Spirit Folio F1 14/2 HELP PLEASE.

[AllergyBeats]

Hello, I am currently running the sound output from my mac through a line input on my mixer, recently I have experienced very strange sound, basically, when playing a song I only hear the hi's and mids, but not the bass or the vocals!! When i remove the audio jack and insert it into the 'ins' which is the socket below the 'line' but which is un effected by the gain, the sound comes through ok. Can anyone point me in the right direction of what may be faulty on my mixer? This problem occurs through each channel so considering that and after inspection of the pcb, I have eliminated that the line terminals need re soldering.

Any help or possible causes of this problem would be greatly appreciated!

Kind Regards,

Dan.

[Enzo]

Does it act this way on ALL the channels, or just the one you've been using? Try going into a different channel. ANd likewise, try some other input into this one.

[AllergyBeats]

Hi Enzo, thanks for the reply.

This fault is effecting all 6 of the mic/instrument channels. On each of the 6 channels I have options for xlr, line and ins. The input effected is the line input, I am currently waiting for xlr leads so cannot test this function and the ins input is ok. The only difference I can distinguish between line and ins is that the gain/Sens control only effects the line input, where as the eq and aux functions effect both line and ins and eq and aux are working fine.

Thanks, Dan.

[Enzo]

INS means Insert. The insert jack is a place in the signal path after the intitial amplifier stage wher you can insert some piece of processing gear, like a compressor or something.

I mentioned trying some other input, meaning plug a guitar or a tape deck or a synthesizer into those line inputs. That way we can see if everything sounds that way in your mixer, or if there is some issue now with your Mac output.

My thinking is there is some problem with the matchup between the Mac and this mixer.

[AllergyBeats]

Oh I see. In that case yes I have tried multiple audio sources and i have determined its definitely the mixer which is faulty. I have also removed the mixer from the equation and just plugged my mac directly into my amp, thus testing leads, soundcard etc etc and all is fine.

I admit, its very strange that every channel is effected. Im an electrician and even looking over the pcb this doesnt seem logical. Hopefully my xlr leads shall not be much longer then I can test those inputs.

Cheers

[Brad1]

..running the sound output from my mac through a line input on my mixer, when playing a song I only hear the hi's and mids, but not the bass or the vocals!!

NOTE: The following is ASSUMING you are running a stereo signal from the MAC to the mixer, and that's what problem you are hearing. If your problem occurs on a mono-input source, then the following can be disregarded, as it won't cause the effect....unless, maybe, you are monitoring through amp or speakers with a polarity shift in their connections, somewhere.

That sounds like the classic "180 degree out-of-phase center-cancellation" effect. Ever hear of those "Karaoke vocal-removal" devices and programs. That's how they do it, and they ALWAYS lose bass. You can demonstrate this with your headphones plugged into your computer. Bring up a stereo tune in your DAW, flip the phase of ONE channel, only, and then listen to it. Sound like your problem?

If you have two signals, and one of their polarities is flipped (+ becomes -, - becomes +) anything that is common to both signals will try to cancel out, greatly reducing the volume of those common signals. What is usually common to both the left and right channels to make it appear as they are coming from the center? The vocals and bass, normally.

Check your cables. Assuming you are using a TRS (3-contact plug) from your computer, that should CHANNEL (not just Y-split) the signals to left and right, with proper + polarity going to the tips of two 1/4" TS cables (NOT TRS cables).

You can use a normal, readily-available "Insert Cable" for that. IF it's a TRS (or, "Stereo out") output on the computer, here's what you should see, if doing a continuity check:

Tip of computer-end TRS plug > Tip of one of the 1/4" TS plugs to mixer input. (That will be either left, or right +.)

Ring of computer-end TRS plug > Tip of the other 1/4" TS plug to mixer input. (That will be left or right +, opposite channel of first.)

Sleeve of computer-end TRS plug to sleeves of BOTH 1/4" TS plugs. (That will be -, or common ground of both.)

Do an experiment, BTW. With the way it's currently set up, play with both mixer channels' pan pots, and see if anything changes...as far as vocal or bass level? If it changes levels of bass/vocals, I'm guessing this is the problem.

Check your cables/adapters to make sure you are using only the proper paths. Check through headphones from the mixer, and see if it's in...or before...the mixer. If things sound OK through headphones, but you have amp/speakers or powered monitors..it may be AFTER the mixer...check the polarity of those paths.

