I was recording a friend of mine play saxaphone for a school project in my house the other day. I ran an AKG mic through a little 6 channel yamaha mixer. Then I made the mistake of routing that audio through my pioneer receiver then to protools on my computer. In the process i blew some component out on my pioneer reciever. I now hear a "crackle" in the left channel. I unpluggled everything, swiched speaker settings. And learned it also comes through the headphones even when the volume pot is all the way down. Basically it sounds like popcorn through the left side. Audio does come out but along with the crackle. Any ideas?

Sounds to me like you blew a resistor... if you are brave, open up your pioneer receiver and take a look at the card that is attached to your "line in" or "mic in" input. Whichever you used (which might be the problem BTW) There should be an obvious tell tale burn mark or place where the solder turned amber looking. This is your bad electronic gizmo. Unsolder it and take it to Radio Shack and see if they have a matching one. Then replace it. Just make sure your soldering skills are good, because there isn't much room to work on.

Alright, Froggy, stop kidding around. You obviously made that whole thing up. Not cool.

I ran the audio through the "CD in" and out of the "Tape REC" out from there into my sound card on my 'puter. But I dont think its on just that bus, When I switch to TUNER or VIDEO or LASER ........i still get the same crackle through those Input buses also even when the volume is completely down.
Thats what confuses me, i wondered if maybe it was the volume pot itself?
But I havent yet opened it to look for burnt components. I was going to wait and ask around to see if anyone could pinpoint the problem.

(Edited by GrungeSlobTearPants at 3:03 pm on Oct. 9, 2003)

You may want to practice your soldering skills before you make the repair.

Smart asses all of ya... running it thru cd in should be alright... I'm assuming you were feeding it line level?

If it was your volume pot, that's just a freak accident that it coincided with your recording. But, my guess is that it's someting more than that, as you would have noticed a dirty pot way before that.

Is it total crackle? Or does it just crackle when you adjust the volume?

It seems like the crackle starts out soft, and the longer i leave it powered up, the louder and more frequent it gets. It doesnt matter if I touch the volume knob or not, it can be left all the way down. and like i said, only the left channel makes the noise. Another reason this may have happened, when i was recording, I ran audio (a click track) from the computer back into the mixer and through the receiver again (CD in LINE level) to be recorded on the computer. Im not sure how to really describe that, but maybe the cycling of this audio caused the problem?

Last night I switched out receivers to an old Quasar reciever that I bought at a yard sale for 5 bucks. Needless to say, the audio quality is horrible. But i did figure out how to bi-pass the reciever and run recordable audio straight to my computer through the echo sends of each channel of the mixer. I wish i had set it up that way to begin with

(Edited by GrungeSlobTearPants at 10:20 pm on Oct. 9, 2003)

My best educated guess is that you blew out the left side of your amplifier. Especially the part about "the longer I leave it on the worse it gets"

Unforunately you are screwed on that, because that's the main component of your receiver. To replace that will cost you more than buying another new one.

The main problem here is that you are using consumer grade stuff in line with pro gear. Why weren't you capturing out of the mixer in the first place? That's where I am lost. Why was the receiver in the loop? (I'm not being a condescending ass here, just trying to understand...)
You can all me or PM me off board here if you want to talk to me more in depth... but I'll warn you, I know just enough about audio to be dangerous and make sound stick to my pictures....

I think you are right on that.

Basically, I had been using the mixer for listening purposes. I run my cd player through 2 channels, computer through 2, and 2 mics through the other 2 (for cheesy karaoke night in my bedroom) and I can EQ and mix any channel that i want. Then I run the mixer audio into a receiver which amplifies 6 speakers. 4 8-inch and 2-10 inch. (more crappy speakers than I really need in my bedroom) Anyway, thats what i had been doing and it worked alright, maybe the level going into the receiver was a bit too hot for consumer gear, I usually boost the mixer until the needles on the VU meters hover around 0. But the speaker set-up required alot of amplification. So it worked alright. I wanted to record this audio, and the mixer requires 1/4 inch or XLR connections on the sends, of which i didnt have at the time, so i chose to route the outgoing audio from the Tape REC out b/c they were nice RCAs. Now i have the correct connection and can by-pass that.

