marantz pm-45

Is this amp OK?
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bigwill
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Joined: Sun Nov 29, 2009 4:35 pm
Location: Leicestershire, England

marantz pm-45

#1 Post by bigwill »

Hi guys I havnt really thought about it till today. My amp has a two core power cable with no earth however when it was bought as a separate system it was all built with two pin plugs that plug in to an earthed multiplug. I now need to change it to a UK plug. The amp has a separate gnd pin on the back now I thought this was for the turn table, how ever can I link that to the wall plug or is this not needed?

Grant Bunter
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Re: marantz pm-45

#2 Post by Grant Bunter »

bigwill wrote:Hi guys I havnt really thought about it till today. My amp has a two core power cable with no earth however when it was bought as a separate system it was all built with two pin plugs that plug in to an earthed multiplug. I now need to change it to a UK plug. The amp has a separate gnd pin on the back now I thought this was for the turn table, how ever can I link that to the wall plug or is this not needed?
Hi Bigwill,
Sounds like your cord is a double insulated power cord for class 2 or II power supply.
(Are you sure the adapter you had/have acutally had the earth wire connected to anything or was it just a blank?
I would have thought it's a blank, or else the active or neutral line would shunt straight to ground/earth.
edit: sorry, re read and are you talking about a multi outlet power board.)

Either way, 2 pin plugs for class 2 or II systems don't require earth.

The gnd pin on your amp is to reduce/remove rumble (50 or 60Hz, depending upon nominal power supply where the device is in use) from your turntable.

I don't think you need to add an earth wire or connect anything to it.
I would try to find an adapter that mated the prongs on the existing cord to UK outlet.
You need to ensure the operating voltage and applicable fuse on your amp are set correctly before turning on the power...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 2 x 28" 3012LF.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

bigwill
Posts: 74
Joined: Sun Nov 29, 2009 4:35 pm
Location: Leicestershire, England

Re: marantz pm-45

#3 Post by bigwill »

Thank you for that. I just thought it would need some sort of protection as you can tell im not that clued up with power supply or how it works :wall: I have been using it for years but its in desperate need of new power cable. I also want to change the binding posts to something decent that will accept 4mm bananas. So if you know anywhere i.e. forums or threads that deal with this sort of old school amp it would be appreciated. Thanks

Grant Bunter
Posts: 6915
Joined: Mon Nov 28, 2011 11:12 am
Location: Ilfracombe Queensland Australia
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Re: marantz pm-45

#4 Post by Grant Bunter »

Since your present power lead is ailing,

Type (Marantz PM45 power lead) into e-bay UK or google and you'll get listings.

Or contact Marantz UK for suitable resellers in your location:
http://www.marantz.co.uk/uk/pages/home.aspx

The second may be the better option as you should be able to get a new lead with UK plug already attached :)

As far as changing the binding posts, errr why?
I can't find exact specs but output should be between 40-50W/channel @ 8 ohms.

If the holes in the binding posts are to small for larger cable (and that's why you want to upgrade the binding posts), snip off enough individual strands of the heavier cable until the remainder fits in the hole, remove again, twist up, then solder the remainding wire strands together.
Another option is to find/buy solder or screw or crimp pins that take larger cable down to the correct size. Any half decent Hi Fi store should have them.

eg:
http://www.ebay.com.au/itm/Elite-Series ... 91e&_uhb=1
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 2 x 28" 3012LF.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

bigwill
Posts: 74
Joined: Sun Nov 29, 2009 4:35 pm
Location: Leicestershire, England

Re: marantz pm-45

#5 Post by bigwill »

The power cable is sorted. Thanks. There's a few reasons for changing the binding posts, firstly the original ones are a bit broken/brittle. I want to fit some that accept 4mm bananas. Now the only thing i need to know, what type of wire should i use to connect the posts to the circuit board as i have to replace the rigid metal connections? many thanks

Grant Bunter
Posts: 6915
Joined: Mon Nov 28, 2011 11:12 am
Location: Ilfracombe Queensland Australia
Contact:

Re: marantz pm-45

#6 Post by Grant Bunter »

Great to hear your power cord is sorted!

I would solder pins eg:
http://www.jaycar.com.au/productView.asp?ID=HP1250
into the circuit board, and solder the wire to the pins. It will be much simpler than trying to put wires into the circuit board.

The wire itself would only need to be something with a surface area of 1mm squared...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 2 x 28" 3012LF.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

bigwill
Posts: 74
Joined: Sun Nov 29, 2009 4:35 pm
Location: Leicestershire, England

Re: marantz pm-45

#7 Post by bigwill »

Thanks mate that looks easier. Would 1mm cary enough current because if anything I want to upgrade it. Solid core or stranded? Also is it worth using silver cable? Thanks

Grant Bunter
Posts: 6915
Joined: Mon Nov 28, 2011 11:12 am
Location: Ilfracombe Queensland Australia
Contact:

Re: marantz pm-45

#8 Post by Grant Bunter »

bigwill wrote:Thanks mate that looks easier. Would 1mm cary enough current because if anything I want to upgrade it. Solid core or stranded? Also is it worth using silver cable? Thanks
1mm squared will carry 7.5A (240V/ 50 Hz) where I am, and your amp puts out say 50W/8 ohms which = 2.5Amps, so that should be more than enough.
You can't get out more than what is there.
If you're actually pulling 50W out of your amp it would probably be distorting like crazy.
I don't think I've ever had the volume on either of my 2 different Marantz systems above 6 out of 10.

I would use stranded because it's insulated and I personaly find stranded easier to twist around pins and put in sockets etc.

Silver cable? Is that magic or something?
Seriously, forget it, none of the wires will be more than 10cm long I imagine, and over that distance, no wire will have significant losses...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 2 x 28" 3012LF.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

bigwill
Posts: 74
Joined: Sun Nov 29, 2009 4:35 pm
Location: Leicestershire, England

Re: marantz pm-45

#9 Post by bigwill »

Ok I see your point. That has settled my mind. Its just audiophile silver wire nonsense. Il get the old girl back in action now. Thanks for the help.

Grant Bunter
Posts: 6915
Joined: Mon Nov 28, 2011 11:12 am
Location: Ilfracombe Queensland Australia
Contact:

Re: marantz pm-45

#10 Post by Grant Bunter »

No worries!
If you need any more help, give us a yell.

Let us know how it goes...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 2 x 28" 3012LF.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

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