How to improve an old marantz pm-55

edusub · 22nd June 2010, 02:01 PM

Hello everybody,

I just bought for a low price an old Marantz PM-55 not 100% OK but enough to perform some mods on it and fix it for a second equipment.

First question: what improvement could I get by changing the original ELNA caps 8200uf, 56V ? Which would be the best replecement for them (in an average budget, not spending too much)?

Second: I have noticed a crispy and intermitent cracking noise in the right channel, both in the two system outputs (PM-55 has exit for two sets of speakers). I have got the service manual but don't know where to look to find the origin of this default in the righ channels. Left channel in the two speaker sets work OK.

Thanks for any help you could provide.

Edu

hew128 · 16th July 2010, 06:17 AM

Hi,

I have a PM-45 and sounds like same problem. Notice the cracking sound occurs more often when I touch the casing e.g leaking current.

Don't suppose you have made any progress on it since the post?

Thanks!

sakis · 16th July 2010, 07:37 AM

the articular amp has room and step for a lot of changes how far and what to improve is only up to you

importand to notice is that improvemnts of any kind will alter the safety margins of the amp ...that is rule #1 and you have to live with that ...

then again improvemnts of anykind will have small percentage of benefit 2% here 3% there and so on ...importand is to think that 10 improvements of 3% each will sum to a result of almost 30% of total improvemnets ...so yes it worth the idea playing arround ...

schematic is available e mail me if you like to have it ... and following that i could give you a wish list of the things i would change or try ...

kind regards sakis

16th July 2010, 07:37 AM	#3
sakis diyAudio Member Join Date: Jan 2006 Location: nea makri athens greece	the articular amp has room and step for a lot of changes how far and what to improve is only up to you importand to notice is that improvemnts of any kind will alter the safety margins of the amp ...that is rule #1 and you have to live with that ... then again improvemnts of anykind will have small percentage of benefit 2% here 3% there and so on ...importand is to think that 10 improvements of 3% each will sum to a result of almost 30% of total improvemnets ...so yes it worth the idea playing arround ... schematic is available e mail me if you like to have it ... and following that i could give you a wish list of the things i would change or try ... kind regards sakis __________________ SERVICE ΕΝΙΣΧΥΤΩΝ ΚΑΙ ΙΑΠΩΝΙΚΩΝ ΜΗΧΑΝΗΜΑΤΩΝ ΗΧΟΥ www.eastelectronics.gr

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 PM 440 and PM 351 Schematic required	Krokotam_	Solid State	0	22nd October 2008 07:36 AM
marantz PM-66SE	kinvig	Solid State	2	2nd April 2008 11:46 PM
Marantz PM 75	Mat	Solid State	6	20th January 2006 06:54 AM
Marantz PM 55	elec972	Solid State	0	6th December 2005 11:57 PM
Marantz PM 55 schematic !!! Help me	pioneervn	Solid State	3	10th September 2005 06:42 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

22nd June 2010, 02:01 PM	#1
edusub diyAudio Member Join Date: Apr 2010	How to improve an old marantz pm-55 Hello everybody, I just bought for a low price an old Marantz PM-55 not 100% OK but enough to perform some mods on it and fix it for a second equipment. First question: what improvement could I get by changing the original ELNA caps 8200uf, 56V ? Which would be the best replecement for them (in an average budget, not spending too much)? Second: I have noticed a crispy and intermitent cracking noise in the right channel, both in the two system outputs (PM-55 has exit for two sets of speakers). I have got the service manual but don't know where to look to find the origin of this default in the righ channels. Left channel in the two speaker sets work OK. Thanks for any help you could provide. Edu

16th July 2010, 06:17 AM	#2
hew128 diyAudio Member Join Date: Jan 2006 Location: Singapore	Hi, I have a PM-45 and sounds like same problem. Notice the cracking sound occurs more often when I touch the casing e.g leaking current. Don't suppose you have made any progress on it since the post? Thanks!