doctorcilantro Posted March 16, 2004 Share Posted March 16, 2004 Hi folks, I am posting this here because I know there are a lot of people who could hope; I have been inundating Ryan Inman with emails since he just made my Sherwood S-5000 sound great, which is part of this whole debacle. I would like to add that, as you all you, Mr. Inman is a top notch tech & and a great person. System: Sherwood S-5000 8 Channel DJ mixer PC w/ M-Audio Delta 44 audio card connects via parellel cable to breakout box which has 4in 4out (2 stereo in 2 stereo out) ...all 1/4" jacks (accepts balanced or unbalanced) Overall plan: To have components run to mixer (tape, tube tuner, cd) and output via rca cable to Sherwood via AUX input. HW-19 inputs into the Sherwood via rca cable into PHONO stage. REC out of Sherwood goes to Delta 44 break out box via (2) rca>1/4" Output of sound card runs to mixer via (2) rca>1/4" cables Problem: When nothing but the REC out of the Sherwood is connected to the breakout box inputs 1&2, I get massive feedback hum on the speakers. This is with any stage selected, AND it doesn't occur on inputs 3&4 of the box. When I unplug the box from the computer the hum/feedback stops on channels 1&2. My box is fried, it won't OUTPUT any sound to my mixer. My question: When I get a new box or soundcard, am I going to have the same problem again. Is there any inherent fault in this setup? I was getting the feedback before a feedback loop fried the box so I am inclined to believe the box was at fault from the beginning. You can use software to mute all inputs of the card etc. to avoid any type of signal loop, which I had never had a problem with with my M-Audio 24/96 audio card. The computer is earth grounded. The audio components are not, they all run into a line conditioner which itself is earth grounded. The mixer has three male prongs on itself but the side that plugs into the conditioner is a two prong. Ryan removed the capacitor the grounded the line voltage to the chassis so I would not have a problem. I did have my tube tuner running into the mixer at the start which has not been worked on. Again, I am inclined to believe either the box was faulty or there is some inherent design in it that will make it not compatible with my setup. Thanks for any advice in advance. Jonathan Quote Link to comment Share on other sites More sharing options...
Griffinator Posted March 16, 2004 Share Posted March 16, 2004 ---------------- On 3/16/2004 12:34:41 PM doctorcilantro wrote: Output of sound card runs to mixer via (2) rca>1/4" cables when nothing but the REC out of the Sherwood is connected to the breakout box inputs 1&2, I get massive feedback hum on the speakers. This is with any stage selected, AND it doesn't occur on inputs 3&4 of the box. When I unplug the box from the computer the hum/feedback stops on channels 1&2. ---------------- This is precisely the problem. You created a feedback loop. Your soundcard feeds the breakout box. Breakout box stereo out feeds one of the mixer channels. Mixer feeds amplifier. Amplifier feeds inputs 1&2, which in turn are monitored (as any full-duplex soundcard will do) constantly on outputs 1&2. See where the feedback loop happens? Reason it doesn't happen on 3&4? Because you don't have 3&4 selected in the software interface, so they're not being monitored. How to fix the problem? Instead of going REC out on the amp to the breakout box, use the aux sends on the mixer (I'm assuming, of course, your mixer has them). Adjust aux send gain levels on the other devices (CD, tuner, tape deck) until you've got good source volume heading to the breakout box for recording to the computer (which is what I presume you're attempting to do there) and make sure there is aux send gain for the computer's output is at ZERO. Quote Link to comment Share on other sites More sharing options...
