Now I got a scope and read power supply. It appears all outs are straight line dc EXCEPT the meter power it has ac in it . Does that point to power supply? Its a simple looking circuit. i've changed the 4700s already the only thing left is 2 1n5402s. The Ds3 is the LED on the supply , correct??
getting closer?,, thanks, doug ----- Original Message ----- From: "Matt Syson" <[email protected]> To: [email protected] Sent: Wednesday, July 20, 2011 5:23:02 AM Subject: Re: NEOTEK: aux noise Hi Bar graph circuits tend to make a noise only when switching led levels, especially LM3915 type systems. Not many have an oscillator running so I am doubtful that it would be the metering. I think you should be chasing poor power and connections around the master sections. You could try unplugging external gear to see if it is a 'ground loop' problem attempting to appear when the desk internal grounds are disturbed but this could be a different problem to the 'noise', (assuming this is a crackly type of sound). Matt S On 20/07/2011 03:09, Doug Easley wrote: > Continuing the chase of aux noises, I noticed today that when I press the > monitor on in the meter select I get a funky ripple buzzy crud added to a > hummy sound. This is the first thing I've found that has affected my noise. > By pressing the peak/rms switches I can make the optional phase meter go back > and forth sometimes and hear a click noise for every LED movement. So maybe > I'm on to something. Then I thought well disconnect the meter power and it > will go away but no such luck. With meter power disconnected the same sound > would happen. There are some meters that only have a few sections working > which hasn't been too much of a problem so far. I can meter in pro tools and > I have analog VUs on the master. Is there some way to bypass the bargraph > meter circuit to see if that's my problem. Are there caps in there that are > supposed to keep it quiet? > > thanks for the responses, doug > > > On Jul 18, 2011, at 4:09 PM, Ike Zimbel<[email protected]> wrote: > >> Hi Doug, >> Following on Matt's suggestions, I would agree that the oscillator section >> could be suspect. I would also check that all of the logic chips are well >> seated and that their leads and sockets look good. Replace them if they >> don't. Also make sure that all of the ground connections, including >> mechanical connections to the front panel (pots, switches etc.) are clean >> and tight. It is unlikely that the Aux sends are creating this noise, but >> more likely they are amplifying noise that's coming from something common to >> them, again as Matt said. I am away from the shop for a couple of weeks so I >> don't have access to my Elan drawings to give you specific chip names, >> locations etc. >> Best, >> Ike >> >> On 11-07-18 8:54 AM, Matt Syson wrote: >>> Hi >>> You are looking for something 'common' as it adds up when listening to more >>> stuff on Solo. >>> It could be supply noise (check with an oscilloscope) or a module which is >>> seriously noisy or even talkback or slate tone circuitry that has access to >>> aux busses although may be nominally 'switched off'. >>> Double check all possible outputs and look for any 'common' circuitry (the >>> 'block diagram' should get you close). Ultimately, pull modules or 'break >>> up' the mix bussing if it is available on plugs. >>> Matt S >>> >>> On 18/07/2011 13:35, [email protected]<mailto:[email protected]> >>> wrote: >>>> >>>> Hello, I think this is the way to post here. >>>> >>>> >>>> I have a 15 year old 40 channel Elan I bought new. It's been very >>>> reliable. It was in a fire 7 years ago. I got it back in commission after >>>> a couple of idle years of storage and cleaning/repairing. It was >>>> recommissioned and has done pretty well, everything works except some >>>> partially working l.e.d. meters. >>>> >>>> Lately the master section has a small ripply sound when cranked all the >>>> way up without channels turned on. Small annoyance, but irritating. >>>> However when you solo the auxes you get a really intense version of hiss >>>> noise ripply trash, sounds like a combination of computer interference >>>> meets bad caps/junk. As I said it's appeared of the last few months. >>>> Soloing A,B,1,2,3,4, just adds to the crap incrementally. When using the >>>> track busses to pro tools, it's fine , goes to pro tools good and quietly. >>>> >>>> I recently tested and or replaced all the resistors in the power supply >>>> and recapped the power supply. I also disconnected the Elcos for everthing >>>> except the monitor one to the amps to make sure it wasn't from another >>>> piece of gear. >>>> I still have the trashy sound in auxes. Any suggestions? Any logical >>>> procedure to locate the source of my noise? >>>> >>>> thanks , doug >> -- >> Ike Zimbel, >> Zimbel Audio Productions Ltd. >> Toronto >> 416-720-0887 >> >> "Studio House Calls". Authorized Warranty service for Allen& Heath, >> Clear-Com, Drawmer, Soundcraft, SPL and Yamaha. Repairs and upgrades to >> analog audio equipment including: AMEK, dbx, Neve, Neotek, MCI, Soundcraft >> and more. Ask about our RF frequency co-ordination services! >> www.zimbelaudio.com >> >> ------ >> >> View the list online at: http://www.mail-archive.com/[email protected] >> >> You can unsubscribe at anytime by sending an email to >> mailto:[email protected] with "unsubscribe neotek" in the message >> body. If you have any difficulties, or questions --please send an email to >> mailto:[email protected]. >> >> The Neotek list is lovingly hosted by Catapult Web. Remember that any >> message or reply sent to the list will be automatically forwarded to all >> subscribers. >> >> Vive Le Neotek! >> >> Thanks. > ------ > > View the list online at: http://www.mail-archive.com/[email protected] > > You can unsubscribe at anytime by sending an email to > mailto:[email protected] with "unsubscribe neotek" in the message body. > If you have any difficulties, or questions --please send an email to > mailto:[email protected]. > > The Neotek list is lovingly hosted by Catapult Web. Remember that any message > or reply sent to the list will be automatically forwarded to all subscribers. > > Vive Le Neotek! > > Thanks. > ------ View the list online at: http://www.mail-archive.com/[email protected] You can unsubscribe at anytime by sending an email to mailto:[email protected] with "unsubscribe neotek" in the message body. If you have any difficulties, or questions --please send an email to mailto:[email protected]. The Neotek list is lovingly hosted by Catapult Web. Remember that any message or reply sent to the list will be automatically forwarded to all subscribers. Vive Le Neotek! Thanks.
