Marantz CD67 and LM4562an

jomatecc · 9th January 2010, 05:20 PM

Hi Im hoping someone can help me with this problem, a month ago I replaced the stock ICs in my Marantz CD67 CD player with 8 pin DIP sockets and a pair of LM4562. The result was very disappointing it generated loud consistent hissing, the level of the noise was more than the music, I received a second pair yesterday and they worked perfect.
Id like to know before jumping to any conclusion if there could be such a wide discrepancy between two different batches of LM4562 to make on unlistenable while the other works so well. And if so what do do to make the other pair usable.

Thanks

Mooly · 10th January 2010, 11:42 AM

Maybe they were fakes.
Opamps don't vary like that.

Having said that the 4562 is a high speed device. Is it possible it could be on the verge of instability.
You need to measure and test them in circuit.

Glenn2 · 10th January 2010, 07:04 PM

When the LM4562 first came out, I ordered 3 engineering samples from Nat Semi.

I only needed two (for my CD67SE too!) but got a spare too.

Good job I did as one of them behaved exactly as the OP described.

When I switched the channels, the problem followed the bad op-amp.

The decoupling/bypassing was solid, and I had no such problems with LM6172 and AD8065x2 for example.

I didn't much care for their sound anyway - too sterile for my tastes. Went with AD825x2 on Brown Dogs in the end (although LM6171+OPA627 worked particularly well also).

I've since tried the LM4562HA (the ones with the metal hats) as people said they sound totally different. They did sound a bit different, still crap though. YMMV.

jomatecc · 11th January 2010, 04:18 AM

Yesterday I made a unity gain buffer circuit to test if they were only unstable in the CD67, turns out they worked in test circuit, no hiss this time but they sounded bloated compared to the other sets.
maybe they were just a bad batch lucky me. The good ones sounds great by the way.
thanks for your replies

Malefoda · 11th January 2010, 09:34 AM

I had an unlistenable OPA2132 once...
As for their sound, in stock player they sound boring even with good caps, I like more even the JRC! Then with 137/337 regs it starts to sing a lot better. Maybe with super regs it's even better? Need a very nice dynamic "pre-opamp CDP" before them...

9th January 2010, 05:20 PM	#1
jomatecc diyAudio Member Join Date: Apr 2008	Marantz CD67 and LM4562an Hi Im hoping someone can help me with this problem, a month ago I replaced the stock ICs in my Marantz CD67 CD player with 8 pin DIP sockets and a pair of LM4562. The result was very disappointing it generated loud consistent hissing, the level of the noise was more than the music, I received a second pair yesterday and they worked perfect. Id like to know before jumping to any conclusion if there could be such a wide discrepancy between two different batches of LM4562 to make on unlistenable while the other works so well. And if so what do do to make the other pair usable. Thanks __________________ Music: Please audition with your ears not your eyes.

11th January 2010, 04:18 AM	#4
jomatecc diyAudio Member Join Date: Apr 2008	Yesterday I made a unity gain buffer circuit to test if they were only unstable in the CD67, turns out they worked in test circuit, no hiss this time but they sounded bloated compared to the other sets. maybe they were just a bad batch lucky me. The good ones sounds great by the way. thanks for your replies __________________ Music: Please audition with your ears not your eyes.

11th January 2010, 09:34 AM	#5
Malefoda diyAudio Member Join Date: Jun 2006	I had an unlistenable OPA2132 once... As for their sound, in stock player they sound boring even with good caps, I like more even the JRC! Then with 137/337 regs it starts to sing a lot better. Maybe with super regs it's even better? Need a very nice dynamic "pre-opamp CDP" before them... __________________ Old simple TT, cheap CDP with wise mods, Class T amp at its best: 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
Marantz CD67 - UK	Spartacus	Swap Meet	0	1st October 2008 03:47 PM
Marantz cd67 cdr problems	leolubin	Digital Source	6	22nd November 2005 09:51 PM
Right speakers for Marantz PM8000 + Marantz CD67-OSE?	betto80	Multi-Way	2	24th May 2005 03:21 PM
Marantz CD67-SE	aaronlubelski	Digital Source	6	2nd May 2005 06:35 AM
Marantz CD67/AD8065 upgrade goes 'well'	dantwomey	Digital Source	12	22nd November 2003 08:56 AM


	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 2010, 11:42 AM	#2
Mooly diyAudio Member Join Date: Sep 2007	Maybe they were fakes. Opamps don't vary like that. Having said that the 4562 is a high speed device. Is it possible it could be on the verge of instability. You need to measure and test them in circuit.

10th January 2010, 07:04 PM	#3
Glenn2 diyAudio Member Join Date: Oct 2006 Location: London, UK	When the LM4562 first came out, I ordered 3 engineering samples from Nat Semi. I only needed two (for my CD67SE too!) but got a spare too. Good job I did as one of them behaved exactly as the OP described. When I switched the channels, the problem followed the bad op-amp. The decoupling/bypassing was solid, and I had no such problems with LM6172 and AD8065x2 for example. I didn't much care for their sound anyway - too sterile for my tastes. Went with AD825x2 on Brown Dogs in the end (although LM6171+OPA627 worked particularly well also). I've since tried the LM4562HA (the ones with the metal hats) as people said they sound totally different. They did sound a bit different, still crap though. YMMV.

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

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