Op amps associated with CDM4

mudihan · 2nd April 2009, 01:58 AM

In all of the Philips/Magnavox CD players that use CDM4/19 that I have seen (several of them), there are always a pair of dual op amps underneath the transport. What do they do?

Thanks!

amc184 · 2nd April 2009, 02:48 AM

One is for focus drive, two are for turntable drive and one is for radial drive. The two opamps for turntable drive aren't two halves of the same dual opamp usually either.

mudihan · 2nd April 2009, 09:10 AM

Thanks for the reply. I remember clearly that changing them to better ones resulted clearly better sound. The change was as noticeable as op amp rolling in the output section. Also, the unique sound characters associated with each op amp (I used AD826, 2xOPA627BP, 2xAD843, and LT1469) were quite the same in both places. Is it possible that they also do something else other than motor control?

amc184 · 2nd April 2009, 09:44 AM

No. I wouldn't have thought that they would have had any effect on the sound.

2nd April 2009, 01:58 AM	#1
mudihan diyAudio Member Join Date: Jan 2004 Location: Texas	Op amps associated with CDM4 In all of the Philips/Magnavox CD players that use CDM4/19 that I have seen (several of them), there are always a pair of dual op amps underneath the transport. What do they do? Thanks! __________________ Composing music>Playing Music>Listening to music>The equipments you use to listen to music

2nd April 2009, 09:10 AM	#3
mudihan diyAudio Member Join Date: Jan 2004 Location: Texas	Thanks for the reply. I remember clearly that changing them to better ones resulted clearly better sound. The change was as noticeable as op amp rolling in the output section. Also, the unique sound characters associated with each op amp (I used AD826, 2xOPA627BP, 2xAD843, and LT1469) were quite the same in both places. Is it possible that they also do something else other than motor control? __________________ Composing music>Playing Music>Listening to music>The equipments you use to listen to music

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
CDM1, or CDM4 pro, or CDM4/21	jovan	Digital Source	7	27th February 2008 01:33 AM
cdm4/21 HELP	dUb	Digital Source	2	29th August 2005 04:56 PM
Wtb Cdm4/19	Mikelo	Swap Meet	0	24th January 2005 12:49 AM
Cdm4/19	halewood	Parts	1	26th October 2004 05:08 AM
Repairing CDM4/19 (with CDM4/31???)	Shaun	Digital Source	4	1st August 2003 12:29 PM

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

2nd April 2009, 02:48 AM	#2
amc184 diyAudio Member Join Date: May 2007 Location: Christchurch	One is for focus drive, two are for turntable drive and one is for radial drive. The two opamps for turntable drive aren't two halves of the same dual opamp usually either.

2nd April 2009, 09:44 AM	#4
amc184 diyAudio Member Join Date: May 2007 Location: Christchurch	No. I wouldn't have thought that they would have had any effect on the sound.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)