problems with soundcraft series 1s mixer

[tomislav.b]

Hello. I'm new to DIY stuff and to music recording in general.
I got involved on recording.org and while I was there, my mixer died. Well it didn't die. Here's the problem:

i have a soundcraft series 1s that i got because i can't afford anything right now.

i've had it for about two weeks, and its worked fine. i just had a dead channel (1) and today the EQ wasn't working on channel five.

Well, a few hours I go to do some work and the sound going into the 8-track was really distorted. i adjusted the peak, it wasn't that. i swithced to a different channel. it wasn't that. i tried different mics, different cables. it wasn't that. finally, i switched the headphones into the mixer from the 8-track. I pushed down 'solo' on a channel to see if it was the mixer that was distorting the sound. It wasn't. i plugged the mic into the 8-track and determined that it wasn't the problem either. Then I came to the conclusion that it was the XLR output from the mixer.

I didn't know what to do, so I turned it off, came back about an hour later.

This time, I try to do things again, but now there's a buzz that goes from being soft to really loud once i turn a channel on. once that buzz comes around, nothing becomes picked up.

yeah. i'm going through a range of emotions right now.
help me out. i hope it's not ready to be thrown out since i was really excited about finally having a mixer, even if it was a dinosaur.

http://error599.net/tomislav/m1.jpg

since then i've messed around with it some more and found out that all of the sound, even from the headphone out on the mixer is being distorted unlike before.

Many people suggest it being the power supply and various other things. Here are two links to my threads on recording.org to get more familiar with my situation. I really don't know much so it would be GREATLY appriated if you could help me out! I have pictures of the inside too if anyone wants to see.

http://recording.org/modules.php?name=Forums&file=viewtopic&t=22845
http://recording.org/modules.php?name=Forums&file=viewtopic&t=22943

 

[Enzo]

Fix one thing at a time, and often other things fal into place.

Have you contacted SOundcraft for the schematics?

If an output line sounds bad no matter what input channel is used, then it is usually the output line driver. Not familiar with that board off the top of my head, I would expect a bad op amp.

I would suspect power supply if all the outputs are affected. If the one main out is bad, but not the other, or if both mains are bad but not the AUX sends or othre sends, then the PS is OK. On some boards, two adjacent channels share ICs. SO a bad IC can affect both L and R channels. Of course only half an IC can be bad and so affect only one channel.

Are there insert points for the bad outputs? If so, take an output from the insert and see if it sounds clean. That will localize the problem as before or after the insert.

 

[tomislav.b]

is there a way i could contact you enzo, via aim or email or something?

i can't quite understand what you said.

 

[Enzo]

I will describe my email address thusly to avoid harvesters:

First part is "tmenzo"
next the symbol for "at"
then MSN
then your dot com

I am happy to try to help, but please try to get the drawings from SOundcraft. Exploring is so much easier with a map.

 

[tomislav.b]

yeah, i got the user manual from soundcraft with has a list of parts and drawings of stuff that i can't understand...

where do i learn how to read this stuff. like i said, i had no clue, but enzo, it would be greatly appretiated if you could help. yeah. thanks man.

 

[Enzo]

What we really need is the service manual, which is probably nothig more than a schematic. If the owners manual is Greek to you, I don't know what the schematic will be for you. Unless the owners manuals include schematics.

Most of the Soundcraft drawings in my files are for the Spirit series.

 

[dnsey]

The regulators in some Soudcraft desks seem to be run 'close to the edge', with minimal heatsinking, and get too hot IMO. I've had a couple which were faulty, but hadn't failed completely, and gave very odd effects. Worth checking.