The loop was basically my cheating way of setting up a click track for the headphone cues. I downloaded a metronome awhile back for my computer and i sent that audio out, and back in to be recorded. I tried to use pro-tools but there's latency due to im using an old PC with a pentium II processor.

Anyway, Thanx for the info. If u can come up with anything else. Let me know.

It's definitely your amp then... by putting the mixer upstream like that, you are essentially creating a pre amp. The CD input is made to take an unamplified signal at line level from the cd or equivalent device (video, DVD, laser etc)

What you did was probably pushing the engineering limits of the amp (it was already receiving an amped source in your setup), and at some point you gave it a little to much juice from the mixer... blowing out the weakest part (left side of your amp).

Let me get this straight...you looped the click because because you were monitoring through the amp and not the computer, right? Was there any way to monitor with headphones from the computer, so you could listen to the click out of pro tools? I guess thats what I'm confused about, why the need to reloop the click into the amp instead of listening direct from the computer? You always want to monitor from the last place the audio hits or from wherever its being recorded i.e. "from tape". Of course there's exceptions if you're doing a cue mix or something but thats opening a whole other can of worms.

Another thing, was there two different CD inputs? You said you put the click back in "again in CD LINE". So were you still running the mixer in through another CD input? IF so, thats wierd, I don't think i've seen two different CD inputs. Different phono inputs i've seen (my amp has three!!)
but not CD inputs. IF that was the case then thats definitely what did it, you fried something with two pretty hot signals.

If it was just one input, we're still right, the signal was too hot for a consumer line amp. Either a high end/hifi amp (which you don't really need hifi in this case) or a workhorse monitor amp like a JBL or Peavey or something is what you need. The latter of course will be much cheaper than the former.

As far as what precisely is wrong in the amp, I'll leave that up to Peacefrog, it sounds like he knows much more than I do about that stuff. You know, Parrish is a wizard at amp repair, or audio repair in general for that matter. If you know him he's really the guy to ask.

I looped it b/c i was creating a click track. I was using a metronome program to create the signal and then i ran the audio out and back in to be recorded. Not the smartest idea, but it was what i came up with at the time. I mixed that track with a guitar track and burned it to cd.

Had I tried using protools and just played the click track while recording the sax, my processor could never support all of that information and there would be latency b/w what he was playing and what he would be hearing, so i decided to burn a cd and use that for a cue mix along with his microphone audio, and send only the mic audio to the computer to be recorded. the click mix was just thrown together to record him, wasnt anything important or anything that i needed to keep.

Im not sure what u mean about the CD line in, I guess my information was a bit sketchy, but basically, I run all of the output audio from the yamaha mixer through the CD in on the receiver, I couldve chosen any input, they are all at line level RCA plugs. I just went with CD. Then the out goes to the computer, REC out.

The loop comes from the computer, into th mixer, into the CD in, then out the REC out, back to the computer......then keeps looping. I had turned the speakers off by this point, but I eventually did get a click recorded from the computer, through the other gear, then back into the computer. I think thats when i blew the circuit though. The track has much distortion and noise.

As far as the level, yeah, it probably was / is too much. I just enjoy hooking up all of my audio gear and seeing what it can do. That level lasted for a long long time though. The Pioneer Amp did a damn good job for months down the road until i tried this little recording session. Now like I said im using an old reciever. It sounds like garbage, but its something to amplify my speaker array, I probably should reduce the speaker set up so that the mixer can amplify without a problem. But as it is set up now, i need the extra kick in the ass from a reciever. I thought about moving the reciever higher in the chain, running audio through it before the mixer, but I think the mixer will distort, it only likes audio around 0 VU on its meters, once it gets higher, distortion is easily heard.

Anyway, thanx for all the info