Rotel RB 993 humming - Page 2

anatech · 10th January 2006, 12:52 PM

Hi MichaelB,
Check lead dress inside in case someone has worked on the unit. The other, most likely problem is the power supply as others have pointed out.

The easiest way to find this out is to hang an oscilloscope on the supplies and have a look.

-Chris

pinkmouse · 10th January 2006, 12:53 PM

Quote:

Originally posted by anatech
Check lead dress..

Good point!

inteificio · 10th January 2006, 05:31 PM

Hi, When I had a fault with my rb-993, Rotel service provided me with a service manual.

I have since deleted it, but if you call and ask them they are surprisingly helpful.

I phoned last week about a fault on my RC-995, the tech talked me through the basic checks on it. it took a while but he explained in great detail everything i needed to do. mostly just discharging caps as I don't have a oscilliscope but give them a call.

tubenut · 10th January 2006, 05:44 PM

I am not sure if the 993 is the amp, I will check with a friend of mine.

There was a Rotel multi channel power amp where the first batch produced had a problem. They needed some re routing done with their earth paths (breaking a track or 2 and running a wire or 2 instead to different points.) Here my friend did this beforte the amps got to market, perhaps some slipped through...
The symptom of the design fault / problem was............................................... .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. ..............wait for it................................HUMMMMMMMMMMMM!! !!

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Service Manual/ schematic for Rotel ROTEL RHCD-10 Michi CD player	Staykov	Digital Source	5	16th May 2012 12:24 AM
Rotel RC-850 Pre Amp + Rotel RB-870BX	bleachershane	Analog Line Level	4	9th February 2009 11:20 AM
Humming	Jorgitox	Solid State	19	29th November 2007 02:42 PM
Rotel RX950 with humming noise	jorgens	Solid State	1	28th March 2007 08:34 PM
humming amp	Pumuckel	Pass Labs	10	26th February 2004 12:40 AM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

10th January 2006, 12:52 PM	#11
anatech diyAudio Moderator Join Date: Jun 2004 Location: Georgetown, On	Hi MichaelB, Check lead dress inside in case someone has worked on the unit. The other, most likely problem is the power supply as others have pointed out. The easiest way to find this out is to hang an oscilloscope on the supplies and have a look. -Chris

10th January 2006, 05:31 PM	#13
inteificio diyAudio Member Join Date: Dec 2004 Location: York	Hi, When I had a fault with my rb-993, Rotel service provided me with a service manual. I have since deleted it, but if you call and ask them they are surprisingly helpful. I phoned last week about a fault on my RC-995, the tech talked me through the basic checks on it. it took a while but he explained in great detail everything i needed to do. mostly just discharging caps as I don't have a oscilliscope but give them a call.

10th January 2006, 05:44 PM	#14
tubenut diyAudio Member Join Date: Nov 2002 Location: South Africa, Jhb	I am not sure if the 993 is the amp, I will check with a friend of mine. There was a Rotel multi channel power amp where the first batch produced had a problem. They needed some re routing done with their earth paths (breaking a track or 2 and running a wire or 2 instead to different points.) Here my friend did this beforte the amps got to market, perhaps some slipped through... The symptom of the design fault / problem was............................................... .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. ..............wait for it................................HUMMMMMMMMMMMM!! !!