ryanm84 Posted November 9, 2013 Share Posted November 9, 2013 Every time I turn around its something new. I had some service done to both my adcom pre and amp. Hook em up to my Cornwalls and notice a constant hum/buzz thru tweeter and possibly squawkers. It's a little quieter when the pre is off. It doesn't seem to get louder with volume. Side note, I had them hooked up to an old sony avr and get a similar buzz. I recently rebuilt these with new crossovers and double checked all connections. Thoughts? Quote Link to comment Share on other sites More sharing options...
willland Posted November 9, 2013 Share Posted November 9, 2013 Every time I turn around its something new. I had some service done to both my adcom pre and amp. Hook em up to my Cornwalls and notice a constant hum/buzz thru tweeter and possibly squawkers. It's a little quieter when the pre is off. It doesn't seem to get louder with volume. Side note, I had them hooked up to an old sony avr and get a similar buzz. I recently rebuilt these with new crossovers and double checked all connections. Thoughts? May be a ground loop. I once had one with my first Acurus A150 amp that I bought. It was pretty noticeable at all volumes but did not change with volume. I switched power outlets from one next to a cable coax outlet to one about eight feet away and ground loop gone. Just a consideration. Bill Quote Link to comment Share on other sites More sharing options...
ryanm84 Posted November 9, 2013 Author Share Posted November 9, 2013 I just tested with my third receiver and no buzz but more like a slight white noise hiss. The denon avr had almost zero noise that I would expect and really just blasted some guns n roses. Same plug (surge protector) as the others. Old house and old wiring. Quote Link to comment Share on other sites More sharing options...
mustang guy Posted November 9, 2013 Share Posted November 9, 2013 What work did you have done? I'm not a tech, but I'm sure those here who are will want to know. Quote Link to comment Share on other sites More sharing options...
jason str Posted November 9, 2013 Share Posted November 9, 2013 Every Adcom preamp i ever owned made that noise, had quite a few over the years. Went with a NAD. Dead silent & sounds better too. Quote Link to comment Share on other sites More sharing options...
ryanm84 Posted November 9, 2013 Author Share Posted November 9, 2013 The tone control on the pre was bad. I also had popping thru the speakers when the amp shutdown. Circuit protection was added and when I powered down today, no pop. Quote Link to comment Share on other sites More sharing options...
beeker Posted November 9, 2013 Share Posted November 9, 2013 (edited) From my experience a buzz is commonly noticed in a mid horn more so than tweeter or woofer. Tweeter is next common in my experience to noticing a hum or buzz due to frequency and rarely i find a hum internally in a speaker cabinet. What is the line up from the power from the wall to your speakers, everything between and then around such as cable tv wires, other electronics etc...a descent power conditioner are you using? Are you powering your amp up last after your pre? This can cause internal issues in both cab and component/s Edited November 9, 2013 by beeker Quote Link to comment Share on other sites More sharing options...
ryanm84 Posted November 9, 2013 Author Share Posted November 9, 2013 I have a basic surge protector and as far as I know, no other wiring in the wall near the equipment. Speakers are in a nook next to no other electronics save a carbon monoxide detector within 3 or 4 feet or so. Pre was turned on first but only by about 30 seconds. Amp was turned off first and buzz was still coming thru mids. It did sound as though the buzz was coming thru tweets and mids. Quote Link to comment Share on other sites More sharing options...
Istari Posted November 9, 2013 Share Posted November 9, 2013 Part of the problem is the effeciency of the speaker itself. and part of the problem is the Adcom gear. I have the Adcom 555II amp and ADCOM 500 tuner. This combination gives off a background hiss all of the time. Just part of th electronics noise inherent in this product line I suppose. I do have several H.H. Scott tube amps and do not have the background noise with them that the Adcoms have. Quote Link to comment Share on other sites More sharing options...
beeker Posted November 9, 2013 Share Posted November 9, 2013 (edited) I'd give it a bit here. I don't sleep for days if i have a noise like that tearing me up sometimes a week if i can't afford or dont know how to fix when it happens. Somebody will chime in and say what it is or is not I took a break halfway thru my reply then Istari replied Edited November 9, 2013 by beeker Quote Link to comment Share on other sites More sharing options...
beeker Posted November 9, 2013 Share Posted November 9, 2013 I have to say i have 2 adcom preamps and 3 adcom amps I use regularly and have had several others. They are made in the usa although they need serviced regularly by a tech that knows what their doing Quote Link to comment Share on other sites More sharing options...
jason str Posted November 9, 2013 Share Posted November 9, 2013 Its the preamp, deal with the noise or get something different. Quote Link to comment Share on other sites More sharing options...
ryanm84 Posted November 9, 2013 Author Share Posted November 9, 2013 Its the preamp, deal with the noise or get something different. Yeah. First time running them with the adcom gear. It might be something I can live with. Maybe not though! Quote Link to comment Share on other sites More sharing options...
Greg Oshiro Posted November 10, 2013 Share Posted November 10, 2013 Ryan-- I own an Adcom GTP-500. It has a high output level capability that can make it seem noisy when that output capability is not used. I suspect your pre-amp is similar. If your volume control is lower than 12 0'clock at your normal listening level, I suspect you are in this situation. You might try some line-level attenuators between the pre-amp and the amplifier. Maybe something like these: http://www.parts-express.com/pe/showdetl.cfm?partnumber=266-244 I have never used these particular things, but I believe others here have. If one pair helps your situation, a pair in cascade might be even better. If you're handy with a soldering iron and would like to build your own custom attenuator, let me know and I'll scrawl something for you. --Greg Quote Link to comment Share on other sites More sharing options...
ryanm84 Posted November 10, 2013 Author Share Posted November 10, 2013 I've got the GTP-600 pre. This could be a relatively inexpensive way to tame the buzz. Quote Link to comment Share on other sites More sharing options...
ryanm84 Posted April 17, 2016 Author Share Posted April 17, 2016 Resurrected to ask a simple question: one pair of attenuators. Do you put them on the amp or the pre to adjust line level and noise from the pre? Seems that I would put them on the amp but I may be thinking about this the wrong way. Quote Link to comment Share on other sites More sharing options...
mustang guy Posted April 17, 2016 Share Posted April 17, 2016 (edited) All those do is attenuate the line level down between the preamp and the amp. Just plug them into the RCA patch cord and hook it back up. It doesn't matter which end it's on. It essentially will allow the system to play lower volume. Edited April 17, 2016 by mustang guy Quote Link to comment Share on other sites More sharing options...
ryanm84 Posted April 17, 2016 Author Share Posted April 17, 2016 Thank you! Quote Link to comment Share on other sites More sharing options...
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