doctorcilantro Posted March 16, 2004 Author Share Posted March 16, 2004 I was thinking that since I had the inputs muted and turned down they would not create the loop but I remember now they will pickup or monitor rather, anyting that is hooked up as you said. I was hoping to run everything through the mixer first because I didn't want to rely on the PC being on to listen to the radio, tape, cd, etc. and also trying to get the tubed signal of the components into the PC via the Sherwood when I make a mix. One way to get around this would be to disconnect the PC audio out or pull the Sherwood's rec out of the breakout box depending on what I want to do make a mix with all the components or archive Lp's. I was trying to use the PC audio out as another source going to the mixer as you said it just won't work. I just didn't htink this through. I upgraded from a 24/96 because I thought it would be nice to have all the components controlled by the mixer then sent to the tubed Sherwood and output to the pc for making a mix. I didn't want to have to unhook or change cables around....but that's exactly what I am going to have to do. Fortunately, I have an XLR mixer and some mics so the card will come in handy for that type of recording. *whew* thanks, Jon Quote Link to comment Share on other sites More sharing options...
tillmbil Posted March 16, 2004 Share Posted March 16, 2004 Just think, I knew that answer all along...RIGHT. Way to go Griffinator!!! Quote Link to comment Share on other sites More sharing options...
Griffinator Posted March 16, 2004 Share Posted March 16, 2004 FWIW, I use a mixer interface with my computer, CD player, etc. How do I get around the feedback problem? Instead of the REC out on my onkyo pre, I use the Tape Monitor out. Hence, when I actually want to record to my PC, I turn the PC out gain down to zero on the mixer, and turn on the tape monitor on the pre. Quote Link to comment Share on other sites More sharing options...
doctorcilantro Posted March 16, 2004 Author Share Posted March 16, 2004 Hey Griff, I need to elaborate here. When I turned off my Sherwood tube amp while the mixer was on I got a massive feedback loop that fried my soundcard. when you mute the inputs on a Delta 44, yes the signal still is monitored as it shows up on the input meter, but the Delta master volume meter will not monitor it until you unmute it. When I want to record a Real audio bcst or a winamp mix (can't seem to get kernel streaming to work) I could take the output right back into the input. I would only get feedback if I unmuted that input signal and raised the fader. If you do that you get that tin can echo feedback. I think this explosive loopback was something else. I remember reading that the mixer should be turned "on last off first" I think that was it. I use the REC out of my mixer because my impression was that it was not amplified like the Master out. The master fader does not change the levels on the channel faders. The other outs are zone and send which are for other "rooms". Zone has a little vol. know and send doesn't. The other night I was using the 1&2 sound card outs to the mixer and then the mixer feeding back to soundcard inputs; I kept those channels muted and let Wavelab record it. I really think this was a result of turning off the Sherwood before the mixer. I haven't tried it again because I don't want to risk damaging the Sherwood....since the card or its breakout box already bit the dust. Jon Quote Link to comment Share on other sites More sharing options...
Griffinator Posted March 16, 2004 Share Posted March 16, 2004 ---------------- On 3/16/2004 7:24:54 PM doctorcilantro wrote: Hey Griff, I need to elaborate here. When I turned off my Sherwood tube amp while the mixer was on I got a massive feedback loop that fried my soundcard. when you mute the inputs on a Delta 44, yes the signal still is monitored as it shows up on the input meter, but the Delta master volume meter will not monitor it until you unmute it. When I want to record a Real audio bcst or a winamp mix (can't seem to get kernel streaming to work) I could take the output right back into the input. I would only get feedback if I unmuted that input signal and raised the fader. If you do that you get that tin can echo feedback. I think this explosive loopback was something else. I remember reading that the mixer should be turned "on last off first" I think that was it. I use the REC out of my mixer because my impression was that it was not amplified like the Master out. The master fader does not change the levels on the channel faders. The other outs are zone and send which are for other "rooms". Zone has a little vol. know and send doesn't. The other night I was using the 1&2 sound card outs to the mixer and then the mixer feeding back to soundcard inputs; I kept those channels muted and let Wavelab record it. I really think this was a result of turning off the Sherwood before the mixer. I haven't tried it again because I don't want to risk damaging the Sherwood....since the card or its breakout box already bit the dust. Jon ---------------- This sounds really weird to me. What brand of mixer was this again? Quote Link to comment Share on other sites More sharing options...
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