spirit soundcraft powerstation 600 mixing desk

[madmaria43]

Hi

I am a newbie so please bear with me and I am not a sound engineer I am just a singer but I am eager to learn. I am completely going crazy with a problem I am having with my mixing desk which is a soundcraft spirit powerstation 600 and it is 10 years old. It has had a few problems over the years but nothing that couldnt be fixed but this time it has got everyone stumped.

 

As I say I am a singer and not a techhead, but I have ears and I know when my sound isnt right well afer 10 years I should do. we have had the desk apart and checked all the boards and all the souldering,checked for liquids being spilt on it, anything that looks blown, anything that is loose and cant find a damn thing. The problem started after I was at a gig and a loud crack came through the speakers and prior to that the problem was intermittent, where it wasnt as powerful as it used to be and I was getting feedback when I never used to get feedback, and all of a sudden it has gone very bright and the mix isnt right. its not mixing instead of it all blending nicely and sounding smooth it sounds like the music and my voice are sitting side by side an I am singing into a tin bucket. The guy who repairs it for me is stumped too at first he said that the left hand channel had blown on the amp and so he said he had sorted that out and said he had tested each knob with a meter of some kind (sorry dont know its name) and he said it is fine but it isn't.

 

What seems to be happening is that it just hasn,t got that round sound anymore and it is very bright, I am having to take the top of my voice and the music right back. It feels like the amp is holding back on the power, if you see what I mean. Like when someone is trying to run but someome else has hold of them so they cant run as fast. or when you try to scream quietly, like something is being supressed, does that make sense? I hope it does to someone. I have checked my speakers and they dont seem to show any signs of damage they are 10 years old jbl eon 15s passive .

please help any ideas I dont care I will try anything thankyou I really appreciate this!! Madmaria43

[Doug Siddons]

Just a thought but maybe the speakers are out of phase with each other, when the amp was repaired something might have got swapped. Try undoing one of the speakons on your speaker leads and swapping the +1-1 connections.

[parky58]

I have a friend with the same mixer amp. He was having problems with intermittent sound and asked me to take a look. The problem was down to the left and right output insert jack sockets in the rear panel. As they were never used the contacts oxidized and produced an intermittent signal path - worth checking.

 

Steve

[KevinE]

Get it looked at by someone who knows what they're doing. A quick test with a signal generator and scope will narrow the problem down to mixer or amp section and then it's fault finding time.

 

If it went 'crack' then something has obviously happened, if this was at the point of failure. I'm sorry but I can't offer a DIY fast fix for this.

[madmaria43]

Hi Guys

Thank you for your help I really appreciate it, and the time you have spent writing back to me. I know it is such a complicated thing to try to explain without you actually taking it apart and looking at every individual solder and connection. I did as you said and had all the input holes cleaned out incase they had dust or whateva in them. I went round with a torch and inspected the board front and back with a mini torch to look for any oxidization, or any change of colour of anything, and I looked for anything that looked burnt out. Two of us went over it and also the lexicon effects board just in case it was that. But neither of us could see any obvious damage. We changed both volume master faders. The two yellow faders.

 

Just to recap prior to us taking it apart we got a sound guy to fix it and he said at first it was the left channel that had blown on the amp (I think that is what he said) Well he definately mentioned the left channel and amp in the same sentance. I didnt know that an amp had a left and right channel does it?? or is he lying to me because he thinks I am stupid??

 

He said he got his friend to check every knob and fader for output with a multi meter and that it was fine. But it is far from fine it may be a bit better but not right by a long way. That smooth round sound of good mix of music and my voice is just not there anymore it is as if my voice and the music are lying side by side instead of blending together. It is far too toppy, tinny and I have to take top off my voice and the music because you get that horrible pitch thing in your ear that makes you screw your face up, I dont mean feedback although it is doing a lot of that as well but more on the base frequency the low end. I am also having to take nearly all of the high frequency off both my voice and the music and it is weird because I have a deep voice sort of like heather small. I never ever had a problem with feedback.

 

Then we went over it again checking each channel and found out that channel 5 and 6 wasnt working properly my friend seemed that the faders were wrecked on these and also the faders on the stereo channels the ones with the red sliders were also faulty as one side was nothing and one side was really low volume.

 

But what I really noticed the other night was that it seemed like the volume or the power was being supressed. The only way I can describe it is(imagine someone trying to scream or shout but something was stopping the sound or restricting the sound coming out of the mouth.) I hope you understand what I mean.

 

I thought maybe the speakon connectors could be faulty on the desk you know the holes at the back of the desk were the speaker cabel goes in? Could that be possible???? Would that make it do what it is doing??