I won't guarantee this is the problem, but it sure sounds suspiciously like it is. Of course, this doesn't explain why you can plug them into your inserts, and the apparent cancellation disappears. That's why I won't GUARANTEE this will work.

Anyway, check all that, and please report back. Could be something else, but you've at least eliminated that possibility, if it's not what I guessed.

Brad1

[AllergyBeats]

Hi Brad1, thanks for your reply.

You are absolutely correct, that is exactly whats happening. All my cables etc have been throughly tested and are all fine. I run a stereo 3.5 jack into an adaptor, then into the line in of any of the mixer channels and the problem remains.

I discovered something interesting this morning on the mixer, there is definitely some leakage somewhere, as when there are no audio sources even connected let alone playing, the L and R meter level is at half!

Another way I confirmed you are correct is by using the pan control in my settings to switch between 0 and L + R.. When it was centred the problem was present, but when I flipped to either L or R, the problem disapeared!

Through many different tests I have definitely identified that the problem lies within the mixer and am pretty sure through logical process of elimiation that the problem is something to do with voltage control of all the amp that are controlled by the sens.

The reason I get good signal from the insert is because it lies directly past the line in, sens and hi pass filter, thus confirming the problem lies somewhere between the line in socket and the hi pass filter.

Kind Regards,

Dan.

[AllergyBeats]

http://www.soundcraft.com/downloads/..._guides&id=690

This is PDF download link to the user guide which contain a schematic of my mixer on page 31, this displays only the paths of the sound signal but no voltage infomation except for the 48v used for the xlr's.

If anyone knows of anywhere I can obtain a detailed circuit diagram of my model, which is, Soundcraft Spirit Folio F1 14/2, I would be extremely grateful.

Dan.

[AllergyBeats]

Oh, an just one more thing, its not only when the polarity is reversed this occurs, its also when L or R drops out altogether, which is I think whats happend in this case.

Thanks again Brad1

[g1]

I run a stereo 3.5 jack into an adaptor, then into the line in of any of the mixer channels and the problem remains.

Have you been using this adaptor in all your tests? If so it is probably your problem.
Find a way to connect a stereo sound source to your mixer without going through the computer or the mini jack adaptor.

[AllergyBeats]

Hi G-one, ive been using this for months and ive also tested it on various other equiptment, its definitely the mixer.

Ive just tested and discovered one of the voltage regulators has failed, which is probably the supply to the sens amplifier chips.. I will write a new post confirming this for anyone experiencing this problem.

Thanks

[Steve Conner]

Let me guess. You're plugging a stereo source into a mono TRS balanced input, and you wonder why you're getting that out of phase sound?

The result is exactly what Brad1 explained, the mixer produces the difference between left and right channels.

I suggest you try a splitter cable that adapts your Mac's stereo jack to two mono ones, before molesting your poor mixer's innards any further.

[g1]

I suggest you try a splitter cable that adapts your Mac's stereo jack to two mono ones, before molesting your poor mixer's innards any further.

I was wondering about damage due to plugging a non-insert type source into the insert jacks, thereby applying signal to the send, or shorting it to ground.

Hi G-one, ive been using this for months and ive also tested it on various other equiptment, its definitely the mixer.

If this is true, it is by coincidence. If you have not reproduced the problem WITHOUT the adaptor, you can not absolutely say the mixer is at fault.
I don't think there is any possible fault that would cause this issue on ALL channels, but only before the insert points.
If the regulator was causing the problem, it would have also been causing problems after the insert points and everywhere else in the mixer.
Maybe the regulator has blown due to another issue.

[Steve Conner]

I was wondering about damage due to plugging a non-insert type source into the insert jacks, thereby applying signal to the send, or shorting it to ground.

Who said to plug it into an insert jack? Take the two mono jacks and plug them into two line input channels, pan the two channels hard left and hard right, it should work.

Or plug them into the two jack inputs of one of the Folio's stereo channels (blue faders). Just understand that the mono inputs are TRS balanced and will not accept a stereo jack.

I had the Spirit M12, which looks pretty similar.

Edit: I forgot to mention that my M12 suffered dreadfully from dirty/bent contacts in the line input jacks, and now I think about it, I remember some weird out-of-phase effects being caused on the stereo inputs by that.

[g1]

Who said to plug it into an insert jack?

This is what the OP was doing to try and diagnose the problem (post #1). You were talking about "molesting your poor mixer's innards any further". I was just speculating on damage that may have already occurred. Sorry for the confusion.