into the amp and plug that into the power supply audio out, then use another good cable to connect the bass to the power supply.

If you can eliminate the cables as an issue then it means the AC filtering in the power supply is at fault. There's not much in there - a transformer, bridge rectifier, and big filter capacitors. Either the rectifiers or the cap may have gone bad.

David Fung
jazzyvee
Senior Member
Username: jazzyvee

Post Number: 2977
Registered: 6-2002
Posted on Monday, June 25, 2012 - 6:31 am:   Edit Post

Thanks David I was hoping you would offer advice. :-)
I have 4 series cables and the problem is the same with them all.
I have also tried using the same good audio jack cable from PSU to amp and the situation is the same. Noise and signal.

(2) I'm not sure what you are suggesting here. So can I clarify this.
Are you suggesting.
(a) good audio jack cable from psu to amp and good series cable bass to psu?
or
(b) good audio jack cable from psu audio out to amp in then, good audio cable from bass to PSU and ignore the series cable?

Cheers
Jazzyvee
dfung60
Senior Member
Username: dfung60

Post Number: 555
Registered: 5-2002
Posted on Monday, June 25, 2012 - 12:34 pm:   Edit Post

Jazzyvee -

Sorry for the confusion... I was up through the night working on something and should be more careful about writing while asleep!

On the second point, what I meant to say was that you want to make sure that the 1/4" cable from PSU audio out to your amp is a good one. One way to make sure that a jumper cable isn't the problem was to temporarily use the cable which gave you good sound from the bass 1/4" out between the PSU and amp and a good 5-pin cable from bass to PSU. That was your interpretation 2a.

The reason to suspect the cables is that crackling noises are more likely to be connector or shielding problems in the cable than something in the power supply or instrument. The best way to determine the point of failure is to systematically swap in a known-good component in the chain one-at-a-time. That's not easy with these unique Series parts.

Sorry again,

David Fung
tbrannon
Senior Member
Username: tbrannon

Post Number: 1509
Registered: 11-2004
Posted on Wednesday, June 27, 2012 - 9:57 am:   Edit Post

Any progress with this, Jazzy?
jazzyvee
Senior Member
Username: jazzyvee

Post Number: 2981
Registered: 6-2002
Posted on Wednesday, June 27, 2012 - 1:45 pm:   Edit Post

No sorry its still a problem, i've tried all combinations of cables today... my head hurts lol.
What I have found is that on the female end of one of the series cables, one of the cores has come loose. Not the solder, but within it's socket it is loose so makes an intermittent connection with the instrument.
This end:



As this is the cable that came with the DS-5 in question I wondered if there was some stress on the cable at some point and maybe the socket on the unit is also cracked but not managed to test that yet.

Everything else I've checked outside the psu and this one one series cable seems fine so I guess it must be something to do with the PSU.

I've contacted a company here today who do musical instrument electronics repairs so I plan to take both PSU's over to him tomorrow morning sometime and see if he can make heads or tails of it.

Is there a circuit diagram I can take too or is it a simple enough device for an electronics repair person to work out what is going on inside?

Jazzyvee
keith_h
Senior Member
Username: keith_h

Post Number: 1763
Registered: 2-2005
Posted on Wednesday, June 27, 2012 - 4:41 pm:   Edit Post

JV,
It is a pretty simple circuit. Sent you a copy of the schematic that I received a few weeks ago.

Keith
dfung60
Senior Member
Username: dfung60

Post Number: 556
Registered: 5-2002
Posted on Wednesday, June 27, 2012 - 5:08 pm:   Edit Post

Jazzyvee -

It's normal for the inner connectors to float around a bit in these plugs. Although it's possible for the contact to get damaged, it will probably seat fine when connected up.

Just on the off chance that this matters... Were you the original owner of instruments? For many years, the only thing that used a 5-pin Cannon connector like this were Series basses. But I believe this connector has since been adopted for the DMX system that's used to connect up stage lighting equipment. I believe this cable will actually work with a Series, but the cable shields won't be right. I'm not sure the best way to tell them apart.

David Fung
jazzyvee
Senior Member
Username: jazzyvee

Post Number: 2983
Registered: 6-2002
Posted on Thursday, June 28, 2012 - 1:35 am:   Edit Post

No I'm not the original owner of the guitar or bass. Two of the cables came to me with the original instruments, one of which the inner connectors float around a bit... ." like that phrase".
The other two I got from a member here and seem pretty sturdy.

Anyway I think I will take the stuff to the electronics man and see what he can do.

thanks again for your input.

In the meantime I will have to get some new Duracells in case I have to use battery power on the gig.

Jazzyvee
jazzyvee
Senior Member
Username: jazzyvee

Post Number: 2985
Registered: 6-2002
Posted on Thursday, June 28, 2012 - 10:53 am:   Edit Post

Right thats it, both DS-5's are at the repair shop with an estimate for fixing both by Monday.

Jazzyvee
terryc
Senior Member
Username: terryc

Post Number: 1885
Registered: 11-2004
Posted on Friday, June 29, 2012 - 5:48 am:   Edit Post

You could use a noise gate but it may make your basses sound crap as the threshold may have to be set quite high
tbrannon
Senior Member
Username: tbrannon

Post Number: 1510
Registered: 11-2004
Posted on Friday, June 29, 2012 - 6:36 am:   Edit Post

Two bad DS-5's? What are the chances of that?? Did the shop give you any indication of what they thought the problem was?
jazzyvee
Senior Member
Username: jazzyvee

Post Number: 2986
Registered: 6-2002
Posted on Friday, June 29, 2012 - 7:44 am:   Edit Post

Thanks TerryC I can see your point but I'm hoping the noise can be got rid of because they are supposed to be quiet instruments noise wise. :-)

Tbrannon, no indication but I showed him the diagram and he didn't think there would be a problem fixing the one that doesn't work but didnt say anything about the noisy one. But just pugging in the series cable and taking a jack out into an amp should let him hear the problem.