 

I also found out that my shure sm58 beta mic has a fault too because one of the little metal bits (there are two metal bits)that stick out on the top of the green board(there are 2 together and one which is to the right, it is the right one where one of the metal bits has come off) the others are in tact. So I would also like to know if this would affect anything.

 

Although as I say I know nothing about these things but I am not convinced it is the faders as my friend seems to think.

 

I have also 2 jbl 15 eon passive speakers could it be something to do with them or have you any ideas of any common problems that these speakers have in general??

 

I know I am hoping for a miracle but please dont give up on me just wrack your brains and suggest anything you may think is the posssible cause and I promise I will check everything you suggest because at least you guys know what makes what do what were as I dont well not everything. If you want to use techno speak that is fine I am sure I will figure out what you mean. thank you again so much and please carry on with your ideas. kind regards mad maria x

 

A concurrent post has been automatically merged from this point on.

 

Get it looked at by someone who knows what they're doing. A quick test with a signal generator and scope will narrow the problem down to mixer or amp section and then it's fault finding time.

 

If it went 'crack' then something has obviously happened, if this was at the point of failure. I'm sorry but I can't offer a DIY fast fix for this.

Hi Kevin

thankyou I am going today to get that tested as you said, it is hard where I live though to find someone who is not going to rip you off, as I havent got any spare money at the mo, hence have been trying to narrow it down myself because the last guy I had had got up to £180 and still not fixed the problem so yu see this is why I have been trying to find out what is wrong myself because I just cant afford any more of anyones time. Anyway heres hoping for a miracle ** laughs out loud ** !!willl let you know the outcome thanks again madmaria x

 

A concurrent post has been automatically merged from this point on.

 

Just a thought but maybe the speakers are out of phase with each other, when the amp was repaired something might have got swapped. Try undoing one of the speakons on your speaker leads and swapping the +1-1 connections.

 

 

Thank you for your advice I will try that too.

 

kind regards madmaria

 

A concurrent post has been automatically merged from this point on.

 

I have a friend with the same mixer amp. He was having problems with intermittent sound and asked me to take a look. The problem was down to the left and right output insert jack sockets in the rear panel. As they were never used the contacts oxidized and produced an intermittent signal path - worth checking.

 

Steve

 

 

Hi parky 58 I thought it may be that so when I have done the test that kevin suggested my next move will be that thankyou kind regard madmaria

[ChazHS]

Hi Maria,

 

Where are you based? That will help you if any of the engineers on here are local to you and might be able to have a look at it.

[vlfaudio]

Hi Maria,

 

you mention something broken on your Beta 58. If the mic's gone "one - legged" ( faulty connection means you're only getting one half of the balanced signal ) this would explain the toppy signal and early onset of feedback. The power station supplies phantom power globally to all channels, if a connection on your mic failed with phantom power applied you would indeed have got a loud crack through the pa which may have caused further failures. Try borrow another mic and cable that is known to be working and test with this. Or try your mic on another desk. If it sounds thin and lacks bottom end you've found the problem, although, as I said, the spike may have caused other failures.

 

Cheers

 

 

Steff

[Lion Tamer]

Hi Maria

 

First let me say that I am working from the service manual for the predecessor to your mixer (as I happen to be mending one at the moment and don't have the one for yours) - I doubt that there is much difference electronically between the 2.

 

Make sure you have a known good sound source and a pair of headphones and then see if you can answer the following questions (you will only get sound through one side of the headphones):-

 

1. Does the fault happen on all channels (mono and stereo)?

2. Try plugging your headphones into the "mix outputs" - do you still have the fault?

3. Try plugging your headphones into the "Aux 1 output" - do you still have the fault?

4. Try plugging your headphones into the "Insert" of your test channel - do you still have the fault?

 

If the answer is yes to all the above questions then I would guess that you have a power supply fault. Double check all the fuses on the lower board - if one of these is blown then it could cause some strange faults.

 

Yes your mixer does indeed have a left and right channel on the amp.

 

I will leave it there for now as you would probably need some form of signal generator and oscilloscope to go much deeper.

 

Jem

[Cheeseweasel]

Hi Maria,

 

you mention something broken on your Beta 58. If the mic's gone "one - legged" ( faulty connection means you're only getting one half of the balanced signal ) this would explain the toppy signal and early onset of feedback. The power station supplies phantom power globally to all channels, if a connection on your mic failed with phantom power applied you would indeed have got a loud crack through the pa which may have caused further failures. Try borrow another mic and cable that is known to be working and test with this. Or try your mic on another desk. If it sounds thin and lacks bottom end you've found the problem, although, as I said, the spike may have caused other failures.