Jazzyvee
tbrannon
Senior Member
Username: tbrannon

Post Number: 1511
Registered: 11-2004
Posted on Friday, June 29, 2012 - 8:20 am:   Edit Post

Hopefully he can get em both dialed in for you, Jazzy. It's a shame to have two amazing series instruments and not be able to use them the way they were intended.
jazzyvee
Senior Member
Username: jazzyvee

Post Number: 2991
Registered: 6-2002
Posted on Monday, July 02, 2012 - 4:11 pm:   Edit Post

Ok some success. The noisy DS-5 ( that came with the Dragon Guitar) has been fixed. The guy said that he added some more smoothing capacitors to the circuit and did something to the earthing and that has removed the noise.

He did ask me if I knew why the power supply was unregulated as he would have expected it to be. I said I haven't a clue to which he replied. Well If that's how Alembic make them then that must be how they went them to be so shouldn't be a problem.


The second DS-5 that came with the Series II bass has a blown transformer so thats gonna be replaced with a 240v transformer and replace the bridge rectifier thats also burnt out and add smoothing capacitors to the circuit too. So it will not have a USA voltage option of 110v which is not gonna be a problem as I doubt if I will ever be taking it on tour over there and in the remote chance that I did, I'd take the one that is still switchable to 110v

As usual thanks for your input guys.
Oh I also got my Roland JC120 fixed too so thats bright and sparkly and quiet with the series I guitar using both channels.

Jazzyvee
tbrannon
Senior Member
Username: tbrannon

Post Number: 1512
Registered: 11-2004
Posted on Monday, July 02, 2012 - 5:18 pm:   Edit Post

Very glad you've got the one working quietly and a plan of attack on the other.

Did you come up with a schematic for these to take to the repair guy? Seems odd that you'd get two bad power supplies. They seem to be pretty robust units.

Does this mean you'll be sporting the Series II on stage for the pre-Olympics gig at the Symphony Hall? If so- some pictures and hopefully a decent video or sound board recording should be in the plans!

(Message edited by tbrannon on July 02, 2012)
jazzyvee
Senior Member
Username: jazzyvee

Post Number: 2993
Registered: 6-2002
Posted on Monday, July 02, 2012 - 5:34 pm:   Edit Post

Yeah I got a schematic drawing emailed to me by Keith which I took with me. Yeah it does seem odd to get two with problems but these things do happen. It would be good exchange for one of the smaller units.
As for the pre-olympic gig that's my plan to take the Series II to that gig. at the moment I don't have any information on what time we are playing and for how long.


I'm just popping over to the gig section to post a picture of the event flyer.
Jazzyvee
terryc
Senior Member
Username: terryc

Post Number: 1891
Registered: 11-2004
Posted on Tuesday, July 03, 2012 - 3:15 am:   Edit Post

jazzyvee..interesting repair, I would have thought as a matter of course that all Alembic PS's have voltage regulation, even the most cheapest PSU from Maplins have this.
Anyway glad you got sorted and looking forward to the pics
jazzyvee
Senior Member
Username: jazzyvee

Post Number: 3051
Registered: 6-2002
Posted on Wednesday, July 25, 2012 - 3:29 am:   Edit Post

Now I don't even know what to think.
I got the DS-5 back on Monday and took it home. Plugged into Mesa boogie Walkabout amp... and got loads of hum still.

Rigged up my Alembic Rig with F1-x and QSC and no noise. Set up the rig in stereo and still no noise. However the bass pickup is still louder when the DS-5 is switched to stereo compared to when both pickups are selected in mono mode. I will wait till my other DS-5 comes back from having the transformer changed and see if it behaves in the same way.


Jazzyvee
ps: you may remember a while back I had problems with a regular clicking noise from my Roland JC120 when using my Dragon Series guitar.
I've found that the problem is due to one of these lovely things.
http://www.pcworld.co.uk/gbuk/devolo-1383-dlan-highspeed-ii-85mbps-powerline-starter-kit-00939029-pdt.html?intcmpid=display~RR~Computing~00939029

When it's on the signals are getting into the amp vial the power socket.
Turned off... silence.
Time to get a filter cable or mains conditioning unit for my gear.

Jazzyvee
jazzyvee
Senior Member
Username: jazzyvee

Post Number: 3052
Registered: 6-2002
Posted on Wednesday, July 25, 2012 - 3:41 am:   Edit Post

Now that "seems" sorted I'm definitely taking my new Series II to the gig.

I did take the bass to rehearsal last night and to be honest it sounded less than ordinary.
It was at a rehearsal room and plugged into a Hartke HA2500 and a peavey 4x10 cab. I usually have my Mesa boogie amp just flat and use the bass to give me the tone I want but this one wasn't giving me anything back, the bottom end was wooly and the treble side was not giving me any punch or the crispness i was expecting.


I know it sounds great through my rig and when I played it through some rigs at the California meet. I hope for this symphony hall gig tonight they have a decent bass rig for me or I may have to take a leaf out of Jimmy Johnson's book and just go into a DI and use the on-stage monitor.

Hopefully someone will be taking photo's and I can get some to post up here.
Jazzyvee
jzstephan
Intermediate Member
Username: jzstephan

Post Number: 105
Registered: 1-2012
Posted on Wednesday, July 25, 2012 - 6:27 am:   Edit Post

http://www.soundstage.com/noisy15.htm

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