 

Cheers

 

 

Steff

 

I agree - one-legged mic would definitely account for the tinniness (as you've effectively put a capacitor in your signal path, which acts as a HP filter), and if one of the wires is hanging off the pcb and you're still able to hear something I guess that's what's happened.

[KevinE]

It is important at this stage to diagnose actually which piece of kit is faulty, before anyone can offer sensible, meaningful advice on the root of the problem. It is no use us thumbing through schematics of amplifiers and mixers to guess at the fault area if it turns out your speakers are shot or your mic or cables are faulty. This just wastes time!

[madmaria43]

Hi Guys just an update took my desk and my jbls to a guy and he said that the speakers had done well to last 10 years because of the neoridyum (or something like that) rare earth magnet, which normally looses its magnetism by then. He said that could be what has happened to my speakers is that right? and is there any way to test to seee if they have lost their magnetism. ?? thank you again your help is really appreciated I am learning all the time maria x

 

A concurrent post has been automatically merged from this point on.

 

Hi Maria,

 

you mention something broken on your Beta 58. If the mic's gone "one - legged" ( faulty connection means you're only getting one half of the balanced signal ) this would explain the toppy signal and early onset of feedback. The power station supplies phantom power globally to all channels, if a connection on your mic failed with phantom power applied you would indeed have got a loud crack through the pa which may have caused further failures. Try borrow another mic and cable that is known to be working and test with this. Or try your mic on another desk. If it sounds thin and lacks bottom end you've found the problem, although, as I said, the spike may have caused other failures.

 

Cheers

 

 

Steff

 

I agree - one-legged mic would definitely account for the tinniness (as you've effectively put a capacitor in your signal path, which acts as a HP filter), and if one of the wires is hanging off the pcb and you're still able to hear something I guess that's what's happened.

Hi guys I am going to send the mic back to shure to repair so that gets rid of one problem ** laughs out loud **!!

[David Lee]

jbls to a guy and he said that the speakers had done well to last 10 years because of the neoridyum (or something like that) rare earth magnet, which normally looses its magnetism by then.

 

Doesn't sound right to me, though I am ready to be corrected.

 

A quick test to see if it is magnetic, get a bit of ferrous metal (iron) and if it sticks to it then there is still magnetism. Whether that is enough to prove that the magnets are good enough is another thing.

[boswell]

neoridyum (or something like that) rare earth magnet, which normally looses its magnetism by then.

 

I think he is trying to pull a fast one and flog you more speakers, though I am open to correction.

[ramdram]

In fault finding the easiest and cheapest way is to try the substitution thing. As mentioned above, you really need to test your desk with other mics and other speakers and those items with other desks etc etc.

 

You need also to check every cable and connector, again as mentioned above.

 

Only then should "you" start delving into the desk proper. Unless you have the schematics/circuit diagram you would be wasting your time...not to mention money.

 

You are correct to be concerned about being told about magnets losing their magnetism...we have even older Eons and they are exposed to huge temperature variations and they still work, despite the attentions of our younger volunteers, ** laughs out loud **. You might care to google for info on this if you have the time and will to live sort of thing.

 

I appreciate you are strapped at the moment but it is not a sensible option to let well meaning folk simply plug away on general principles...without them having at least a circuit diagram and manual.

 

Again as mentioned above, were you to indicate your location you might get some good advice on where to take your desk for expert attention. You must appreciate too that your desk is not in its first flush of youth and it is not unreasonable to find that components are failing.

 

There is no quick answer to this, certainly via the forum(s), as you have found already.

 

Therefore your options are to google for a Soundraft dealer/repairer in your location and simply bite the bullet when you get the bill. It may be the repair/service/overhaul may reveal all sorts of gunky stuff in the connectors, say, etc so will be worth the cash outlay.

 

You have sent off the mic so you are on the right lines already so to speak.

 

Secondly, indicate where you are based and hope the forum members can suggest a reputable repair facility near where you live.

 

If you are reliant on the desk for your living then the stark truth is no desk = no income.

 

HTH

[madmaria43]

Hi guys

thank you once again for all your advice but just to summarise main problem too much top end havingto take it off voice and music and desk normally has more ooomph than it is putting out at present .I have now got some clue to what is faulty on the desk but dont know the cause . First of all the stereo chanels are faulty and 2 of the other chanels are faulty. Does that help anyone ?? I will by you all a paket of smarties if you crack this or even get somewhere close. ** laughs out loud **!!

I am going to see the guy now will update you on what he says later thanks again maria.

ps I am listening to what you say but literally I am broke so at the mo I cant go down the route of sending it to sound craft and you are also right I need the income catch 22 is what I am in at the mo. hence me doing all this. I hava a feelling in my gut that I can find out what it is just need your help thankyou mariaxxx